When engineers use chemicals
to make fire-resistant clothing for firefighters, they often have to make
numerous unsuccessful prototypes before something usable results.
The same goes for scientists making artificial body tissues — they may wind up with substances that are either liquid or rock hard at room temperature before achieving the perfect level of solidity and flexibility for the human body.
However, Marina Guenza, assistant professor of theoretical physical chemistry at the University, has developed a solution to these problems: She uses computer simulations to
predict how untested chemicals will perform outside the lab.
Guenza investigates polymer
liquids. According to Guenza’s Web site, examples of natural polymer liquids are proteins, cellulose, silk, rubber and DNA. When synthetically produced, polymers include fibers, plastics and glasses.
Given the physical structure of a polymer molecule, Guenza uses computer simulations to determine the molecule’s properties.
“We can study and understand very complicated properties that happen on a large scale,” Guenza said.
Understanding the properties of a molecule before using the molecule in engineering lessens the guesswork of making new materials.
“When you want to devise a new polymeric system, you have to go through a trial and error system, unless you have a theory of properties based on input into a simulation,” said chemistry graduate student Edward Sambriski, who collaborated with Guenza on a recent paper.
“Having the models of these things can save a lot of time and money,” Guenza said.
The simulation software Guenza uses is available over the Internet, Sambriski said. Guenza simplifies the process, calculating data for the equivalent of one unit of a chemical chain rather than the whole chain.
“The calculations are basically very reduced,” Sambriski said. However, he added that the reduction does
not interfere with the accuracy of
the calculations.
Guenza’s research has been published in Physical Review Letters and other scientific journals.
“When I submitted my publication, it was accepted without any changes,” she said. “That, for me, is really a lot.”
In the past, some researchers have done numerical calculations after the fact to understand the properties of chemicals they work with. Guenza’s work is unique because she used a theoretical approach to come up with a formula usable with multiple molecules.
“I was able to derive an analytical solution,” Guenza said. “What people have been doing up to now is writing down results from what they had already.”
Another application of Guenza’s research is understanding protein folding in the human body as it relates to treating cancer.
“You want to know how these big molecules fold together inside the human body,” she explained.
Chemistry graduate student Esther Caballero-Manrique, who works with biological polymers
in Guenza’s lab, said their cancer
research actually uses proteins
from bacteria.
“The dynamics are similar, but if we can understand how this works, we can understand research of cancer,” Caballero-Manrique said. “Very, very interesting experimental results are coming out every day, and we need to
understand these big models,” Guenza said.