Effect of free surfaces on the glass transition temperature of thin polymer films
Effect of free surfaces on the glass transition temperature of thin polymer films
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DOI：
10.1103/physrevlett.77.2002
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发表时间：
1996-09-02
影响因子：
8.6
通讯作者：
Dutcher, JR
中科院分区：
文献类型：
--
作者：
Forrest, JA;DalnokiVeress, K;Dutcher, JR
我们首次测量了自立式聚苯乙烯 (PS) 薄膜的玻璃化转变温度 T-g。我们使用布里渊光散射来测量不同厚度的独立薄膜的 T-g。我们发现，当 h 小于或等于 700 埃时，T-g 随薄膜厚度 h 线性降低，对于 h = 290 埃的薄膜，T-g 降低 70 K。这些测量明确地表征了敌人表面对聚合物薄膜 T-g 的影响。将结果与支持的 PS 薄膜的类似结果进行比较 [Keddie 等人，Europhys。莱特。 27, 59 (1994)]，我们发现它们的测量值受到基材的强烈影响。
We report the first measurements of the glass transition temperature T-g for thin freely standing polystyrene (PS) films. We have used Brillouin light scattering to measure T-g for freely standing films of different thicknesses. We find that T-g decreases linearly with film thickness h for h less than or equal to 700 Angstrom, with a reduction of 70 K for a film with h = 290 Angstrom. These measurements characterize unambiguously the effects of the foe surface on T-g of thin polymer films. Results are compared to similar results for supported PS films [Keddie er al., Europhys. Lett. 27, 59 (1994)], and we find that their measured values are influenced strongly by the substrate.