Minimizing Biofouling of Membrane Polymers

Background

Polymer membranes act as a filter to separate one substance from another.  In the area of biofuels, the precious fuel needs to be separated from the solid feedstock (i.e., corn or switchgrass) and the biological agents (i.e., yeast) which convert the feedstock into the fuels.  The use of membranes is an optimal choice because they can be cheaper and can be selective to the fuels we need.  However, the chemicals within the mixture accumulate biofouling onto the membrane polymer, which leads to inefficient separations and purification. The goal of this project is to use models to determine which polymers are best for bioseparation in a cost-effective manner. While some polymers have shown to be effective, they still do not meet the desired criteria.  Below is an example of two "clean" membranes:

After a number of "filtrations," they begin to look like below:

However, the system on the left performs better because of how it interacts with the biochemicals. 

Project Details

The student on this project will build representative systems to mimic the mixture of biochemicals interacting with the polymeric membrane. An example polymer system can be seen below:

By studying how the biomolecules interact with the polymer and comparing these interactions between polymers, you will be able to identify the ideal characteristics of a new membrane polymer.  For example, the biomolecules may really like alcohol groups, but hate acid groups.  The experimentalists can utilize this knowledge to design new polymers with acid groups to best minimize biofouling. The project will first start by duplicating interactions that have been observed in experiments and extend to newer polymer functionality.

Skills Development

• Work in UNIX environments
• Run molecular dynamics (MD) simulations
• Minor programming
• Property analysis with MD simulations
• Polymer physics
• Biomolecular physics

Research Duties

• Make configurations of systems
• Test and develop model methods against experimental observations
• Systematically alter polymer to identify relationships 
• Build upon relationship knowledge to propose new polymers for separations
• Test hypothesis with regards to effectiveness of new polymer structure in model
• Propose polymer structure to experimentalists to physically test new structure

Impact of Research

By providing the modeling research, the experimentalists can efficiently identify new polymers for their membrane separations.  In addition, by establishing the relationship between polymer structure and the degree of biofouling, we can identify new candidates for the membrane even quicker.  On a broader scale, if the new polymers can prevent biofouling, we will provide the biofuel industry with a more efficient way of purifying the fuels to make ethanol production a more viable and cost-effective process.  As such, this greener process will allow us to avoid the need for oil and natural gas.

Research Team

You will be working with both Dr. Hadley and Dr. Menkhaus.

Dr. Hadley has expertise in modeling smart materials with molecular dynamics. He will serve as the lead on the project.

Dr. Menkhaus has experience in developing polymers for membrane systems.  He will provide experimental insight on the biofouling phenomenon in addition to making and testing new polymeric membranes.

For more details on this project, contact the lead investigator:

kevin.hadley@sdsmt.edu