玻璃聚合物的表面流动性的直接定量测量
1Department of Physics and Astronomy and Guelph-Waterloo Physics Institute, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Science (New York, N.Y.)
|March 1, 2014
概括
薄聚合物薄膜表现出独特的动态. 在玻璃过渡温度 (Tg) 下,只有表面层流动,这一发现是有效建模的,并且对于纳米石墨等应用至关重要.
科学领域:
- 聚合物物理 聚合物物理
- 材料科学 材料科学 材料科学
- 表面科学是一门学科.
背景情况:
- 与其散装状态相比,薄聚合物薄膜显示出不同的动态行为.
- 了解玻璃过渡温度 (Tg) 附近的聚合物流动性对于材料应用至关重要.
研究的目的:
- 为了研究Tg以上和以下的薄聚合物薄膜的移动性,使用阶段薄膜几何学.
- 为了区分全膜流和表面局部流.
- 开发和验证Tg以下表面移动性的模型.
主要方法:
- 在基板上制造阶段性聚合物薄膜.
- 在各种温度范围内对薄膜动态的实验观测,包括在Tg附近.
- 分析薄膜模型的开发,专注于表面流量.
主要成果:
- 在Tg以上,整个聚合物薄膜表现出流动.
- 在Tg以下,流量仅限于接近表面的区域,由界面能量驱动.
- 分析模型准确地预测了亚Tg流动行为.
- 从全薄膜到表面局部流量的过渡发生在批量Tg附近.
结论:
- 这项研究量化了薄聚合物薄膜中的表面流动性,其限制和基板效应最小.
- 这些发现可以精确控制玻璃类风湿学,有利于纳米石墨和其他先进应用.
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