Transcript
Gandhinagar Institute of Technology
NanophysicsBranch:-IT
Prepared By:-1.Akabari Nirali v.
2.Prajapati Nikita a.
3.Bharadia Shivani p.
4.Bhut Vidhi r.
5.Kapadiya Tinkle r.
Introduction
What is nanophysics?
Nanophysics is the physics of structures and artefacts with dimensions in the nanometer range or of phenomena occurring in nanoseconds.
Nanophysics are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering.
Nanophysics is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers.
It’s hard to imagine just how small nanotechnology is. One nanometer is a billionth of a meter, or 10-9 of a meter. Here are a few illustrative examples:
A sheet of newspaper is about 100,000 nanometers thick.
There are 25,400,000 nanometers in an inch.
On a comparative scale, if a marble were a nanometer, then one meter would be the size of the Earth.
Physicist Richard Feynman, the father of nanotechnology
Nanophysics involve the ability to see and to control individual atoms and molecules. Everything on Earth is made up of atoms—the food we eat, the clothes we wear, the buildings and houses we live in, and our own bodies.
But something as small as an atom is impossible to see with the naked eye. In fact, it’s impossible to see with the microscopes typically used in a high school science classes. The microscopes needed to see things at the nanoscale were invented relatively recently—about 30 years ago.
Although
modern nanosci
ence and
nanotechnology
are quite new,
nanoscale
materials were used for
centuries.
Alternate-sized
gold and silver
particles created colors in
the stained
glass window
s of medieva
l churche
s hundred
s of years
ago. The artists back then just
didn’t know
that the process
they used to create these
beautiful works of art
actually led to
changes in the
composition of
the material
s they were
working with.
Today's scientists and engineers are finding a wide variety of ways to deliberately make materials at the nanoscale to take advantage of their enhanced properties such as higher strength, lighter weight, increased control of light spectrum, and greater chemical reactivity than their larger-scale counterparts.
History Of Nanophysics
The first use of concepts in ‘nano-technology was in: There’s plenty of the room at the bottom ,a talk given by Richard Feynman. Feynman described a process by which the ability to manipulate individual atoms and molecules might be developed ,using one set of precise tools to build and operate another proportionally smaller set, and so on down to the needed scale.
In the course of this, he noted, scaling issues would arise from the changing magnitude of various physical phenomena gravity would become less important, surface tension and van der waals attraction would become more important,etc.this basic idea appears plausible, and exponential assembly enhances it with parallelism to produce a useful quantity of end products.
The term ‘nanophysics’ was defined by Tokyo Science University Professor Norio Tanguchi in a 1974 paper as [4] as follows :
‘Nano-technology’ mainly consists of separation , consolidation, and deformation of materials by one atom or by one molecule.’
In the 1980s the basic idea of this definition was explored in much more depth by Dr. K. Eric Drexler , who promoted the technological significance of nano-scale phenomena and devices through speeches and the books Engines of Creation.
The Coming Era of Nanophysics (1986) and Nanosystems : Molecular Machinery , Manufacturing , and Computation , [5] and so the term acquired its current sense. Engines of creation : The Coming Era of Nanophysics is considered the first book on the topic of Nanophysics . Nanophysics and nanoscience got started in the early 1980s with two major developments.
A Fundamental concepts ,
One nanometer (nm) is one billionth , or 10-9, of a meter . By comparison , typical carboncarbon bond lenghts , or the spacing between these atoms in a molecule , are in the range 0.12-0.15 nm , and a DNA double-helix has a diameter around 2 nm. On the other land, the smallest cellular life-forms , the bacteria of genus Mycoplasma , are around 200 nm in length.
Application of nanophysics
The project lists all of the products in a publicly accessible online inventory.
Most applications are limited to the use of ‘first generation’ passive nonmaterial which includes titanium dioxide in sunscreen, cosmetics and some food products; carbon allotropes used to produce gecko tape; silver in food packaging, clothing, disinfectants and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst.
Application in different field
Nano-membranes have been produced that are portable and easily-cleanaed systems that purify, detoxify and desalinate water meaning that third-world countries could get clean water, solving many related health issues.
1.Medicine 2.Chemestiry and Environment 3.Energy 4.Information and Communication 5.Heavy Industry 6.Consumer Goods
1. Medicine
Nano-medicine seeks to deliver a valuable set of research tools and clinically helpful devices in the future.
The national Nano-technology initiative expects new commercial applications in the pharmaceutical industry that may include advanced drug delivery systems,new therapies,and in vivo imaging.
Neuro-electronic interfaces and other nanoelectronics-based sensors are another active goal of research.
Further down the line,the speculative field of molecular Nano-technology believes that cell repair machine could revolutionize medicine and the medical field.
2. Chemistry And EnvironmentChemical catalysis and filtration are two prominent examples where Nano-technology already plays a role.
The synthesis provides novel materials with tailored features and chemical properties: for example,Nano-particles with a distinct chemical surrounding,or specific optical properties.
In a sense,all chemical synthesis can be understood in terms of Nano-technology,because of its ability to manufacture certain molecules.
Thus,chemistry forms a base for Nano-technology providing tailor-made molecules, polymers, etcetera, as well as clusters and Nano-particles.
3. Energy
The most advanced Nano-technology projects related to energy are:
Storage, Conversion, Manufacturing improvements by reducing materials and Process rates, Energy saving, and Enhanced renewable energy sources.
4. Information And Communication
Current high-technology production processes are based on traditional top down strategies, where Nano-technology has already been introduced silently.
The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.
5. Heavy IndustryAn inevitable use of Nano-technology will be in heavy industry.
Such as in the field of Aerospace, Construction, Refineries, Vehicle manufactures, and so on
6. Consumer GoodsNano-technology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant.
Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become smart, through embedded wearable electronics.
Already in use are different nanoparticle improved products .
Especially in the field of cosmetics, such novel products have a promising potential.
Case Study
What are Carbon nanotubes ?
Carbon nanotubes (CNTs) are allotropes of carbon. These cylindrical carbon molecules have interesting properties that make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of materials science, as well as potential uses in architectural fields. They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Their final usage, however, may be limited by their potential toxicity.
How CNTs are made ?• CNTs Can be found in the
carbon soot of graphite electrodes during an arc discharge involving high current. This process yields CNTs with lengths up to 50 microns.
Arc discharge
• In the laser ablation process, a pulsed laser vaporizes a graphite target in a high-temperature reactor while an inert gas is inserted into the reactor. Nanotubes develop on the cooler surfaces of the reactor as the vaporized carbon condenses.
Laser Ablation
StrengthElectricalThermalDefects
Properties
Strength Properties
Carbon nanotubes have the strongest tensile strength of any material known.
It also has the highest modulus of elasticity.
Electrical PropertiesIf the nanotube structure is armchair then the electrical properties are metallic
If the nanotube structure is chiral then the electrical properties can be either semiconducting with a very small band gap, otherwise the nanotube is a moderate semiconductor
In theory, metallic nanotubes can carry an electrical current density of 4×109 A/cm2 which is more than 1,000 times greater than metals such as copper
Thermal PropertiesAll nanotubes are expected to be very good thermal conductors along the tube, but good insulators laterally to the tube axis.
It is predicted that carbon nanotubes will be able to transmit up to 6000 watts per meter per Kelvin at room temperature; compare this to copper, a metal well-known for its good thermal conductivity, which transmits 385 watts per meter per K.
The temperature stability of carbon nanotubes is estimated to be up to 2800oC in vacuum and about 750oC in air.
Defects
Defects can occur in the form of atomic vacancies. High levels of such defects can lower the tensile strength by up to 85%.
Because of the very small structure of CNTs, the tensile strength of the tube is dependent on its weakest segment in a similar manner to a chain, where the strength of the weakest link becomes the maximum strength of the chain.
Thank You!
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