Monovalent Salt Induced Liquid-Liquid Phase Separation of Polyguanidinium
발표자
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초록
내용
Liquid-liquid phase separation (LLPS) of polyelectrolyte (PE) solution, called coacervation, is induced by non-covalent intermolecular association. Especially, simple coacervation is LLPS of a single PE solution induced by adding salts that reduces Columbic repulsion. Herein, we demonstrate that LLPS of positively charged polyguanidinium solution by addition of monovalent salt. Guanidinium-functionalized poly(allyl glycidyl ether) (G-PAGE) was synthesized by anionic ring-opening polymerization and post-modification, producing ideal polymer system to investigate LLPS in aqueous media. The LLPS shows upper critical solution temperature (UCST) behavior, and the phase transition temperature is modulated by salt concentration. Also, molecular dynamics (MD) simulation, infrared (IR) spectroscopy and surface forces apparatus (SFA) results confirm that the strong π-π interaction between guanidinium moieties plays a critical role to induce the LLPS without oppositely charged PE.