Entropy-driven segregation of nanoparticles to cracks in multilayered composite polymer structures
Entropy-driven segregation of nanoparticles to cracks in multilayered composite polymer structures
复制标题
DOI：
10.1038/nmat1582
复制
发表时间：
2006-03-01
期刊：
影响因子：
41.2
通讯作者：
Russell, TP
中科院分区：
文献类型：
--
作者：
Gupta, S;Zhang, QL;Russell, TP
联合收割机将韧性聚合物与脆性薄膜结合在一起的多层复合材料构成了光通信、微电子和生物工程应用的重要部件。然而，裂纹形成是这些材料中的一个关键问题;因此，设计能够响应环境变化并进行自我修复的分层系统对于一系列技术尤为重要。在这里，发现分散在聚合物基质中的纳米颗粒迁移到聚合物和玻璃层之间的界面处产生的裂纹。纳米粒子向裂纹的偏析取决于聚合物和纳米粒子之间的相互作用和熵。特别是，在聚（甲基丙烯酸甲酯）矩阵中的聚（环氧乙烷）覆盖的5.2纳米球形纳米粒子扩散到相邻的氧化硅层中的裂纹，而三正辛基氧化膦覆盖的纳米粒子没有。这些结果指出了一种简单的方法来制造可以自我修复的系统，提高多层系统的耐用性，或形成自动响应材料的基础。
Multilayer composites, which combine ductile polymers with brittle films, constitute vital components for optical communications, microelectronics and bio-engineering applications. However, crack formation is a critical problem in these materials; thus, designing layered systems that can respond to environmental changes and undergo self-healing is particularly important for a range of technologies. Here, nanoparticles dispersed in a polymer matrix were found to migrate to a crack generated at the interface between the polymer and a glassy layer. Segregation of the nanoparticles to the crack depended on both the enthalpic and entropic interactions between the polymer and nanoparticles. In particular, poly( ethylene oxide)- covered 5.2-nm spherical nanoparticles in a poly( methyl methacrylate) matrix diffused to cracks in the adjoining silicon oxide layer, whereas tri-n-octylphosphine oxide-covered nanoparticles did not. These results point to a simple means of fabricating systems that can self-heal, improving the durability of multilayered systems, or form the basis for auto-responsive materials.