This study performs a novel examination of the gas transport properties in the poly(lactic acid)/montmorillonite (PLA/MMT) interface layer by comparing the permeation parameters of dry gases and those dissolved in water. Furthermore, the relationship between the transport properties of oxygen and carbon dioxide in the gas and water phases and the crystallinity/crystal structure of the PLA/MMT composite films prepared by varying the MMT content in the PLA polymer and cooling conditions was systematically investigated. The results showed that the crystallinity of the PLA/MMT composite film increased with decreasing cooling rates, while the oxygen and carbon dioxide permeabilities increased with increasing MMT content and crystallinity. A small continuous space of size ranging from a few nanometers to a few dozen nanometers wherein the gas molecules easily diffuse around the interface might be formed between the crystalline and amorphous regions, which could not be observed by microscopic analysis. This interfacial space caused an increase in the selective permeation of carbon dioxide, which exhibits higher solubility in water, and the selective elimination of oxygen, which exhibits lower solubility in water.

中文翻译：

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纳米填料诱导的结晶对聚乳酸/蒙脱土复合薄膜阻气性能的影响

这项研究通过比较干燥气体和溶解于水中的气体的渗透参数，对聚乳酸/蒙脱土（PLA / MMT）界面层中的气体传输性质进行了新颖的研究。此外，系统地研究了氧气和二氧化碳在气相和水相中的传输性质与通过改变PLA聚合物中MMT含量和冷却条件而制备的PLA / MMT复合膜的结晶度/晶体结构之间的关系。结果表明，PLA / MMT复合膜的结晶度随冷却速率的降低而增加，而氧气和二氧化碳的渗透率随MMT含量和结晶度的增加而增加。在结晶区域和无定形区域之间可能会形成一个小的连续空间，其大小范围从几纳米到几十纳米，其中气体分子容易在界面周围扩散，这是无法通过显微镜分析观察到的。该界面空间导致二氧化碳的选择性渗透增加，这表现出在水中的较高溶解度，而氧气的选择性消除则表现出在水中的较低溶解度。