钠盐对聚丙二醇与β-环糊精超分子聚集体的组成、结构和降解的影响(英文)

Effect of Sodium Salt on Composition,Structure and Degradation of Supramolecular Assemblies of Polypropylene Glycol with β-Cyclodextrin

本文报道了一系列钠盐在调控聚1,2-丙二醇(PPG)与β-环糊精(β-CD)超分子组装过程中的重要作用。首先,几个从钠盐溶液中沉淀出来的组装体在PPG与β-CD的化学计量比上存在着差异,对于NaCl和Na2CO3得到的是PPG-(β-CD)7,对于NaAsO2得到的是PPG-(β-CD)8,此结果与从水中得到的产物PPG-(β-CD)5以及从锂盐溶液得到的产物PPG-(β-CD)6完全不同;其次,基于3个独立的实验(包括黏度、表面张力、摩尔电导率)所得结果的比较可以部分地解释产物组成上的差别;最后,场发射扫描电子显微镜、热重分析表征结果表明:产物即使具有相同的组成,它们的表面结构和物理性质也相当不同,这说明了盐效应在设计、构建超分子聚集体中的重要性和复杂性。

The present work reveals that there is a significant effect of sodium salt in mediating supramolecular assemblies between 1,2-polypropylene glycol（PPG） and β-cyclodextrin（CD）.First,several molecular aggregates precipitated from different sodium salt solutions exhibit different stoichiometric ratios of PPG to β-CD： PPG-（β-CD）7 for NaCl and Na2CO3 and PPG-（β-CD）8 for NaAsO2,both of which are completely different from PPG-（β-CD）5 for pure water and from PPG-（β-CD）6 for lithium salts.Second,the current results obtained from three independent experiments（viscosity,surface tension and molar conductivity） may partially explain the difference in composition of the aggregates.Third,field emission scanning electron microscopy and thermogravimetric analyses indicate that the supramolecular assemblies prepared,even though with the same composition,have rather different surface features and physical properties.These findings emphasize the importance and complexity of salt effect in designing and constructing supramolecular assemblies.