Finally, researchers at Cornell University have developed some pretty remarkable innovations in ultrafiltration (UF) membrane technology. Specifically, they’re working to overcome the long-standing challenges of separating molecules of equal size but different chemistry. Join Professor Wiesner and the team on a thrilling expedition into groundbreaking approaches. More specifically, they are trying to improve unique top separation layers that distinguish UF membranes from other membrane types.
Today’s UF membranes mainly use size to differentiate molecules from each other. Yet, this approach breaks down when faced with molecules of equal size but varying chemistry. To address this limitation, Wiesner’s group is diving into the details of the membranes’ surface chemistry. They do this by mixing together up to three different types of block copolymers. This strategic approach allows them to influence the interactions that dictate how different chemical structures will form inside the membrane’s pores.
Wiesner noted, “While in principle this is a really simple idea, in practice, developing this experimentally is really difficult.” This complexity makes groundbreaking their basic research all the more innovative, and there is great potential for large steps forward in UF technology.
What is proving to be the most fruitful inspiration for these smart advancements are biological systems. This is because specific chemistry of the pore wall allows protein channels to selectively separate even between equally sized metal ions. Analogously, Wiesner’s team wants to create UF membranes with diverse chemical surfaces. This has the potential to transform implementations in pharmaceutical manufacturing and other process industries.
In their recent work, published in Nature Communications, it was this third pathway that the scientists found. This strategy allows a tailored design of chemically diverse pore surfaces in UF membranes. As for micelles, this project was led by Lilly Tsaur, Ph.D., an alum of Wiesner’s group. She investigated the effects of neutral and repulsive interactions on their self-assembly in the membrane’s uppermost layer. Fernando A. Escobedo and Luis Nieves-Rosado, Ph.D. performed molecular simulations that served as a complement to her work. Their research showed the basic principles that dictate micelle structure.
“This necessitated the use of highly coarse-grained models and numerous calibrations to capture the time and length scales involved in the experimental process,” Escobedo explained.
The significance of this research reaches far beyond the walls of the classroom. Wiesner’s prior innovations in block copolymer self-assembly led to the establishment of Terapore Technologies. This young company aims to make ultrafilter membranes much cheaper so they can more widely be used in separating out viruses from biopharma. Today, Rachel Dorin, Ph.D., founder of Terapore Technologies, uses Wiesner’s scalable processes as the basis for her company which creates filter membranes.
Wiesner emphasized the potential impact of their work on industry practices, stating, “Companies simply want to change the recipe, the ‘magic dust,’ that goes into the same process they’ve been using for decades in order to give membranes chemically diverse pore surfaces.” He sees this innovation as the catalyst to a big change for operations based out of UF.
In theory, the post-fabrication processes can accomplish this, but for industry to adopt it, the cost would be too much. This new approach has the potential to really change the game for ultrafiltration,” Wiesner said.
Our team is currently exploring UF membranes with more chemically diverse pore surfaces. They are poised to transform the way industries adopt and implement advanced filtration technologies.