Frank CW, Rao V, Despotopoulou MM, Pease RFW, Hinsberg WD, Miller RD, Rabolt JF
C. W. Frank, V. Rao, and M. M. Despotopoulou are in the Department of Chemical Engineering, Stanford University, Stanford, CA 94305-5025, USA. R. F. W. Pease is in the Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA. W. D. Hinsberg, R. D. Miller, and J. F. Rabolt are at the IBM Almaden Research Center, IBM Research Division, 650 Harry Road, San Jose, CA 95120-6099, USA.
Science. 1996 Aug 16;273(5277):912-5. doi: 10.1126/science.273.5277.912.
The molecular organization in ultrathin polymer films (thicknesses less than 1000 angstroms) and thin polymer films (thicknesses between 1000 and 10,000 angstroms) may differ substantially from that of bulk polymers, which can lead to important differences in resulting thermophysical properties. Such constrained geometry films have been fabricated from amorphous poly(3-methyl-4-hydroxy styrene) (PMHS) and semicrystalline poly(di-n-hexyl silane) (PD6S) by means of spin-casting. The residual solvent content is substantially greater in ultrathin PMHS films, which suggests a higher glass transition temperature that results from a stronger hydrogen-bonded network as compared with that in thicker films. Crystallization of PD6S is substantially hindered in ultrathin films, in which a critical thickness of 150 angstroms is needed for crystalline morphology to exist and in which the rate of crystallization is initially slow but increases rapidly as the film approaches 500 angstroms in thickness.
超薄聚合物薄膜（厚度小于1000埃）和薄聚合物薄膜（厚度在1000至10000埃之间）中的分子排列可能与本体聚合物有很大不同，这可能导致所得热物理性质的重要差异。这种具有受限几何形状的薄膜是通过旋涂法由非晶态聚（3 - 甲基 - 4 - 羟基苯乙烯）（PMHS）和半结晶聚（二正己基硅烷）（PD6S）制成的。超薄PMHS薄膜中的残留溶剂含量要高得多，这表明与较厚薄膜相比，由于氢键网络更强，其玻璃化转变温度更高。PD6S在超薄薄膜中的结晶受到显著阻碍，其中存在晶体形态需要150埃的临界厚度，并且在薄膜厚度接近500埃时，其结晶速率最初较慢，但会迅速增加。
