Fluorescent-brightener-mediated thiol-ene reactions under visible-light LED: A green and facile synthesis route to hyperbranched polymers and stimuli-sensitive nanoemulsions

Abstract

LED-triggered polymerization is a well-known technique for the production of polymers, which requires less energy consumption and can resolve the issue of solvent pollution. Obtaining stimuli-responsive latexes especially within the nanoscale, however, is quite challenging via this low intensity photopolymerization method. Here, we demonstrate a one-pot synthetic strategy that integrates a visible-light LED-triggered photopolymerization and a thiol-ene click reaction: (i) the bulk form of which allows the facile formation of hyperbranched polymers in an efficient manner, (ii) the emulsion form of which contributes to the construction of a simpler and eco-friendlier preparation platform toward the synthesis of smart nanoparticles with pH-, redox- and UV-responsive properties, wherein the fluorescent brightener-based photoinitiating system is particularly critical for this synthetic approach. In parallel with retaining the robustness of step-growth polymerization, this approach simultaneously brings along two new features: visible light and aqueous reaction conditions, besides, which possesses the superiorities of low-energy, high-performance, photocatalyst-free, VOC-free and easy set-up.