Dr. Hemali Rathnayake
Joint School of Nanoscience and Nanotechnology
AWRN Lunchtime Colloquium 10/14/22, MHRA 1607
Dr. Rathnayake’s presentation argued that Nanotechnology makes more things possible. It offers solutions to many of the challenges we’re facing today, like the California drought, which makes water scarcity now a permanent feature in California. Coming from a third-world country—Sri Lanka—has made Dr. Rathnayake aware that we always are struggling with the accessibility of fresh water. Furthermore, with so many populations using plastic products, much discarded plastic ends up in the ocean, and it becomes a huge problem when microplastics and other impurities get into the water. All of these issues with pollution, energy, and water she identifies the need of an interdisciplinary approach to the food-energy-water (FEW) nexus.
The grand societal challenges which we face now are climate change, global health, and the FEW nexus. Nanotechnology can help us achieve a digitally transformed and more sustainable world.
We usually try to access each of the problems – like water scarcity and climate change – as separate pieces, but what we need to do is address all of these issues together with a more interdisciplinary approach. Technology is extremely important in facing these day-to-day challenges, and needs to be developed quickly, rather than waiting ten years when our environment will be facing deeper challenges.
Dr. Rathnayake considers this question: can we address these global challenges in a circular economy? Can we use technological solutions to engage the FEW nexus, and can we change our mission to create clean energy, fresh water accessibility, and sustainable agriculture while tackling these larger issues of climate change and global health more quickly? The COVID vaccine is an example – when we were under a tight timeframe, the vaccine was developed much more quickly than it would have been otherwise (because we were able to employ the nanotechnology approaches quickly). We’ve already missed the window of opportunity for climate change – so now we need to be working harder and faster to catch up.
Why nanotechnology? Why is it the best interdisciplinary approach to address these challenges? If you look at recent articles, nanotechnology is now recognized as the core of technology-based solutions. It offers disruptive, game changing breakthroughs and innovations that can provide immediate answers and solutions to help our society, environment, and the planet.
Let’s discuss what ‘nano’ means. The word comes from the Greek prefix for ‘dwarf’ – it depicts one thousand millionth of a meter. We understand it as ‘one prefix that builds the core’ of the next generation’s technologies.
Why do we say nano can build everything? In 1959, Richard Feynman introduced the concept of ‘plenty of room at the bottom’ because nano covers a much larger area. For example, when we take one sphere, we can slice it into really small spherical technologies called colloidosomes, which can be used to deliver drugs. And of course, one of the most important, amazing nano-materials is the atomically thin graphene.
‘Nano’ is very interconnected with other disciplines. Nanotechnology utilizes nanoscience in practical application, the translation of nanoscience to the community.
Dr. Rathnayake’s group works to develop the materials through nanoscience, and practically applies nano-technology-enabled solutions to problems in the FEW nexus. They purify water to address water scarcity while extracting critical minerals, particularly targeting lithium.
The group’s first mission was finding a unique nanomaterial, which Dr. Rathnayake calls the “magic material.” It is like a sponge with very large surface area that can absorb so much material and act as a filter to purify. Such is the exponential multiplication of surface area accomplished by nanoscience that one gram of this nanomaterial can cover an American soccer field.
Why target lithium, and why chase it? The buzz word nowadays is the Electric Vehicle (EV) revolution – lithium-ion batteries are a very profitable market. If we replace one full petroleum-powered car, how much carbon dioxide can we avoid leaking into the environment? One car emits 4.6 metric tons of CO2. Most businesses and corporations are chasing the lithium battery gold rush with heavy tolls on the environment.
Are current and new methods of energy generation environmentally sustainable? Lithium mining and solar evaporation leave a lot of energy and water behind. Environmental activists and corporations are trying to have a conversation about whether we should chase lithium to heal the environment.
In a traditional solar evaporation, the lithium recovery time is 18-24 months, and has an efficiency of 30-50%. But mining has a high market cost and high capital investment.
This is where Dr. Rathnayake’s lab developed the Nano-Mosaic sorbent technology. Using plant polyphenols, they make nanosorbents, and use nanofiber mats to clean water. They are energy efficient, don’t use very much water (30,000 galloons versus 500,000 galloons), and are very fast (48 hours).
How does nano-mosaic technology work? It makes it easier to extract the lithium and purify the water. Two columns have a filter material. The process sends wastewater or brine or sea water through the first column, and it removes 90% of the dissolved impurities, and then in the second column, it is specifically activated to extract the lithium. Then the extracted lithium is converted to battery-grade lithium. Dr. Rathnayake’s group can make multiple filters and have created a mobile unit taking seawater and treating the water to get more usable water. These filtration/extraction columns are multifunctional – they work on desalination and heavy metal removal. They call these components “magic materials” because they are both multifunctional and single-system.
The economic impact of this process is being studied. The group uses brine from the natural deposits in the wells and goes to spots where the brine is rich in lithium. Even the pilot scale of this nanomaterial we can filter 171 gallons of water per minute. Right now, battery-grade lithium is $17 per kilogram, and it is only getting higher as the markets are chasing it. If someone wanted to take it to the commercial scale, this technology can generate 10 metric tons of lithium, which is worth $250 million per year.
We are now in the new era of nanotechnology, which played a huge role in nanomedicine in 2020 to 2022. Nanotechnology created the world’s smallest tic-tac-toe board game using just DNA in 2018 – to illustrate the fact that if we can alter your DNA to such a different design, then we can do surgeries and medicines more easily with nanobots.
Nanotechnology is actually traced to the 5th Century BC, when the concept of the atom was first introduced by the Greeks. Actual atoms were first identified during the age of scientific discovery by John Dalton in the early 1800s, and atomic theory developed further through the 19th and 20th centuries, when the first device capable of viewing atoms was developed.
The question is: will Atlantic World history and nanotechnology merge?