Cornelia Rosu
Georgia Tech

Soft Responsive Materials Enabled by Polypeptides

Location: EB1 Room 1011

Friday, February 24th 2017 - 11:00 am

Possessing precise amino acid sequences and regular domain structure, polypeptides are feasible and sustainable sources for soft responsive materials with tunable properties. This talk will present insights into polypeptide composite particles (PCPs) as disease-inspired materials (DIMs), PCP-based complex fluids and polypeptide-assisted semiconducting networks.

One effective way to deliver polypeptides is to couple them to a core particle. The hybrid materials, PCPs, resemble the structure of natural viral assemblies that have a variety of shapes but their formation mechanisms and functions are not well understood. The ability of PCPs to undergo unique helix-to-coil transitions in response to external stimuli will be discussed as an appealing mimicry of viruses' conformational changes.

Due to their chiral nature, polypeptide mesogens self-assemble and form cholesteric liquid crystals. When mixed with particles, their self-assembly property becomes a versatile tool to create ordered structures of soft and bioinspired colloidal crystals. For example, anisotropically shaped PCPs immersed in a shell-matching liquid crystal matrix self-organized into remarkably stable structures with hexagonal packing. The intrinsic properties of these complex fluids make them suitable for use in devices that require control of light.

The elegant polypeptide self-assembly power to organize other entities such as semiconducting polymers, can be harnessed for the production of superior electroactive materials. Confinement of ?-conjugated polymers into a gel network formed by polypeptides in toluene led to thermoreversible and light responsive hybrid materials. The most interesting characteristic demonstrated by these gels is the ability to reversibly switch on and off their photophysical properties. Consequently, they may provide a foundation for the development of sensors for biomedical applications, wearable/implantable electronic devices and detectors to evaluate the quality of packaged foods.

Bio:
Cornelia Rosu is currently a postdoctoral fellow in the School of Chemical and Biomolecular Engineering at Georgia Institute of Technology, with prior positions in the School of Materials Science and Engineering (Georgia Institute of Technology) and in the Department of Chemistry (Louisiana State University). She received her BS degree in chemistry and physics from Al. I. Cuza University of Iasi, Romania. Right after college she worked as a chemistry and physics teacher for a few years. Then she moved to Baton Rouge (LA, USA) where she earned her MS and PhD degrees in chemistry from Louisiana State University. She was awarded the Excellence in Polymer Research Award (ACS POLY Division, 2013) and Dow Chemical Excellence Award (Department of Chemistry, LSU, 2011). She and her team participated in the final of the national science competition "150 Years of BASF" organized by BASF in 2015 with the theme: "Lightweight Solutions for a Sustainable Future". Her research interests encompass polymers and complex fluids with a focus on designing soft materials with tunable properties as well as engineering bioderived electroactive materials for use in implantable/wearable devices or sensors for detecting the quality of packaged foods. She is a member of the American Chemical Society and American Polypeptide Society.

North Carolina State University