Two Acid sites PEG thermoregulated ionic liquid was prepared and used as the catalyst for the esterification of aromatic acid and alcohol.The yield of esterification catalyzed by ionic liquid was 99% in 1 h at 80 ℃ w...Two Acid sites PEG thermoregulated ionic liquid was prepared and used as the catalyst for the esterification of aromatic acid and alcohol.The yield of esterification catalyzed by ionic liquid was 99% in 1 h at 80 ℃ with 0.1%(molar fraction)acidic PEG ionic liquid.The catalyst system could be applied to a wide range of esterification of aromatic acids and alcohols.The ionic liquid has the advantages of both homogeneous and heterogeneous phase at different temperature with a high product yield and the ease of product as well as catalyst separation.The ionic liquid studied plays the role of catalyst and is recycled up to seven times without any significant loss of activity.Morover,by simple phase separation the ionic liquid phase could be re-utilized up to seven times without leaching.展开更多
Microspheres containing an antimetabolite drug 5-Fluorouracil were prepared from (poly(lactic) acide)(PLA) or poly(lactic acid)-polyethylene glycol(PLA-PEG) as the carrier by using a water-in-oil-in-water emulsion sol...Microspheres containing an antimetabolite drug 5-Fluorouracil were prepared from (poly(lactic) acide)(PLA) or poly(lactic acid)-polyethylene glycol(PLA-PEG) as the carrier by using a water-in-oil-in-water emulsion solvent evaporation technique. The conditions of the microspheres preparation such as polymer concentration in organic solvent, relative molecular weight of PLA-PEG and PLA/PEG mass ratio were discussed. The surface morphology and the size of the microspheres were observed by SEM. The drug content of microspheres was examined by TGA and the drug release in vitro was evaluated. According to the results, the drug content increased with the nano-silica used. The highest drug content in this study was 39.9%. The drug-release kinetics satisfied the requirements of controlled drug-release.展开更多
文摘Two Acid sites PEG thermoregulated ionic liquid was prepared and used as the catalyst for the esterification of aromatic acid and alcohol.The yield of esterification catalyzed by ionic liquid was 99% in 1 h at 80 ℃ with 0.1%(molar fraction)acidic PEG ionic liquid.The catalyst system could be applied to a wide range of esterification of aromatic acids and alcohols.The ionic liquid has the advantages of both homogeneous and heterogeneous phase at different temperature with a high product yield and the ease of product as well as catalyst separation.The ionic liquid studied plays the role of catalyst and is recycled up to seven times without any significant loss of activity.Morover,by simple phase separation the ionic liquid phase could be re-utilized up to seven times without leaching.
文摘Microspheres containing an antimetabolite drug 5-Fluorouracil were prepared from (poly(lactic) acide)(PLA) or poly(lactic acid)-polyethylene glycol(PLA-PEG) as the carrier by using a water-in-oil-in-water emulsion solvent evaporation technique. The conditions of the microspheres preparation such as polymer concentration in organic solvent, relative molecular weight of PLA-PEG and PLA/PEG mass ratio were discussed. The surface morphology and the size of the microspheres were observed by SEM. The drug content of microspheres was examined by TGA and the drug release in vitro was evaluated. According to the results, the drug content increased with the nano-silica used. The highest drug content in this study was 39.9%. The drug-release kinetics satisfied the requirements of controlled drug-release.
