关键词: atomic force microscopy kinetic roughening polymer film growth surface roughness vapor deposition polymerization

来  源:   DOI:10.3390/polym16111535   PDF(Pubmed)

Abstract:
The kinetic roughening of polymer films grown by vapor deposition polymerization was analyzed using the widely accepted classification framework of \"generic scaling ansatz\" given for the structure factor. Over the past two decades, this method has played a pivotal role in classifying diverse forms of dynamic scaling and understanding the mechanisms driving interface roughening. The roughness exponents of the polymer films were consistently determined as α=1.25±0.09, αloc=0.73±0.02, and αs=0.99±0.06. However, the inability to unambiguously assign these roughness exponent values to a specific scaling subclass prompts the proposal of a practical alternative. This report illustrates how all potential dynamic scaling can be consistently identified and classified based on the relationship between two temporal scaling exponents measured in real space: the average local slope and the global slope of the interface. The intrinsic anomalous roughening class is conclusively assigned to polymer film growth characterized by anomalous \"native (background slope-removed) local height fluctuations\". Moreover, the new analysis reveals that interfaces exhibiting anomalous scaling, previously classified as intrinsic anomalous roughening, could potentially belong to the super-rough class, particularly when the spectral roughness exponent αs is equal to 1.
摘要:
使用针对结构因子给出的广泛接受的“通用缩放ansatz”分类框架,分析了通过气相沉积聚合生长的聚合物薄膜的动力学粗糙化。在过去的二十年里,这种方法在分类各种形式的动态缩放和理解驱动界面粗糙化的机制方面发挥了关键作用。聚合物膜的粗糙度指数一致地确定为α=1.25±0.09,αloc=0.73±0.02,和αs=0.99±0.06。然而,无法明确地将这些粗糙度指数值分配给特定的缩放子类,从而提出了一种实用的替代方案。该报告说明了如何基于在实际空间中测量的两个时间缩放指数之间的关系来一致地识别和分类所有潜在的动态缩放:界面的平均局部斜率和全局斜率。固有的异常粗糙化类最终被分配给以异常\“天然(去除背景斜率)局部高度波动\”为特征的聚合物膜生长。此外,新的分析表明,界面表现出异常的缩放,以前被归类为固有异常粗糙,可能属于超级粗糙阶层,特别是当光谱粗糙度指数αs等于1时。
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