Collaborative Research: Investigation of Biopolymer-Mineral Surface Interaction Mechanisms

About This Grant

This project aims to support the development of an environmentally responsible infrastructure improvement solution by reducing the environmental impact of synthetic polymers commonly used in geotechnical construction and mining industries. The research team will investigate the use of biopolymers as alternatives for soil modification and treatment of mine waste. 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 viscosity. These same properties make biopolymers a promising material for a wide range of geotechnical engineering and mining applications. Biopolymers can help reduce soil erosion, improve soil strength, and enhance sedimentation without the environmental risks associated with widely used synthetic polymers. To fully understand and unlock the potential of biopolymers for use in geotechnical and mining applications, the research team will combine laboratory experiments with advanced computer simulations. The team will investigate how various biopolymers interact with different soil (mineral) types under a wide range of realistic environmental conditions, including changes in pH and salt concentration. These interactions will be analyzed at multiple scales, from individual molecules to bench scale tests designed to model typical field conditions. The findings will guide engineers in selecting the most effective biopolymers for specific geotechnical and mining applications, such as stabilizing loose soil or enhancing dewatering of mining slurry waste. In addition, the project will provide training opportunities for undergraduate and graduate students and develop hands-on educational modules for classrooms. These efforts aim to inspire and prepare the next generation of scientists and engineers to lead the transition to environmentally responsible materials and practices. By deepening our understanding of how biopolymers work at the molecular level, this research has the potential to drive science-based innovations across construction, mining, and beyond. This project integrates laboratory experiments and molecular dynamics simulations to identify and predict dominant biopolymer-mineral surface interaction mechanisms for typical soils and environmental conditions. Biopolymers—naturally derived polymers such as xanthan gum, guar gum, and chitosan—are increasingly being explored as alternatives to synthetic polymers like polyacrylamide for soil improvement in geotechnical and mining applications. Despite promising results in erosion control, flocculation, and soil stabilization, the use of biopolymers remains limited in the field due to a lack of understanding of how they interact with soil minerals at the molecular scale. This research focuses on understanding interactions between charged and neutral mineral surfaces and biopolymers with varying molecular weights and charge types under diverse environmental conditions (pH and ionic strength of salt). At the nanoscale, coarse-grained molecular dynamics simulations will be used to characterize polymer conformations and quantify interaction energies with mineral surfaces. Experimental techniques, such as Fourier Transform Infrared spectroscopy (FTIR), zeta potential, dynamic light scattering, and atomic force microscopy, will validate simulation results and quantify biopolymer adsorption mechanisms, including hydrogen bonding, electrostatic attraction, and polymer bridging. The interaction mechanisms of biopolymers with mineral surfaces will be compared to those of polyacrylamide, a widely used synthetic polymer. At the bench scale, sedimentation, rheological, and flowability tests will be performed on biopolymer-amended kaolinite to evaluate how nanoscale interactions influence macroscale soil behavior. The project will generate predictive models that correlate polymer structure and environmental conditions with soil performance. Project outcomes will provide a framework for optimizing biopolymer selection, thereby enabling environmentally friendly soil treatment techniques and reducing reliance on synthetic polymers, which pose environmental risks. Findings will inform engineering design in geotechnical engineering, mining, and waste management and contribute to a molecular-level framework for environmentally responsible technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.