Surface characterization of oil-containing polyterephthalamide microcapsules prepared by interfacial polymerization.
Surface characterization of oil-containing polyterephthalamide microcapsules prepared by interfacial polymerization.
复制标题
界面聚合制备的含油聚对苯二甲酰胺微胶囊的表面表征
DOI：
10.1080/02652040110055243
复制
发表时间：
2001
影响因子：
3.9
通讯作者：
A. Foissy
中科院分区：
文献类型：
--
作者：
S. Alexandridou;C. Kiparissides;F. Mange;A. Foissy
通过油溶性单体（对苯二甲酰二氯，TDC）和两种水溶性单体（二亚乙基三胺，DETA 和 1, 6-己二胺，HMDA）的混合物的界面聚合合成了含油聚对苯二甲酰胺微胶囊。深入研究了几个合成参数（例如两种胺单体的浓度比、搅拌速率、空间稳定剂PVA的浓度）对微胶囊的尺寸分布、膜形态和动电性能的影响。电子显微镜形态分析表明膜的外部形态对水溶性胺单体的功能有很强的依赖性。乳化过程中的高稳定剂浓度和搅拌速率有利于生产具有无孔和刚性膜的较小微胶囊。使用电位测量、电导测量和动电测量相结合的方法研究了微胶囊的电化学界面特性。平均表面电荷密度对 pH 值的依赖性揭示了微胶囊外表面上基本上存在两种化学基团（例如氨基和羧基）。测量表面化学基团的总浓度和等电pH值作为微胶囊合成条件的函数。使用实验数据和适当的界面电离模型，对表面基团密度之比 R = (S - COOH)/(S NH3(+) ) 进行评估，并根据微胶囊合成参数进行合理化。
Oil-containing polyterephthalamide microcapsules were synthesized by the interfacial polymerization of an oil-soluble monomer (terephthaloyl dichloride, TDC) and a mixture of two water-soluble monomers (diethylenetriamine, DETA, and 1, 6-hexamethylenediamine, HMDA). The influence of several synthesis parameters (e.g. concentration ratio of the two amine monomers, stirring rate, concentration of the steric stabilizer PVA) on the size distribution, the membrane morphology and the electrokinetic properties of the microcapsules, was thoroughly investigated. Morphological analysis by electron microscopy showed a strong dependence of the membrane external morphology on the functionality of the water-soluble amine monomer. High stabilizer concentrations and agitation rates during emulsification favoured the production of smaller microcapsules with non-porous and rigid membranes. The electro-chemical interfacial properties of the microcapsules were investigated using a combination of potentiometric, conductimetric and electrokinetic measurements. The dependence of the mean surface charge density on pH revealed the presence of essentially two kinds of chemical groups (e.g. amino and carboxylic groups) on the microcapsule external surface. The total concentration of surface chemical groups and the isoelectric pH were measured as a function of the microcapsule synthesis conditions. Using the experimental data and an appropriate interfacial ionization model, the ratio of the surface groups densities, R = (S - COOH)/(S NH3(+) ), was evaluated and rationalized with respect to the microcapsules synthesis parameters.