Preparation of Thermo–responsive and Cross–linked Fluorinated Nanoparticles via RAFT–mediated Aqueous Polymerization in Nanoreactor

【作者】 Jiachen Ma； Zhiyuan Huo； Congcong Zhai； Luqing Zhang； Bing Geng； 徐安厚； 张书香；

【Author】 Jiachen Ma;Zhiyuan Huo;Congcong Zhai;Luqing Zhang;Bing Geng;Anhou Xu;Shuxiang Zhang;Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, Shandong Engineering Research Center for Fluorinated Material, School of Chemistry and Chemical Engineering, University of Jinan;

【机构】 Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, Shandong Engineering Research Center for Fluorinated Material, School of Chemistry and Chemical Engineering, University of Jinan；

【摘要】 Thermo–responsive and cross–linked fluoropolymer nanoparticles were successfully prepared by RAFT–mediated aqueous polymerization with a thermo–responsive diblock copolymer poly（N–isopropylacrylamide–b– dimethylacrylamide）（PDMA–b–PNIPAM） as a nanoreactor and macro–RAFT agent. ¹H NMR and ¹⁹F NMR spectra showed that diblock P（DMA–b–NIPAM） and cross–linked PTFEMA particles were successfully synthesized. The cross–linked polymer particles proved to be spherical–like structure of about 50 nm in diameter with relatively narrow particle size distribution.Influence of the amount of ammonium persulfate（APS）, molar ratio of monomers with RAFT agent and influence of the amount of cross–linker on aqueous polymerization were investigated. Monomer conversion increased from 44 % to 94 % with increasing the molar ratio of APS and P（DMA–b–NIPAM） from 1: 9 to 1: 3.As the reaction proceeded, the particle size increased from 29 to 49 nm due to the consumption of TFEMA monomer. Thermo–responsive diblock copolymer PDMA–b–PNIPAM was introduced into the surface of the cross-linked microspheres since it acted as a macro-RAFT agent. The size of cross–linked nanoparticles sharply decreased from 50.3 to 40.5 nm over the temperature range 14–44 °C by DLS analysis, suggesting good temperature sensitivity for these nanoparticles.更多还原

【Abstract】 Thermo–responsive and cross–linked fluoropolymer nanoparticles were successfully prepared by RAFT–mediated aqueous polymerization with a thermo–responsive diblock copolymer poly（N–isopropylacrylamide–b– dimethylacrylamide）（PDMA–b–PNIPAM） as a nanoreactor and macro–RAFT agent. ¹H NMR and ¹⁹F NMR spectra showed that diblock P（DMA–b–NIPAM） and cross–linked PTFEMA particles were successfully synthesized. The cross–linked polymer particles proved to be spherical–like structure of about 50 nm in diameter with relatively narrow particle size distribution.Influence of the amount of ammonium persulfate（APS）, molar ratio of monomers with RAFT agent and influence of the amount of cross–linker on aqueous polymerization were investigated. Monomer conversion increased from 44 % to 94 % with increasing the molar ratio of APS and P（DMA–b–NIPAM） from 1: 9 to 1: 3.As the reaction proceeded, the particle size increased from 29 to 49 nm due to the consumption of TFEMA monomer. Thermo–responsive diblock copolymer PDMA–b–PNIPAM was introduced into the surface of the cross-linked microspheres since it acted as a macro-RAFT agent. The size of cross–linked nanoparticles sharply decreased from 50.3 to 40.5 nm over the temperature range 14–44 °C by DLS analysis, suggesting good temperature sensitivity for these nanoparticles.更多还原