Near-surface crystallization of PET
Near-surface crystallization of PET
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DOI：
10.1016/j.polymer.2012.09.048
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发表时间：
2012-11
期刊：
影响因子：
4.6
通讯作者：
Kei Shinotsuka;V. Bliznyuk;H. Assender
中科院分区：
文献类型：
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作者：
Kei Shinotsuka;V. Bliznyuk;H. Assender
本文研究了不同厚度的聚对苯二甲酸乙二酯薄膜的近表面结晶行为。在铸态下，薄膜是无定形的，具有无特征的形态。绘制了膜厚度（在3 nm-700 nm的范围内）、等温退火温度（环境温度至150 °C）和结晶形态之间的关系。观察到两种不同的形态，这是与表面特定的结晶和散装结晶（产生更粗糙的膜表面）。表面结晶过程与较低玻璃化转变温度的顶表面区域（测量为深度约13 nm）相关联，其中，在表面和本体结晶温度之间的温度下，仅更易流动的表面区域中的材料能够重组以形成晶体。对于所研究的所有厚度的膜都观察到这种现象，因此得出结论，这不是特定的薄膜现象，而是在任何厚度的材料中可能存在的表面特定现象。
The near-surface crystallization behaviour of poly(ethylene terephthalate) films of various thickness, spin-cast from solution onto silicon substrates, has been studied. In the as-cast state, the films are amorphous, with featureless morphology. A relationship is mapped between the film thickness (in the range 3 nm–700 nm), the isothermal annealing temperature (ambient to 150 °C), and the crystalline morphology. Two distinct morphologies are observed which are associated with surface-specific crystallization and bulk crystallization (producing much rougher film surfaces). The surface crystallization process is associated with a top-surface region (measured to be of about 13 nm in depth) of lower glass transition temperature, where, at temperatures between the surface and bulk crystallization temperatures, only the material in the more-mobile surface region is able to reorganize to form crystals. This phenomenon is observed for films of all the thicknesses studied and it is therefore concluded that this is not specifically a thin-film phenomenon, rather a surface-specific phenomenon possible in material of any thickness.