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Content

• Definition
• Applications of Nano Technology
  • Nanotechnology in Textile sector
  • Nanotechnology in Health sector
  • Nanotechnology in Agriculture sector
  • Environmental Applications
  • Structural Engineering Applications
  • Environmental Nanotechnology
• Future Potential Applications
• Limitations

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Definition

• Nanotechnology is science, engineering, technology, conducted at the nanoscale which is 1 to 100 nanometers. Nanotechnology and Nanoscience involve the ability to see and to control individual atoms and molecules. In other words, nanotechnology is the engineering of the functional system at molecular scale.
• Richard Feynman, the father of nanotechnology, in his 1959 talk described nanotechnology as a field which can manipulate and control things on the scale of a nanometer. He expected that matter will have surprising properties at Nano level and thus provide for enormous number of applications
• General Purpose Technology:

Applications of Nano Technology

Nanotechnology in textile sector

• Nanotechnology is an amazing general-purpose technology that has proven its potential in all the fields, and the textile sector is not an exception.

• How antibacterial properties are obtained: A nano-silver based suspension can be applied on the fabric surface. Other compounds such as zinc, copper, and their oxides coupled with metal nanoparticles can also be used as antibacterial agents. Titanium oxide (TiO₂) is another strong antimicrobial material that conducts the phenomenon known as “Photocatalysis”.
  • The anti-microbial textiles are most essential in the medical sector, especially in the present deadly pandemic conditions, for e.g., in curtains, bed covers, face masks, aprons used in the hospitals and diagnostics center.
  • It can also serve for best hygiene in sportswear, baby products, sanitary napkins, wound healing dressings and so on.
  • Self-cleaning garments using Titanium oxide particles save detergent, water, and electricity simply.
• “Wearable sunscreen” are garments using Titanium Oxide nanoparticles which provide protection against
• Thermoregulation: Clothings respond to changes in the body temperature and maintain comfort by either heating or cooling. The Phase Change Material is incorporated into the fabric to fulfill this function.
• The Polymeric micro-capsules filled with perfumes/deodorants/insect repellents can be integrated with fabric for slow release.
• Fabric Used in Air Filters: A thin coating of nanofibers on the fabric used in air filters for air conditioners and automobiles’ exhaust, stops ultrafine particles thereby increasing the efficiency of the filters.
• Technical Textiles are used in special applications. For e.g., fireproof and flame-retardant fabric is required in the suit used by firefighters. The high temperature stable materials are combined with thermally insulating and fireproof materials such as nano-porous silica aerogel for this application. Other examples of technical textiles include functions like electro-magnetic field shielding, electrical conducting, anti-static, camouflaging, stealth, water repellency, and so on. The nanomaterials used in these applications are generally carbon nanotubes, nanoparticles of metals, metal oxides, clay, semiconductors, polymers etc.

Way Forward

• Nanotechnology has a great potential in the textile industry. Functional and smart textiles can play an important role in the economy of a nation. However, there are limitations in applications due to scientific complexity and the cost adhered to it.
• Therefore, a proper study is necessary to find any toxic effects of handling and wearing the nano materials to eliminate any health risks due to short- or long-term exposure.

Nanotechnology in Health Sector

• Nanomedicine is the medical application of nanotechnology. It ranges from the medical applications of nanomaterials and biological devices to nanoelectronics biosensors, and even possible future applications of molecular nanotechnology such as biological machines.
• What difficulties nano-medicines will overcome?
  • Problems with conventional drugs
    • Less soluble conventional medicine, which are not absorbed properly and thus don’t impact the required target
    • Even if drug molecule is soluble, body removes the drug before it has had long enough to provide a benefit.
    • Conventional drugs could have side effects due to poor delivery at the actual site of disease.
      • For e.g. drugs targeting cancer must avoid the healthy tissues and organs or damage can be caused.
    • Nanomedicines therefore can play an important role in ensuring enough of the drugs enter the body, that the drugs that enters stays in the body for long periods and is targeted specifically in areas that need treatment.

• Medical Applications:
  • Prevention of disease:
    • Nanoparticles of silver embedded into fibers have anti-microbial action. It is used in food packaging, clothing, disinfectants, and household appliances. Bandages are being infused with silver nanoparticles to heal cuts faster.
    • Gold Nanoparticles have anti-bacterial properties
    • Water Purification: Special Filters using nanomaterials can remove objects as tiny as viruses from water.
• Diagnostics: By studying and identifying individual molecules, it is possible to diagnose disease in time to improve the prognosis for the patient.
• Improved Treatment
• Indian Institute of Nano Science and Technology (INST) is developing Magnetic Hyperthermia mediated cancer therapy – delivery and localization of magnetic material within the targeted tumour site followed by subsequent application of an alternating Magnetic Field (AMF), thereby generating heat at the tumour site
• E.g: Scientist are using gold nanoparticles to target prostate cancer. Here the nanoparticles or nano shells are made of small payers of Silica glass formed into a sphere and wrapped in a thin layer of gold. This is made to reach the tumour site and then harnessed to cause the tumorous tissue to pulse with extreme temperature when light is applied through a laser specifically designed to excite the particles
• A team of scientists from IISc Bengaluru have developed nano robots to be used in dental procedure (like root canal therapy).
• With more advancement in Nanomachines – complex surgical procedures would become less intrusive and less complicated

Using Nanorobots for Dental Procedure (Aug 2021)

Background/Need

• A significant percentage of root canal treatments fail, because the procedure leaves out some bacteria that are located deep within the dentinal tubules.

The new method:

• Scientists have developed Spiral Silica robots measuring 300 nanometers to travel through dentinal tubules and target bacterias.

How do they work:

• These spiral silica nanobots with a bit of iron embedded in them are not more than 300 nanometers. They are suspended in water or water like biocompatible medium. There are about a billion nanorobots in 0.5 ml water. This is almost a trillion times lower than the amount of silica found in a pint of beer and is effectively harmless for a human body. 

About Magnetic Hyperthermia-mediated Cancer Therapy (MHCT)

• It is a non-invasive cancer treatment It involves the delivery and localization of magnetic material within the targeted tumour site followed by subsequent application of an alternating Magnetic Field (AMF), thereby generating heat at the tumour site.
• It can efficiently act against deep-seated inaccessible solid tumors like glioblastoma and is highly thermo-sensitive towards normal cells with minimal toxicity against healthy counterparts.
• Scientists are working on new material which can make this treatment more efficient.

Nanotechnology in Agriculture Sector

Nano Urea

Introduction:

• India has become the first country in the world to have developed and roll out nano-fertilizers.

  • So far, it has launched nano-versions of two fertilizers – Urea and Diammonium Phosphate (DAP).
  • While nano-Urea has been made available to farmers since late 2021, nano-DAP was launched in April 2023.
• The Indian Farmers Fertilizer Cooperative Limited (IFFCO), which had developed the variants using propriety technology, claims that Nano-UREA and Nano-DAP have several advantages over their conventional granular counterparts.

More Details:

• Both Nano-Urea and Nano-DAP come in liquid form.
• IFFCO claims that a 500 ml bottle of nano-urea can replace at least a 45 kg bag of granular urea and a bottle of 500 ml nano-DAP can replace a 500 kg bag of granular DAP.

Advantages:

• Soil Health: Nano-UREA can address the imbalanced and excessive used of conventional urea in the country, which accounts for around 82% of nitrogenous fertilizers applied to majority of the crops.
• It costs lesser than subsidized conventional fertilizer thus reducing the cost for farmers.
• They also result in better productivity and higher income for farmers.
  • The PSC report notes that it has average 8% higher crop yield.
• Experts also believe that these nano-fertilizers will lead to reduced import dependency of fertilizers and save forex reserves.
• It will also contribute to reduced fiscal burden of government because of reduced fertilizer subsidy cost.

Limitations:

• Doubts about Yield gain: DTE has reported interviews of several farmers who had to resort back to traditional fertilizers after, nano-fertilizers didn’t give good results.
• Labour cost for spraying fertilizer is increasing the overall input cost for farmers.
• Complaints about farmers being forced to buy Nano-Urea.
• Issue of Evaluation/Trial: ICAR has given results of field trail based on a year (two seasons) of experiments in its affiliated labs. This was an exception as ICAR normally tests a new fertilizer for 2 years (or three seasons) before giving go ahead to a new fertilizer.

Conclusions: Nanotechnology could play a crucial role in promoting sustainable agriculture in India and nano-urea is an example of that. At the same time, it should be ensured that any new technology-based product is properly evaluated in its efficacy, environmental impact and economic impact on farmers.

Question:

• “The Nano-Fertilizer technology can change the contours of not just Indian agriculture but also the economy” Critically analyze [10 marks, 150 words]

Environmental Applications:

• Iron nanoparticles can be used to effectively clean-up organic solvents that are polluting the ground water. The nanoparticles disperse throughout the water and decompose the organic solvents in place.
• Adding a little boron to Carbon while creating nanotubes produce solid, spongy, reusable blocks that can absorb large quantities of oil spilled in water.
• Nanotechnology based smart windows have energy saving, easy cleaning, UV controlling and photovoltaic properties.
• Renewable Energy Generation
  • New and Cheap Solar Cells use nanoparticles of Titanium oxide coated with dye molecules to capture the energy of visible light and convert it into electricity.
  • A novel catalytic nanosheet from of a nickel molybdenum-nitride, a thousand time cheaper than traditional platinum, is the new model for harvesting hydrogen from water for use as fuel.

• Electronics
  • Graphene is used in transparent electrodes for solar cells, LCD, robust non-volatile atomic switches, chemical and biological sensors and in spintronic devices.
  • Semiconducting nanowires are highly versatile optoelectronic components, for a wide variety of applications such as nano-LEDs and nano-Lasers, solar cells, and biomedical sensors.

Structural Engineering Applications

• Nano-enhanced Cement contained by addition of nanoparticles like nano silica (silica fume), nanostructured metals, CNTs and carbon nanofibers give stronger, more durable, self-healing, air purifying, fire resistant, easy to clean quick compacting structure.
• Nano-enhanced Construction Ceramics such as floor and wall tiles and sanitary ware have self-cleaning, anti-bacterial, hygienic, and scratch resistant features.
• Nano-enhanced paints can reduce emission of Nitrogen-di-oxide, hydrocarbons, and carbon monoxide in the atmosphere. It can also make paint scratch proof, easy cleaning, air purifying, UV resistant, water repellant, flame resistant, and anti-bacterial.
• Nanotechnology based smart windows have energy-saving, easy cleaning, UV controlling and photovoltaic properties.
• Fire resistant glasses are produced by addition of fumed silica nanoparticles in glasses.

Nanotechnology can promote different forms of insulation solutions like coatings, vacuum insulations glazing and nanofoams.

Nano whiskers on clothes create a cushion of air around the fabric so that liquids can’t stain them.

Cosmetics: Nanoparticles like Zinc oxides and titanium oxides are used in sunscreen and related products. They provide protection from UVA rays.

Environmental Nanotechnology

Introduction

• Environmental nanotechnology refers to use of nanotech products, processes, and applications to contribute to environment and climate protection.
• It may contribute by cleaning the pollutants, reducing the pollutants, making our devices more efficient and reducing cost of green technologies.

Key areas where nano-material researchers are working:

• Ensuring Potable Drinking Water – Use of Graphene based water filters are expected to increase the accessibility of clean drinking water in coming future.
• Removing pollutants from water
  • Cleaning up organic chemicals polluting ground water
    • Iron nanoparticles can be used to effectively clean-up organic solvents that are polluting the ground water. The nanoparticles disperse throughout the water and decompose the organic solvents in place.
  • Cleaning up of oil spills
    • Using photocatalytic cooper tungsten oxide nanoparticles to break down oil into bio-degradable compounds.
• Generating Less pollution during manufacturing of materials
  • E.g., Use of silver nano particles as catalysts can significantly reduce the polluting by products in the process used to manufacture propylene oxide.
    • Propylene oxide is used to produce common materials such as plastics, paint, detergents and brake fluid.
• Producing solar cells that generate electricity at competitive cost
  • E.g. Silicon nanowires embedded in a polymer result in low cost but high efficiency solar cells.
• Increasing the electricity generated by windmills
  • E.g. use of carbon nanotubes in windmill blades results in stronger and lower weight windmill blades. This helps in more amount of electricity generated by each windmill.
• Reducing cost of fuel cells
  • Changing the spacing of platinum atom in fuel cells increases the catalytic ability of the platinum. This allows the fuel cells to function with 80% less platinum, significantly reducing the cost of the fuel cells.

Conclusion: Nanotechnology is thus brimming with potential solutions to various environmental and climate change related issues being faced by India. It’s high time that India’s Mission on Nano Science and Technology is restructured to include R&D in the field of environment as one of its key goals

Example Questions

• What is environmental nanotechnology? Discuss with some practical applications. [10 marks, 150 words]

Future Potential Applications

• Advancements like nano-machines will lead to development in the field of nano-medicines, more advanced electronics circuitry, quantum computing.

Concerns and Limitations

• Due to their extremely small dimensions, large surface area and high reactivity, they have the potential ability to penetrate living cells quite readily. As a result, their unique nano-features may also make them potentially hazardous for human health and environmental safety.
• Health
  • Inhaling airborne nanoparticles and nanofibers may lead to a number of pulmonary diseases, g., fibrosis. Some form of carbon nanotubes could be as harmful as asbestos if inhaled in sufficient quantities.
  • Experiments with rats have also shown impact on skin (ageing) and brain.

• Toxicity
  • Lack of investment on nanotoxicology research

• Environmental impact
  • Lack of research on potential harmful impact: Lack of study on Impact of nanomaterial on non-human species, on ecosystem or the global environment.
  • g. bacteriostatic silver nanoparticles used in socks to reduce foot odor are being released in the wash. These particles are then flushed into the wastewater stream and may destroy bacteria which are critical component of natural ecosystem, farms, and wastewater treatment processes.

• More dangerous Weapons
  • As a general-purpose technology, it will be dual use, meaning it will have many commercial uses and it also will have military uses – making for more powerful weapons and tools of surveillance.
  • A technology this powerful could easily be misused. The rapid development cycle and massive manufacturing capability may lead to an unstable arms race between competing power

• Other Concerns
  • May lead to loss of jobs in traditional farming and manufacturing sector
  • May bring about crash in certain markets due to lowering of oil and diamonds due to possibility of developing alternative source of energy that are more efficient and won’t require use of fossil fuels. Also, because people would be able to develop products at molecular level, diamond will lose its significance.
  • Atomic weapons may become more accessible and more powerful and more destructive.

Past Year Mains Questions (since 2013)

• What do you understand by nanotechnology and how is it helping in health sector? (2020)
• Why is nanotechnology one of the key technologies of the 21st century? Describe the salient features of Indian Government’s Mission on Nanoscience and Technology and the scope of its application in the development process of the country (2016)

 Other Practice Questions

• What is Nanotechnology? Why is it called a general-purpose technology? [10 marks, 150 words]
• “Their unique nano-features may also make them potentially hazardous for human health and environmental safety” Discuss the key concerns associated with nanotechnology. [10 marks, 150 words]
• What are molecular machines? Discuss the significant role that it may play in various socio-economic sectors. [10 marks, 150 words]
• Discuss the key provisions of the Mission on Nanoscience and Technology [10 marks, 150 words]
• Write a short note on key properties and applications of:
  • Graphene
  • Carbon Nano Tube (CNT)
  • Nanodrums
  • Schwarzites
• Suggest some measures to promote nano-technology research in the country. [10 marks, 150 words]
• “Nano Machines are going to have serious economic, social, environmental and military implications” Elaborate. How far does Indian Government’s Mission on Nanoscience and Technology prepare India for these implications? [15 marks, 250 words]
• What is Nano-UREA? How is it going to solve the various problems faced by fertilizer sector in India? [10 marks, 150 words]