chemistry presenation on nanoparticles
TRANSCRIPT
NanoparticlesPRESENTED BY;- PREETHAM CHANDRA(INTRODUCTION) SHAGUN BHATIA(APPLICATIONS) MADHAV MALPANI(GRAPHENE) LAKSHAY GAUR(NANOTUBES) APOORAV (NANOTUBES) MOHIT GUPTA(NANO-COMPOSITES)
What is a Nanoparticle?
Nanoparticle is defined as “A nanoparticle is a microscopic particle with at least one dimension less than 100 nm.”
It usually refers to inorganic materials.
Small vs Bulky Particles AS THE SIZE OF THE
PARTICLE GOES DOWN THE PROPERTIES OF THE MATERIAL TEND TO CHANGE
THIS IS A PICTURE OF HIRAKU DORODANGO,WHICH IS THE JAPANESE ART. THEY ARE MADE COMPLETELY OUT OF MUD BUT ARE UNBELIEVABLY SHINY WHEN MADE PROPERLY
Nanoparticle in the Past NANOPARTICLE THOUGH CONSIDERED
A MODERN SCIENTIFIC BREAKTHROUGH IT HAS BEEN USED BEFORE IN HISTORY
ITS USE IS SPOTTED IN THE MESOPOTAMIAN POTS IN WHICH METALS SUCH AS COPPER AND SILVER WERE ADDED AS SALTS WITH VINEGAR, OCHRE, AND CLAY ON ALREADY GLAZED SURFACES AND HEATING IT.
AS MUSLIMS WERE NOT ALLOWED TO USE GOLD UTENSILS THEY FOUND THIS TECHNIQUE TO GET A LUSTRE EFFECT.
What makes it so special?
What makes it so special?
Nanoparticle bridge the gap between bulky materials and atomic or
molecular structures
Typically the diameter of an atom ranges from 0.1 to 0.5 nanometers.
Nanoparticles have a very high surface area to volume ratio
A bulk material should have constant physical properties regardless of its
size, but at the nano-scale this is often not the case.
1 kg of particles of 1 mm3 has the same surface area as 1 mg of particles of 1 nm3
Example of change in Property
Normally copper is highly ductile, that is can be drawn into wires and is also malleable, that is it can be beaten into sheets
But copper nanoparticles smaller than 50 nm are considered
super hard materials that do not exhibit the same malleability and ductility as bulk copper.
Not always a desirable changeFerroelectric materials smaller than 10 nm can switch their magnetisation direction using room temperature thermal energy, thus making them useless for memory storage.
Unusual behaviour with lightNanoparticles often have unexpected visible properties because they are small enough to confine their electrons and produce quantum effects.
There are two types of nanoparticles already being added to sunscreen; titanium dioxide (TiO2) and zinc oxide (ZnO)
Where is it applied?
Bio-medical (a special type of drug delivery system)
Optics (like in the case of sunblock) Electronics (silicon chips)
Since they have a high surface are to volume ratio they have a tremendous driving force for diffusion.
The large surface area to volume ratio also reduces the incipient melting temperature of nanoparticles.
Application's of Nanoparticles
Using nanotechnology, materials can effectively be made to be stronger, lighter, more durable, more reactive or better electrical conductors, among many other traits by the help
of nanoparticles.
Sector's in which nanoparticles are used
Uses in Medical IndustryQuantum dots are semiconducting nanocrystals that can enhance biological imaging for medical diagnostics. When illuminated with ultraviolet light, they emit a wide spectrum of bright colors that
can be used to locate and identify specific kinds of cells and biological activities. These crystals offer optical detection up to 1,000 times better than conventional dyes used
in many biological tests, such as MRIs, and render significantly more information.
Gold nanoparticles can be used to detect early-stage Alzheimer’s disease.
The solution of the drug and organic molecules The diblock co polymers
Micelles formation Anti cancer ligands -> antibodies
Leaky walls of tubovacular veins
Nanoparticles conc on tumour tissue
Ligands Bining to reseptor
Receptor medator endocytosys Formation of endosomes
Releaseof anti cancer drugs
Program to cell death
Tumour slowly dissapearing
Nanoscale additives in polymer composite materials for baseball bats, tennis rackets, motorcycle helmets, automobile bumpers, luggage, and power tool housings can make
them simultaneously lightweight, stiff, durable, and resilient.
Daily Life uses of Nano particles
Nanoscale additives to or surface treatments of fabrics help them resist wrinkling, staining, and bacterial growth, and provide lightweight ballistic energy deflection in personal body armor.
Displays for many new TVs, laptop computers, cell phones, digital cameras, and other devices incorporate nanostructured polymer films known as organic light-emitting diodes,
or OLEDs. OLED screens offer brighter images in a flat format, as well as wider viewing angles, lighter weight, better picture density, lower power consumption, and longer lifetimes.
Nanoscale thin films on eyeglasses, computer and camera displays, windows, and other surfaces can make them water-repellent,
antireflective, self-cleaning, resistant to ultraviolet or infrared light, antifog, antimicrobial, scratch-resistant, or electrically conductive.
New solar panel films incorporate nanoparticles to create lightwieght,flexible solar cells. (Image by Nanosys)
Foldable glasses ,mobile screen glasses , batteries, photovoltech cells
You would have heard about graphene the ultra-thin, ultra-light, ultra-flexible, ultra-strong material that has the potential to be used in all kinds of groundbreaking innovations.
Now researchers think they've found a new use for this revolutionary modern material: creating night vision lenses that are both incredibly thin and incredibly powerful at the same time.
GRAPHENE & CARBON NANOTUBES
Carbon nanotubes (CNTs) are an allotrope of carbon.
They take the form of cylindrical carbon molecules and have novel properties that make them potentially useful in a wide variety of applications in nanotechnology, electronics, optics and
other fields of materials science.
GRAPHENETHE WONDER MATERIAL
Production
Micromechanical Exfoliation: Using Sticky tape to exfoliate graphite to generate
mono layered graphene Labor extensive process Not ideal for industrial production
Liquid Phase Exfoliation: Using a non-polar solvent and ultrasoniation Yield is limited due to restacking Use of Immiscible liquids to counter restacking Not ideal for industrial production
Production
Growth on SiC Depending on the face yield is decided the yield on Silicon side is more compared to
Carbon side One of the industrial method
Chemical Vapor Deposition (CVD) Use of transition metals like Ir, Cu, Ni, Pt Hydrocarbon is bombarded on these metals Most common industrial method
Properties
One ATOM thick Slightly smaller than ‘nano’
Allotrope of Carbon Parent graphite, diamond and fullerene It’s organic It will decompose easily
Strength Hardest known material Even harder than diamond Pure Covalent Bonds
Applications Pollution Control
Structure of Graphene High surface to mass ratio Can interact differently Enhanced by doping
Types of Graphene Pristine Graphene Graphene Oxide (GO) Reduced Graphene
Oxide(rGO)
Application Desalination
Water Scarcity is a problem Recent droughts
Graphene can be used to create a water purifier and a device to desalinate water
There are two models proposed to desalinate water
Some other exciting Applications
The advancements in electronic world Moore’s Law SuperCapacitors Semiconductor World
The Daily Savior The mobile phone Unbreakable Screens Charge once use forever Slimmer than paper
Automobile world Night Vision enabled Super Electric cars
Nano C
hemistry
29
CARBON Nanotubes• Introduction
• Structures• Application
• Potential
IntroductionINTRODUCTION
Carbon nanotube is a tube shaped material ,made of carbon having a diameter of nanometer scale i.e. one-billionth times thinner than a human hair. These are basically the allotropes of carbon with cylindrical nanostructure having unusual properties valuable to enormous filed of material sicence and technology.Eg. i) Conductive CNTs used is brushes for commercial motors providing better electrical and thermal stability. ii) Cleaning polluted water by using carbon nanotube filters iii) Boosting solar energy by a storage factor of 10,000 iv) Medical usage : size and shape contribute only half the reason why their great electrical and thermal properties help them exchange information inside and outside of the cell leading to vast usage
potential in Bio-Technology.
30
Allotrope : different forms of same element
Structure and Bonding
31Carbon nanotubes : Structure Nanotubes are members of the fullerene structural family .They comprise of long, hollow structure with walls formed by one-atom thick sheets of carbon, called graphene. These sheets are rolled at specific and discrete angles and the combination of rolling angle and radius decides the nanotube properties. These can be single or multi-walled structures.• Free movement of charge• Hexagonal arrangement• Vibration of atoms• Synchronisation of atoms of diff. tubes
BONDINGThe chemical bonding of nanotubes is composed of sp2 bonds providingthem their unique properties.
Fullerene structural family : A fullerene is a molecule of carbon in the form of a hollow sphere, ellipsoid, tube, and many other shapes.
Chiral Vector
32CHIRAL VECTORR = na1 + ma2
R : Chiral vector
Blue line : tube axisYellow line : armchair lineRed arrow : chiral vector
Wrapping angle : determines the structure of the tubeAnd is measured between R and armchair line
armchair : if = 0 zig-zag : if = 30chiral : if 0<<30
• The value of ‘n’ and ‘m’ define the chirality or twist of
the nanotubes. This chirality in turn affects the conductance, density, lattice structure and other properties .
PROPERTIES WHY CARBON NANOTUBES?
Strength Carbon nanotubes are the strongest and stiffest materials yet
discovered in terms of tensile strength and elastic modulus respectively.
This strength results from the covalent sp2 bonds formed between the individual carbon atoms.
In 2000, a multi-walled carbon nanotube was tested. The carbon nanotube with area of cross section 1 square millimeter was able to endure tension of a weight equivalent to 6,422 kilograms-force .
Under excessive tensile strain, the tubes will undergo plastic deformation, which means the deformation is permanent.
Wettability The surface wettability of CNT is of importance for its
applications in various settings. Although the intrinsic contact angle of graphite is around 90°,
the contact angles of most as-synthesized CNT arrays are over 160°, exhibiting a superhydrophobic property.
The picture (a) depicts critical angle (b)depicts critical angle of CNT .
Thermal conductivity All nanotubes are expected to be very good thermal
conductors along the tube, exhibiting a property known as "ballistic conduction", but good insulators lateral to the tube axis.
SWNT has a room-temperature thermal conductivity along its axis of about 3500 W·m−1·K−1 .(Which is very high in comparison with copper = 385 W·m−1·K−1).
SWNT has a room-temperature thermal conductivity across its axis (in the radial direction) of about 1.52 W·m−1·K−1 .(Which is about as thermally conductive as soil).
Kinetic property Multi-walled nanotubes are multiple concentric nanotubes precisely
nested within one another.
These exhibit a striking telescoping property whereby an inner nanotube core may slide, almost without friction, within its outer
nanotube shell, thus creating an atomically perfect linear or rotational bearing.
This property has been utilized to create the world's smallest rotational motor.
Hardness Standard single-walled carbon nanotubes can withstand a pressure
up to 25 GPa without [plastic/permanent] deformation. They then undergo a transformation to superhard phase nanotubes. Superhard phase nanotubes are single-wall carbon nanotubes. They
have a bulk modulus of 465-546 GPa(1GPa = 109). Due to there hardness and light weight they are used to make
baseball bats.
APPLICATIONS
What are they used for?
Current use and application of nanotubes has mostly been limited to the use of bulk nanotubes, which is a mass of rather unorganized fragments of nanotubes.
Bulk carbon nanotubes have already been used as composite fibers in polymers to improve the mechanical, thermal and electricalproperties of the bulk product.
Easton-Bell Sports , inc. has been in partnership with Zyvex performance materials, using CNT technology in a number of their bicycle components—including flat and riser handlebars, cranks, forks, seatposts, stems and aero bars.
Used in making atomic force microscopes. In tissue engineering- CNT can act as scaffolding for bone
growth .
WITH MANY PROS THEY ARE SOME CONS TOO Yes , we are talking about Health problems
The toxicity of carbon nanotubes has been an important question in nanotechnology.
University of Technology in Sweden shows that
extremely small fibers such as carbon nanotubes can make their way far into the lungs, which in the worst case can present an increased risk of developing cancer.
NANOCOMPOSITES
Nanocomposites IntroductionNANOCOMPOSITE IS A MULTIPHASE SOLID MATERIAL WHERE ONE OF THE PHASES HAS ONE, TWO OR THREE DIMENSIONS OF LESS THAN 100 NANOMETER (NM), OR STRUCTURES HAVING NANOSCALE REPEAT DISTANCES BETWEEN THE DIFFERENT PHASES THAT MAKE UP THE MATERIAL. IN THE BROADEST SENSE THIS DEFINITION CAN INCLUDE POROUS MEDIA, COLLOIDS, GELS AND COPOLYMERS, BUT IS MORE USUALLY TAKEN TO MEAN THE SOLID COMBINATION OF A BULK MATRIX AND NANODIMENSIONAL PHASE(S) DIFFERING IN PROPERTIES DUE TO DISSIMILARITIES IN STRUCTURE AND CHEMISTRY.
Advantages of Nanocomposites
Mechanical Properties Gas Barrier Dimensional stabililty Thermal Expansion Thermal conductivity Chemical resistance
Disadvantages of Nanocomposites
Viscosity increase(limits process ability) Dispersion difficulties Optical Issues Sedimentation Black color when different carbon containing
nanoparticles are used
It was reported in 2010, the worldwide production is estimated to exceed 600,000 ton and is set to cover key areas in the next five to ten years.
Applications
Food Packaging
• Because of gas barrier property it has enhanced considerably the shelf life of many types of food.
• The gaseous barrier property improvement that can result from incorporation of relatively small quantities of nanoclay materials is shown to be substantial. Data provided from various sources indicates oxygen transmission rates for polyamide-organoclay composites which are usually less than half that of the unmodified polymer.
Cool Fact
Triton Systems and the US Army are conducting further work on barrier performance in a joint investigation. The requirement here is for a non-refrigerated packaging system capable of maintaining food freshness for three years.
A somewhat more esoteric possibility arising from enhanced barrier performance recently suggested has been blown–films for artificial intestines!
Fuel Tanks
The ability of nanoclay incorporation to reduce solvent transmission through polymers such as polyamides has been demonstrated.
As a result, considerable interest is now being shown in these materials as both fuel tank and fuel line components for cars.
Films In comparison to conventionally filled
polymers, nanoclay incorporation has been shown to significantly enhance transparency and reduce haze.
Nano-modified polymers have been shown, when employed to coat polymeric transparency materials, to enhance both toughness and hardness of these materials without interfering with light transmission characteristics. It can resist high velocity impact and has substantially improved abrasion resistance.
Environment Protection
Water laden atmospheres have long been regarded as one of the most damaging environments which polymeric materials can encounter. Thus an ability to minimise the extent to which water is absorbed can be a major advantage.
Nanoclay incorporation can reduce the extent of water absorption in a polymer.
Flammability reduction
Nanoclay incorporation can reduce the flammability of polymeric materials.
Flammability behaviour could be restricted in polymers such as polypropylene with as little as 2% nanoclay loading.
Bibliography and reading further
IBM and Graphene circuits Graphene and Moore’s Law Graphene Production Pollution Control Image Source
Wikipedia page for nanocomposites
https://en.wikipedia.org/wiki/Nanocomposite For applications www.understandingnano.com/
nanocompositesapplications.html
https://en.wikipedia.org/wiki/Carbon_nanotube
https://www.sciencedaily.com/terms/carbon_nanotube.htm
http://www.understandingnano.com/what-are-carbon-nanotubes.html
https://www.youtube.com/results?search_query=carbon+nanotubes
Bibliography and reading further