Efremov Mikhail Yu, Olson Eric A, Zhang Ming, Zhang Zishu, Allen Leslie H
Department of Materials Science and Engineering, Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Phys Rev Lett. 2003 Aug 22;91(8):085703. doi: 10.1103/PhysRevLett.91.085703.
The ultrasensitive differential scanning calorimetry is used to observe the glass transition in thin (1-400 nm) spin-cast films of polystyrene, poly (2-vinyl pyridine) and poly (methyl methacrylate) on a platinum surface. A pronounced glass transition is observed even at a thickness as small as 1-3 nm. Using the high heating (20-200 K/ms) and cooling (1-2 K/ms in glass transition region) rates which are typical for this technique, we do not observe appreciable dependence of the glass transition temperature over the thickness range from hundreds of nanometers down to 3 nm thick films. The evolution of calorimetric data with film thickness is discussed in terms of broadening of transition dynamics and loss of transition contrast.
采用超灵敏差示扫描量热法观察了铂表面上聚苯乙烯、聚（2-乙烯基吡啶）和聚（甲基丙烯酸甲酯）的旋涂膜（厚度为1-400nm）中的玻璃化转变。即使在低至1-3nm的厚度下也观察到明显的玻璃化转变。使用该技术典型的高加热速率（20-200K/ms）和冷却速率（在玻璃化转变区域为1-2K/ms），我们未观察到玻璃化转变温度在从数百纳米到3nm厚的薄膜厚度范围内有明显的依赖性。根据转变动力学的展宽和转变对比度的损失，讨论了量热数据随膜厚度的变化。
