Reconfigurable assembly of charged polymer-modified Janus and non-Janus particles: from half-raspberries to colloidal clusters and chains

摘要: Understanding the dynamic and reversible assembly of colloids particles into complex constructs, inspired by natural phenomena, is fundamental significance for fabrication multi-scale responsive reconfigurable materials. In this work, we investigate pH-triggered structures composed binary mixtures oppositely charged polyacrylic acid (PAA)-modified non-Janus poly(2-dimethylamino)ethyl methacrylate (PDMAEMA)/poly(N-isopropylacrylamide) (PNIPAM)-modified Janus driven electrostatic interactions. Three different target are visible both in dispersions dry state: half-raspberry structures, colloidal clusters chains depending on mass, numerical particle size ratio. All formed well-defined stable a certain pH range. Half-raspberry-like obtained at 6 ratios NJP/PAA-HP 1 : 500 (for 200-PAA-HP), 1 : 44 450-PAA-HP) 1 : 15 650-PAA-HP), respectively, due to interactions between central JP excessive PAA-HP. Colloidal cluster-like generated 4 : 5 4 : 3 450-PAA-HP), 4 : 1 650-PAA-HP). Moreover, smaller “connecting” PAA colloid, larger average length chain. Depending ratio SJP/PAA-HP, some observed can be disassembled demand changing value either close IEP PDMAEMA half-raspberries) or chains) then reassembled new many times. The results open pathway pH-controlled mixture polymeric-modified particles, which allow reuse building blocks.