Learn more about silica - a versatile mineral
Learn more about silica - a versatile mineral
Cancer medicine of the future and next generation fuel cells – silica can be a problem solver in such widely different areas of application.
Silica is truly versatile and researchers constantly find new ways of using it. At Frontiers of Silica 2019, held at Chalmers University of Technology, we have asked some of them what they are working on.
Associate Professor Anna Martinelli from Chalmers University of Technology uses silica in her research, with the aim to make future fuel cells more efficient.
“For me, collaboration with industry is important. I cooperate with Nouryon who provides me with silica particles,” she says.
Anna Martinelli conducts research on new proton-conducting materials for the fuel cell technology of tomorrow. She explains that, with a silica-based nanoporous membrane filled with a protic ionic liquid, the fuel cell can become more efficient – and at the same time, the material costs can be reduced.
“Even if I’ve explored this for a long time, I’ve begun developing a new material concept in recent years. It focuses on trying to use ionic liquids instead of water, primarily as a proton-conducting electrolyte, but also to structure nanoporous silica,” she says and continues.
“The application we have in mind is fuel cells. Technically, this is very exciting. The hope is that we’ll find a material that can solve certain problems with today’s fuel cell technology – and then the fuel cells can be run at higher temperatures, which implies higher efficiency and stability.”
Anna Martinelli spoke about her research at the Frontiers of Silica Research symposium, which has become an international meeting place for researchers, companies and doctoral students who are interested in the multitude of possibilities of silica.
“Having an opportunity to speak for and discuss with others who understand the possibilities of silica is both interesting and relevant.”
So how does it look in terms of time. When does Anna Martinelli believe that her research and her colleagues’ research will take the next step?
“What we are doing now is still fundamental research, but if these materials work as well as we hope, we will like to test them in a real fuel cell within two years.”
Where do you think this can gradually be put to use? Where are the end users?
“It may be in many different products and applications. In the transportation industry, in mobile chargers for mobile phones and stationary power banks, but also in large power plants,” she says.
The silica she uses in her research is delivered as samples from Nouryon’s silica research lab. Anna also believes in future collaboration with Nouryon’s own researchers.
“Today, I get silica samples from them. In the future, we might be able to tailor-make new silica structures together. There are many exciting possibilities.”
Professor Mika Lindén came into contact with silica-based materials during his post-doctoral research in Frankfurt more than 20 years ago. Then, the breadth and possibilities of the chemistry of silica captured his attention.
“Today, my research team and I focus on developing nanoparticles as carriers of medication in cancer medicine,” he says.
Mika Lindén comes from Finland and earned his PhD at Åbo Akademi University in 1996, but since then he has primarily been based in Germany, spending the past 10 years at Ulm University in Baden-Würtemberg.
Right now, the focus for Mika Lindén and his research team of 10-12 people is using porous nanoparticles in medication contexts, especially in chemotherapy against cancer. They are also conducting research directed at several other applications as well.
“There are medications that are effective at killing cancer cells, but the problem is that the side-effects are critical. Using silica nanoparticles, we want to get the medications to act more selectively, then doses can be reduced and treatment becomes more effective,” he explains.
He held a lecture on this research at the Frontiers of Silica Research symposium at Chalmers University of Technology in Gothenburg, Sweden in April.
“The flexibility of the chemistry of silica is incredible. The reason we use mesoporous nanoparticles is that we can control their size and shape – and we can functionalise them as much as we want, which is very exciting.”
There is no doubt about Mika Lindén’s enthusiasm for the future possibilities of silica research.
“There was a lot of hype around these particles a few years ago and people believed in quick results, but this kind of research takes time. I believe that formulation of silica used in hybrid materials, often together with organic molecules is a flourishing field of research where the research potential is endless.”
How long do you think it will be before the cancer medicines can become more effective using nanoparticles that carry the medications directly to the sick cells?
“A guess is around ten years. This is not yet being used in clinical trials in the cancer medicines, but the first tests with silica nanoparticles on humans are under way in the United States. We aren’t directly connected to those experiments, but many people conducting research and cooperating is crucial.”
When Nouryon recruited an industrial PhD student who was to focus on silica research and surface chemistry, Sanna Björkegren was chosen. Later this year, she will earn her PhD.
“My project concerns fundamental research and I feel that I might have contributed to a small step forward in this field,” she says.
Chalmers University of Technology in Gothenburg and Nouryon’s Silica Development department in Bohus (outside Gothenburg) have been Sanna Björkegren’s two homes over these years and she has two supervisors at each place.
“It has been very smooth and a great advantage for me to have access to the resources of both industry and academia. I’ve been able to work with colleagues at Nouryon who are specialized in silica and have been able to discuss things with them,” she says and adds:
“In my project, I modify the surface of particles to give them new characteristics – and I use them to stabilize emulsions. An emulsion, which is a mixture of oil and water, will phase-separate into a layer of oil and a layer of water, unless a stabilizing agent is added. This is where my nanoparticles come in; the particles can arrange at the interfaces between the oil and water layers and enables creation of stable micro-sized emulsion droplets. This way, an emulsion can be stable for years,” explains Sanna.
What can this be used for in purely concrete terms?
“My research is on the fundamental level, and one can subsequently continue and develop various applications. There are a lot of everyday examples of emulsions, for instance mayonnaise and skin lotions.”
Do you feel as if you can already see the benefit of your research?
“Yes, to some extent. The articles I’ve published have been cited. This means that I’ve contributed to taking a small step forward in the field – and what I’ve learned during this time is something I can use also in other fields.”
Professor Bradley Chmelka at the University of California, Santa Barbara, develops analytical methods and applies them to understand and design new materials that are technologically useful for industry.
“The possibilities for adapting and using silica are enormous – and despite science long being aware of it, many things about silica are still poorly understood,” he says.
The American Brad Chmelka became interested in silica during his studies and his interest has lasted over his entire career.
“Silica is everywhere. It’s one of the most abundant elements in the earth, and therefore encapsulates many advantages that are central to the goals of sustainability. It has very diverse chemistry and is versatile in applications – and it’s also inexpensive,” he says.
Since the mid-1990s, Brad Chmelka has had scientific contacts in Sweden and they have grown in number and deepened over time. He collaborates with the Chalmers University of Technology in Gothenburg, Stockholm University, and other academic institutions in Sweden. In 2015, he was elected to the Royal Swedish Academy of Sciences (KVA) and in 2017 to the Royal Swedish Academy of Engineering Sciences (IVA).
Through Chalmers, Brad came into contact with Nouryon (then named AkzoNobel Specialty Chemicals), and he has been on the company’s scientific advisory board for several years.
“My connection to Sweden has deepened, but I have also been working in Germany, France, Israel and Switzerland and I am involved in many different collaborative scientific efforts,” he points out.
With his close contacts at both Chalmers and Nouryon, Brad Chmelka has been a much appreciated lecturer at four out of five Frontiers of Silica Research conferences. This year, he spoke about “Understanding surface hydration and dissolution of silica and silicates at the nanoscale”.
“My coworkers and I in the Department of Chemical Engineering at UC Santa Barbara have developed and applied state-of-the-art methods of nuclear magnetic resonance, NMR, spectroscopy that make it possible to understand materials at an atomic level. This opens innovative opportunities to understand and design new materials with novel properties,” he says.
Nouryon recently began its first research project together with Brad Chmelka to benefit from his unique characterization methods and his expertise. The aim is for Nouryon to gain a tool to better understand how the silica is affected when it is modified. In extension, it will provide possibilities to be able to even more accurately customize silica for diverse applications.
Text: Monica Rossing
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