Synthesis of nanoparticles physical, chemical and biological means

SYNTHESIS OF
NANOPARTICLES -

PHYSICAL, CHEMICAL AND BIOLOGICAL MEANS
(CASE STUDIES)
PRIYA BHATT
201643
M.SC. BIOTECHNOLOGY

NANOPARTICLES
A nanoparticle or ultrafine particle is usually defined as a particle of
matter that is between 1 and 100 nanometres (nm) in diameter
The properties of nanoparticles often differ markedly from those of
larger particles of the same substance.
Nanoparticles occur in a great variety of shapes, which have been
given many informal names such as nanospheres, nanorods,
nanochains, nanostars, nanoflowers, nanoreefs, nanowhiskers,
nanofibers, and nanoboxes.
Application as potential drug delivery system, dietary supplements
, Titanium dioxide nanoparticles provides antibacterial properties to
paints
https: //en.wi ki pedi a.org/wi ki /Nanoparti cl e

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PHYSICAL METHODS
PLASMA
CHEMICAL VAPOR DEPOSITION
MICROWAVE IRRADIATION
PULSED LASER METHOD
SONOCHEMICAL REDUCTION
GAMMA RADIATION
BIOLOGICAL METHODS
BACTERIA
FUNGI
PLANTS
CHEMICAL METHODS
POLYOL METHOD
MICROEMULSION
THERMAL DECOMPOSITION
ELECTROCHEMICAL SYNTHESIS

Top-down methods comprise of milling, lithography, and repeated quenching. This approach
does not have good control of the particle size and structure
Bottom-up method is the approach that is mostly used by scientists in the synthesis of
nanoparticles as it involves building up a material from bottom: atom-by-atom, molecule-by
molecule, and cluster-by-cluster
2 SYNTHESIS APPROACHES

CHEMICAL
http: //dx.doi .org/10.5772/i ntechopen.90771
POLYOL METHOD
Strong reducing capability
High dielectric constant
High boiling point
Cross linking agent
Polyol minimizes surface oxidation and agglomeration
It allows flexibility of controlling of size, texture and
shape of nanoparticles
Used for large scale production of nanoparticles.
It can be taken as sol-gel method in the synthesis of oxide, if
the synthesis is conducted at moderately increased
temperature with accurate particle growth control.
Solvent used i synthesis of metal oxide nanoparticle is
ethylene glycol as it has :-
This method is also used for the synthesis of bimetallic alloys
and core shell nanoparticles
ADVANTAGES :

MICROEMULSIONS
An emulsion is a liquid in liquid dispersion
Emulsion is divided according to size of droplet - macro, mini
and micro
Microemulsion synthesis is widely used for the production of
inorganic nanoparticles.
The preparation procedure of metallic nanopartcles in water in
oil microemulsion consists of mixinf of 2 microemulsions
containing metal salt and a reducing agent.
CHEMI CAL
Wongwailikhit et al. reported the formation of iron (III) oxide,
Fe2O3 using water in oil microemulsion by combining the
required amount of H2O in a stock solution of Sodium Bis (2-
Ethylhexyl) Sulfosuccinate (AOT) in n-heptane.
Sarkar et al. reported the formation of pure monodispersed
zinc oxide nanoparticles of different shapes.
Maitra was the first to establish Chitosan nanoparticles by
microemulsion technique. Chitosan nanoparticles were
prepared in the aqueous core of reverse micellar droplets and
crosslinked through glutaraldehyde

THERMAL DECOMPOSITION
It is also known as thermolysis.
Chemical decomposition caused by heat.
The chemical bonds are broken(endothermic reaction)
Arshad et al. reported on thermal decomposition of metal
complexes of type MLX2 [M = Co (II), Cu (II), Zn (II), and Cd (II);L
= DIE; X = NO3 1−] .
The complexes and ligands decomposed in a two-step
process when heated to 740°
CHEMI CAL

CHEMICAL
ELECTROCHEMICAL SYNTHESIS
It is the synthesis of chemical compounds in an
electrohemicial cell.
It is based on the dissolution of a metallic anode in an
aprotic solvent or acetonitrile containing
tertrabutylammonium ranged from 2-7nm.
Presence of two different clusters seen via. UV-Vis
spectrophotometry.
Dobre et al. also reported on the electrochemical synthesis
of colloidal silver solutions. PVP and sodium lauryl sulfate
(Na-LS) were used as a stabilizer and co-stabilizer,
correspondingly. Spherical Ag particles with the size
approximately 10–55 nm were synthesized.
In the journey of producing long lived Ag NPs, the
scientists succeeded in making the one which remained
stable for more than 7 years.

PHYSICAL METHODS
PLASMA
PULSED LASER METHOD
SONOCHEMICAL REDUCTION
GAMMA RADIATION

PLASMA
Plasma is generated by radio frequency heating
coils.
The initial metal is enclosed in a pestel and the
pesle is enclosed in an evaluated chamber.
The metal is then heated above its evaporation
point by high voltage RF coils wrapped around the
evacuated chamber.
He gas is used which forms high-temperature
plasma in the region of the coils after flowing into
the system.
The metal vapour nucleates on the He gas atoms
and diffuses upto a cold collector rod. This is where
nanoparticles are collected and passivated by
oxygen gas

REBROLENS PHOTO ACADEMY
Widely used in the synthesis of organic, inorganic and
inorganic-organic hybrid materials.
A study was conducted in 2003 by Tiwari et al. to
synthesize silver nanoparticle in aqueous medium by a
simple, efficient and economic microwave-assisted
synthetic route using hexamine as the reducing agent and
bipolymer pectin as stabilizer.
Characterization by UV- Vis , Spectroscopy, Energy
dispersive Xray(EDX), XRD and Transmission electron
microscopy(TEM) techniques.
Rate of reaction was found to increase with increase in
temperature.
ZnS NPs were synthesized and found to be of approx 6nm.

PULSE LASER METHOD
It is mostly used for the synthesis of Ag NPs at a high rate of
production of 3gm/min.
AgNO3 solution and reducing agent are poured into a blender
like device.
Device is composed of a solid disc that rotates with the
solution.
The disc is exposed to pulses from a laser beam to create hot
spots on the surface of the disc.
Hot spots are where the silver nitrate reacts with reducing
agent to produce Ag particles that can be sepearated by
centrifuge.
The particle size is controlled by the energy of the laser and
angular velocity of the dic.

SYNTHESIS OF NANOPARTICLES USING PULSED LASER
METHOD
APPARATUS TO PRODUCE SILVER NANOPARTICLES
USING A PULSED LASER BEAM THAT MAKES HOT
SPOTS ON THE SURFACE OF A ROTATING DISK

SONOCHEMICAL
REDUCTION
Obreja et al. conducted a study on alcoholic reduction Platinum
nanoparticle synthesis by sonochemical reduction.
H2PtCl6 was reduced with methanol, ethanol and propanol
working as solvents and reducing agents, in the presence of
capping polymers such as chitosan, PEG,
poly(amidehydroxyurethane).
Produed nanoparticles were of size approx 3nm.

GAMMA RADIATION
Preferred method for nanoparticle synthesis because it is
reproducible, may control the shape of particles, yields
monodisperse metallic nanoparrticles, easy, cheap, uses less
toxin precursors. It uses least number of reagents, uses a
reaction temperature close to room temperature witha few
synthetic steps as possible, minimizes the quantities of
generated byproducts and waste.
The primary effects of the interaction of high energy gamma
photons with a solution of metal ions are the exccitation and
the ionization of the solvent.

BIOLOGICAL SYNTHESIS

BACTERIA
FUNGI
PLANTS

BACTERIA
http://dx.doi.org/10.4172/2157-
7439.1000233
GOLD NPs
Johnson et al. reported the production of pure gold
nanoparticles by the bacterium Delftia acidovorans which
produced a small non ribosomal peptide called delftibactin.
This delftibactin was responsible for the generation of Au NPs.
He et al. observed extracellular production of 10-20nm sized
gold NPs by Rhodopseudomonas capsulata.
SILVER NPs
Bacillus licheniformis was obserbed to produce intacellular Ag
NPs when it was subcultured into media containing AgNO3.
URANIUM NPs
Pollmann and group studied the ability of Bacillus spharicus JG-
A12 to accumulate high conc. of toxic metals such as Cu, Pb,
Cd and U.
The S-layer of the B. sphaericus are responsible for the
bioremediation of uranium from aqueous environment.

FUNGI
SILVER NPs
Fusarium oxysporum synthesizes pure silver NPs at a size
range of 5-15nm.
Aspergillus fumigatus reduces silver ions NPs within 10 mins of
exposure.
Trichoderma reesei produces extracellularly
GOLD NPs
Verticillium species
Many well studied fungi such as F. oxysporum are pathogenic
and therefore might pose a safety risk
Trichoderma asperellum and T. reesei are both fungi that
produce Ag NPs when exposed to silver salts and have been
proven non-pathogenic ideally for commercial use.
http://dx.doi.org/10.4172/2157-
7439.1000233

PLANTS
http://dx.doi.org/10.4172/2157-7439.1000233
SILVER NPs
Lukman et al. reported the production of AgNPs using
Medicago sativa seed exudates. Ag+ reduction occurred
almost instantly as AgNPs were observed within 1 minute of
exposure to the silver salt.
In a study by Kasthuri et al., phyllanthin was extracted from the
plant Phyllanthus amarus and subsequently used for the
production of Ag and AuNPs.
Phyllanthin concentrations played a key role in the size and
shape of the nanoparticle produced.
GOLD NPs
Extracellular synthesis of AuNPs was illustrated using extracts
from a lemongrass plant, Cymbopogon flexuosus
Liquid-like nanotriangles were obtained when the extract was
incubated with gold tetrachloride.
PLATINUM NPs
Song et al. attempted to create PtNPs using the leaf extract of
Diopyros kaki. A greater than 90% reduction of Pt ions into
nanoparticles was illustrated in approximately 2.5 hours

THE TABLE ILLUSTRATING METALLIC NANOPARTICLES FORMED
BY DIFFERENT ORGANISMS
http://dx.doi.org/10.4172/2157-7439.1000233

REFERENCES
http://dx.doi.org/10.4172/2157-7439.1000233
Ihttp://dx.doi.org/10.5772/intechopen.90771
https://en.wikipedia.org/wiki/Nanoparticle
http://dx.doi.org/10.5772/intechopen.90771
http://dx.doi.org/10.4172/2157-7439.1000233

Synthesis of nanoparticles physical, chemical and biological means

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