Newsletter: June 2016

Imagine if a laptop could weigh less than 100 grams or a water filter had enough efficiency to clean more water in half the time current water filters take? Better yet, imagine wearing just one coat in extreme cold or taking a single tablet or capsule to cure all known chronic diseases? What if a drop of soap could efficiently wash a bag of clothes and thermo-responsive walls became a reality rendering air-conditioners and heaters unnecessary?

Innovative, durable, eco-friendly and low cost products are highly sought after by today’s generation and the development of nanotechnology is assisting in making these a reality in our world.

A glass of drinking water from the tap should have the ability to flush out toxins generated during metabolic activities from the body. However that is not always the reality because some of the water today has invisible chemical and biological pollutants.

Nanotechnology has provided us with many prototypes and products that use combinations of technologies, using nanofilters, nanomembranes, nano-adsorbents and nano-photo catalysts to provide pollutant-free, drinkable water.

The power of nanotechnology is not limited to its ability to solve some water related issues. To understand the importance of nanotechnology in today’s society, we can take a look back at how this interesting field has developed.

Richard Feynman envisioned the future during his talk titled “There’s plenty of room at the bottom” in 1959, at the California Institute of Technology. The father of nanotechnology emphasised the possibility of controlling and manipulating the chemical structure at an atomic and molecular level.

Twenty-two years after this historical speech, Prof. Norio Taniguchi from Japan coined the term “nanotechnology” in 1981. The invention of a scanning electron microscope that could visualise material at an atomic and molecular level gave the researcher confidence to work towards developing materials at the nanoscale. This major discovery won Gerd Binning and Heinrich Rohrer at the IBM Zurich Research Lab the Nobel prize in Physics in 1986.

It is also important to note that the previous year, Harry Kroto, Richard Smalley and Robert Curl had successfully developed fullerene which is a carbon nanomaterial also known as the C₆₀ or bucky tubes.

The wonder world of small scale technology took a giant leap at the start of the twentieth century when a number of concepts were proposed and nanotechnology became an integral part of all sciences. Scientists across the globe had more than one hundred elements to investigate and tried to develop nanomaterials of different shapes and sizes using specialised technologies.

This led to the conceptualisation of nanotechnology. Within a chemical structure the confinement of particles and quasi particles in a unique direction allows the modification of physical properties in that direction.

This confinement is achieved using some of the well-known technologies such as the arc discharge method, chemical vapour deposition, vapour phase deposition, spray pyrolysis, ultrasonication, sol gel technology and carbon-thermal reduction, the hydrothermal method and many more. These nanomaterials can be zero, one, two or three dimensional, possessing extraordinary physical and material properties.

Today the beauty of these advanced technologies is that nanomaterials can be formed in interesting shapes such as nanotubes, nanofibres, nanoribbons, nanoflowers, nanobrushes, nanorods, nanosheets, nanolayers, nanopillars, nanoparticles and many others. To the normal human eye, this may appear as an ordinary powder, a thin strip, glass coating or may be a lump, but under the advanced microscope the view of the same material becomes unbelievable and almost magical.

Nanomaterials have fascinating properties and have been used to reinforce design hybrids and nanocomposites. The properties can be thermal, electrical, optical, magnetic, antifouling, catalytic and photo-catalytic, anticorrosive, oxidation resistant, fire resistant and stimuli responsive, among many other properties.

Some of the latest commercial developments and innovations using nanotechnology include:

• Nanomedicine: customised nanoparticles for targeted drug delivery to the cancer cell, thereby reducing or maybe eradicating chemotherapy,
• Nano-electronics: light weight electronics with reduced power consumption,
• Biosensors: commercially available glucose sensors and cholesterol sensors,
• Gas sensors: for detecting harmful gases and aiding in controlling air pollution,
• Mechanical aspects: light weight space crafts with reduced fuel consumption and better oxidation resistance,
• Sports: mechanically strong tennis and badminton rackets with lower levels of imperfections,
• Textile: improvements in fabric texture, colour and weight with the use of nanomaterials and nanocomposites  in the raw material,
• Solar cells and batteries: with improved efficiency at a lower cost level,
• Food industry: enhanced flavour, shelf-life and freshness of food using nanomaterials,
• Household products: nano-engineered materials for stain removal, paints, air-purifiers and antibacterial coating in washing machines and dish washers,
• Environmental appliances: nanosensors for detecting pollutants, antimicrobial sprays in aircrafts and hospitals.

Nanotechnology has led to the creation of materials with excellent absorption, degradation and remediation efficiency that have the capability to remove inorganics such as heavy metals, radionuclides, rare earth metals, organics such as dioxins, phenols, dyes, pharmaceutical and nutraceutical wastes from industrial and municipal waste water.

At this stage the wonder world of nanotechnology has just touched the tip of the iceberg of commercialisation. Only time will expose the full capability of nanotechnology.

By Prof Shivani Bhardwaj Mishra