Article pubs.acs.org/Macromolecules
pH-Responsive Hairy Particles Synthesized by Dispersion Polymerization with a Macroinitiator as an Inistab and Their Use as a Gas-Sensitive Liquid Marble Stabilizer Syuji Fujii,†,* Kodai Aono,† Motomichi Suzaki,† Sho Hamasaki,† Shin-ichi Yusa,‡ and Yoshinobu Nakamura†,§ †
Department of Applied Chemistry, Faculty of Engineering, Osaka Institute of Technology, 5-16-1 Ohmiya, Asahi-ku, Osaka 535-8585, Japan ‡ Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280, Japan § Nanomaterials Microdevices Research Center, Osaka Institute of Technology, Osaka, Japan S Supporting Information *
ABSTRACT: We studied dispersion polymerization in detail using well-def ined pH-responsive poly[2-(diethylamino)ethyl methacrylate]- (PDEA-) based macroinitiators as an inistab (initiator + stabilizer). Colloidally stable polystyrene (PS) latex particles carrying pH-responsive PDEA hair (PDEA−PS particles) were successfully synthesized in polymerization media with solubility parameters ranging between 22.3 (MPa)1/2 and 26.0 (MPa)1/2. The number-average particle diameters were finely controlled between 90 and 460 nm. The PDEA−PS latex particles were dispersed in acidic aqueous media in which the PDEA hair was protonated and solvated, and were flocculated in basic aqueous media in which the PDEA hair was deprotonated and precipitated. The dried PDEA−PS particles served as an effective gas-responsive stabilizer for liquid marbles. The liquid marbles were stable in H2O vapor for over 18 h, but disintegrated immediately (
