Weixing Xiong,Xiyu Wang,Yuanyuan Liu,Caihui Luo,Xinhua Lu,Yuanli Cai
Polymerization-induced electrostatic self-assembly (PIESA) represents a powerful method for the scalable synthesis of polyion complex (PIC) nanoparticles with various morphologies. Previous PIESA was driven by Coulombic interactions. Yet, biomimetic multivalent interactions, e.g., ionic hydrogen bonds omnipresent in proteins and potentially enabling access to new materials, remain unexplored. Herein, we update PIESA using arginine-like full-spectrum guanidinium ionic hydrogen bonds. Kinetic studies unravel that, at guanidinium-starving n+/n– (0.84), guanidinium interactions evolve from opposite-charge (6–73% conversion) into like-charge ionic hydrogen bonds (84 to >99% conversion), leading to ultrasmall clusters (2–5 nm, at 6–84% conversion) and size-tunable “large compound micelles” (14–25 nm, at 90 to >99% conversion). Longer guanidinium-block length results in the transformation of charge-neutral worms to positive-charge micron-scale large-area monolayer lamellae to multilayer platelets to tubular networks to vesicular aggregates, suggesting that the like-charge ionic hydrogen bonds are strong enough to overwhelm Coulombic repulsive interactions, and thus to revolutionize our PIESA chemistry for the precision synthesis of next-generation nanostructured biomimetic functional materials.
Jie Cai,Xiyu Wang,Yuanyuan Liu,Caihui Luo,Xinhua Lu,Yuanli Cai
We herein report a site-specific polymerization-induced electrostatic self-assembly (PIESA) that enables the precision synthesis of highly charged salt-tolerant nanoreactors. Site-specific PIESA is achieved using an anionic aromatic–aliphatic sulfonate block copolymer in photoinitiated reversible addition-fragmentation chain transfter (photo-RAFT) polymerization of a cationic monomer in water at 25 °C. Preferential complexation of cationic growing chains to the aromatic sulfonate block results in not only site-specific molecular recognition but also unique salt-tolerant PIC nanoparticles. Neutral block incorporation leads to ultrafast reaction of very dilute monomer (2.0% w/w) and exclusive formation of more salt-tolerant smaller spheres or 4 nm fibril-structured 10 nm ultrathin lamellae. The ultrathin lamellae can induce a sequence-controllable ultrafast copolymerization of oppositely-charged dilute monomers with perfect shape/size preservation up to 100% conversions, and thus can be viewed as a nanoreactor. This work opened up an avenue for the precision synthesis of highly charged salt-tolerant PIC functional nanoparticles, providing a versatile platform for easy access to structural and functional complexity from simple mixtures.
Ye Wang,Chao Li,Lei Ma,Xiyu Wang,Kai Wang,Xinhua Lu,Yuanli Cai
Development of spatially restricted liquid–liquid phase separation (LLPS) systems emulating biomolecular condensates is a major challenge in coacervating materials science, due to lack of approaches for spatially restricted coacervation of sequence-defined zwitterionic segments resembling intrinsically disordered proteins. Herein, we present interfacial LLPS-driven polymerization-induced electrostatic self-assembly, namely, interfacial LLPS-PIESA. The asymmetric charge sequence patterning of zwitterionic growing segments is achieved via spontaneous polymerization of ion-pair monomers within a nanoparticle core–shell interface. We show that charge sequence can profoundly affect the self-coacervation, leading to droplet dispersions, dense coacervates, and free-standing hydrogels. Moreover, the interfacial LLPS-PIESA shows a programmed hierarchical condensation self-assembly mechanism involving vesicles-to-lamellae transition, interfacial self-coacervation, lamellae-to-sheets transition, layer-by-layer sheet self-assembly, spatially restricted condensation and agglomeration, and redispersing into fibril network condensates under dynamic evolving surface charge regulation. The spatially restricted asymmetric charge sequence patterning, interfacial self-coacervation, and programmed hierarchical condensation self-assembly, all these elements can serve as the primary principles for the asymmetric charge sequence patterning design of hierarchically nanostructured condensates that emulate cellular biomolecular condensates.