Nanoparticles & Nanotechnology: Providing innovative solutions to complex problems: “Great Things from Small Things”

It’s been 10+ Years for us here at GNT, writing about, investigating, building Relationships with key Research Universities, developing and investing in “Great Things from Small Things” – What a Ride!

Nanoparticles are substances whose dimensions range from 1 nanometre to 100 nanometres and can be of any shape or colour. Simply put, nanoparticles are very tiny and ultra minute substances that are not visible through naked eyes and have their size range from 1 nm to 100 nm, where 1 nanometre is equal to one billionth of a metre.  In fact, more than 500,000 nanoparticles can sit on a cross section of a human hair. Interestingly, If we compare the width of a human DNA helix that is 2nm to the size of a human body it is equivalent to the comparison of a human body to the size of the sun.

Nanoparticles are very different from bulk particles as they show very different Optical properties, Electrical properties, Mechanical properties, Magnetic properties and Catalytic properties.

Nanotechnology: a “maturing” new technology

Nanotechnology is the development and use of techniques which are targeted to study physical phenomena of nanoparticles and to develop new devices and material structure using nanoparticles. Similarly, Nanoscience is a term which identifies as the study and application of extremely tiny things that can be further useful for other science related fields. Presently, Nanotechnology or Nanotech is developing rapidly with scientists and developers deliberating about every possible field where Nanotech can be applied. 

One of the unique features of Nanoparticles is their high surface-area-to-volume ratio. This feature enables them to have unique physicochemical properties, various functionalities and enhancement in reactivity. 

Nanotech can also be understood as a technology which has the capabilities of controlling and modification of materials and substances at the nanometer-scale.

Nanotechnology in health care system

Nanotech is gradually gaining momentum in our healthcare system, with the creation of nanomicelle, colloidal structures useful for drug delivery systems along with Antiviral Nano-coatings that are applied on face masks and PPE kits being some of the prominent examples of Nanotech.

The technology is also being used to detect heart attacks with Nanotech detectors, along with Nanochips to check plaque in arteries and Nanocarriers for eye surgery, chemotherapy etc.

Nanotechnology in environment

Nanotech possesses vast potential for providing solutions to various environmental challenges. It could be one of the best possible ways to provide innovative solutions for reducing pollution, water treatment, environmental sensing and making alternative energy more cost-effective.

A prominent example could be a Nanogrid made of photocatalytic copper tungsten oxide nanoparticles, which is used when there is an Oil spill in oceans, rivers. These Nanoparticles break the oil down into biodegradable compounds when activated by sunlight and helps in conservation of water and aquatic animals.

Nanotech can be useful for water purification, sensing and detecting chemical and biological contamination at low concentration, separating carbon dioxide from waste gases which could contribute in cleansing of air.

Major Government initiatives

As per, Ministry of Electronics and Information Technology the government is taking various steps for the promotion of Nanotech, including establishment of Nanoelectronics centres, Indian Nanoelectronics Users Programme (INUP) which is being implemented at Centre of Excellence in Nanoelectronics (CEN) at IISc and IIT Bombay. 

The Government of India has also launched a Mission on Nanoscience and Technology also known as Nano Mission in May 2007 with an aim to build capacity in the field of Nanotech in the country. The nodal agency of the Nano Mission is Department of Science and Technology with phase 2 of the initiative being commenced in the year 2014 with an allocation of 650 crore. 

According to the Department of Science and Technology, India’s Nano Mission has achieved a significant milestone by securing the third position in the global rankings due to its contribution to the field of Nanoscience.

Carbon Nanotubes Could Revolutionize Everything from Batteries and Water Purifiers to Auto Parts and Sporting Goods: Update from Lawrence Livermore National Laboratory

Vertically aligned carbon nanotubes growing from catalytic nanoparticles (gold color) on a silicon wafer on top of a heating stage (red glow). Diffusion of acetylene (black molecules) through the gas phase to the catalytic sites determines the growth rate in a cold-wall showerhead reactor. Credit: Image by Adam Samuel Connell/LLNL

Scientists at the Department of Energy’s Lawrence Livermore National Laboratory (LLNL)  are scaling up the production of vertically aligned single-walled carbon nanotubes (SWCNT). This incredible material could revolutionize diverse commercial products ranging from rechargeable batteries, sporting goods, and automotive parts to boat hulls and water filters. The research was published recently in the journal Carbon.

Most carbon nanotube (CNT) production today is unorganized CNT architectures that is used in bulk composite materials and thin films. However, for many uses, organized CNT architectures, like vertically aligned forests, provide critical advantages for exploiting the properties of individual CNTs in macroscopic systems.

“Robust synthesis of vertically-aligned carbon nanotubes at large scale is required to accelerate deployment of numerous cutting-edge devices to emerging commercial applications,” said LLNL scientist and lead author Francesco Fornasiero. “To address this need, we demonstrated that the structural characteristics of single-walled CNTs produced at wafer scale in a growth regime dominated by bulk diffusion of the gaseous carbon precursor are remarkably invariant over a broad range of process conditions.”

The team of researchers discovered that the vertically oriented SWCNTs retained very high quality when increasing precursor concentration (the initial carbon) up to 30-fold, the catalyst substrate area from 1 cm² to 180 cm², growth pressure from 20 to 790 Mbar and gas flowrates up to 8-fold.

LLNL scientists derived a kinetics model that shows the growth kinetics can be accelerated by using a lighter bath gas to aid precursor diffusion. In addition, byproduct formation, which becomes progressively more important at higher growth pressure, could be greatly mitigated by using a hydrogen-free growth environment. The model also indicates that production throughput could be increased by 6-fold with carbon conversion efficiency of higher than 90% with the appropriate choice of the CNT growth recipe and fluid dynamics conditions.

“These model projections, along with the remarkably conserved structure of the CNT forests over a wide range of synthesis conditions, suggest that a bulk-diffusion-limited growth regime may facilitate preservation of vertically aligned CNT-based device performance during scale up,” said LLNL scientist and first author Sei Jin Park.

The team concluded that operating in a growth regime that is quantitatively described by a simple CNT growth kinetics model can facilitate process optimization and lead to a more rapid deployment of cutting-edge vertically-aligned CNT applications.

Applications include lithium-ion batteries, supercapacitors, water purification, thermal interfaces, breathable fabrics, and sensors.

Reference: “Synthesis of wafer-scale SWCNT forests with remarkably invariant structural properties in a bulk-diffusion-controlled kinetic regime” by Sei Jin Park, Kathleen Moyer-Vanderburgh, Steven F. Buchsbaum, Eric R. Meshot, Melinda L. Jue, Kuang Jen Wu and Francesco Fornasiero, 29 September 2022, Carbon.
DOI: 10.1016/j.carbon.2022.09.068

Other LLNL authors are Kathleen Moyer-Vanderburgh, Steven Buchsbaum, Eric Meshot, Melinda Jue and Kuang Jen Wu. The work is funded by the Chemical and Biological Technologies Department of the Defense Threat Reduction Agency.