it contains a brief idea about nano materials

1. Physics and Chemistry of nanomaterials
Nanomaterials are corner stones of nanoscience and nanotechnology.Nanotechnology,the
manipulation of matter at the atomic and molecular scale to create materials with
remarkably varied and new properties,is a rapidly expanding area of research with huge
potential to revolutionize our lives and to provide technological solutions to ours problems
in agriculture,energy,the environment and medicine.Nanotechnology are interdisciplinary
fields,involving chemistry,physics,material science,biology and engineering.
Nanomaterials defined as a substances where at least one dimension is less than
approximately 100nm. When a substance goes from bulk to nano size various properties of
substance like mechanical,optical,electrical,magnetic and other properties will changed.The
properties of materials can be different at nanoscale for two reasons;
First,Nanomaterials have a relatively larger surface area when compared to the same mass
of material produced in larger form.Nanoparticles can make materials more chemically
reactive and affect their strength or electrical properties.
Second,quantum effects can begin to dominate the behaviour of matter at nanoscale.
Nanomaterials are divided into three category;
ZERO DIMENSION-Length,breadth and heights are confined at single point.Ex-quantom dots
ONE DIMENSION-It has only one parameter either length(or) breadth (or) height.Ex-
Nanorods,nano wires
TWO DIMENSION-It has only one length and breadth.Ex-Thin film,nanosheets
THREE DIMENSION- It has all parameter of length,breadth and height.Ex-Nanoparticles
There are two general method to the synthesis of nanomaterials.1)Bottom-up 2)Top-down
1)Botttom-up:-This method includes the minimization of materials components( upto
atomic level)With further self-assembly process leading to the formation of
nanostructures.All the bottom-up techniques,the starting material is either gaseous state or
liquid state of matter.It involves two physical and chemical processing methods.Physical
techniques includes PVD,Sputtering,Plasma Arching,Laser Ablation etc.Chemical techniques
includes CVD,Sol-gel method,Electrolytic deposition,microemulsion route etc.
2)Top-down:-Begin with larger(macroscopic) initial structures,which then reduced to from
nanostructures.Here the starting material is solid state.It involves only physical processing
methods which includes cutting,ball milling ,etching,photo lithography,electron beam
lithography etc.
There are different types of nanomaterials available.These includes carbon based
nanomaterials,nanocomposites,metal based nanomaterials,biological nanomaterials etc.
Carbon based nanomaterials-These materials composed of pure carbon,most commonly
taking the shape of hollow spheres,ellipsoids or tubes.Ex-fullerenes,Carbon nano
tubes(CNT).Due to the large surface area,CNT are interesting media for electrical energy

2. storage.The electrical and mechanical properties of CNT like electrical conductivity,heat
transmission capacity,heat stability,high strength or low density make them use as
fillers,film,coatings.Carbon nano tubes are suitable supports for cell growth,electrodes of
microbial fuel cells can be built using CNT.
Nanocomposites-Nanocomposite means nanoparticles(metals,semiconductors,dielectric
materials)embedded in different materials(ceramics,glass,polymer).It is a multiphase solid
materials.Nanocomposites classified two types.i)Polymer based nanocomposites ii)Non
polymer based nanocomposites.Nanocomposites have properties like thermal
stability,electrical conductivity,surface appearance and optical density etc.Due to those
various properties it is used in UV protection gels,coatings,food packaging,superior strength
fibre and films,drug delivery system etc.
Metal based nanomaterials-The component of these materials is metal.These nanomaterials
includes quantum dots,nanogold,nanosilver,and metal oxides,such as titanium dioxide,zinc
oxide,iron oxide etc.Quantum dots are tiny semiconductor particles of few nanometer size
which have properties like optical and electrical used in application like
transistors,coating,thin film,medical imaging,LEDS etc.Gold nanoparticles have properties
like optical,plasmonic and fluroscence used as sensors,photodynamics therapy & electronics
etc.
Dendrimers-Highly branched macromolecules with dimension nanometer-scale.The surface
of a dendrimer posses numerous chain which can be modified to from specific chemicals
function.This property could also useful for catalysis.it can also used for drug delivery.
These materials have created a high interest in recent years by virtue of his unusal
property.Due to its property it can be used in interdisciplinary science of application like
cosmetics,drug delivry,fuel cell,imaging,displays,batteries,waterpurifiers,military battle suits
etc.