Summary

Science and Technology Class 08

Multiple choice question discussion from the topics covered in the previous class (5:08 PM)

The uniqueness of Nanotechnology (continued)(5:37 PM)

(c) Most of the biology occurs at the nanoscale. For example, Haemoglobin has a 5 nm diameter, and DNA molecule 2 nm diameter.
Medical researchers are working on designing tools, treatments, and therapies that are more precise, with the help of nanotechnology.
(d) Nanomaterials exhibit phenomena of self-assembly.
Self-assembly describes the process in which a group of components forms an ordered structure driven by mutual interactions.

Nanomanufacturing (5:49 PM)

There are mainly two approaches to making nanomaterials
(a) Top-down approach
A large piece of material is reduced all the way down to the nanoscale.
This leads to wastage.
Surface characteristics cannot be controlled.
But it is simpler and cheaper.
(b) Bottom-up approach
It creates products building them atom-by-atom, molecule-by-molecule.
It can be time-consuming, and expensive but surface characteristics can be regulated.

Dimensionality of Nanomaterials (6: 00 PM)

Nanomaterials can have zero dimensions. It means that all dimensions are at the nanoscale. For example, Quantum dots
One-dimension
In two dimensions it is at the nanoscale. In the third direction, it is at the macroscale. For example, Nanotubes
Two-dimension
It is at the nanoscale, only in one direction. In the other two directions, it is at the macroscale. For example, Thin Films
3-D bulk nanomaterial
All dimensions are at the macro scale. For example, polycrystals

Applications of Nano Technology (6:11 PM)

Daily life applications
(a) Nanoscale additives can make fabric acquire properties such as anti-wrinkling, anti-staining, or even inhibit bacterial growth.
(b) Nanoscale films on eyeglasses and displays, make them anti-reflective, scratch-resistant, water-repellent, etc.
(c) Lightweighting of automobiles
Lightweighting of automobiles with the help of nanomaterials can make them more energy efficient.
(d) Cosmetics- sunscreen lotions, lipsticks, etc.
Applications in Healthcare
(a) Cancer Treatment
Certain nanomaterials such as gold have proven to be effective in destroying a tumour.
(b) Targeted drug delivery
A nanoparticle can encapsulate or otherwise help to deliver medication directly to diseased tissues.
This reduces the side effects of the medicines.
(c) Gene Editing
Gene editing requires precision, and many gene editing techniques use nanomaterials to attain such precision.
(d) Vaccines
Researchers are looking at ways that how nanotechnology can improve vaccines, including their delivery.
(e) Anti-microbial resistance
When microbial organisms such as bacteria, viruses, protozoans, etc develop resistance against the very medicine that we take to kill them, it is called anti-microbial resistance.
For example, antibiotic-resistant bacteria.
Researchers have found out that certain nanomaterials such as quantum dots are very effective at killing such bacteria.

Application in electronics (6:59 PM)

(a) Flexible, foldable, and bendable displays are possible because of nanotechnology.
(b) Ultra-high-definition display in televisions with the help of quantum dots.
Quantum dots or QLED displays are more energy efficient compared to other displays.
(c) Transistors, basic switches that enable all modern computing have become smaller and smaller with the help of nanotechnology.
Applications in the environment
(a) For water filtration, nano-membrane has proven to be more effective than conventional filters.
(b) To control air pollution, certain changes have been introduced in the engines of automobiles, or in thermal power plants, which is facilitated by nanotechnology.
(c) Similarly to tackle oil spills, researchers are using water-repellent nanoparticles.

Carbon nanotubes (7:11 PM)

Carbon nanotubes are cylindrical molecules that consist of a single layer of carbon atoms called graphene.
Graphene in itself is an amazing nanomaterial, known for high thermal and electrical conductivity, and high tensile strength, despite being lighter than steel.
Carbon nanotube acquires some of these properties but depending on how we are folding, the size, and the number of layers, they can acquire different properties.
For example, a carbon nanotube can be a conductor or semiconductor.
The hollow part of the carbon nanotube can be filled with nanomaterials.
These nanomaterials will be separated and shielded from their surroundings.
Because of these properties, carbon nanotubes have applications in many areas such as electronic devices, lithium-ion batteries, hydrogen storage cells, and biosensors among others.

Quantum Dots (7:36 PM)

Quantum dots are nanoscale semiconductors.
They can emit light of various colours, just by changing their size.
Their potential application includes solar cells, medical imaging, and quantum computing.
They already have applications in display technology.

Nanotechnology in India (7:38 PM)

(1)National Mission on nanoscience and technology
Nano Mission was launched in 2007 under the Department of Science and Technology.
The first phase was in 2007-12, and the second phase was in 2014-20.
Objectives
(a) basic research promotion in Nanotechnology
(b) Infrastructure development in the research institutes.
(c) International Collaboration
(d) Private sector participation
(e) Human Resource Development
(f) Using nanotechnology to solve the issues being faced by India.
(2) The Ministry of Electronics and Information Technology has a Nanotechnology initiative division, which is working on developing indigenous products in the electronics sector.
It is being implemented with the help of IIsc Bengaluru and IIT Bombay.
(3) Nano urea
IIFCO (Indian Farmers Fertiliser Cooperative Limited) has developed a new fertilizer called nano urea, which is a nanoparticle of nitrogen in a stable form.
Typically, one bag of urea contains 45 kg of fertilizer, which has about 20 kg of nitrogen.
This one bag can be replaced with 500ml of nano urea, which has about 20 grams of nitrogen.
Because of increased surface area, nano urea is more reactive and can be absorbed directly by the stomata of plants.
Thus, overall urea consumption reduces, which has environmental benefits.
Also, the government can reduce the burden of fertilizer subsidies which has economic benefits.

The topics for the next class: Concerns with Nanotechnology, Information, and computing technology.