Complex coacervation core micelles. Colloidal stability and aggregation mechanism
Complex coacervation core micelles. Colloidal stability and aggregation mechanism
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DOI：
10.1021/la035012n
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发表时间：
2004-02-17
期刊：
影响因子：
3.9
通讯作者：
Stuart, MAC
中科院分区：
文献类型：
--
作者：
van der Burgh, S;de Keizer, A;Stuart, MAC
用不同的聚电解质和相反电荷的两嵌段共聚物制备了复合凝聚核胶束。两嵌段共聚物由带电嵌段和水溶性中性嵌段组成。我们的实验技术是动态光散射和滴定相结合。在聚电解质混合物的过量电荷近似为零的混合比下，可以形成胶束。胶束的胶体稳定性取决于两嵌段共聚物的嵌段长度和均聚物的相对分子质量。此外，电晕块的化学性质和聚电解质离子基团的性质也影响着稳定性和聚集机制。比核心块长三倍的电晕块是稳定胶束的先决条件。如果这一比例进一步增加，均聚物的相对分子质量以及离子基团的类型开始发挥主要作用。对于非常不对称的嵌段长度比，不会形成胶束。此外，如果中性段太短，聚合物混合物会形成宏观沉淀。通过中性电晕聚合物胶束的标度模型预测，在核心段不变的情况下，聚集数随着电晕段长度的增加而减少。
Complex coacervation core micelles were prepared with various polyelectrolytes and oppositely charged diblock copolymers. The diblock copolymers consist of a charged block and a water-soluble neutral block. Our experimental technique was dynamic light scattering in combination with titrations. At mixing ratios where the excess charge of the polyelectrolyte mixture is approximately zero, micelles may be formed. The colloidal stability of these micelles depends on the block lengths of the diblock copolymers and the molecular weight of the homopolymers. In addition, the chemical nature of the corona blocks and nature of the ionic groups of the polyelectrolytes also influence the stability and aggregation mechanism. A corona block that is three times longer than the core block is a prerequisite for stable micelles. If this ratio is further increased, the molecular weight of the homopolymers as well as the type of the ionic groups starts to play a major role. With very asymmetric block length ratios, no micelles are formed. In addition, if the neutral block is too short, the polymeric mixture forms a macroscopic precipitate. With a constant core block, the aggregation number decreases with increasing corona block length, as is predicted by scaling models for polymeric micelles with a neutral corona.