LAUSR

Abstract Polyelectrolyte complexes (PECs) are attractive soft materials with many promising applications, such as drug delivery and coatings. Study on the solution properties of α-helical polypeptide based PECs are still rare. Herein, new PECs composed of α-helical sulfonium-based polypeptides (PPBLG-DMS-I) and polysaccharides (i.e., carboxymethyldextran sodium salt, CMD) were prepared and investigated on their solution property. PPBLG-DMS-I were synthesized by an ultrafast ring-opening polymerization (ROP) and subsequent alkylation of methylthio groups with high grafting efficiency. The aggregation size of the polypeptide-polysaccharide based PECs was in the range of 450–600 nm at room temperature depending on the cationic/anionic weight ratios (RCAs) and polypeptide concentrations. It decreased by about 300 nm with increasing of the temperature by 40 °C. PEC solutions showed salt induced sharp phase transitions accompanied by the formation of coacervate droplets at low salt concentrations (e.g., 1.5 mg·mL−1). pH induced phase transitions of PEC solutions at both acidic (e.g., pH = 2.5) and basic conditions (e.g., pH = 11.5).