Coacervation between Two Positively Charged Poly(ionic liquid)s.

Complex coacervates are usually formed through electrostatic attraction between oppositely charged polyelectrolytes, with a few exceptions such as coacervates of like‐charge proteins and polyelectrolytes, both in vivo and in vitro. Understanding of the preparation and mechanisms of these coacervates is limited. Here, a positively charged poly(ionic liquid), poly(1‐vinyl‐3‐benzylimidazolium chloride) (PILben), is designed that bears benzene rings in repeating units. Fluidic coacervates are prepared by mixing the PILben aqueous solution with a like‐charge poly(ionic liquid) named poly(dimethyl diallyl ammonium chloride) (PDDA). The effects of polymer concentration, temperature, and ionic strength in the PILben‐PDDA coacervate are studied. Raman spectroscopy and 2D 1H‐13C heteronuclear single quantum coherence (1H‐13C HSQC) characterizations verify that the coacervate formation benefits from the cation‐π interaction between PILben and PDDA. This work provides principles and understandings of designing coacervates derived from like‐charge poly(ionic liquids) with high charge density. [ABSTRACT FROM AUTHOR]