Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the pres...Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads＇ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy （SEM） and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also results in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1：2, DVB content is at the range of 40%-60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydroquinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.展开更多
Two kinds of St/DVB copolymer beeds containing (1 - pyrenyl) formyl and(1 -pyrenyl) methyl groups respectively have been synthesized by both functionalization and copolymerization. The fluorescence spectra of the swo...Two kinds of St/DVB copolymer beeds containing (1 - pyrenyl) formyl and(1 -pyrenyl) methyl groups respectively have been synthesized by both functionalization and copolymerization. The fluorescence spectra of the swollen polymers synthesized are similar in shape to those of the corresponding model compounds, whilethe intensity ratio of excimer to monomer shows clear dependence on the contents ofthe pyrene groups.展开更多
基金Natural Science Foundation of Guangdong Province （No.05006556）.
文摘Functional porous microspheres used for the slow release carrier of actives in cosmetics or pharmaceuticals were prepared by modified suspension polymerization of styrene （ST） with divinylbenzene （DVB） in the presence of toluene, cyclohexanol and heptane as porogenic diluents. The use of ultrasonic dispersion decreases the beads＇ size and improves the uniformity. The effects of the porogen mixture, DVB content and solvent extraction on the surface performance of the synthesized beads were studied. The microspheres were characterized by scanning electron microscopy （SEM） and BET surface area determination. It was found that a great proportion of the non-solvating porogen increases the pore diameter and the specific surface area. High DVB concentration also results in the great specific surface area and porosity. When the ratio of toluene/cyclohexanol is 1：2, DVB content is at the range of 40%-60% and methylene chloride was used as extractant, the beads with good spherical shape and pore size were obtained. The prepared porous microspheres were applied as active carriers and showed satisfactory slow release effect. Over 10h constantly sustained release was observed in vitro releasing test for hydroquinone-loaded microspheres. Great surface area promoted high concentration of released hydroquinone.
文摘Two kinds of St/DVB copolymer beeds containing (1 - pyrenyl) formyl and(1 -pyrenyl) methyl groups respectively have been synthesized by both functionalization and copolymerization. The fluorescence spectra of the swollen polymers synthesized are similar in shape to those of the corresponding model compounds, whilethe intensity ratio of excimer to monomer shows clear dependence on the contents ofthe pyrene groups.
