The document discusses molecular dynamics of water responsive polymers like chitosan and their applications. Chitosan is a polysaccharide obtained from chitin and has many commercial and biomedical uses. The document studies the self-folding property of chitosan films in water due to changes in surface hydrophilicity. Different chitosan films prepared with HAP or glutaraldehyde were observed to fold at different time intervals and deflection angles when exposed to water. The rate of water absorption in chitosan films followed Fick's law of diffusion. Potential applications of chitosan include drug delivery, wound healing, and water filtration.
4. optimization of culture condition for enhanced decolorization of reactive ...Darshan Rudakiya
Many synthetic azo dyes and their metabolites are toxic, carcinogenic, and
mutagenic so removal of azo dyes using cost-effective and eco-friendly method is
major aspect.Comamonas acidovorans MTCC 3364 has been routinely reported for
different steroid bioconversion and heavy metal removal. The main purpose of this
study is to check the decolorization efficiency of Comamonas acidovorans MTCC
3364 for different dyes and to optimize the condition which gives maximum
decolorization of Reactive Orange 16 dye. The effect of various physicochemical
parameters including condition, carbon and nitrogen sources, temperature,pH and
dye concentration were studied. The % decolorization of dye was determined by
UV Visible spectroscopy. This bacterial strain efficiently decolorizes Reactive
Orange 16 at 37oC, pH 6.85 within 24 hours giving 99.03 ± 0.5 % dye
decolorization under optimum environmental conditions.
It's simple to understand the synthesis. Hydrothermal method is a chemical reaction in water in a sealed pressure vessel, which is in fact a type of reaction at both high temperature and pressure.
4. optimization of culture condition for enhanced decolorization of reactive ...Darshan Rudakiya
Many synthetic azo dyes and their metabolites are toxic, carcinogenic, and
mutagenic so removal of azo dyes using cost-effective and eco-friendly method is
major aspect.Comamonas acidovorans MTCC 3364 has been routinely reported for
different steroid bioconversion and heavy metal removal. The main purpose of this
study is to check the decolorization efficiency of Comamonas acidovorans MTCC
3364 for different dyes and to optimize the condition which gives maximum
decolorization of Reactive Orange 16 dye. The effect of various physicochemical
parameters including condition, carbon and nitrogen sources, temperature,pH and
dye concentration were studied. The % decolorization of dye was determined by
UV Visible spectroscopy. This bacterial strain efficiently decolorizes Reactive
Orange 16 at 37oC, pH 6.85 within 24 hours giving 99.03 ± 0.5 % dye
decolorization under optimum environmental conditions.
It's simple to understand the synthesis. Hydrothermal method is a chemical reaction in water in a sealed pressure vessel, which is in fact a type of reaction at both high temperature and pressure.
Parametric Studies on Detergent Using Low Cost SorbentIOSR Journals
: Water is a valued natural resource for the existence of all living organisms. Indian rivers are
polluted due to the discharge of untreated sewage and industrial effluents. Management of the quality of this
precious resource is, therefore, of special importance. In these study industrial effluents samples from the
various detergent factories were collected and analyzed for physicochemical and bacteriological evaluation of
pollution. The use and effectiveness of granular and powder activated carbon made from agricultural waste i.e.
coconut husk and that coconut husk is a suitable adsorbent for such an effluent. Maximum adsorption capacity
is a derived from Langmuir isotherm. A series of fixed bed experiments was carried out and the results were
applied to a bed-depth/service time model for column adsorption. The validity of such a model is discussed. In
the removal of organic matter in wastewater effluents from a industry waste water were investigated. The effect
of process variables such as carbonization temperature, carbonization duration and activation temperature on
the production and quality of activated carbon was studied as well as adsorption capacity was studied
Discussion about hydrothermal & gel growth method of crystalMostakimRahman1
1.Definition, procedure, advantage, and disadvantage of hydrothermal growth method of crystal.
2.Definition, procedure, advantage, and disadvantage of gel growth method of crystal.
In this study, kinetics of demineralization of chitin extraction from snail shells was
investigated. Chitin was extracted from snail shells by demineralizing the
deproteinized shells in 1.2 M HCl solution. Prior to demineralization, the raw snail
shells were deproteinized using 1 M NaOH solution to remove proteins and organic
matter present in the shells. The product was dried before the demineralization
process was carried out. The results showed that based on the R2 values obtained for
each of the shrinking core models considered which include; fluid film diffusion
(FFD), ash layer diffusion (ALD), and chemical reaction control (CRC), it was noted
that the CRC model was prevalent for all the various range of particle sizes analyzed
(6.3 – 4.75 mm, 4.75 – 2 mm, 2 – 1 mm, and 600 – 300 μm). The surface morphologies
and the Fourier Transform Infra-Red (FTIR) bands of the extracted chitin were
similar to previous studies
Phylogenetic Analysis of the Potential Microorganism for Remediation of Heavy...CSCJournals
The present research work has been carried out to study the waste disposal contaminated site for its physico chemical and microbial characterization and identification of potential microorganism capable of bioaccumulation and biodegradation of heavy metals. The ambient conditions present in the metal contaminated environment shows the values: pH(5.4),temperature(30°C), moisture(11.71%), nutrients; Nitrogen(0.2mg/l), phosphorus(22.65mg/l) and sulphur(559.3mg/l) respectively. The biological parameters studied indicate Dissolved oxygen (7.4mg/l), Biological oxygen demand (3.8 mg/l), Chemical oxygen demand (64.6 mg/l). The microbial consortium identified was found to survive and multiply in the present environmental conditions. Microbial consortium was sequenced and compared using Bioinformatics tools like BLAST, ClustalW and PHYLIP. In order to identify potential microorganism, microbial consortium was exposed to increasing concentrations of heavy metals viz 5mg/l, 25mg/l, 50mg/l, 100mg/l up to 800mg/l with special reference to Iron. At a concentration of 500mg/l, only one microorganism was found survived and multiplied. This shows that potential microorganism was only survived at higher concentration of iron. The 16SrRNA sequence and phylogenetic tree characterized the organism as Klebsiella pneumoniae, which was also confirmed by biochemical tests. The potential microorganism identified by BLAST technique can be used for remediation of the heavy metal from contaminated environment.
Parametric Studies on Detergent Using Low Cost SorbentIOSR Journals
: Water is a valued natural resource for the existence of all living organisms. Indian rivers are
polluted due to the discharge of untreated sewage and industrial effluents. Management of the quality of this
precious resource is, therefore, of special importance. In these study industrial effluents samples from the
various detergent factories were collected and analyzed for physicochemical and bacteriological evaluation of
pollution. The use and effectiveness of granular and powder activated carbon made from agricultural waste i.e.
coconut husk and that coconut husk is a suitable adsorbent for such an effluent. Maximum adsorption capacity
is a derived from Langmuir isotherm. A series of fixed bed experiments was carried out and the results were
applied to a bed-depth/service time model for column adsorption. The validity of such a model is discussed. In
the removal of organic matter in wastewater effluents from a industry waste water were investigated. The effect
of process variables such as carbonization temperature, carbonization duration and activation temperature on
the production and quality of activated carbon was studied as well as adsorption capacity was studied
Discussion about hydrothermal & gel growth method of crystalMostakimRahman1
1.Definition, procedure, advantage, and disadvantage of hydrothermal growth method of crystal.
2.Definition, procedure, advantage, and disadvantage of gel growth method of crystal.
In this study, kinetics of demineralization of chitin extraction from snail shells was
investigated. Chitin was extracted from snail shells by demineralizing the
deproteinized shells in 1.2 M HCl solution. Prior to demineralization, the raw snail
shells were deproteinized using 1 M NaOH solution to remove proteins and organic
matter present in the shells. The product was dried before the demineralization
process was carried out. The results showed that based on the R2 values obtained for
each of the shrinking core models considered which include; fluid film diffusion
(FFD), ash layer diffusion (ALD), and chemical reaction control (CRC), it was noted
that the CRC model was prevalent for all the various range of particle sizes analyzed
(6.3 – 4.75 mm, 4.75 – 2 mm, 2 – 1 mm, and 600 – 300 μm). The surface morphologies
and the Fourier Transform Infra-Red (FTIR) bands of the extracted chitin were
similar to previous studies
Phylogenetic Analysis of the Potential Microorganism for Remediation of Heavy...CSCJournals
The present research work has been carried out to study the waste disposal contaminated site for its physico chemical and microbial characterization and identification of potential microorganism capable of bioaccumulation and biodegradation of heavy metals. The ambient conditions present in the metal contaminated environment shows the values: pH(5.4),temperature(30°C), moisture(11.71%), nutrients; Nitrogen(0.2mg/l), phosphorus(22.65mg/l) and sulphur(559.3mg/l) respectively. The biological parameters studied indicate Dissolved oxygen (7.4mg/l), Biological oxygen demand (3.8 mg/l), Chemical oxygen demand (64.6 mg/l). The microbial consortium identified was found to survive and multiply in the present environmental conditions. Microbial consortium was sequenced and compared using Bioinformatics tools like BLAST, ClustalW and PHYLIP. In order to identify potential microorganism, microbial consortium was exposed to increasing concentrations of heavy metals viz 5mg/l, 25mg/l, 50mg/l, 100mg/l up to 800mg/l with special reference to Iron. At a concentration of 500mg/l, only one microorganism was found survived and multiplied. This shows that potential microorganism was only survived at higher concentration of iron. The 16SrRNA sequence and phylogenetic tree characterized the organism as Klebsiella pneumoniae, which was also confirmed by biochemical tests. The potential microorganism identified by BLAST technique can be used for remediation of the heavy metal from contaminated environment.
En esta presentación introduzco algunos conceptos sobre SEO que todo programador debería tener en cuenta. Aunque sólo te dediques a la programación deberías conocer estos conceptos si quieres que el posicionamiento de tus aplicaciones web no sean un desastre.
Background- Chitosan is the most abundant natural amino polysaccharide. Researchers have found that chitosan is biocompatible, biodegradable and nontoxic, which have made wide applicability in the pharmaceutical field. Objectives- Aim of the study was to prepare Chitosan from chitin and characterize them. Methods- Chitosan was prepared by deacetylation of chitin and characterized by U.V Spectrophotometry, FTIR (Fourier transform infrared spectroscopy), DLS (Dynamic Light Scattering), and Scanning electron microscopy (SEM). Results- The present study showed that Chitosan was successfully prepared by deacetylation of chitin. The obtained chitosan was characterized for further study. Conclusion- Our study confirms the preparation by Chitosan from Chitin for further study. Key-words- Chitin, Chitosan, Deacetylation, DLS, FTIR, SEM
1 functional characterization of chitin and chitosanDuy Thanh Tran
Chitin and its deacetylated derivative chitosan are natural polymers composed of randomly distributed -(1-4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). Chitin is insoluble in aqueous
media while chitosan is soluble in acidic conditions due to the free protonable amino groups present in the D-glucosamine
units. Due to their natural origin, both chitin and chitosan can not be defined as a unique chemical structure but as a family of polymers which present a high variability in their chemical and physical properties. This variability is related not
only to the origin of the samples but also to their method of preparation. Chitin and chitosan are used in fields as different
as food, biomedicine and agriculture, among others. The success of chitin and chitosan in each of these specific applications is directly related to deep research into their physicochemical properties. In recent years, several reviews covering
different aspects of the applications of chitin and chitosan have been published. However, these reviews have not taken
into account the key role of the physicochemical properties of chitin and chitosan in their possible applications. The aim
of this review is to highlight the relationship between the physicochemical properties of the polymers and their behaviour.
A functional characterization of chitin and chitosan regarding some biological properties and some specific applications
(drug delivery, tissue engineering, functional food, food preservative, biocatalyst immobilization, wastewater treatment,
molecular imprinting and metal nanocomposites) is presented. The molecular mechanism of the biological properties such
as biocompatibility, mucoadhesion, permeation enhancing effect, anticholesterolemic, and antimicrobial has been updated.
Wastewater Treatment Process by Physico Chemical Methodsijtsrd
Contaminated water contains particles of different sizes which can be classified as dissolved 0.08 µm , colloidal 0.08 1 µm , supracolloidal 100 100 mm and settleable 100 µm . The type of treatment selected depends on the size of particles present in the wastewater. In practice, treatment efficiency also depends on particle size. Solids of the size that are visible to the naked eye can be separated either by settling under the influence of gravity or by flotation, depending on the relative densities of solids and water. They may also be easily separated by filtration. However, very fine particles of a colloidal nature called colloids, size 1 µm which have high stability are significant pollutants. The reason for this stability is that these particles have electrostatic surface charges of the same sign usually negative . This means that repulsive forces are created between them, preventing their aggregation and subsequent settling. It has therefore proved impossible to separate them by settling or flotation. It is not possible to separate these solids by filtration because they pass through any filter. However, separation by physico chemical treatments is possible. Physico chemical treatment of wastewater focuses primarily on the separation of colloidal particles. This is achieved through the addition of chemicals called coagulants and flocculants . These change the physical state of the colloids allowing them to remain in an indefinitely stable form and therefore form into particles or flocs with settling properties. Dr. Bhoopendra Singh "Wastewater Treatment Process by Physico-Chemical Methods" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-6 , October 2022, URL: https://www.ijtsrd.com/papers/ijtsrd51862.pdf Paper URL: https://www.ijtsrd.com/chemistry/other/51862/wastewater-treatment-process-by-physicochemical-methods/dr-bhoopendra-singh
speciality polymers are the class of some high perfomance polymers ,including plastic,polymers,fluids,membranes,smart hydrogels,and elastomers that are designed to meet the critical requirement that engineers face everyday in key industries including plastic, automobiles, aeronautics, smart devices, health care, pharmacy, energy production and storage. this article is a short but diversified study of post grad. students in the area of speciality polymers, the types and applications in engineering, technology ,life sciences and research. it include diverce applications of iconic polymer metal composites liquid crystal polymers ,synthetic polymer membranes, smart hydrogels, and dendritic polymers.
1. Molecular Dynamics of Water Responsive
Polymers and Applications.
By
Koushik .B
4th
year B.Tech Chemical Engineering
SSN College of Engineering
ACKNOWLEDGEMENT
The internship opportunity I had with Applied Mechanics Department, IIT
Madras was a great platform for learning and professional development.
Therefore, I consider myself as a very lucky individual as I was provided
with an opportunity to be a part of it. I am using this opportunity to express
my deepest gratitude and special thanks to Dr. Pijush Ghosh who guided me
2. and kept me on the correct path and allowed me to carry out my project at
their esteemed organization.
I express my deepest gratitude to Ms. Amrita Rath, for taking part in useful
decision & giving necessary advices and guidance. I choose this moment to
acknowledge her contribution gratefully.
I perceive this opportunity as a big milestone in my career development. I
will strive to use the gained skills and knowledge in the best possible way,
and I will continue to work on their improvement, in order to attain the
desired career objectives.
ABSTRACT
Chitosan is a linear polysaccharide, which is generally found in shrimp’s
shells. Chitosan has significant applications in commercial and biomedical
sector. It is observed that the chitosan film undergoes deformation due to
water uptake, where the surface hydrophilicity undergoes changes. The
report deals with the study of this self-folding property of chitosan in the
presence of water. The chitosan films used in the study were prepared by the
process of deacetylation of chitin where HAP or glutaraldehyde was mixed
with 1:1 v/v glacial acetic acid. The parameters used in the study are,
deformation of those samples at different time intervals and variation of
deflection angles.
Keywords: Polysaccharides, hydrophilicity, deacetylation.
INTRODUCTION
3. Chitosan is a polysaccharide that is obtained from chitin, which is found in
the hard outer skeleton of shellfish, crab, lobster and shrimp.
It is composed of randomly distributed β-(1-4)-linked D-glucosamine
(deacetylated unit) AMD N-acetyl-D-glucosamine (acetylated unit).
MANUFACTURE
Chitosan is a chemically processed form of chitin, which is the structural
element in the exoskeleton of crustaceans (such as crabs and shrimp) and cell
walls of fungi. It is done so by deacetylation of chitin. The degree of
deacetylation (%DD) can be determined by NMR spectroscopy, and the
%DD in commercial chitosans ranges from 60 to 100%. On average, the
molecular weight of commercially produced chitosan is between 3800 and
20,000 amu (atomic mass units). A common method for the synthesis of
chitosan is the deacetylation of chitin using sodium hydroxide in excess as a
reagent and water as a solvent. This reaction pathway, when allowed to go to
completion (complete deacetylation) yields up to 98% product. In the project
done, two varied samples of chitosans, cross linked polymers and HAP
polymers are used. The chitosan films used in the study were prepared by
mixing HAP or glutaraldehyde with 1:1 v/v glacial acetic acid.
APPLICATIONS
4. Chitosan has a wide range of uses in pharmaceutical, agricultural and
commercial sector. It can be used as a soluble dietary fiber, a
biopesticide, a seed treatment, an anti – bacterial agent and also in
cosmetic and fabric industry. Though controversial, there are instances
where chitosan has been used to treat obesity, high cholesterol, and
Crohn’s disease. It is claimed that it might block absorption of dietary
fat and cholesterol to support the former situation.
The agricultural and horticultural uses for chitosan are primarily for
plant defense and yield increase. Here the glucosamine polymer
influences the biochemistry and molecular biology of the plant cell. In
the case of plant defense, it acts as ecologically friendly bio pesticide
substance that boosts the innate ability of plants to defend themselves
against fungal infections. Whereas in the other case, chitosan increases
photosynthesis, promotes and enhances plant growth, stimulates
nutrient uptake, increases germination and sprouting, and boosts plant
vigor.
The commercial uses include those of water filtration, as a fining agent
in wine making and as a polyurethane coating etc.
Whereas in the case of pharmaceutical industry, it is used as hemostatic
agent in bandages. Also chitosan's properties allow it to be used in
transdermal drug delivery. The popular usage includes transportation of
insulin.
SELF FOLDING PROPERTY
Self-folding broadly refers to self-assembly processes wherein thin films or
interconnected planar templates curve, roll-up or fold into three dimensional
(3D) structures such as cylindrical tubes, spirals, corrugated sheets or
polyhedral.
Self-folding methods are important for drug delivery applications since they
provide a means to realize 3D, biocompatible, all-polymeric containers with
5. well-tailored composition, size, shape, wall thickness, porosity, surface
patterns and chemistry. Self-folding is also a highly parallel process, and it is
possible to encapsulate or self-load therapeutic cargo during assembly. A
variety of therapeutic cargos such as small molecules, peptides, proteins,
bacteria, fungi and mammalian cells have been encapsulated in self-folded
polymeric containers.
Self-folding can occur spontaneously when 2D planar structures are released
from a substrate, typically on dissolution of a sacrificial layer, or in response
to stimuli such as electrical signals, pH, temperature, magnetic fields or
chemicals.
CHITOSAN IN THE PRESENCE OF WATER
It has been observed that, chitosan samples undergo the same self – folding
phenomenon in the presence of water. In this case, this effect is observed due
to the differential surface hydrophilicity after water is absorbed by the
polymer when exposed to it.
The deformations of different chitosan samples used are as follows:
1. CCLCSHAP200 (Successive images at a time interval of 5sec)
6. CLCSHAP300 (Successive images at a time
interval of 5sec)
2. CLCSHAP500 (Successive images at a time interval of 5sec)
9. 4. PURE SAMPLE
The deflection angle of a chitosan sample in the folding phenomenon is the
angle subtended by the tangent at the extreme point of the sample with
respect to the horizontal.
10. The deflection of the different samples and the rate of change of those angles
at different time intervals are as follows:
1. CLCSHAP200
2. CLCSHAP300
3. CLCSHAP500
11. 4. CSHAP10
5. PURE SAMPLE
Rate of Diffusion studies
Fick's first law relates the diffusive flux to the concentration under the
assumption of steady state. It postulates that the flux goes from regions of
high concentration to regions of low concentration, with a magnitude that is
proportional to the concentration gradient (spatial derivative), or in simplistic
terms the concept that a solute will move from a region of high concentration
to a region of low concentration across a concentration gradient.
Log(qT/qE)= nlog(T)+log(K)
Where,
12. qT= mass of water at time T.
qE= mass of water at time =infinity.
n is a constant of proportionality, which decides the type of diffusion.
Time Wt1 Wt2 Wt3 DIff1 Diff2 DIff3
0 3.3 3.5 3.6
10 7.14 7.3 7.22 3.84 3.8 3.42
20 8.68 8.74 8.58 5.38 5.24 4.98
30 8.9 9.02 8.94 5.6 5.52 5.34
40 9.24 9.16 9.08 5.94 5.66 5.48
50 10.16 10.18 9.88 6.86 6.68 6.28
60 11.15 10.88 10.66 7.85 7.38 7.06
70 11.27 11.15 11.2 7.97 7.65 7.6
80 11.33 11.32 11.39 8.03 7.82 7.79
90 11.37 11.37 11.31 8.07 7.87 7.71
SUPER ABSORBING POLYMERS
Sodium polyacrylate is an example of a super-absorbing polymer. It is
a cross-linked (network) polymer that contains sodium atoms. It
absorbs water by a process called osmosis.
When the (sodium-containing) polymer is placed in contact with water,
there is a tendency for the sodium to distribute equally between the
network and the water.
That means, some of the sodium atoms want to leave the network and
move to the water. When these sodium atoms leave, they are replaced
with water molecules. Water swells the polymer network to try to keep
the sodium concentration balanced between the polymer and the water.
The cross-links that connect the chains together prevent them from
dissolving/breaking apart in the water. Sodium polyacrylate can absorb
13. 800 times its weight in distilled water, but only 300 times its weight in
tap water, since tap water contains some sodium, calcium and other
mineral salts.
SWELLING MEASUREMENTS
Each sample was placed into distilled water for swelling at room
temperature. Swelling process was controlled by weighting. The ability
for swelling was expressed as the swelling ratio, W, in which M1 and
M2 are the weights of swollen and dry samples:
W = M1/M2
Effect of additional temperature treatment at the temperatures 120, 150,
180 °C after complete water evaporation on swelling ability was
measured.
FOLDING PATTERNS ON HYDROGELS
OBSERVATIONS
The following conclusions can be drawn from these readings:
1. The deflection is seen more in Pure sample and CSHAP10, where there
are chances for a deflection of 180 degrees or more.
14. 2. In the case of cross linked polymers, as the concentration of chitosan
increases, the folding property subtly decreases.
3. The folding process is slower in cross linked polymers (which in this
project took around a time interval of 30sec), whereas in the case of pure
sample and HAP polymer, its comparatively faster (took around 10sec to
deflect completely).
4. In the case of cross linked polymers, the chances of getting a deflection
angle as supplementary is comparatively less.
5. The rate of change of deflection angle decreases after a particular time.
Which is obvious, as the sample gradually slows down the deformation and
returns to its original state in the reverse process.
Future Scope
To study the different surface patterns on the chitosan films.
To study whether inert gases like nitrogen, helium can be absorbed in
chitosan films.
To coat temperature resistant materials on the film surface to study
folding characteristics at elevated temperatures.
Work on the implementation chitosan in its potential applications.
REFERENCES:
1. https://en.wikipedia.org/wiki/Chitosan
2. http://www.researchgate.net/publication/6437739_Water_Absorption_a
nd_Degradation_Characteristics_of_Chitosan-
Based_Polyesters_and_Hydroxyapatite_Composites
3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3462897/#R88
4. http://www.webmd.com/vitamins-supplements/ingredientmono-625-
chitosan.aspx?activeingredientid=625&activeingredientname=chitosan
http://www.drugs.com/npc/chitosan.html