Micellization of Diblock Copolymers in Polymeric Solvents
Micellization of Diblock Copolymers in Polymeric Solvents
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DOI：
10.1021/acs.macromol.3c00283
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发表时间：
2023-08
期刊：
影响因子：
5.5
通讯作者：
Yapeng Diao;Yuci Xu
中科院分区：
文献类型：
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作者：
Yapeng Diao;Yuci Xu
我们通过稀溶液热力学研究了长度为N1的A-B二嵌段共聚物的胶束化与长度为N的聚合物溶剂中不溶性嵌段fB的体积分数。对于短链溶剂，胶束是“湿的”，临界胶束条件由转变时的最佳聚集数mc.m.*∼N1/2p3/2（p=b2/v02/3为刚度参数）给出，与扩展的Lifshitz理论一致。然而，“干”胶束的胶束化点位于长链溶剂内。理论分析表明，胶束化点是表观尺度变量xm==N/fBN1的通用函数。有趣的是，结合 mc.m.* 的标度行为，(χN)c.m. 表现出具有内在标度变量 x≡ (pN)3/2/m*fBN1 的通用标度行为，该变量具有明确的物理意义，即聚合物溶剂的渗透体积与胶束核的物理体积之间的比率。此外，经过适当的无量纲化后，胶束密度分布和胶束化点处的界面厚度也显示出与 xmandx 的通用行为。重要的是，具有数条至数千条链的胶束在药物和基因递送诊断、纳米反应器和微胶囊中显示出巨大的应用潜力。
We study micellization forA–Bdiblock copolymers of lengthN1with the volume fraction of the insoluble blockfBinApolymeric solvents of lengthNby dilute solution thermodynamics. For short-chain solvents, the micelle is “wet”, and the critical micelle condition is given bywith the optimal aggregation number at the transitionmc.m.*∼N1/2p3/2(p=b2/v02/3is the stiffness parameter), in agreement with the extended Lifshitz theory. However, the micellization point for the “dry” micelle iswithin the long-chain solvents. A theoretical analysis shows that the micellization point is a universal function of the apparent scaling variablexm≡N/fBN1. Interestingly, on combining the scaling behavior ofmc.m.*, (χN)c.m.shows a universal scaling behavior with an intrinsic scaling variablex≡ (pN)3/2/m*fBN1, which has a clear physical meaning as the ratio between the pervaded volume of the polymeric solvent and the physical volume of the micellar core. In addition, after proper nondimensionalizing, the micelle density profile and the interfacial thickness at the micellization point also show universal behaviors with bothxmandx. Importantly, micelles with several to thousands of chains show great potential for application in drug and gene delivery diagnostics, nanoreactors, and microcapsules.