---

Presenter: Rayyan Khan

Faculty Sponsor: Sarah L. Perry

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

Session: Poster Session 5, 3:15 PM - 4:00 PM, 165, D3

ABSTRACT

As we focus more on sustainability, there is a search for materials made from natural and biomass sources. Complex coacervation (a liquid-liquid phase separation phenomenon that occurs when oppositely charged polyelectrolytes mix in an aqueous solution) is a uniquely enabling strategy for developing films, coatings, encapsulation strategies, and adhesive from biopolymers. Here, we investigate the effects of pH, charge stoichiometry and viscoelastic behavior complex coacervates of the biopolymer system carboxymethyl cellulose (CMC) and diethylaminoethyl dextran (DEAE-Dex). We quantified the effects of charge stoichiometry (on an ionizable monomer basis) and pH dependance, with changing salt concentration (KBr) using turbidity assays and optical microscopy. We assessed the phase behavior of the coacervate phase using thermogravimetric analysis (TGA) and Viscoelastic behavior was assessed via parallel-plate rheology. Ultimately, these findings demonstrate that adjusting pH and salt concentration provides a quantitative method to precisely tune the physical and viscoelastic properties of biomass derived coacervates.