在化学不相似的聚合物矩阵中,聚合物移植纳米粒子的湿湿和分散聚合过渡是不同的
Tyler B Martin1,2, Katrina Irene S Mongcopa3, Rana Ashkar4,5
1Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
Journal of the American Chemical Society
|August 4, 2015
概括
在不同的矩阵中移植的聚合物纳米颗粒显示了从分散到聚合状态的急剧相位过渡. 这种行为与化学相同的复合材料和自由聚合物混合物不同.
科学领域:
- 材料科学
- 聚合物科学
- 纳米技术
背景情况:
- 聚合物矩阵中的聚合物移植纳米粒子 (PGN) 对先进材料至关重要.
- 了解这些复合材料的相位行为是控制形态和属性的关键.
- 植入物和矩阵聚合物之间的温度依赖相互作用影响混合物形态.
研究的目的:
- 在化学上不同的聚合物矩阵中研究PGN的相变行为.
- 为了区分观察到的阶段过渡和湿脱湿过渡.
- 将行为与化学相同的PGN复合材料和自由聚合物混合物进行比较.
主要方法:
- 粗的分子动力学模拟.
- 进行X射线散射实验.
- 使用化聚烯 (dPS) 接种和聚乙烯 (PVME) 基质的中子散射实验.
主要成果:
- 随着温度的增加,人们观察到从分散到聚合形态的急剧相位过渡.
- 这种转变是由混合物成分之间越来越多的排斥性有效相互作用驱动的.
- 观察到的转换不同于连续的湿化-脱水转换,与化学上相同的系统不同.
结论:
- 具有化学特征的聚合物的PGN的相位转换从根本上不同于湿现象.
- 这一发现挑战了长期以来的假设,即这些转换在移植矩阵复合材料中是同义词.
- 这项研究突出了PGN系统中具有特定体相互作用的独特自组合机制.
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