The effect of organic solvents on the coacervation of zwitterionic homopolymers

• Main Author: Loo, Kenny Kah Kin
• Other Authors: Yu Jing
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Coacervation; Zwitterionic homopolymer; Organic solvent; Mixed solvents; PSBMA
• Online Access: https://hdl.handle.net/10356/176276
• Institution: Nanyang Technological University

Zwitterionic polymers are a class of macromolecules that possess moieties with both cationic and anionic groups. Due to their unique molecular structure, they exhibit outstanding antifouling properties and biocompatibilities, enabling them to resist nonspecific protein adsorption in diverse environments. As a result, they hold great potential for specific biological applications. Coacervates, dense polymer-enriched microdroplets resulting from liquid-liquid phase separation (LLPS), have garnered significant interest for their potential applications in encapsulation. However, the formation of simple coacervates using only zwitterionic homopolymers remains largely unexplored. Previous studies have predominantly focused on coacervation involving polyelectrolytes and polyampholytes, investigating various solvent qualities and manipulating different parameters. In this study, we reported on the influence of different organic solvents on coacervate formation in zwitterionic homopolymers, such as PSBMA and PMPC. We observed coacervation of PSBMA occurring within a limited solvent polarity range, while no coacervation was observed for PMPC. Moreover, we demonstrated that two types of coacervates formed with PSBMA in a water-DMSO binary mixture, and we examined their composition and viscoelastic behaviour. We also attempted to construct a phase diagram of the ternary PSBMA system by tuning the polymer concentration and mixed solvent ratio.