Protic acid-induced LCST rigid-chain polymeric gel with enhanced blue emission via weakened conjugation effect

Abstract Rigid-chain polymeric gels with excellent performance and multi-functions are rarely reported due to the difficulty in balancing solubility and precipitation caused by π-π stacking. Herein, a rigid aromatic polyamide organogel containing benzimidazole moiety was prepared successfully by utilizing protonation effect of protic acid HCl. Due to protonation, coplanarity of stacking structures was destroyed and the dissolution interaction of benzimidazole moiety and solvent was weakened. With increasing temperature, the further decreased solvation capacity led to the formation of interchain hydrogen bonds with a self-assembly process that induced gelation. What’ s more, due to weakened conjugation of protonated PABI, aggregation-induced quenching (ACQ) was suppressed, and this LCST-type organogel showed aggregation-induced emission (AIE) phenomenon with enhanced blue-light emission. This paper provides an ingenious approach via regulating conjugation and solvation for constructing functional rigid-chain polymer gels.