L‑Histidine Salt-Bridged Monomer Preassembly and Polymerization-Induced Electrostatic Self-Assembly
Yuanyuan Liu, Xiyu Wang, Caihui Luo, Jie Cai,Yuting Li,Ying Cao, YuanliCai*(蔡远利)
State-Local Joint Engineering Laboratory for Novel Functional Polymer Materials, Suzhou Key Laboratory of Macromolecular Designand Precision Synthesis, Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123
Macromolecules, 2023, 56, 6655−6666
Abstract：Salt bridges are predominant in protein construction and stabilization, yet largely unexplored for polymer nanoparticle synthesis. We herein report the use of l-histidine salt bridges to drive monomer preassembly and two-dimensional electrostatic self-assembly in aqueous photo-RAFT polymerization. l-histidine salt bridges drive the monomer clustering nucleation, complex coacervation, and Coulombic stabilization, leading to the 2 nm ultrasmall clusters and coacervate droplets. Homopolymerization leads to a precision two-dimensional electrostatic self-assembly via a droplet-monolayer-multilayer transition, i.e., salt-bridged homo-polymerization-induced self-assembly (PISA). Block copolymerization does not disturb the “salt-bridged homo-PISA” mechanism. Enhanced Coulombic repulsion via seeded polymerization of charged monomers using as-achieved multilayer lamellae (seeds) yields supercharged 5 nm ultrathin monolayer lamellae with high colloidal stability upon dilution, salting, and long-term storage, urgently needed for bioapplications. This work opens up a new avenue to use amino acid salt bridges for PISA synthesis of biologically important, yet hitherto inaccessible, salt-resistant ultrathin polyelectrolyte complex nanomaterials.
链接：//pubs.acs.org/doi/10.1021/acs.macromol.3c01143
