Biopolymers have shown promising results in erosion control, coagulation, and soil stabilization. Yet very few studies have been performed that take a systematic approach to understanding the interaction between biopolymers and mineral surfaces at the molecular scale.
Angel Palomino, an associate professor in the Department of Civil and Environmental Engineering, is trying to advance the research through a collaborative National Science Foundation grant that investigates biopolymer-mineral surface interaction mechanisms. Biopolymers are natural polymers produced by the cells of living organisms, making them more sustainable and environmentally friendly than synthetic versions.
Palomino is the principal investigator for the interdisciplinary project, which totals $750,000 over three years. She is collaborating with two researchers from Syracuse University—Civil and Environmental Professor Shobha Bhatia and Biomedical and Chemical Engineering Department Chair Shikha Nangia.
Palomino’s group at UT is doing the physical testing for the project while her Syracuse colleagues are doing the molecular-level simulations. They will be testing kaolinite, a soft white clay mineral commonly used in geotechnical applications as well as consumer products such as paper, ceramics, cosmetics, and certain medications.
The group’s goal is to identify how various biopolymers interact with different soil types under varied environmental conditions to optimize and adapt their use for more sustainable solutions for construction and mining.
“There’s very little literature out there that really tries to answer the question of how these molecules actually stick to the mineral surface and is that a reversible or irreversible mechanism. That’s what our study is looking at,” Palomino said. “We are trying to come up with a model that can then later be applied to other minerals and other biopolymers.”
Developing a Framework
Biopolymers like xanthan gum and guar gum have been used in the food and pharmaceutical industries for many years due to their ability to bind small particles together and alter fluid consistency. These same properties make biopolymers a promising material for a wide range of geotechnical engineering and mining applications.
An example of where biopolymers may be impactful is for landfill liners in geotechnical engineering. Many are currently comprised of bentonite mixed with synthetic polymers that are impervious to fluids and swell when mixed with water to help the sealing process. Finding a biopolymer that works in a similar fashion could be more sustainable and environmentally friendly.
“We want to have a good understanding of, does pH of the surrounding fluid matter? Does the ionic concentration matter? If we have a lot of salt in the system, how does that change the interaction, or does it?” Palomino said. “Those are the kinds of questions that come up, because a lot of these biopolymers are sensitive to the surrounding fluid chemistry.”
Palomino is hoping the findings from her group’s research can eventually help guide engineers in selecting the most effective biopolymers for specific geotechnical and mining applications.
“I want to expand our testing to other clay types and make this more broadly applicable,” she said. “It’s more about developing a framework where certain tests will tell you whether a specific biopolymer and clay type are a good match or not.”
Contact
Rhiannon Potkey (rpotkey@utk.edu)