Study on Elementary Reaction for Plasma Polymerization Using in situ Mass Spectroscopy

为了向等离子体聚合物添加高功能，需要将官能团引入等离子体聚合物。在这项研究中，根据等离子体中各种活性中间体的原位质谱和分子轨道计算结果，讨论了聚合物的离子交换能力作为等离子体聚合物的函数。将用于形成聚合物主链和添加官能团的两种单体同时引入反应室中。使用苯氟化物和苯氯化物作为加成官能团的单体。两种化合物的化学结构彼此非常相似。然而，理论分子轨道计算提供了这些起始单体在等离子体中的稳定活性物种的差异。在氟化物的情况下，可以将磺基引入等离子体聚合物中。在氯化物的情况下，磺基可能会受到电子的攻击，形成包括S元素的其他化合物（磺是希望引入磺酸基的，因为它可以通过用碱性溶液水解而容易地变成磺酸基。）使用这些起始单体时的活性物质的原位质谱分析显示，结果与分子轨道计算的预期结果很好地对应。在优化条件下制备的氟化物等离子体聚合物薄膜的离子交换能力为0.99的高阳离子迁移数和10^-4Scm^-1的高离子电导率。等离子体聚合物薄膜非常薄，实际电阻率与商业化的阳离子交换膜(Nafion 117)相当。

The introduction of functional group into plasma polymer is necessary for the addition of a noble function to plasma polymer. In this study, an ion exchange ability of polymer was discussed as the function of plasma polymer from the results of in situ Mass spectroscopy and molecular orbital calculation for various active intermediates in plasma. Both monomers for the formation of polymer backbone and the addition of functional group were introduced into a reaction chamber simultaneously. Benzenefluoride and benzenechloride were used as a monomer for the addition of functional group. The chemical structures of both compounds were very similar each other. However, the theoretical molecular orbital calculation provides the difference in the stable active species of these starting monomers in plasma. In the case of fluoride, sulfone group may be introduced in the plasma polymer. In the case of chloride, sulfone group may be attacked by electron to form other compounds including S element (Sulfone is desirable to the introduction of sulfonic acid group, because it can be easily changed to sulfonic acid group by hydrolysis with alkaline solution.) The in situ mass spectroscopy for the active species when using these starting monomers are used, shows the well corresponding result to the expectation from the molecular orbital calculation. The ion exchange ability of the plasma polymer thin film prepared from fluoride under optimized conditions has a high cationic transference number of 0.99 and a high ionic conductivity of 10^<-4>S cm^<-1>. The plasma polymer thin film was so thin that the practical resistivity was comparable with the commercialized cation exchange membrane (Nafion 117) .