In Utah winters, smoggy skies are a forgone conclusion, and people muddle through as best as they can by staying inside or wearing protective facemasks. But what if smog wasn’t a problem? What if Utah could be beautiful and healthy all year round?
Professor Milton Lee, from the Department of Chemistry and Biochemistry, and his research group are helping to eliminate smog, one monolithic structure and nanometer sieve at a time.
“That misty cloud has got stuff in there,” Lee said. “The cloud isn’t made up of just one chemical; there are a whole bunch in there. We want to analyze it to see what we are breathing.”
In his two most recent publications (“Thin-film microfabricated nanofluidic arrays for size-selective protein fractionation” and “Highly crosslinked polymeric monoliths with various C6 functional groups for reversed-phase capillary liquid chromatography of small molecules”), Lee and his group have pioneered two new tools to separate gas and liquid mixtures and to detect their constituent parts.
The first separation tool was created by a joint enterprise with Lee’s research group, BYU professor Dr. Aaron Hawkins from the Department of Electrical and Computer Engineering, and BYU Professor Adam T. Woolley from the Chemistry and Biochemistry Department.
“We have fabricated micro-fluidic chips that have nanometer-type dimensions, so it’s like a sieve,” Lee said. “These nano-holes are less than 200 nm in diameter. It’s tiny, tiny; you can’t see that size. When we direct a fluid that contains these articles into these Nano sieves, they basically filter and trap the particles. So the idea is to be able to trap particles like viruses or lipoproteins.”
The second separation tool is formed from monolithic stationary phase structures. These monoliths are akin to sponges placed inside a capillary tube. The porous nature of the monolithic structure allows the solution to filter through and have the different parts of the solution isolated for analysis.
“Usually what people do with columns is take the capillary tube and pack it with small spherical particles,” Lee said. “You fill a tube with those and then you push the liquid or the gas through and it causes a separation of compounds.”
Lee and his group started researching a different filtering structure. The spherical particles were effective, but didn’t work very quickly. Lee and his group started working on a material that would work faster than the previous method, and they ended up with the monolithic structure.
“We just got interested in the monoliths replacing this packing material with a monolith that we can form a lot quicker. By inserting a solution inside the pre-polymer solution inside a capillary and then putting it under UV light, forms this spongy monolith, and so it’s a lot faster of a technique,” Lee said. “So far it has not performed quite as well as the small spheres, but we are getting closer.”
Monolith structures can also be helpful when approaching the dissection of air pollutants, and with this technology, scientists can determine more precisely which harmful chemicals are being produced from fumes and work with industries to refine the production process and eliminate the harmful chemicals.
“Once you know what the chemicals are, you can figure out what is producing them and go to the source,” Lee said. “Engineers can develop methods to make the exhaust better so that the power plant doesn’t produce these compounds that cause pollution. So it’s all linked together. Our research just deals with the beginning of the process: to identify what is there.”