Xiao Li, an assistant professor in the Department of Materials Science and Engineering, is researching a new way to develop and improve material performance and reliability while also decreasing the cost of future Army systems.

Funded with a $59,864 grant from the Army Research Office, an element of the U.S. Army Combat Capabilities Development’s Army Research Laboratory, Li and her team of graduate students will explore ways to understand the fundamental principles of how to controllably push polymer-based materials systems away from equilibrium towards asymmetric nanostructures.

“We want to use interfacial energy, dissipative solvent vapor and directed self-assembly to trigger the asymmetric structure of block copolymers during the phase separation process,” said Li. “By doing so, we’ll be able to control the material’s overall structure, allowing us to manipulate it as needed.”

Triggering the block copolymers – polymers made up of two monomers as blocks of repeating units– to shift from equilibrium to non-equilibrium state will broaden the accessible range of morphologies and tunability of material structures as well as make it possible for researchers to create gradient or asymmetric hierarchies.

“The foundations established here will support the realization of advanced smart materials concepts like reconfigurable optics and electronics, bio-mimetic materials, and other adaptive, multi-functional materials that dynamically respond to their environment,” she said. “The resulting gradient structural polymer film can be utilized to mimic moth eyes or squid eyes for achieving optical functionality, and as a template to sculpt other classes of materials, such as metal or semiconductors, thereby enriching various applications.”

Li joined UNT Engineering in fall 2019. Her research focuses on directed self-assembly of soft materials; structure-property relations in polymers, liquid crystals, and active matter; multi-functional surface coatings; liquid crystal elastomer for sensor and biomedical applications; and nanofabrication and 3D printing of soft materials.