Fragmentation of Fiberlike Structures: Sonication Studies of Cylindrical Block Copolymer Micelles and Behavioral Comparisons to Biological Fibrils
Fragmentation of Fiberlike Structures: Sonication Studies of Cylindrical Block Copolymer Micelles and Behavioral Comparisons to Biological Fibrils
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DOI：
10.1021/ja805262v
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发表时间：
2008-11-05
影响因子：
15
通讯作者：
Winnik, Mitchell A.
中科院分区：
文献类型：
--
作者：
Guerin, Gerald;Wang, Hai;Winnik, Mitchell A.
聚（异戊二烯-b-二茂铁基二甲基硅烷）（PI-b-PFS）嵌段共聚物在烷烃溶剂中形成纤维状胶束，这与淀粉样蛋白纤维等生物纤维有很大的相似性。这两个系统都表现出纤维生长的成核自组装机制，并在暴露于超声辐照的剪切力后迅速碎片。通过静态光散射和电子显微镜定量研究了PI-b-PFS圆柱形胶束的超声处理。这两种技术是非常一致的，并表明，超声处理胶束的重量平均长度作为超声处理时间的函数下降。使用不同的断裂模型的胶束的分裂的模拟表明，胶束的碎片化遵循高斯模型和断裂是高度依赖于胶束的长度，相反，DNA和聚合物链的断裂。我们推测，生物纤维，这是相似的长度和刚度的PFS嵌段共聚物胶束，片段由一个类似的机制时，进行超声处理。
In alkane solvents, poly(isoprene-b-ferrocenyldimethylsilane) (PI-b-PFS) block copolymer forms fiberlike micelles, which show intriguing similarities with biological fibers such as amyloid fibers. Both systems exhibit fiber growth by a nucleated self-assembly mechanism and rapidly fragment upon exposure to the shear forces of ultrasonic irradiation. Sonication of PI-b-PFS cylindrical micelles was studied quantitatively by static light scattering and by electron microscopy. Both techniques are in excellent agreement and show that the weight-average length of sonicated micelles decreases as a function of sonication time. Simulation of the cleavage of micelles using different scission models shows that micelle fragmentation follows a Gaussian model and that the scission is highly dependent on micelle length, in contrast to DNA and polymer chain scission. We speculate that biological fibers, which are similar in length and rigidity to PFS block copolymer micelles, fragment by a similar mechanism when subjected to sonication.