聚合物类型如何影响聚合物溶液中的水蒸发速度?
Masahiko Tanaka1, Susumu Inasawa1,2
1Graduate School of Bio-Application and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-Cho, Koganei, Tokyo, 184-8588, Japan. inasawa@cc.tuat.ac.jp.
Physical chemistry chemical physics : PCCP
|December 5, 2024
概括
聚合物溶液的干燥速度随着聚合物在接口上积累而减缓. 较低的聚合物扩散性,而不是分子量,决定了这种降低的水蒸发率.
科学领域:
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
- 物理化学 物理化学
背景情况:
- 水性聚合物溶液对于薄膜形成至关重要.
- 由于聚合物度在接口处减少了水蒸发的机制尚未完全理解.
- 不同聚合物间的蒸发动力学变化需要进行研究.
研究的目的:
- 为了研究聚合物积累对水蒸发速度的影响.
- 确定不同聚合物如何影响干燥动力学.
- 阐明聚合物特性与干燥行为之间的关系.
主要方法:
- 干燥实验使用单向干燥电池与聚乙烯醇 (PVA),聚乙烯罗立和聚乙烯甘醇溶液.
- 水蒸发速度的量化 (J).
- 在现场测量干燥接口附近的聚合物度概况,使用差异干扰对比显微镜来估计扩散常数 (Ds).
主要成果:
- 在所有研究的聚合物中,在干燥过程中,水蒸发率 (J) 显著降低 (至1/10).
- 逆蒸发率 (J^-1) 与被运送到接口的聚合物量呈现线性关系,其特点是电阻系数 (A).
- 与其他聚合物相比,聚乙醇溶液表现出更高的抗性因子 (A),表明蒸发率下降更明显. 聚合物分子重量与A没有相关,但A与聚合物的扩散常数 (D) 有负相关.
结论:
- 聚合物分子在干燥界面的扩散性和积累是控制聚合物溶液整体干燥动力学的关键因素.
- 电阻系数 (A) 与聚合物的扩散常数 (D) 相反.
- 了解这些关系对于控制电影形成过程至关重要.
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