Journal of Colloid and Interface Science, Vol.547, 318-329, 2019
Preparation of photochromic liquid core nanocapsules based on theoretical design
Photochromic materials have attracted considerable attention for their practical applications in optoelectronic devices. In this study, we developed the photochromic liquid core nanocapsules by polymerization of oil-in-water (O/W) nanoemulsion monomer droplets on the basis of Hansen solubility parameters. The thermoresponsive amphiphilic block copolymers (POEGMA(m)-b-PSt(n) and POEGMA(m)-b-PMMA(n)) were synthesized by sequential reversible addition fragmentation chain transfer (RAFT) polymerization of hydrophilic oligo(ethylene glycol) methyl ether methacrylate and hydrophobic styrene or MMA. The O/W nanoemulsion methyl methacrylate (MMA) droplets, dissolving dipropylene glycol methyl-n-propyl ether (DPMNP) and (E)-3-(adamantan-2-ylidene)-4-[1-(2,5-dimethyl-3-furyl) ethylidenejdihydro-2,5fur andione (Aberchrome 670) as a core liquid and a photochromic dye, respectively, were obtained through the phase inversion temperature emulsification technique using POEGMA(m)-b-PSt(n) as a surfactant. As theoretically predicted in terms of the spreading coefficients, the DPMNP solution of Aberchrome 670 was successfully encapsulated by coacervation of the crosslinked PMMA condensed phase. Aberchrome 670 dissolved in a liquid core was found to photoisomerize twice as fast as that dispersed in the solid polymer matrices. (C) 2019 Elsevier Inc. All rights reserved.