Single-ion nano-features formed by a Li-containing block copolymer synthesized via PISA

Abstract

Single-ion block copolymer nanoparticles of (poly(ethylene glycol) monomethyl ether monomethacrylate-co-poly(3-((trifluoromethane)sulfonamidosulfonyl) propyl methacrylate))-b-polystyrene, (PEGMA-co-PLiTFSI)-b-PS, were prepared using an efficient RAFT-controlled aqueous emulsion polymerization protocol. The macro-chain transfer agent (macroCTA) used, which stabilized the nanoparticles, is a lithium-ion based conductor that can be used for the formation of single-ion polymer electrolytes (SIPEs). This SIPE macroCTA was used as the stabilizer for the synthesis of PS under emulsion conditions at 70 °C, achieving near complete conversion. Kinetic studies revealed good control over the synthesis of the block copolymer (confirmed by NMR spectroscopy and GPC) and formation of spherical nanoparticles of different diameters depending on the length of the hydrophobic (PS) block (confirmed by DLS and TEM). The final high molecular weight diblock copolymer with narrow molecular weight distribution was used to prepare nanostructured films via combined solution-casting and solvent vapour annealing (SVA). Nanostructured films were characterised using AFM and GISAXS.