Monodisperse poly（poly（ethyleneglycol） methyl ether acrylate-co-acrylic acid） （poly（PEGMA-co-AA）） microspheres were prepared by distillation-precipitation polymerization with divinylbenzene （DVB） as crosslin...Monodisperse poly（poly（ethyleneglycol） methyl ether acrylate-co-acrylic acid） （poly（PEGMA-co-AA）） microspheres were prepared by distillation-precipitation polymerization with divinylbenzene （DVB） as crosslinker with 2,2＇- azobisisobutyronitrile （AIBN） as initiator in neat acetonitrile without stirring. Under various reaction conditions, four distinct morphologies including the sol, microemulsion, microgels and microspheres were formed during the distillation of the solvent from the reaction system. A 2D morphological map was established as a function of crosslinker concentration and the polar monomer AA concentration, in comonomer feed in the transition between the morphology domains. The effect of the covalent crosslinker DVB on the morphology of the polymer network was investigated in detail at AA fraction of 40 vol%. The ratios of acid to ethylene oxide units presenting in the comonomers dramatically affected the polymer-polymer interaction and hence the morphology of the resultant polymer network. The covalent crosslinking by DVB and the hydrogen bonding crosslinking between two acid units as well as between the acid and ethylene oxide unit played key roles in the formation of monodisperse polymer microspheres.展开更多
The ordered two dimensional arrays of uniform copolymer microspheres had been fabricated on a substrate by the liquid capillary meniscus attraction force method. Thin aluminium film was deposited on the latex monolaye...The ordered two dimensional arrays of uniform copolymer microspheres had been fabricated on a substrate by the liquid capillary meniscus attraction force method. Thin aluminium film was deposited on the latex monolayer through vacuum evaporation. After ultrasonic etching and dissolving of polymer spheres a surface with features remained. Different patterings of net, islands and separate spots can be obtained by controlling the ultrasonic treatment time. The interaction among the metal, microspheres and the substrate as well as its effect on the micropatternings has been discussed.展开更多
The styrene(St) butyl acrylate(BA) copolymer was first prepared as seed emulsion and the final latex of St BA MA was then obtained from it with methyl acrylate(MA). The hollow polymer particles were obtained from poly...The styrene(St) butyl acrylate(BA) copolymer was first prepared as seed emulsion and the final latex of St BA MA was then obtained from it with methyl acrylate(MA). The hollow polymer particles were obtained from poly(St BA MA) in the presence of dodecyl sulfonic sodium through alkaline and acid treatments. In this paper the effects of pH value, temperature and time of acid treatment on the hollow structure of polymer particles were investigated. The results showed that the largest hollow size can be obtained when acid treatment conditions were: pH 2 5, 85 ℃ and 3 hours.展开更多
基金This work was supported in part by the National Science Foundation of China (No. 20504015)the starting project for young teachers from the Ministry of Education, China.
文摘Monodisperse poly（poly（ethyleneglycol） methyl ether acrylate-co-acrylic acid） （poly（PEGMA-co-AA）） microspheres were prepared by distillation-precipitation polymerization with divinylbenzene （DVB） as crosslinker with 2,2＇- azobisisobutyronitrile （AIBN） as initiator in neat acetonitrile without stirring. Under various reaction conditions, four distinct morphologies including the sol, microemulsion, microgels and microspheres were formed during the distillation of the solvent from the reaction system. A 2D morphological map was established as a function of crosslinker concentration and the polar monomer AA concentration, in comonomer feed in the transition between the morphology domains. The effect of the covalent crosslinker DVB on the morphology of the polymer network was investigated in detail at AA fraction of 40 vol%. The ratios of acid to ethylene oxide units presenting in the comonomers dramatically affected the polymer-polymer interaction and hence the morphology of the resultant polymer network. The covalent crosslinking by DVB and the hydrogen bonding crosslinking between two acid units as well as between the acid and ethylene oxide unit played key roles in the formation of monodisperse polymer microspheres.
文摘The ordered two dimensional arrays of uniform copolymer microspheres had been fabricated on a substrate by the liquid capillary meniscus attraction force method. Thin aluminium film was deposited on the latex monolayer through vacuum evaporation. After ultrasonic etching and dissolving of polymer spheres a surface with features remained. Different patterings of net, islands and separate spots can be obtained by controlling the ultrasonic treatment time. The interaction among the metal, microspheres and the substrate as well as its effect on the micropatternings has been discussed.
文摘The styrene(St) butyl acrylate(BA) copolymer was first prepared as seed emulsion and the final latex of St BA MA was then obtained from it with methyl acrylate(MA). The hollow polymer particles were obtained from poly(St BA MA) in the presence of dodecyl sulfonic sodium through alkaline and acid treatments. In this paper the effects of pH value, temperature and time of acid treatment on the hollow structure of polymer particles were investigated. The results showed that the largest hollow size can be obtained when acid treatment conditions were: pH 2 5, 85 ℃ and 3 hours.
