i
CHEMICALLY DERIVED NANO-PIGMENT FOR ANTIBACTERIAL ACTIVITY,
SURFACE COATING AND IN-VITRO CYTOTOXICITY TESTS ON FIBROBLASTS
Dissertation submitted to the
MANONMANIAM SUNDARANAR UNIVERSITY
in partial fulfillment of the requirement for the degree of
MASTER OF SCIENCE
IN
NANOSCIENCE
Submitted By
G. PADMA
(Reg. No. 20174012517109)
Under the Guidance of
Dr. A.G. Murugesan
Senior Professor
MANONMANIAM SUNDARANAR UNIVERSITY,
SRI PARAMAKALYANI CENTRE OF EXCELLENCE IN
ENVIRONMENTAL SCIENCES,
ALWARKURICHI-627412, TAMILNADU.
MAY 2019

ii
MANONMANIAM SUNDARANAR UNIVERSITY
Sri Paramakalyani Centre of Excellence in Environmental Sciences
Alwarkurichi-627412, Tamil Nadu, India.
Tel (O): 04634-283883
Tel (R): 04633-257657
Moblie:9443407457
agmspkce@rediffmail.com
Dr A.G.MURUGESAN, PhD F NABS FAZ FAEB FASc AW.FST FAScC FSESc
Senior Professor
CERTIFICATE
This is to certify that this thesis entitiled “Chemically Derived Nano-Pigment for
Antibacterial Activity, Surface Coating and In-Vitro Cytotoxicity Tests on Fibroblasts”
submitted by Miss G. PADMA (Reg. No. 20174012517109) in partial fulfilment of the
award of Master of Science in Nanoscience to the Sri Paramakalyani Centre of
Excellence in Environmental Sciences, Manonmaniam Sundaranar University, is based
on the results of the studies carried by her under my supervision. Further certified that
this work has not been submitted elsewhere for any other degree.
Head of the Department Signature of Guide
Place: Alwarkurichi External examiner
Date:

iii
MANONMANIUM SUNDARANAR UNIVERSITY
SRI PARAMAKALYANI CENTRE OF ENVIRONMENTAL
SCIENCE ALWARKURICHI-627412, TIRUNELVELI
TAMILNADU, INDIA
DECLARATION
I here declare that the thesis entitled “CHEMICALLY DERIVED NANO-PIGMENT
FOR ANTIBACTERIAL ACTIVITY,SURFACE COATING AND IN VITRO
CYTOTOXICITY TESTS ON FIBROBLASTS” Submitted by me for the degree of
master of science in NANOSCIENCE is the result of my original and independent work
carried out under the guidance of DR.A.G. MURUGESAN, Professor, Sri
paramakalyani centre of Excellence in Environmental sciences, Manonmanium
Sundaranar University, Alwarkurichi. This work has not been submitted for the award of
any degree of any University/Institute.
DATE :
PLACE: Alwarkurichi
(G. PADMA)

iv
ACKNOWLEDGEMENT
First of all we express my profound gratitude to Almighty God for the inspiration and
guidance at all stages of this project work.
Generally, I wish to give my grateful acknowledgements to all members of our
institute who provide a great atmosphere where I spent more than 2 years of happy time
Firstly, I would like to express my sincere gratitude to my advisor
Dr. G. Annadurai, Professor and Head, in Nanoscience, for suggesting the topic and his
constant words of encouragement and prudent suggestions which helped me to enable
this project destination.
We have unique pleasure and honor in thanking my guide Dr. A.G. Murugesan,
Professor, Sri paramakalyani center of excellence in environmental sciences,
Manonmaniam Sundaranar University, Alwarkurichi, for the excellent ideas, outstanding
guidance and patient monitoring during the entire period of the project work.
My sincere thanks to other faculties Dr. S. Senthil Nathan, Dr. R. Sornam,
Dr. M. Muralidharan, Dr. M. Vanaja and Dr. M. Sivakavinesan, Sri Paramakalyani
Centre for Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi
for their valuable suggestions and encouragement during the course of work.
I wish to pen my heartfelt gratitude to Mrs. M. Perachi Selvi, for her constant help,
sensible suggestion and special interest in this project work.
I wish to express my heartfelt gratitude to my beloved friends S. Aarthi, J. Jenson
Samraj, V. Harinath, Srinivasan, Sajeen azeem, G. Sabeena,
P. Barani who taught me how to perform research at a competitive level, for their
continued support and guidance throughout my work to complete my thesis.
I would like to express my heartiest thanks to my father G. Gurusamy, and my
mother G. Vijaya for their motivation, encouraging supports.
We express my thanks to the Dr. Earnest Stephan Gnanadoss, Namakkal for
furnishing required FT-IR spectrum of the sample.
Further, I would like to thank all Ph.D. Scholar and Non-Teaching staffs of this center,
who gave me moral support and motivation, not only as scholars also as brothers and
sisters.
Last but not the least; I thank all who have helped me directly or indirectly.
(G. PADMA)

v
ABSTRACT
The aim of this research is to synthesize nanopigment of black pigment of
Magnetite (Fe3O4), red pigment of hematite (α-Fe2O3), and yellow pigment
of ghoetite (α-FeOOH) from the iron sand for the antibacterial acitivity,
surface coating and In-vitro cytotoxicity of the fibroplast. The black pigment
of Fe3O4 and the yellow pigment α-FeOOH nanoparticles were synthesized
by coprecipitation method with variation of pH. This report provides a
review on the safe use of nano-sized pigments when used by professionals,
workers or consumers. Extensive literature searches were carried out in
combination with analyses of data from national nano-inventories to capture
the current state of play. The report provides a list of nano-sized pigments
currently identified on the EU market and discusses potential risks arising
from their use in paints, coatings, printer toner cartridges, personal care
products, tattooes as well as other potential uses of nanopigments. Data for
hazard and risk assessment are not available for the vast majority of
identified nanopigments. Evidence-based conclusions on the safety of most
nanopigments uses cannot be drawn, however, some general observations
and conclusions can be derived. Dry pigments present the highest concern
because they can be easily inhaled and ingested. Exposures to nano-sized
pigments that are integrated into polymer, paint or coating matrices are not
thought to be significant, and the risks to consumers from such uses are low.
The report also discusses uncertainties associated with the identification of
nanopigments (and nanomaterials in general), measurements of exposure to
nano-sized pigments and methods of toxicity testing.
KEYWORDS: Nanoparticles, Iron Oxide Pigments, Co-precipitation.

vi
TABLE OF CONTENTS
CHAPTER
NO
TITLE PAGE NO
ABSTRACT iv
LIST OF TABLES vi
LIST OF FIGURES vii
I INTRODUCTION 1
II LITERATURE REVIEW 15
III EXPERIMENTAL 40
3.1 CHARACTERIZATION 40
3.2 X-RAY DIFFRACTOMETER (XRD) 40
3.3 FE-SEM 42
3.4 EDAX 44
3.5 FTIR 45
3.6 SAMPLE ANALYSIS PROCESS 46
4.0 FLOW CHART PIGMENT 48
IV RESULT AND DISCUSSION 49
V SUMMARY 54
CONCLUSION 56
REFERENCE 57

vii
LIST OF TABLE
TABLE NO TITLE PAGE NO
1.1 Importance of Layers in Coating System 7
1.2 Ingredient functionality in Coating 8
3.1 Characteristic infrared absorption frequencies 16
5.1 Different kinds of bacteria and their measurement 16

viii
LIST OF FIGURES
FIGURE NO TITLE PAGE NO
3.1 Bragg’s law 41
3.2 XRD analysis instrumentation 42
3.3 FE-SEM electro interaction 43
3.4 Energy dispersive X-ray spectroscopy 45
3.5 Michelson Interferometer 46
4.0 Synthesis of Nano pigment 48
5.0 Biological method synthesized of La2O3-CeO2
Nanoparticles
49
5.1 FT-IR analysis 50
5.2 SEM image of synthesized Lanthanum nitrate 51
5.3 DLS analysis 51
5.3.2 (a) Zone of inhibition E. coli 53
5.3.2 (b) Zone of inhibition Bacillus subtilis 53
5.3.2 (c) Zone of inhibition Enterobacter 53
5.3.3 Surface Coating on plastic and glass substrate by using
Nano-pigment
53

0
CHAPTER 1
INTRODUCTION
1.1 Nanotechnology
Nanotechnology is a rapidly developing field in modern science, however, the central
concepts of nanotechnology are developed long years ago (Shunmugam 2010). The main
goal of nanotechnology is to develop the materials smaller than 100 nanometers(nm). The
prefix of nanotechnology derives from ‘Nanos’- the Greek word for dwarf. A nanometer is
a billionth of a meter or put it comparatively about 1/80000 of the diameter of a human hair
(Karkare2008).
The idea of nanotechnology was first offered by physicist Richard Feynman, in a lecture
entitled Room at the bottom, he revealed the possibilities available in the molecular world;
Feynman’s vision spawned the discipline of nanotechnology, and we are now gathering the
tools to make his dream a reality (Goodshell2004).
Zsigmondy is attributed with coining the term nanometer for characterizing the particle
size. He was who determined it as 1/1,000,000 of a millimeter. He has developed a system
of classification based on particle size in the nanometer range (Shanmugam 2010). Richard
Smalley was the foremost leader in nanotechnology. He has often been noted as the “Father
of Nanotechnology.” Richard Smalley is mostly known for his work with carbon nanotubes
(Mongillo 2007). Nanotechnology provides tunable material properties were stated in
Norio Taniguchi’s paper where the term nanotechnology was first used in a scientific
publication (Zhang a Webster 2009).
In recent years, research in this field has grown exponentially continue to develop
nanomaterials with unique and enhanced properties. Nearly every field of science has been
affected by the tools and ideas of nanotechnology, and breakthroughs have been made in
computing, medicine, sensing, energy production, and environmental protection (Poole and
Owens 2009). Advances in this field largely depend on the ability to synthesize nanoparticles
of various materials size, and shapes, as well as to efficiently assemble them into complex
architectures’ (Evanoff and Chumanov 2005).
1.2 Pigments
Pigments are the chemical substances that absorb the light of the visible region. The
produced color is because of the chromophore, a molecule specific structure which
captures the sun energy and causes excitation of an electron from external orbital to a
higher orbital, where the non-absorbed energy is refracted or reflected to be captured by

1
the eye. The modern meaning related to the word pigment has its origin in the twentieth
century, meaning a substance constituted of small particles which are practically insoluble
in the applied medium and is used due to its colorant, protective or other properties.
Pigments are compounds with the uniqueness of importance to many industries. In the food
industry, they are used as additives, antioxidants, color intensifiers, etc. Pigments come in
a wide selection of colors, some of which are water soluble.
The terms pigment and color are generally applied for the food coloring matters,
sometimes indistinctly [2-3]. Until the mid-19th
century, all colorants were attained from
plant or animal extracts. The textile industry used natural pigments, such as cochineal,
wood madder, turmeric, or henna. In 1856, H. Perkin established the first factory of
organic synthetic colors to produce mauve. A few years later the discovery of diazotization
and a coupling reaction by Peter Griess was the next major step forward for the
development of the color industry. In the 19th
century, synthetic organic dyes were
developed, creating a more economical and broader range of colorants. Since then their
quality has been enhanced due to extensive research and development. The economic
consequence of the color industry is clearly reflected in a large number of synthesized
compounds; as many as 700 colorants are currently available. They have widely been used
in foodstuff, dyestuff, cosmetic and pharmaceutical manufacturing processes; encompass
various hazardous effects.
All synthetic food components suffered severe criticism, including synthetic additives
and predominantly food pigments. Today, all food color additives are cautiously regulated
by federal authorities to ensure that foods are safe to eat and accurately labeled Pigments
produced from natural sources are of worldwide interest and is gaining significance. These
are looked upon for their safe use as a natural food dye in substitute of synthetic ones in
spite of having of undesirable market. It is, therefore, essential to explore various natural
sources of food grade pigments and their potentials. The utilization of natural pigments in
foodstuff, dyestuff, cosmetic and pharmaceutical manufacturing processes has been
mounting in recent years. Natural colorants or dyes derived from flora and fauna are
believed to be secure because of non-toxic, non-carcinogenic and biodegradable in nature.
Natural pigments are attained from ores, insects, plants, and microbes.
1.3 Microbial Pigment
Microbial pigments are dominant sources. The microbial production of carotenoids,
pigments from vegetables or chemical synthesis, have problems of seasonal and

2
geographic variability in production and marketing. The microbial production of
carotenoids, They are of great interest owing to the stability of the pigments produced and
the accessibility of cultivation technology. The advantages of pigment production from
microorganisms comprise easy and fast growth in the cheap culture medium, independence
from weather conditions and colors of different shades the economic advantages of
microbial pigments include growth on natural substrates such as red rice wine, red bean
curd as carbohydrate source Microbial colorants are in use in the fish industry already, for
example, to improve the pink color of farmed salmon In nature, color rich and pigment
producing microorganisms (fungi, yeasts, and bacteria) are fairly common.
Microorganisms produce various pigments like carotenoids, melanins, quinones, flavins,
prodigiosins and more specifically monastics, violacein or indigo.
Carotenoids such as β-carotene and xanthophylls like astaxanthin play central roles in the
metabolism of the eye's macula and retina and in retaining healthy vision. β-carotene play a
constructive role in the prevention of cancer and as chemo-protectives. In addition, it, also
act as neutraceutical that averts carcinogenesis through anti-oxidative, anti-free radical or
other mechanisms. The production of microbial pigments is very much affected by the
temperature of incubation, depending upon the type of microorganism.
The growth of Monascus sp. entails 25-28 °C for the production of pigment, whereas
Pseudomonas requires 35-36 °C for its growth and pigment production. the pH of the
medium is another parameter that affects the growth and kind of pigment produced by the
in which microorganisms are grown. The yield of astaxanthin from Phaffia rhodozyma was
325 to 212 µg/g astaxanthin at a pH of 6.5 to 3.5. Pigment production is also affected by
carbon sources like glucose, fructose, lactose, maltose, galactose, etc and nitrogen source
depending upon the microorganism Minerals also has a significant role in pigment
production. Zn (2x10-3
M and 3x10-3
M) inhibited the growth in liquid medium whereas in
solid medium vigorous growth and pigmentation was observed. The optimization of growth
conditions of microorganisms, particularly physical and nutritional parameters are of prime
importance in the development of any pigment production process owing to their impact on
the economy and practicability of the process.
Medium optimization and physical conditions have been customarily performed using
one-factor-at-a-time method. The disadvantages of such a classical method are that it is
time-consuming, laborious and expensive; in addition, it fails to resolve the combined
effect of different factors. Eyeing on maximizing the pigment yield, productivity and
minimizing the production costs, most of the recent optimization efforts have relied on

3
statistical experimental design and response surface analysis and, to a smaller extent,
artificial intelligence techniques such as genetic algorithms Statistical design is a potent
tool that can be used to account for the main as well as interactive influences of
fermentation parameters on process performance. It is an efficient way to generate useful
information with limited experimentation, thereby limiting the process development time
and cost. Therefore, researchers are encouraged to apply statistical experimental
approaches such as Taguchi method and response surface methodology (RSM), which
provide a great amount of information based on only a small number of experiments.
On summing up, the growing apprehension over the eventual harmful effects of
synthetic colorants on both the consumer and the environment has raised preferential
interest in natural coloring alternatives.Among all, microbial colorants popularly known as
pigments have some advantages over plant and animal-based colorants Extensive studies
proved that microbes are known to produce a large number of stable pigments. Large
amounts of agro-industrial and domestic residues are generated from diverse economic
activities; utilization of these residues as inexpensive substrates to support the growth of
microorganisms to generate value-added products like pigments are of biotechnological
interest in recent years Several processes and methodologies have been developed and
developing that utilizes a variety of cheaper substrates and wastes as alternative substrates
for the production of microbial pigments. The utilization of several wastes as or raw
materials notably helps in solving pollution problems, while their disposal may otherwise
cause. In addition to the above, screening of different resources, establishing simple
methodologies, and exploring the microbial synthesis of pigments on inexpensive
substrates is an attractive option to develop commercial scale production Aiming at natural
pigments on readily available agro-industrial materials, this study mainly focuses on
(i) Isolation of pigment-producing microorganisms and the production of pigments
(especially carotenoids and melanins),
(ii) Simple production of commercial pigments in higher amounts by purchased strains
(which are at the developmental stage) and
(iii) Optimization of key parameters influencing pigment production where ever
necessary.
Over the years, alternatives for natural pigments have been sought. The ability to synthetically
create pigments suitable for coatings would be beneficial due to the ability to tightly control and
optimize their properties. Currently, pigments are mined, processed, in some cases modified, and
then sold to various paint and coating companies. Being able to synthetically produce pigments
would help to curb shortages on certain pigments, reduce costs, and save time and energy. It is

4
inevitable that the market trends for the paper industry will continue to significantly change. Due to
electronic media, paper producers have had to increase the quality of their products to be able to
compete for customers. This has caused an increase in competition between paper companies
and in turn, increased the demand for quality at a decreased cost. One of the areas that have seen
the biggest increase in competition has been in paperboard in the form of product displays and
packaging. This is due to a demand for better print quality, where as in the past, these grades
weren't printed as much or had lower standards. This means that printed paperboard is now
competing in markets where it did not compete before. Coated paperboard currently accounts for
about 6 million tons/year and is increasing compared to coated paper grades which account for 7.5
million tons/yr but are decreasing. The demand for coated paper will most likely continue to
decrease, as it has for the past 7 years, as the markets for coated paper products decrease, i.e.
magazines, catalogs, and photographs. Even with the new demand for coated paperboard, uncoated
paperboard products still outweigh the production of coated paperboard products. This leaves an
encouraging potential for an increase in the future production of coated paperboard as technologies
improve and the gap in production between coated paperboard and other markets decrease.
1.4 Iron oxide Pigment
Iron oxide has been used as pigments since long before owing to its advantage of pure
hue, consistent properties, and tinting strength. The building materials industry is the
greatest client of iron oxide pigments. Utilizations incorporate concrete cement and mortar
on account of their great dispensability and great tinting quality. They are broadly utilized
as a part of the assembling of paving blocks, checker tiles, designer tiles, stamped concrete
and so on Paints industry is the second biggest client of iron oxide pigments. Pigments
utilized as a part of plastics need high immaculateness, tinting quality, high heat resistance
and great dispensability Unique applications incorporate that in ceramic colors, cosmetics,
cork sheets, rubber, brake linings, drugs, wood polish, fertilizers, and cattle feed. New
applications incorporate impetuses in the petroleum industry, in oil boring apparatuses, in
compound shades, duplicate machine powder, and attractive separate materials.
1.5 Natural and synthetic iron oxide pigment
Natural pigments are products that have been obtained from selected minerals. Iron
minerals that are dug for steel must be fit for being mined and lessened to iron on a
competitive business premise. These minerals are chosen on the premise of iron content
and handling financial aspects. It is subsequently abnormal when iron minerals for steel
generation are suitable for utilization as mineral pigments. The characteristic color of
resources are chosen for their extraordinary physicochemical characteristics and have the
capacity to charge a premium cost over the iron minerals utilized for steel producing

5
Synthetic pigments, and in this occasion iron oxides, are pigments delivered from
fundamental chemicals. A synthetic chemical produces pigmentary particles
straightforwardly, rather than the utilization of comminution, the system basic to set up all
common iron oxide pigments.
1.6 Classification
Pigments have been classified on the basis of its color. Some of the important
pigments are as follows:
1.7 Coatings
Paper coatings at their most basic definition help to improve certain desired qualities
that the substrate doesn't provide. These qualities could be roughness, opacity, surface
quality, functionality, and improved print properties. A coating is defined as a material
which is applied onto a surface and appears as either a continuous or discontinuous film
after drying. It is first applied to a substrate, metered, dried, and then smoothed. Coatings
are designed to be able to flow in between the voids of the fibers in the substrate, which
results in a more uniform layer.
The deviations between the pigment particles are much less than the deviations between
fibers, which increases the smoothness of the sheet. Coatings that are applied to paper
substrates can be separated into two broad categories: pigmented coatings and functional
coatings. Functional coatings add a unique property besides the classical properties of a
coating (i.e. smoothness and opacity). The unique properties that can be added to these
types of coatings can be but are not limited to: friction control, release properties, abrasion
resistance, barrier properties (grease, oil, water, vapor), and certain printing characteristics.
The structure system of a coating can be thought of in four regions: substrate, film,
substrate/film interface, and film/air interface. Understanding how all of the regions or
layers interact and work together are key to creating an ideal product. Table 1 shows the
Yellow Oxide
Pigments
Goethite
(α-FeOOH)
Lepidocrocite
(γ-FeOOH)
Red iron
oxide
pigments
Hematite
(α-Fe2O3)
Siderite
(calcined)
Brown iron
oxide
pigments
Umbers
Limonite
(calcined)
Black iron
oxide
pigments
Magnetite
Slate
(mixed
minerals)

6
importance of each layer and how it affects the rest of the system. Since each layer of a
coating system builds upon each other, having a suitable substrate is very important. The
quality of the paper substrate has a direct effect on the appearance of the coating. If the
base sheet is too open (too many voids between the fibers) or closed, or the uniformity is
bad, the finished coated product will show signs of this. For instance, the coating film
could be uneven, resulting in high roughness or the coating could look non- uniform,
which would cause poor print quality.
Table 1.1 Importance of Layers in Coating System [3]
A coating is made up of several ingredients that work together to provide the desired
enhancements. A coating can consist of pigments, binders, and additives. Depending on
what is required of the coating, the ratios and combinations of these ingredients will vary.
Table 2 shows examples of various coating ingredients and why they are used.
Region Properties/Importance
Film/Air Interface Light Reflection (Gloss)
Friction Control
Surface Hardness
Surface Porosity
Surface Energy
Film Opacity Color
Water/Solvent Uptake Barrier Properties
Substrate/Film
I Interface
Adhesion
Durability
Substrate Surface Quality Sheet Porosity
Ingredient Function
Pigments, Clay, Calcium Carbonate,
TiO2, Talc
Provides the foundation of the coating
Impact brightness and smoothness
Impacted by the substrate being used
Binders, Starch, Latex, Protein Binds the pigments together
Lubricants
Allows particles within the coating to slide past one
another which can achieve higher solids and better gloss
Rheology Modifiers Adjusts the viscosity and water retention of the coating to

7
Table 1.2 Ingredient functionality in Coating
Along with all of the benefits of using coatings, the cost is another very important
reason coatings are used. Pigments that are used in coatings are less expensive than using
fibers. This results in a more cost-effective product by maintaining a grade weight but
using fewer paper fibers. The coating can account for up to 5-20% of the weight of a
coated paperboard grade. By using coatings, not only can the quality of the surface and
functionality of the paper increase, but the cost of production of a specific grade is
decreased. Coatings can be applied to a substrate through many techniques, all of which
have unique benefits. The coating methods used are dictated by the speed of the machine,
substrate type, and the desired quality of the coating. Coated paper mills may need the
coating embedded into the paper.
This is accomplished by using a size press coater. The need for a coating of uniform
thickness and high coverage is best achieved with an air knife or curtain coater. A very
smooth coating surface is best achieved with a blade coater. All of these methods also have
disadvantages as well, as in decreased sheet strength, rougher surfaces, and non-uniform
coating thickness, respectively. For coated paperboard, an air knife or curtain coater is
often used to meter the applied top coating layer. Using a metering technique that applies a
uniform coating layer is very critical when coating paperboard.
The color of the darker substrate and higher surface roughness present in these grades
must be taken into account. Ideally, the mill would like to have the smoothest sheet
possible. The balance between increasing the smoothness to help increase print quality and
low mottle and high stiffness is difficult. Blade metering provides high smoothness but
results in a coating layer of varying thickness. This is because it meters more coating into
the valleys of a rough surface and less coating onto its peaks. So in the case where the
substrate is much darker than the coating, mottle occurs. Therefore, for these applications,
metering techniques are used where a coating layer of uniform thickness is achieved. This
helps to provide a coating layer that makes the darker surface more uniformly bright.
However, the drawback is that the coating won't be as smooth, even upon calendering.
maximize runnability
Brightening Agents Adds brightness to the coating when pigments don't
suffice
Defoamers Decreases accumulation of foam during application
Crosslinkers Chemically bonds the binders for added strength and
durability

8
1.8 Paperboard Substrates
Paperboard is distinguished from a paper by its higher basis weight, which can range
between 150-800 g/m2
. Paperboard may be made out of one or multiple layers of paper
which may also contain recycled fibers. The layers are bonded together either by fiber-to-
fiber bonding or adhesives. Paperboard has a relatively high absolute strength in
comparison to other paper but is produced at slower rates. Due to the lower speeds of
production and the higher comparative basis weights, machine sheet breaks don't happen
frequently.
This results in a high uptime for the machine and therefore the coating is done online
instead of offline. Also, by coating on-line, the curl of the paperboard can be controlled.
The formulation of a top-coating formulation for paperboard depends greatly on the
nature of the substrate. Paperboard is pre-coated to reduce consumption of the more
expensive top coating. A pre-coat is applied as a cheaper alternative to achieve the quality
desired from the finished product while reducing cost. To do this, pre-coatings are made
with less expensive pigments and usually less expensive ingredients.
1.9 Calendering
Calendering is a mechanical action used to modify coated and uncoated paper and is
most often used to increase the gloss and smoothness of a sheet. Other properties such as
density, blackening, brightness, and opacity are also affected. Calendering is a process of
running paper through a nip point where two rolls meet under pressure to flatten the paper
and coating. This flattening process is designed to also align the fibers and the pigment
particles, which causes a smoother surface. Nip pressure, dwell time, roll elasticity, roll
temperature and smoothness are all factors that influence the results. Increasing the nip
pressure and roll hardness will decrease the caliper, lowering stiffness, while the
increasing temperature may allow for the particles in the paper and coating to move a
little easier, thus being able to decrease the load pressure to achieve smoothness with less
loss in calipers.
1.10 Coating Pigments
The demands for runnability and optical property performance for all coating
pigments are constantly increasing. Thus, the pigment properties of particle size,

9
impurities, surface shape, and surface area are increasingly more important. These factors
help to determine the packing arrangement of the pigment particle and pigment particle
interactions. The way in which the particles pack in the dry coating layer determines all
of the properties attributed to the finished product. One author has described what the
factors affecting particle packing as the "Seven S factors": size, shape, surface, spacing
(geometric), structure, spread (size distribution), and stirring[6]. Knowing and
understanding these factors, the properties desired from an ideal pigment would be:
(i) Appropriate particle size and narrow particle distribution
(ii) Free from impurities
(iii) Good dispersibility for easy mixing with water and low water absorption
(iv) High chemical stability and low solubility in water
(v) Good compatibility with other coating components
(vi) Good light reflectivity at all wavelengths for high brightness
(vii) The high refractive index for good opacity
(viii) Good glossing properties for eye-pleasing coating gloss and high print gloss
(ix) Low binder demand
(x) Good flow properties in an aqueous suspension and low abrasiveness
(xi) Cheapness
Because any one pigment does not offer all of these desired properties mixtures of
different pigments (i.e. Clays, Calcium Carbonates, Titanium Dioxide, and Talc) are used
to combine their strengths to include as many of the properties listed above. Since a
coating formulation may be adjusted by changing the ratios of the pigments used,
understanding the weight-versus-volume substitutions of pigments is very important in
terms of binder demand and optical property performance.
Binder demand can be understood as the amount of binder necessary to fully fill the
voids in between all of the pigment particles in the system. The term invented in themid-
1950s by the paint industry, Critical Pigment Volume Concentration (CPVC), describes
how much binder is needed to eliminate the air voids between pigments. A PVC of 100%
is understood to be all pigment while a PVC of 0% is all binder. These extreme PVC
values are not ideal because a coating containing both binder and pigment is desired. These
values do however help describe where the CPVC value lies. A PVC value above the
CPVC value means air voids are created due to a lack of binder and a PVC below the
CPVC value means the pigments start to lose contact with one another due to too much
binder.
As the PVC increases, the air voids increase and the binder in the coating decreases.

10
The binder acts as glue to hold the pigment particles together. As the ratio of the binder
and pigment changes, the gloss of the coating is the most noticeable property to change. As
there is less binder in the coating, the air voids become more prominent, which increases
the porosity of the coating. This also increases the opacity of the coating as air has a lower
refractive index than a binder. The corrosion resistance decreases as the amount of binder
in the system decreases because the strength of the coating decreases. It should be noted
that all paperboard coatings are made above the CPVC value to ensure air voids are
present. Properties such as porosity, gloss, and blister resistance can be altered in other
ways than PVC, such as calendering.
1.11 Dispersing
In order to maximize the effects of the pigments used in the coatings, the pigments must
be in a stable dispersed suspension. To disperse the pigment particles means to break apart
each particle into the smallest form possible. Pigments like to clump together when
allowed to sit over time and eventually settle out of suspension. High-speed dispersing
refers to a saw-blade-type impeller mounted on a shaft rotating at high speed, which is
vertically centered in an upright cylindrical tank. This impeller works to apply mechanical
energy to the clumps of particles to break them apart to create a suspension of pigment
particles. A well-dispersed pigment is always sought after to minimize coating viscosity,
optimize surface area, and increase the optical properties. Pigments are completely
dispersed when the particles are completely wetted.
This means that the particles are completely separated and the viscosity of the pigment
will no longer drop with the addition of more dispersing agent. A peripheral velocity of the
impeller must reach about 4,900 rpm or higher for the good dispersion of pigment for
roughly 15-20 minutes under ideal conditions. There are three forces to consider when
creating any suspension: Electromagnetic, Electrostatic, and Steric Hindrance[6].
Dispersing agents are added to control the interactions of these forces to achieve the
highest solids for the coating while maintaining a stable suspension. Higher solids are
desirable because they help create a more uniform binder distribution to due reduced
migration into the base paper, achieve a faster immobilization by containing less water, and
generate significant savings in the dryer energy required.
Electromagnetic forces are attractive in nature and must be overcome to ensure the
flocculation of particles is prevented. As flocculation of particles occurs, the suspension
loses stability and the runnability of the coating on the machine is negatively affected. The
electromagnetic forces can be attributed to Van der Waals forces which are caused by

11
interactions of the dipoles within the particles acting on one another. Electrostatic forces
are caused by like charges repelling each other. For instance, two negatively charged
particles will repel each other. The repulsion caused by the electrostatic forces increases
the stability of the suspension by increasing the distance between particles. This is caused
by an unequal distribution of ions in the solution around the particle and at its surface.
This implies a coating must have excess ions in the solutions and by increasing or
decreasing the pH of the solution, particle interactions can be controlled. The addition of
an electrolyte into the slurry during dispersing is also needed to control electrostatic
forces. These electrolytes are commonly referred to as dispersing agents. They work by
attaching themselves to the generally negatively charged particles and in doing so can
make the particle nonpolar. By creating a nonpolar shell around the particle, usually of
only one molecule thick, the effective diameter is reduced. This is achieved by replacing
several layers of water molecules that were present before the electrolyte was added.
Now, the particles are less inclined to see each other and therefore decrease the viscosity
of the slurry. This is an important role as the number of solids achievable for any given
slurry can now be increased.
The higher the solids that a slurry of pigment can be made, the more cost efficient the
coating process will be. Steric hindrance is also helpful in creating a stable coating
suspension, especially when used in combination with electrostatic forces. Steric
hindrance is caused when materials are adsorbed on the surface of a particle. The
adsorbed layer acts as a mechanical barrier between approaching particles. Materials such
as proteins, gums, starches, and cellulosic derivatives work well. These protective colloids
are especially effective because they are strongly hydrophilic, giving them the ability to hold the
water around them, creating even more steric hindrance.
1.12 Opacity
Opacity can be defined as the ratio of light being reflected off a black backing to the
reflectance of light offwhite backing. It is impacted by the refractive indexes of the
particles and air voids in the system. The refractive index of a material is equivalent to
the velocity of light in a vacuum divided by the velocity of light in a given medium. The
greater the differences in R.I. between coating components, the higher the opacity will be.
Thus, maximizing these differences results in higher hiding power.The light that reflects
off the surface of the coating at the same angle of incidence is called specular reflectance,
also known as the gloss of the surface. Light can also reflect at different angles depending
on its contact with the particles in the coating system. This is known as diffuse

12
reflectance. The light that passes through the solid interfaces is considered as diffuse
transmittance. Minimizing the amount of light that can pass through the coating and
paper board layers increases the opacity.
1.13 Titanium Dioxide Pigment
Air is used as the standard when rating refractive indices of pigments and hasan R.I. of
1. Depending on the type of pigment used, R.I. will be different. When comparing the
refractive indices of TiO2, anatase has an R.I. of 2.56 and rutile hasan R.I. of 2.71.
Comparing these refractive indices to the refractive indices of fibers and other pigments
(Talc, CaCO3, and Clay), they all fall within a small R.I. range of roughly 1.55-1.65.
Water has a refractive index of 1.33 which explains why substrates and coatings lose
opacity when water replaces the air voids within these structures.
The light scattering ability of pigments in coatings is determined by the difference in
refractive indices. By subtracting known R.I.'s between a particle and the fluid it is
encompassed by, the amount of light scattering can be understood. As the opacity of a
coating increases, the light scattering increases as well. Maximizing the opacity of a
coating is achieved by passing light through TiO2 and air voids as these are the coating
components greatest difference in R.I.
1.14 Rare earth pigment
Cerium nitrate refers to a family of nitrates of cerium in the three or four oxidation
state. Often these compounds contain water, hydroxide, or hydronium ions in addition to
cerium and nitrate. Double nitrates of cerium also exist. Cerous nitrate crystal with Miller
index notation Anhydrous cerous nitrate, also called cerium(III) nitrate, is the anhydrous
salt with the formula Ce(NO3)3. Cerium nitrate hexahydrate, with the formula
Ce(NO3)3.6H2O, is the most common nitrate of cerium(III). It is a component in a burn
treatment cream that also includes silver sulphadiazine. Concentrations used are 0.5 M for
the cerium nitrate. For very serious burns it reduces the death rate. At 150 °C, the
hexahydrate loses water of crystallization to make a trihydrate, which itself decomposes
above 200 °C. Cerous nitrate hexahydrate has pinacoidal triclinic crystals.
Hydronium cerium (III) nitrate hydrate, Ce (NO3)5(H3O)2..H2O[5] It is monoclinic with
space group P2/c. The diaquapentanitratocerate(III) anion (Ce(NO3)5(H2O)2)2− occurs in
several salts. The salts have extreme non-linear optical properties Cerium tetranitrate
pentahydrate is prepared by evaporating a solution of ceric nitrate in concentrated nitric
acid. It forms orthorhombic crystals with bipyramidal shape. The common crystal face

13
Miller index is {111}, But it can have smaller faces with Miller index {010} and {110}.
The density is 2.403 g/cm3. Its optical properties are that it is biaxial with 2V of 34°, and
strongly dispersive. On its B and C axes it appears yellow, but orange-red on the A axis.
Ceric nitrate is quite soluble in nonpolar solvents such as ethyl ether. Ether will extract the
cerium nitrate from 5N nitric acid. In nitric acid nitrate ceric acid (H2[Ce(NO3)6] and
H[Ce(NO3)5.H2O]) is present.
Owing to its solubility of this nitrate in non-polar solvents allows the separation of
cerium from other rare earth. Basic cerium(IV) nitrate has the formula
Ce(NO3)3.OH.3H2O. It also forms upon evaporation of solutions of cerium(IV) in nitric
acid. When this meets ammonia in water solution it reacts to form ceric ammonium nitrate
and ceric hydroxide. Basic dicerium nitrate has the formula Ce2O(NO3)6(H2O)6·2H2O.
Again it crystallizes from solutions of cerium(IV) in nitric acid. It crystallizes as
monoclinic crystals with space group P21lc with unit cell [11dimensions a=8.723 Å
b=8.940 Å c=13.981 Å, β = 94.91°. Each unit cell contains two formula units
Ce2O(NO3)6(H2O)3 and Ce2O(NO3)6 form when this basic nitrate is heated slowly to
180 °C in a vacuum] The diaquapentanitratocerate (III) anion (Ce(NO3)5(H2O)2)2−
occurs
in several salts. The salts have extreme non-linear optical properties.
Lanthanum is a chemical element with symbol La and atomic number 57. It is a soft,
ductile, silvery-white metal that tarnishes rapidly when exposed to air and is soft enough to
be cut with a knife. It is the eponym of the lanthanide series, a group of 15 similar elements
between lanthanum and lutetium in the periodic table, of which lanthanum is the first and
the prototype. It is also sometimes considered the first element of the 6th-period transition
metals, which would put it in group 3, although lutetium is sometimes placed in this
position instead. Lanthanum is traditionally counted among the rare earth elements.
Lanthanum has no biological role in humans but is essential to some bacteria. It is not
particularly toxic to humans but does show some antimicrobial activity. Lanthanum usually
occurs together with cerium and the other rare earth elements.
Lanthanum was first found by the Swedish chemist Carl Gustav Mosander in 1839 as
an impurity in cerium nitrate – hence the name lanthanum, from the Ancient Greek
λανθάνειν (lanthanein), meaning "to lie hidden". Although it is classified as a rare earth
element, lanthanum is the 28th most abundant element in the Earth's crust, almost three
times as abundant as lead. In minerals such as monazite and bastnäsite, lanthanum
composes about a quarter of the lanthanide content. It is extracted from those minerals by a
process of such complexity that pure lanthanum metal was not isolated until 1923.
Lanthanum compounds have numerous applications as catalysts, additives in glass, carbon

14
arc lamps for studio lights and projectors, ignition elements in lighters and torches,
electron cathodes, scintillators, GTAW electrodes, and other things. Lanthanum carbonate
is used as a phosphate binder in cases of renal failure. It is also an element in the 6th
period
and in the 3rd group.

15
CHAPTER 2
LITERATURE REVIEW
2.0 Objective
(i) To synthesize the yellow Nano pigment by using a chemical method.
(ii) To characterize the synthesized Nano pigment by X-ray Diffraction, FT-IR
spectroscopy, Particle size analyzer, Thermogravimetric analyzer (TGA), Fluorescence
microscopy.
(iii) To investigate the antibacterial activity of yellow Nano pigment against both
Gram positive and Gram negative bacterial (Escherichia coli, Bacillus subtilus,
Enterobacter) organisms by well diffusion method.
2.1 Literature Review
Bellie's et al 2006; Electron energy-loss spectroscopy (EELS) in combination with
scanning transmission electron microscopy (STEM) reveals that the La enrichment at the
surface of cerium-lanthanum solid solutions is an average defect and that segregation
occurs in a mixed oxide phase. This separation occurs within a crystalline particle, where
the dopant-rich phase is located at the surface of the dopant-deficient phase. The limiting
structure appears to be a solid solution with a La fraction of x) 0.6 in the bulk and x) 0.75
at the surface. Up to all fraction of 0.6, this phase will coexist with a lanthanum-type
structure in different proportions depending on the dopant amount. STEM-EELS appears
to be a powerful technique to clarify the existence of a multiphase system, and it shows
that XRF, XPS, and XRD measure averaged results and do not show the phase complexity
of the solids. The multi-technique approach using Raman, XRF, XRD, XPS, and STEM-
EELS presented in this work allowed us to identify the different phases of the Ce1-
xLaxO2-x/2 system. To our knowledge, for the first time, STEM-EELS has been applied
lanthanum-cerium mixed oxides, and this study confirms the complexity of these systems.
The presence of a single fluorite (CeO2) structure is maintained until the dopant ionic
fraction reaches a value of about0.5 in lanthanum. At this point, an A-type (La2O3)
hexagonal structure appears. The fluorite structure disappears up to an infraction of 0.9 in
lanthanum. The solid-state reaction at a high temperature of the nitrate precursors leads to
phase separation into dopant-rich and -deficient phases. STEM-EELSmeasurements reveal
that the enrichment at the surface is not simply an enrichment of La as initially suggested
by average results from XRF and XPSbut segregation into a mixed oxide phase.

16
F. Moghimi Nejad et al 2015; Based on the CMYK color system, it is possible to obtain
the full-color spectrum with mixing the four colors cyan, magenta, yellow and key (black).
In this research, ceramic nano pigments including CoAl2O4 (cyan), Au(magenta), (Ti, Cr,
Sb)O2 (yellow) and CoFe2O4 (key) were mixed together with different ratios and applied
on glazed tiles and the color specifications of the samples were measured. The Colours
Software (CSA) was used for predicting the ratios of the pigments for obtaining a target or
reference color. For comparison, equivalent micro pigments,namely CoAl2O4,
Cd(S,Se):ZrSiO4, (Ti,Cr,Sb)O2 and CoFe2O4 were also examined. It was observed that
using the present nano pigments, it was possible to cover the fourth quarter of the CIELab
circle close to the a+ axis, while this was not possible with the micro-pigments. This was
attributed to the blue tint present in Au nano pigment. It was also revealed that reaching the
colors of grey, brown and beige shades was possible by both nano and micro sets of
pigments while making orange and yellow colors were difficult. Also, it was revealed that
yellow nano and micro-pigments did not have thermal stability at high temperatures.
However, thermal stability depends on the type of both nano pigments and ceramic
matrices; it is high in the case of black, cyan and magenta colors, which are stable in the
whole firing range tested although less intense colors are achieved with respect to
conventional micro-pigments. Nano-titania is less stable at high temperature, but its yellow
coloration is better than that of the corresponding micro pigment. It was concluded that it is
possible to reach various colors by mixing the pigments according to the CMYK system,
provided proper pigments are chosen. The severe difficulty in simulating orange and
yellow colors was the instability of the yellow pigments used in this work. Hence, it is
intended to use stable yellow pigments in future experiments. However, simulation of
beige, brown and grey colours, which are very commonly used for decorating tiles, were
successfully accomplished in this work.
N. Mufti1et al 2014; The aim of this research is to synthesize nanoparticles of black
pigment of Magnetite (Fe3O4), the red pigment of hematite (α-Fe2O3), and yellow
pigment of ghoetite (α-FeOOH) from the iron sand. The black pigment of Fe3O4 and the
yellow pigment α-FeOOH nanoparticles were synthesized by coprecipitation method with
a variation of pH. Whereas, the red pigment Fe2O3 was synthesized by sintering Fe3O4
nanoparticles at a temperature between 400 oC and 700 oC for 1hour. All the pigments

17
have been characterized using X-ray diffraction and SEM. The XRD results show that the
particle size of the black pigment Fe3O4, red pigment Fe3O4, and yellow pigment α-
FeOOH are around 12, 32, and 30 respectively. The particle size of Fe2O3 nanoparticles
increases by increasing sintering temperature from 32 nm at 400 to 39 nm at 700 oC. For
the yellow pigment of α-FeOOH, the particle size increase by increasing pH.SEM results
show that the morphologies of black, yellow and red pigments are agglomerated. In this
study, we show how to synthesize iron oxide black, red and yellow nanoparticles pigments
directly from iron sand. The black pigment is Fe3O magnetite(Fe3O4) nanoparticles with a
particle size of 11.7 nm. The red pigment is hematite (α-Fe2O3) 4 nanoparticles with a
particle size of 39.5 nm, and the yellow pigments goethite (α-FeOOH) nanoparticles with a
particle size of 48.7 nm. The brightness and particle size of the pigments increase by
increasing sintering temperature for red pigment synthesis, or by increasing for yellow
pigment synthesis.
Claudia Pelosi1et al 2010; Artificial yellow pigments (lead-tin yellow type I and type II,
lead antimonate yellow and lead-tin-antimony yellow) have been produced, starting from
various recipes and from pure chemicals, in different experimental conditions. The
products were analyzed using micro-Raman spectroscopy. Differences in stoichiometric
ratios, in melting temperatures and in crucible typologies were examined. Other
analyticaltechniques were required to characterize the stoichiometricratios of the obtained
products (X-ray diffraction,scanning electron microscopy with energy
dispersivespectroscopy and differential thermal analysis).The resultsare analysed and
discussed in terms of correlations amongchemical composition, melting conditions and
colour hue. Raman, XRD and SEM-EDS analyses showed thatlead-tin yellow type I
(Pb2SnO4), lead-tin yellowtype II (PbSnO3 or PbSn1-x SixO3) and lead-tin-
antimonyyellow (Pb2SnSbO6,5) may be produced aspure materials whereas lead
antimonate yellow isvery difficult to be obtained. Very often mixtures ofcompounds with
different stoichiometric ratiosresult. Experimental tests showed that temperatureplayed an
important role in the composition andcolour of the produced pigments. The
stoichiometricratio of the metal elements in the chemicaloxides was also an important
parameter. In factthe use of a volume, ratio led to the production ofthe expected pigments
but some reagentsremained in the final product. In this preliminaryphase of the research,
we chose to make a simplificationof the recipes, in particular to eliminatesome ingredients

18
whose role was not completelyclear. Further experimental tests will be tried outfor a better
understanding of the role of theseingredients (tuccia, tartaro emetico and NaCl) indicatedin
the recipes.The study of lead, tin and antimony based yellowpigments, produced inthe
laboratory with the ancient procedure, is also useful for investigations on similarmaterials
used in works of art.32 Indeed, it is very probable that artists chose their paintingmaterials
by selecting the colour hue, whichdepended on the production method.
Algernon T.et al 2014; Aggregation of organic pigment nanoparticles in organic solvent
produces poor quality thin-film coatings. The nonuniformity of surface layers produced by
dense aggregates within films of nanopigments can be detrimental for light transmission.
Formulating dispersions composed of an organic pigment and an organic solvent with
minimized aggregation must be achieved for use as precursors for high-performance
optical thin-films. The goal of our investigation was to determine the influence of
deaggregating dispersants with and without a surface-modifying synergist, as well as the
influence of solvent polarity on the dispersion properties. The work was focused on
establishing nanoparticles smaller than 50 nm in size, which is an area not broadly
published for solvent-based systems. A working hypothesis of using an acid-functionalized
synergist capable of establishing stable acid/base ionic-pair interactions was investigated.
Our work demonstrated that a synergist that incorporates acid functional groups can be
combined with an amine-functionalized polymeric dispersant to form a stable organic
solvent-based dispersion composed of dispersed pigment nanoparticles that also
incorporate amine functional groups. Stabilizing ionic-pair interactions are proposed. The
dispersion and coating of the dispersion were characterized using dynamic light scattering
(DLS), transmission electron microscopy (TEM), and atomic force microscopy (AFM).
Optical properties of thin films were evaluated from transmission spectroscopy
measurements. Within this study, a correlation was established between spectral properties
of coated dispersions and detected nanoparticle aggregation. An acid-functionalized
synergist can be used for enhancing the interaction between an amine functionalized
polymeric dispersant and PY-185 which also incorporated amine functionality. Data
support the formation of strong ion pair interactions with the synergist that links the
dispersant to the surface of generated nanoparticles. Specifically, with supporting data
from DLS, TEM and AFM analyses, it was determined that the presence of the acid
functionalized synergist reduced nanoparticle aggregation. Data also indicated that solvent

19
polarity possibly plays a role in nanoparticle aggregation. This study produced a very low
viscosity dispersion consisting of uniformly dispersed PY-185 nanoparticles less than 50
nm in size. These properties were observed with a pigment concentration that measured
close to 10 wt %. Total transmission spectroscopy studies showed advancement of
dispersion properties could be leveraged to provide improved optical properties of coated
films composed of pigment nanoparticles. The investigation provides insight on how to
advance the performance of optical thin films that incorporate pigment nanoparticles.
P.M.T. Cavalcante1et al 2009; Ceramic nano-pigments have been recently developed for
ink-jet printing decoration of ceramic tiles by the quadrichromy technology (cyan,
magenta, yellow, and black colors). The coloring mechanisms and performance of these
nano-pigments (CoAl2O4, Au, (Ti, Cr, Sb)O2, CoFe2O4) were investigated by DRS,
XRD, and colorimetry. Nano-pigments were dispersed in several ceramic glazes and glassy
coatings and their color performance compared with that of conventional micro-pigments.
Each nano-pigment is characterized by its own color mechanism and chemical-physical
stability in ceramic applications. Intense colors are achievable, besides the very small
particle size of pigments (< 50 nm) even though the color of high-quality
micropigmentsappears to be more saturated. Limitations to the use of nano-pigments arose
for very high firing temperatures (>1200ºC) due to particle growth (e.g. Au) or dissolution
in the glassy phase (e.g. titania). Ceramic nano-pigments, designed for quadrichromy
(cyan, magenta, yellow and black)ink-jet printing of ceramic tiles, has been applied in
several glazes and glassy coatings, Published on Dyes and Pigments, 80 (2009) 226-
232.7comparing their color performance with that of correspondent conventional micro-
pigments. Each nano-pigment is characterized by its own color mechanisms (i.e. surface
plasmonic resonance for nanogold; Co2+ dissolution in the glassy phase for
CoAl2O4;anatase-to-rutile transformation and change of the band structure induced by
Cr3+doping innanotitania; extensive Co-O and Fe-O charge transfer in CoFe2O4). The
color performance of ceramic pigments is a compromise between the efficiency of
coloration, that is thought to be improved by small sizes, and dissolutions kinetics inthe
ceramic matrix, that is expected to be faster when particle size is reduced. From this
standpoint, nano-pigments behave satisfactorily, bestowing intense colors on
ceramicwares, besides their very small particle size (mostly <50 nm). However, the
thermal stability depends on the type of nano-pigments and ceramic matrices, being high in

20
the case of black, cyan and magenta colors, which are stable in the whole firing range
tested(800-1200 ºC) although less intense colors are achieved with respect to conventional
micro-pigments. Nano-titania is less stable at high temperature, but its yellow coloration is
better than that of the correspondent micro-pigment.
Gagnon et al 2016; Biomaterials as implants are being applied more extensively in
medicine due to their on-going development and associated improvements, and the
increase in human life expectancy. Nonetheless, biomaterial-related infections, as well as
propagating bacterial resistance, remain significant issues. Therefore, there is a growing
interest in silver-based drugs because of their efficient and broad-range antimicrobial
activity and low toxicity to humans. Most newly-developed silver-based drugs have an
extremely fast silver-ion release, increasing adverse biological impact to the surrounding
tissue and achieving the only short-term antimicrobial activity. Nanoencapsulation of these
drugs is hypothesized as beneficial for controlling silver release and thus is the aim of the
present study. Initially, an amorphous or crystalline (anatase) titania (TiO2) coating was
synthesized around silver nanoparticle-containing (AgNP) ceria (CeO2) nanocontainers
using a sonication method forming AgNP/CeO2/TiO2 nanocontainers. These
nanocontainers were characterized by high-resolution transmission electron microscopy,
scanning electron microscopy, powder X-ray diffraction, gas sorption experiments, and
energy-dispersive X-ray spectroscopy. Silver release, monitored by using inductively
coupled plasma optical emission spectroscopy, showed that these containers prevented
silver release in the water at neutral pH, and released the silver in concentrated nitric acid
solution (pH = 1.1). The AgNP/CeO2/TiO2 nanocontainers showed antibacterial activity
against E. coli, however, a concentration-dependent cytotoxicity towards a model epithelial
barrier cell type (A549 cells) was observed. These nanocontainers offer the concept of
potentially controlling silver delivery for the prevention of implant-associated infections.
Ceria-based nanocontainers were coated with TiO2 in a very efficient and reproducible
manner. This yielded both CeO2/ TiO2 and AgNP/CeO2/TiO2 nanocontainers. In the case
of AgNP/CeO2/TiO2 nanocontainers, the AgNPs were mainly encapsulated within the
CeO2 shell inside the TiO2 layer and only a small amount were present on the outer
surface of the TiO2 layer. These nanocontainers demonstrated exceptional control over the
silver release with only 7%of the silver content released when immersed in water over a 3
month period, and the release of the remaining silver able to be triggered on the addition of

21
nitric acid. The AgNP/CeO2/TiO2 nanocontainers demonstrated an increased antibacterial
activity against E. coli, although increased cytotoxicity towards a model epithelial barrier
cell type (A549 cells) compared to AgNP/CeO2 nanocontainers. Despite improvements
needed regarding their mammalian cell biocompatibility, these Nano containers have some
potential for possible application in the controllable delivery of silver for preventing
implant-related infection.
Xiaofei Huang et al 2016; this study, catechol-conjugated chitosan (CSS) was synthesized
to prepare silver nanoparticles in1
aqueous solution as both a reducing and stabilizing
agent. The entire reaction process complied with the principles of green chemistry. The
stability and physicochemical properties of CSS-coated silver nanoparticles (CSS–Ag NPs)
were well characterized by a series of techniques. A narrow diameter distribution and
excellent stability were observed in the target CSS–Ag NPs. Determination of the
minimum inhibitory concentration (MIC) and the disk diffusion test was applied to
evaluate the antibacterial activities with respect to quantity and quality, respectively. The
cytotoxic effects on HepG2cells were also evaluated with a series of essays. The resulting
CSS–Ag NPs combined the unique properties of chitosan and silver nanoparticles, showing
effective antibacterial activities and low cytotoxicity. The effective toxic concentration of
CSS–Ag NPs towards E. coli and S. aureus is too low to damage HepG2 cells. The results
demonstrated that CSS–Ag NPs could be a potential candidate for use in biological and
pharmaceutical areas to prevent infections caused by microorganisms. In this study,
catechol-conjugated chitosan was synthesized to prepare CSS–Ag NPs with narrow size
distribution and high stability, and this acted as both a reducing and stabilizing agent
during the preparation process. The entire preparation process complied with the principles
of green chemistry. The resulting CSS–Ag NPs combined the unique properties of chitosan
and silver nanoparticles, showing significant potential in biological and antibacterial fields.
On one hand, CSS–Ag NPs effectively inhibited the growth of E. coli and S. aureus due to
the excellent dispersibility of the silver nanoparticles. On the other hand, the cytotoxic
effect of CSS–Ag NPs on HepG2 cells was improved by the stabilization effect of
chitosan. The effective toxic concentration of CSS–Ag NPs towards E. coli and S. aureus
is significantly lower than that towards HepG2 cells.

22
S. Bhakyaa et al 2016; In the present study, the Helicteres isora stem bark extract for the
biosynthesis of AgNPs is described. It was observed that the aqueous silver (Ag+) ions,
once associate in nursing stem bark extract, were reduced in solution, thereby leading
resulting information of the stable AgNPs. These AgNPs were characterized by several
techniques. The nanoparticles show maximum absorbance at 419 - 431 nm on ultraviolet-
visible spectra. The presence of steroid sapogenin was identified as by Fourier transform–
infrared (FTIR) spectroscopy. The reduction of Ag+ ions to silver element was
characterized by X-ray photoelectron (XRD) spectrophotometry. The transmission electron
micrograph (TEM) revealed the formation of monodispersed with low polydispersity
nanoparticles of 25.55 nm, and the presence of elemental silver was confirmed by energy
dispersed spectroscopy (EDX) analysis. AgNPs showed antioxidant activity such as DPPH,
Hydrogen peroxideand nitric oxide radical scavenging and Reducing power against the
standard. The antibacterial effect was determined against test strains showing significant
inhibition. Antiproliferative activity of AgNPs was demonstrated on oral carcinoma (KB)
cells by MTT and confirmed by Ao/EtBr, Comet assay, DCFH-DA, and Rhodamine 123
staining. For toxicity study, the significant mortality rate was observed against Artemia at
IC50 concentration 70 ug/ml at 108 h exposure. NPs showed to be cytotoxic against
Artemia at 108 h, so they are cytotoxic at high concentrations and prolonged exposures. A
stable, simple and eco-friendly techniquebiosynthesizing AgNPs were effectively
established by using H. isorastem bark extract. H. isora stem bark contains more
phytosterolsand saponins that play major roles as reducing as well as cappingagents to be
used in green synthesis of AgNPs. The extract acts asreducing and stabilizing agent which
was confirmed by FTIR studies.TEM and XRD reports revealed that biosynthesized
AgNPs werecrystalline in nature with a mean particle size of 25.55 nm. Thisbiosynthesized
AgNPs were found to be multifunctional with goodantioxidant and antimicrobial activities.
The stem bark extractcapped AgNPs solution showedthe significant dose-
dependentcytotoxic effect to KB cells. Nauplii showed significant mortality at108 h of
exposure to AgNPs. Thus, it was concluded that thecolloidal AgNPs were nontoxic to
Artemia. This green synthesismethod might be a good alternative to physical and chemical
nanosynthesis methods. Hence, this method might be scaled up forindustrial production,
manufacturing of ultrafiltration membranesand food packaging as well and might be of
value for manybiological and medical applications.

23
Shambhu Sharan Kumar et al 2015; For the purpose of corrosion protection and
embellishment, the surface coating is the most universally used practice. The applications
of nanotechnology in the fields of corrosion protection and surface coatings can
significantly improve the adhesion property, stiffness, chemical resistance, weathering
resistance and robustness among all other important properties of surface coatings. In this
work, nano particles applied surface coatings have been used to protect various types of
metals and alloys from corrosion and other degradation. For this purpose, epoxy-zeolite
self-cleaning super hydrophobic and antimicrobial corrosion resistant coatings have been
used to protect metals and alloys from corrosion. The corrosion protection efficiency has
been improved when nanoparticles have been incorporated and dispersed into paint media.
Nano coatings have been introduced as smart materials; produced by shrinking the
materials at the nano scale level to form a denser product to protect the surfaces with the
superior approach. Nanoparticles applied coatings demonstrated a number of advantages
such as better surface appearance, chemical resistance, thermal and electrical conductivity,
and improved corrosion resistance. Incorporation of nanoparticles in paint formulations
improved the corrosion resistance property of antimicrobial zeolite coatings. On the basis
of rigorous coating performance test as per ASTM/BIS methods, coating-film passed 3200
hours in salt spray corrosion test, 100% gloss and 100% adhesion; confirmed extraordinary
improvement in the fields of corrosion protection and surface coatings. Index Terms
Nanoparticles, polymeric nanocoatings, epoxy-zeolite coatings, corrosion protection.
Incorporation and optimum dispersion of appropriate nanoparticles in paint formulation
enhance the corrosion protection efficiency and adhesion property of polymeric surface
coatings. Both theoretical and experimental analysis show enhancement in the overall
performances of the surface coatings. Therefore, it is recommended that the rutile TiO2
with nano TiO2, nano ZnO and zeolite as pigment particles can be used in paint
formulations for the purpose of overall improvement in coating properties. Both theoretical
and experimental analysis show enhancement in the performance of the coatings:
Roohangiz Zandi Zand et al 2012; The aim of this work was to investigate the effect of
the cerium concentration on the morphology and anti-corrosion performance of cerium–
silane hybrid coatings on hot-dip galvanized (HDG) steel substrates. 3-
glycidoxypropyltrimethoxysilane (GPTMS) and bisphenol A (BPA) were employed as

24
precursors to prepare the sol-gel based silane coating. Cerium nitrate hexahydrate was
added to the silane coatings as a dopant in five different concentrations. The morphology
of the coatings before and after the corrosion test was examined by scanning electron
microscopy (SEM), indicating an effect of the cerium concentration. Very low and very
high cerium concentrations deteriorate the corrosion inhibition in the sol-gel matrix and
consequently, there is an optimum concentration of cerium nitrate. Accelerated salt spray
testing showed that corrosion near an artificial scratch is blocked efficiently by high
cerium nitrate contents, whereas uniform corrosion is inhibited effectively with
comparatively low ceria contents. Electrochemical studies indicate a general beneficial
effect of the incorporation of cerium nitrate, although the performance of the coated
substrate depends on the cerium nitrate content. The results of electrochemical impedance
spectroscopy (EIS) and electrochemical polarization confirmed that the corrosion
resistance of the coatings initially increases and then decreases as the cerium concentration
goes up. Optimal corrosion resistance was obtained at a cerium concentration of 0.05 M.
M.L. Zheludkevich et al 2005; Nanostructured hybrid sol-gel coatings doped with cerium
ions were investigated in the present work as pre-treatments for the AA2024-T3 alloy. The
sol-gel films have been synthesized from tetraethylorthosilicate (TEOS) and
3glycidoxypropyltrimethoxysilane (GPTMS0)precursors. Additionally, the hybrid sol was
doped with zirconia nanoparticles prepared from hydrolyzed tetra-n-propoxyzirconium
(TPOZ). Cerium nitrate, as a corrosion inhibitor, was added into the hybrid matrix or into
the oxide nanoparticles. The chemical composition and the structure of the hybrid sol-gel
films were studied by XPS (X-ray photoelectron spectroscopy) and AFM (atomic force
microscopy), respectively. The evolution of the corrosion protection properties of the sol-
gel films were studied by EIS (electrochemical impedance spectroscopy), which can
provide quantitative information on the role of the different pre-treatments. Different
equivalent circuits, for different stages of the corrosion processes, were used in order to
model the coating degradation. The models were supported by SEM (scanning electron
microscopy) measurements. The results show that the sol-gel films containing zirconia
nanoparticles present improved barrier properties. Doping the hybrid nanostructured sol-
gel coatings with cerium nitrate leads to additional improvement of the corrosion
protection. The zirconia particles present in the sol-gel matrix seem to act as nano
reservoirs providing a prolonged release of cerium ions. The EIS method can be used to

25
model the metal/coating interface of the sol-gel pre-treatments on aluminum alloys. The
corrosion resistance of the coating and the kinetics of the corrosion process in chloride
solution were evaluated for the AA2024-T3 coated with hybrid sol-gel films. Incorporation
of zirconia nanoparticles leads to improvement of the barrier properties of the
organosiloxane hybrid sol-gel coatings. Additional corrosion protection is conferred by
doping the sol-gel film with cerium-based inhibitor. However, the too high concentration
of cerium nitrate leads to degradation of the barrier properties of the sol-gel matrix. The
hybrid sol-gel coatings with incorporated zirconium oxide nanoparticles doped with cerium
inhibitor provide long term corrosion protection and can be prospective candidates for the
development of new environmentally friendly pretreatments. The nanostructured zirconia
particles play the role of nano reservoirs for storage and controllable release of the
inhibitor.
Benjamin K. Simpson et al 2012; Nature has endowed living organisms with different
pigments for a plethora of functions. These include enhancing the visual appeal of the
source material, a means for camouflage and concealments, as an index of food quality,
and even as sex attractants. The interest in natural pigments as food-processing aids derives
from the increasing consumer aversion to the use of chemicals and synthetic compounds in
foods. The chapter provides information on the major types of natural food pigments and
their major sources, their functions and uses in food, their health benefits, and their fate
under various processing and storage conditions. The chapter also provides information on
their relative advantages over their counterparts perceived as artificial food colorants.
Mohammad Mizanur Rahman et al 2018; Waterborne polyurethane (WBPU)/cerium
nitrate (Ce(NO3)3) dispersions were synthesized with different defined Ce(NO3)3 content.
All pristine dispersions were stable with different poly(tetramethylene oxide) glycol
(PTMG) number average molecular weights (Mn) of 650, 1000, and 2000. The interaction
between the carboxyl acid salt group and Ce(NO3)3 was analyzed by Fourier-transform
infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) techniques.
Coating hydrophilicity, water swelling (%), water contact angle, leaching, and corrosion
protection efficiency were all affected when using different Ce(NO3)3 content and PTMG
molecular weights. The maximal corrosion protection of the WBPU coating was recorded
using a higher molecular weight of PTMG with 0.016 mole Ce(NO3)3 content.

26
R. Poornima et al 2015; The investigation on bio-color production for use is food through
fermentation and evaluation of the yellow pigments secreted by Thermomyces sp in
submerged culture, using sucrose and ammonium sulfate as carbon and nitrogen sources
are reported. After extraction and purification, these colorants were suspended in water for
evaluation. The stability of the extract was tested in different environmental conditions
such as pH, heat, light, antioxidants and chemical preservatives. It has been shown that
increasing the pH, temperature or exposure to light does not affect the stability of the
yellow pigment. The pigment extract was more stable at pH 5.1 and 8.0, the temperature at
10OC, 20OC and 30OC both in the presence and absence of light, however, moderate
stability was observed in antioxidants and preservatives. Thus, yellow pigment obtained
fromThermomyces sp has a high potential to be used as a natural food colorant.
Kamla Malik et al 2016; The pigment-producing bacteria and fungi were isolated from
soil, damping site, compost, industrial effluent, spoiled fruits, and vegetables. A total of
fifteen bacterial and nine fungal pigment-producing isolates were obtained and screened on
nutrient agar and potato dextrose medium, respectively. The pigments from selected
isolates were extracted by solvent extraction (acetone and methanol). The antimicrobial
activity of selected isolates was determined by disc agar diffusion technique against
standard isolates of Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli, and
Fusarium oxysporum. The cytotoxicity was studied by using yeast toxicity test (YTT).
Bacterial isolates BP-8 exhibited the inhibitory effect against Saccharomyces cerevisiae
and E.coli. The Rf value of pigment extract from different bacterial isolates varied from
0.86 to 0.91 whereas it was 0.92 by fungal isolate FP-6 as determined by thin layer
chromatography (TLC). ). The bacterial isolates BP-2 and BP-6 were Gram+ve and BP-8
was Gram-ve. Out of these BP-6 and BP-8 were non-spore former. These bacterial isolates
belonged to the genus Bacillus, Micrococcus, and Serratia. The fungal isolate was
identified as Aspergillus sp.
Chao-Sung Lin et al 2006; Cerium conversion coatings are a potential alternative to
chromium conversion coatings for improving the corrosion resistance of magnesium
alloys. This study detailed the microstructure and corrosion resistance of cerium
conversion coatings on AZ31 magnesium plates treated in 0.05 kmolm3 cerium nitrate

27
solution, with and without 0.25 kmolm3 hydrogen peroxide. The results indicate that the
corrosion resistance of the coating was related to the microstructure of the major overlay,
and to the defects of the coating. The major overlay changed from a fibrous structure to a
compact layer, as hydrogen peroxide was added to a cerium nitrate solution. Meanwhile,
severely-damaged areas were observed on the coating formed in the presence of hydrogen
peroxide. Although the compact coating displayed better corrosion resistance than its
fibrous counterpart, both coatings were locally corroded during the polarization test.
F. Moghimi Nejad et al 2015; Based on the CMYK color system, it is possible to obtain
the full-colour spectrum with mixing the four colors – cyan, magenta, yellow and key
(black). In this research, ceramic nano pigments including CoAl2O4 (cyan), Au (magenta),
(Ti, Cr, Sb)O2 (yellow) and CoFe2O4 (key) were mixed together with different ratios and
applied on glazed tiles and the color specifications of the samples were measured. The
Colours Software (CSA) was used for predicting the ratios of the pigments for obtaining a
target or reference color. For comparison, equivalent micro pigments, namely CoAl2O4,
Cd(S, Se): ZrSiO4, (Ti, Cr, Sb)O2 and CoFe2O4 were also examined. It was observed that
using the present nano pigments, it was possible to cover the fourth quarter of the CIELab
circle close to the a+ axis, while this was not possible with the micro-pigments. This was
attributed to the blue tint present in Au nano pigment. It was also revealed that reaching the
colors of grey, brown and beige shades was possible by both nano and micro sets of
pigments while making orange and yellow colors was difficult. Also, it was revealed that
yellow nano and micro-pigments did not have thermal stability at high temperatures.
Claudia Pelosi et al 2010; Artificial yellow pigments (lead-tin yellow type I and type II,
lead antimonate yellow and lead-tin-antimony yellow) have been produced, starting from
various recipes and from pure chemicals, in different experimental conditions. The
products were analyzed using micro-Raman spectroscopy. Differences in stoichiometric
ratios, in melting temperatures and in crucible typologies were examined. Other analytical
techniques were required to characterize the stoichiometric ratios of the obtained products
(X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy and
differential thermal analysis). The results are analyzed and discussed in terms of
correlations among chemical composition, melting conditions, and color hue.

28
Supreet Kaur et al 2017; Solid state fermentation was carried out for the production of
pigments by using agricultural wastes. Yellow pigments were produced; the absorbance
maxima of Pigment extract was measured by spectral analysis. Out of these agricultural
wastes, broken wheat (0.996 OD) was best for the pigment production. The maximum
pigment yield (137.8 U/g) was seen at the 12th day. The study revealed that the addition of
nitrogen source improves the metabolic activity of the organism. Various parameters were
optimized to check pigment stability. Pigments showed high stability at low temperatures
(30-60°C) and become low at high temperature (above 60°C) and high stability at near
neutrality pH values (8.0) when compared to acidic pH values (4.0-6.0). FTIR analysis was
performed to determine the chemical bonds in a molecule by infrared absorption spectra of
Pigments. IR indicated that it is a phenolic compound and has broad stretching OH, C=C
and C-H groups of the aromatic ring. It can be concluded that the microbial pigment
produced can find application in the areas of textile, pharmaceuticals and food industries.
Narendhar. C et al 2013; The samples synthesized by the Cuminum cyminum extract
were all reduced to elemental form by virtue of the concentration of the extract used. The
samples synthesized using lesser dosage from 2ml to 6 ml tended to take 4-5 hours for a
complete change of color. The sample synthesised by using 10 ml of the extract tended to
aggregate soon during the observation period. The sample synthesized using 8ml of extract
formed iron crystal very soon and it was stable during the one week observation period.
The particle size analysis confirmed that the particle remained in the Nano range although
the 10 ml sample contained more fractions of aggregates. The zeta potential of the desired
sample synthesized by the 8ml extract of Cyminum Cuminum had a value of -2.7 mv which
shows excellent hydrodynamic stability The iron nanoparticles showed considerable
toxicity to all the microbial species. This was evident in the lack of increase in the OD
values which corresponds to the growth of the microbial population in the vials.
Pseudomonas was the severely affected microbe which had reduced values right from the
lesser dosage of to the higher dosage.
P. Nehra et al 2017; The emergence of resistance against antimicrobial agents has led to
the development of more efficient agents and new techniques for treatment of various
microbial infections. The aim of the present study is to determine the antibacterial and

29
antifungal activity of bare and chitosan coated Fe3O4 nanoparticles (NPs) against five
organisms, Escherichia coli, Bacillus subtilis, Candida albicans, Aspergillus niger and
Fusarium solani.
Manoranjan Arakha et al 2015; Investigating the interaction patterns at the nano-bio
interface is a key challenge for safe use of nanoparticles (NPs) to any biological system.
The study intends to explore the role of interaction pattern at the iron oxide nanoparticle
(IONP)-bacteria interface affecting the antimicrobial propensity of IONP. To this end,
IONP with magnetites like the atomic arrangement and negative surface potential (n-
IONP) was synthesized by co-precipitation method. Positively charged chitosan molecule
coating was used to reverse the surface potential of n-IONP, i.e. positive surface potential
IONP (p-IONP). The comparative data from Fourier transform infrared spectroscopy,
XRD, and zeta potential analyzer indicated the successful coating of IONP surface with
chitosan molecule. Additionally, the nanocrystals obtained were found to have spherical
size with 10–20 nm diameter. The Bac Light fluorescence assay, bacterial growth kinetic
and colony forming unit studies indicated that n-IONP (<50 μm) has insignificant
antimicrobial activity against Bacillus subtilis and Escherichia coli. However, coating with
chitosan molecule resulted ina significant increase in the antimicrobial propensity of IONP.
Additionally, the assay to study reactive oxygen species (ROS) indicated relatively higher
ROS production upon p-IONP treatment of the bacteria. The data, altogether, indicated that
the chitosan coating of IONP result in an interface that enhances ROS production, hence
the antimicrobial activity. The findings conclude that n-IONP has antimicrobial activity at
relatively very high concentrations. The activity can be further moderated by changing the
surface potential and accessible surface functional groups. The changes cause a change in
interaction pattern at the Nano-bio interface, hence play a crucial role in determining the
antimicrobial propensity of IONPs. However, the enhanced production of ROS because of
the interaction potential at the interface is the principal cause for the antimicrobial
propensity of the NPs. As a conclusion, the interaction pattern at the Nano-bio interface
plays a vital role in determining the antimicrobial activity of metal oxide nanoparticles.
Sudhanshu Shekhar Behera et al 2012; The iron oxide nanoparticles have been
synthesized in co-precipitation method using an aqueous solution of ferric and ferrous ions
with sodium salt. The synthesis of iron-oxide nanoparticleswas validated by UV-Visible

30
spectroscopy which showed a higher peak at 370 nm as the valid standard reference. An
average size of iron oxide nanoparticle found by diffraction light scattering (DLS) particle
size analyser, ranges approximately between 10 nm to 120 nm with a mean particle size of
66 nm. The X-ray power diffraction (XRD) analysis revealed the crystallographic structure
of magnetic particles. Characterization of the mean particle size and morphology of iron
oxide nanoparticles confirmed that the iron oxide nanoparticles are nearly spherical and
crystalline in shape. Further, the antibacterial effect of iron oxide nanoparticles was
evaluated against ten pathogenic bacteria which showed that the nanoparticles have
moderate antibacterial activity against both Gram positive and Gram negative pathogenic
bacterial strains and retains potential application in pharma-ceutical and biomedical
industries.
S. Arokiyaraj et al 2013; The present study intended for the chemical synthesis of iron
oxide nanoparticles (IO-NPs) followed by characterization and evaluation of antibacterial
activity after treating with Argemone mexicana L. leaf extract. The formation of IO-NPs
was confirmed by the color change and further examined by UV–vis spectroscopy. The
morphology was characterized by using SEM and TEM, which showed spherical particles
of uniform size ranged between 10 and 30 nm and the crystallites were determined through
XRD. The peaks in XRD pattern are in good agreement with that of the face-centered
cubic form of iron oxide nanoparticles. FT-IR spectroscopy confirmed the attachment of
bioactive molecules of the plant on the IO- NPs surfaces. Furthermore, the antibacterial
efficacy of IO-NPs, plant extract and IO-NPs treated with plant extract were screened
against Escherichia coli MTCC 443, Proteus mirabilis MTCC 425 and Bacillus subtilis
MTCC 441. The results showed a noteworthy inhibition on P. mirabilis and E. coli with
IO-NPs treated plant extract. This outcome may have a way for using the magnetic
nanoparticles as a drug carrier system to cure bacterial diseases. The synthesized IO NPs
treated with leaf extract of A. Mexicana L. proved to have outstanding antimicrobial
efficacy against the bacterial pathogens. The biological approach on IO-NPs treated with
A. Mexicana L. leaf extract material is the most rapid and eco-friendly method and it has a
wide scope in opting as an excellent drug delivery system. The present study proved that
the immobilized nanomaterials of magnetite can effectively improve the drug loading and
the antibacterial efficiency against the microbial pathogens.

31
Azad Kumar et al 2017, The oxidation rates and efficiency of the photocatalytic system
are highly dependent on a number of operational parameters that govern the
photodegradation of the organic molecule. Several studies has been reported the
significance of operational parameter. The photodegradation depends on some basic
parameters which are concentration of substrate, amount of photocatalyst, pH of the
solution, temperature of reaction medium, time of irradiation of light, the intensity of light,
surface area of photocatalyst, dissolve oxygen in the reaction medium, nature of the
photocatalyst, nature of the substrate, doping of metal ions and non metal and structure of
photocatalyst and substrate. The photodegradation of organic compound has been studied
by several scientists and conclude the optimum conditions for the photodegradation of
organic compound.
Agata Włodarska et al 2017; Several new cyclopentadienyl nickel complexes were
synthesized and characterized. All the complexes exhibited catalytic activity in Suzuki–
Miyaura cross-coupling reaction with conversion rates from 10 to 80% and very high
selectivity. The catalytic activity of the complexes strongly depended on their composition
and structure. It was shown that ionic complexes are better catalysts than their covalent
analogs; increased electron density in the cyclopentadienyl ligand improved their catalytic
activity; bromide complexes provided better results than chloride ones. Two
CpNi(NHC)Cl complexes were tested as initiators in the oligomerization of ethyl acetate
carbine confirming our earlier observation that N-heterocyclic carbene from the catalyst
precursor was incorporated into the oligomer chain.
Saikat Sarkar et al 2018; elemental analyses, spectroscopic (IR, Electronic, NMR)
methods, conductivity, and molecular measurements. The crystal structure of the complex
(2) has been determined by using single crystal X-ray diffraction method and it suggests a
distorted octahedral geometry around nickel(II) having a NiN6 coordinating atmosphere.
The non-coordinated OeH group on the ligand L remain engaged in H-bonding interactions
with the S end of the coordinated thiocyanate moiety. These H-bonding interactions lead to
OES separations of 3.132 Å and play a prominent role in crystal packing. It is observed
that the mononuclear units are glued together with such OH…S interactions and finally
results in a 1D supramolecular sheet-like arrangement. DFT/ TDDFT based theoretical
calculations were also performed on the ligand and the complexes aiming at the;

32
accomplishment of idea regarding their optimized geometry, electronic transitions, and the
molecular energy levels. Finally, the catalytic behavior of the complexes for the oxidation
of styrene has also been carried out. A variety of reaction conditions like the effect of
solvent, effect of temperature and time as well as the effect of the ratio of substrate to
oxidant were thoroughly studied to judge the catalytic efficiency of the Ni (II) coordination
entity.
Muhammad Imran Din et al 2018; Nickel (Ni) and nickel oxide (NiO) nanoparticles
(NPs) were successfully synthesized by using a simple, novel and green synthetic route
using metal salt and leaves extract of a wild plant “Calotropis gigantea” which act as
reducing as well as stabilizing agent due to extra availability of phenolic contents and
antioxidants in it. Optimization was carried out by varying different parameters controlling
the reaction and the best yield was obtained at 80°C temperature, 90 min incubation time,
pH 12, 1 mM precursor concentration and 20% extract concentration. Characterization was
made by using various characterizing techniques. UV/VIS absorption peak was at 400 nm
for synthesized Ni NPs and at 415 for NiO NPs. The average size of the particles was 20–
40 nm, in the case of NiO NPs and< 60 nm for Ni NPs confirmed by X-ray diffraction
analysis and Scanning electron microscope (SEM). Functional groups indication was made
by using Fourier transform Infrared (FT-IR) spectroscopic analysis of materials. Catalytic
efficiency was investigated against methylene blue dye, the maximum degradation
efficiency was 98.8%, followed by first-order reaction kinetics. Synthesized NPs were
highly stable i.e. till 3 months. Biological test results exposed that synthesized Ni and NiO
nanoparticles have broad-spectrum antibiotic abilities against E. coli and Bacillus subtilus.
Hongchao Wang et al 2018; Highly ordered mesoporous materials synthesized by a
Nanocasting method offer vast opportunities in catalytic applications. However,
considerable debates remain as to the mechanism by which the mesoporous structure
results in enhanced performance. We demonstrate new insights into the role of ordered
mesoporous metal oxides in the catalytic oxidation reaction by preparing nickel (II) oxide
(NiO) rather than a multiple valence compound such as Co3O4 as a model catalyst.
Mesoporous NiO using KIT-6 as a template (m-NiO-k) achieved total formaldehyde
(HCHO) mineralization at 90 C using oxygen (O2) as oxidant, while bulk NiO (b-NiO-c)
oxidized HCHO completely at 170 C. Moreover, using ozone (O3) as oxidant, m-NiO-k

33
attained increased HCHO conversion by 34% with a twofold increase in CO2 selectivity
and a 100% O3 decomposition rate. We conclude that the surface sodium functionalization
of m-NiO significantly promotes the total oxidation of HCHO with O2, likely via
contributing to hydroxyl regeneration during the reaction. Furthermore, the extra active
oxygen species and undercoordinated NiO on the mesoporous surface owing to the
properties of mesoporous structures contribute almost exclusively to the high activity and
selectivity in the simultaneous catalytic removal of HCHO and O3, which are also
involved in the further enhanced activity for HCHO oxidation using m-NiO with O2.
These findings provide additional new insight into engineering efficient mesoporous metal
oxides for VOCs catalysis under mild condition. Furthermore, they provide an innovative
perspective on optimizing other reactions employing Nanocast mesoporous catalysts. Our
findings clearly demonstrate that sodium surface modification offers an effective strategy
for optimizing the catalytic performance of HCHO oxidation using oxygen as oxidant.
Modifying the surface of metal oxide catalysts by sodium functionalization significantly
promotes the total oxidation of formaldehyde, likely via contributing to hydroxyl
regeneration during the HCHO oxidation reaction. However,structure-function
relationships vary with experimental parameters. Sodium surface modification is
ineffective for HCHO catalytic oxidation with ozone. The extra adsorbed active oxygen
species and NiO with an undercoordination state on the surface of m-NiO contribute
almost exclusively to the high activity and selectivity (to CO2) in the simultaneous
catalytic removal of HCHO and ozone at room temperature, which are also involved in the
further enhanced activity for HCHO oxidation using m-NiO with oxygen. This work thus
not only provides new insight in engineering efficient mesoporous materials for
environmental catalysis, but also extends our understanding of the structure-function
relationship of metal oxides in catalytic applications.
Zheng Gu et al 2004; Nanoscale copper oxide and nickel oxide, prepared by a modified
sol-gel process, were investigated for their destruction efficiencies for methanol. The
activity, selectivity, and stability of nanoscale CuO and NiO were compared with those of
commercial microscale CuO and NiO. Nanoscale CuO and NiO were highly active and
stable catalysts for complete methanol oxidation, catalyzing methanol oxidation at
temperatures 100 °C lower than their microscale counterparts. The higher activity per gram
of the nanoscale catalysts can be attributed to their higher surface areas, which were

34
roughly 2 orders of magnitude higher than the microscale catalysts. Nanoscale CuO and
NiO prepared using a modified sol-gel technique are active methanol oxidation catalysts,
catalyzing 90% methanol at temperatures of only 210 and 220 °C, respectively. These
materials display much higher activity per gram than their macroscale counterparts, in
general giving equivalent conversion at 100 °C lower temperatures. This higher activity is
due to a surface area of approximately 2 orders of magnitude higher than that of
commercially manufactured metal oxides. Both catalysts form formaldehyde as the
primary product at low temperatures, though CuO begins to favor CO2 at temperatures of
70 °C lower than NiO.
DeJong He et al 2016; The nickel catalysts supported on the bare MgO and its binary Mg-
Al, Mg-La, and Mg-Fe metal oxides were prepared and used for carbon dioxide reforming
of methane to syngas. The effects of Al, La, and Fe metal oxides on the structural
properties, reducibility and metal-support interaction of the Ni catalysts supported on the
MgO-based binary metal oxide were investigated. The XRD, TEM, and H2-TPD analyses
show that the nickel nanoparticles were highly dispersed on the supports. It is found that
the Al ions can be well incorporated into the MgO lattice to form uniform Mg-Al oxides,
while isolated lanthanum oxides and iron oxides were observed in the Mg-La and Mg-Fe
binary systems by TEM, respectively. The Ni/Mg-Al metal oxide exhibits greatly
improved catalytic activity owing to the formation of homogeneous Mg-Al oxide matrix
with small particle sizes of Ni nanoparticles compared to the bare Ni/MgO. Very low
conversions for both CH4 and CO2 were obtained on the Ni/Mg-La and Ni/Mg-Fe metal
oxides even at a high temperature of 800 ℃ due to the incomplete reduction of the nickel
nanoparticles.
Shuirong Li et al 2014; Owing to the considerable publicity that has been given to
petroleum-related economic, environmental, and political problems, renewed attention has
been focused on the development of highly efficient and stable catalytic materials for the
production of chemical/fuel from renewable resources. Supported nickel nanoclusters are
widely used for catalytic reforming reactions, which are key processes for generating
synthetic gas and/or hydrogen. New challenges were brought out by the extension of
feedstock from hydrocarbons to oxygenates derivable from biomass, which could
minimize the environmental impact of carbonaceous fuels and allow a smooth transition

35
from fossil fuels to a sustainable energy economy. This tutorial review describes the recent
efforts made toward the development of nickel-based catalysts for the production of
hydrogen from oxygenated hydrocarbons via steam reforming reactions. In general, three
challenges facing the design of Ni catalysts should be addressed. Nickel nanoclusters are
apt to sinter under catalytic reforming conditions of high temperatures and in the presence
of steam. Severe carbon deposition could also be observed on the catalyst if the surface
carbon species adsorbed on the metal surface are not removed in time. Additionally, the
production of hydrogen-rich gas with a low concentration of CO is a challenge using nickel
catalysts, which are not so active in the water gas shift reaction. Accordingly, three
strategies were presented to address these challenges. First, the methodologies for the
preparation of highly dispersed nickel catalysts with strong metal–support interaction were
discussed. A second approach—the promotion in the mobility of the surface oxygen—is
favored for the yield of desired products while promoting the removal of surface carbon
deposition. Finally, the process intensification via the in situ absorption of CO2 could
produce ahydrogen-rich gas with low CO concentration. These approaches could also
guide the design of other types of heterogeneous base-metal catalysts for high-temperature
processes including methanation, dry reforming, and hydrocarbon combustion.
Vineeta Panwar et al 2015; A polyaniline/graphene oxide composite was readily
synthesizedby liquid−liquid interface polymerization of aniline in the presence of a
sulfonated graphene oxide suspension using hydrogen peroxide and iron (III) chloride as
oxidants. Subsequently, nickel nanoparticles were decorated on the synthesized hybrid
material and used for the hydrogenation of phenylacetylene and its derivatives at room
temperature under 100 psi of hydrogen pressure. The synthesized hybrid catalyst showed
excellent catalytic activity and was readily recovered by centrifugation at the end of the
reaction. The recovered catalyst was successfully used for several runs without any
significant loss in the catalytic activity. Importantly, no leaching was observed during this
course. In summary, we have developed a novel SGR/PANI/Ni for the selective
hydrogenation of terminal alkynes to the corresponding alkene in moderate-to-good yields.
The presence of PANI and SGR in the synthesized hybrid exhibited a synergistic effect and
enhanced the catalytic activity of the nickel catalyst for hydrogenation of alkynes. The
synthesized catalyst was found to be highly stable and worked efficiently for various runs
without loss of activity. Furthermore, the use of a readily available and cost-effective

Here are the key points about pigments:- Pigments are chemical substances that absorb light in the visible region of the electromagnetic spectrum, which gives them their color. - The color is produced by chromophores, which are molecular structures within the pigment that absorb specific wavelengths of light. - When light is absorbed by the chromophore, electrons within the molecule get excited to higher energy levels. The light that is not absorbed is reflected or refracted and detected by the eye, allowing us to see the color.- Modern usage of the term "pigment" refers to colored substances that are made of small particles. This particulate nature allows pigments to be easily mixed and blended.- Common pig

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