Kinetics of magnetic field-induced orientational ordering in block copolymer/superparamagnetic nanoparticle composites.
Kinetics of magnetic field-induced orientational ordering in block copolymer/superparamagnetic nanoparticle composites.
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DOI：
10.1002/marc.201400373
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发表时间：
2014-12
影响因子：
4.6
通讯作者：
V. Raman;T. Hatton;B. Olsen
中科院分区：
文献类型：
--
作者：
V. Raman;T. Hatton;B. Olsen
结合外势动力学和布朗动力学研究了嵌段共聚物/超顺磁性纳米颗粒复合材料中的取向有序动力学，其中颗粒小于畴间距，优先分离成共聚物的一个嵌段。这种模拟方法考虑了颗粒之间的排斥体积相互作用和偶极相互作用，以量化配向动力学。二维模拟表明，较高的偶极相互作用强度导致更快的对齐的嵌段共聚物，其中的取向动力学服从指数速率定律。观察到的对齐率随偶极相互作用强度的增加而增加，并且取决于嵌段共聚物的初始状态。取向有序的主要机制被认为是单体链段的重新分配，导致桥接和增长的嵌段共聚物域周围的纳米粒子。
The combination of external potential dynamics and Brownian dynamics is introduced to study the kinetics of orientational ordering in block copolymer/superparamagnetic nanoparticle composites where the particles are smaller than the domain spacing and preferentially segregate into one block of the copolymer. This simulation method accounts for both excluded volume interactions and dipolar interactions between particles to quantify alignment kinetics. Two-dimensional simulations reveal that higher dipolar interaction strengths lead to faster alignment of the block copolymer, where the orientation kinetics obeys an exponential rate law. The observed rate of alignment increases with increasing dipolar interaction strength and is dependent on the initial state of the block copolymer. The primary mechanism of orientational ordering is found to be the redistribution of monomer segments leading to bridging and growth of the block copolymer domains around the nanoparticles.