Team led by Chemical Engineers Awarded $2 Million to Develop New Separation Membranes Inspired by Biological Cells

For more than 60 years, synthetic separation membranes-manufactured barriers that selectively filter out unwanted substances in industrial, biomedical, desalination, gas separation and other processes-have been made the same way, using the same chemicals. But a team of researchers led by the University of Massachusetts Amherst is looking to change the established paradigm and create new, biological-based membranes that can be made without the use of toxins.

With a $2 million award from the U.S. National Science Foundation, this collaboration with researchers from the University of Illinois Urbana-Champaign, the University at Buffalo and the Air Force Research Lab, takes inspiration from how human cells allow some small molecules to enter through the cell wall while filtering others out.

"The current generation of membranes is an amazing technology, but as emerging contaminants are present in our waste streams, we need new technologies that can separate them out and keep our water safe," says Jessica Schiffman, professor of chemical engineering at UMass Amherst and project co-investigator.

Sarah Perry, UMass Amherst professor of chemical engineering and principal investigator of this Designing Materials to Revolutionize and Engineer our Future (DMREF) project, says the team isn't just looking to tweak the existing chemical process - they want to change the paradigm of how membranes are created, harnessing biology-like selectivity and the chemical versatility of synthetic membranes.

"We are hoping that we could do this entirely from water, just the way that cells do," she says. "It's a really interesting challenge to figure out how to do this, because all these pieces exist, but nobody's put them together. And that's what our team is looking to do."

In a cell, the membrane is made of molecules called lipids together with specialized proteins. "We want to take advantage of the ability of lipids to arrange themselves into different structures on a molecular level. However, just as the membranes of cells require specialized proteins, we want to use carefully designed natural polymers to help stabilize the resulting membranes and tune what can or cannot pass through," says Perry.

One of the big challenges in approaching this kind of molecular-level materials design is the number of possible permutations. "It would be impossible for us to test every single possible lipid molecule and polymer," says Perry. In addition to running experiments in the lab, this project will use computer simulations to test how different molecules interact. "We can then feed both that data and our experimental results into a machine learning algorithm that will help to identify new promising molecules or conditions to test."

Ultimately, the team aims to create a foundational platform that would enable scientists to generate a membrane specifically tuned to filter out the desired material, with a broad range of applications. Within water purification, such membranes could be used for desalination and water treatment of various pollutants.

"There are also tons of applications where we need to separate out different types of molecules when we're trying to make things," Perry adds, such as new therapeutics or antibody treatments where the target compound is made within a cell and needs to be separated out. For many of these processes, membrane separation could be a far more efficient and cost-effective strategy, but the right membrane might not yet exist. "If such membranes did exist, we could save huge amounts of money because the way that they're doing it right now is very energy intensive."