Calorimetric Glass Transition of Single Polystyrene Ultrathin Films
Calorimetric Glass Transition of Single Polystyrene Ultrathin Films
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DOI：
10.1021/ma3020036
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发表时间：
2013-01
期刊：
影响因子：
5.5
通讯作者：
Siyang Gao;Yung P. Koh;S. Simon
中科院分区：
文献类型：
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作者：
Siyang Gao;Yung P. Koh;S. Simon
使用商业快速扫描芯片量热计测量作为冷却速率和膜厚度的函数的单聚苯乙烯嵌段共聚物膜的量热玻璃化转变（Tg）。薄膜的制备有两种方法：将薄膜旋涂在一层惰性油或油脂上，以及将薄膜直接旋涂在量热芯片的背面。对于油或油脂上的膜，160 nm厚的膜显示出与通过常规DSC测量的本体样品的结果一致的结果。另一方面，在油上的47 nm厚的膜和在油和油脂上的71 nm厚的膜显示出Tg降低，其随着冷却速率的增加而降低; Tg降低的幅度与文献中报道的大多数移动的基底支撑的膜的结果相似。对于直接旋涂到传感器上的膜，对于47和71 nm厚的膜没有观察到Tg降低，但是对于16 nm厚的膜观察到Tg降低。这些结果也在文献报道的支撑膜数据范围内。
The calorimetric glass transition (Tg) is measured for single polystyrene ultrathin films using a commercial rapid-scanning chip calorimeter as a function of cooling rate and film thickness. Films have been prepared in two ways: spin-cast films placed on a layer of inert oil or grease and films directly spin-cast on the back of the calorimetric chip. For the films on oil or on grease, the 160 nm thick films show results consistent with those of a bulk sample measured by conventional DSC. On the other hand, the 47 nm thick film on oil and 71 nm thick films both on oil and on grease show a Tg depression which decreases with increasing cooling rate; the magnitude of the Tg depression is similar to results reported in the literature for the most mobile substrate-supported films. For films directly spin-cast onto the sensor, a Tg depression is not observed for 47 and 71 nm thick films but is observed for a 16 nm thick film. These results are also within the range of the data on supported films in the literatur...