本研究以電漿輔助化學沉積法 (PECVD)的方式,來製備一濕度感測器。以電極做為基材使用六甲基二矽胺烷(Hexamethyldisilazane,HMDSZ)單體沉積一層有機薄膜,做為接著活化電極表面。此薄膜表面具有疏水性又具活性基與過氧化基的特性,活性基與過氧化基以利後續接枝聚合。利用UV 光誘導接枝聚合不同比例聚乙烯醇(Polyvinyl Alcohol,PVA)與水溶性單體丙烯醯胺 (Acrylamide, AAm),但製備出來後此感測膜的感測特性並不佳,從實驗結果可看的出來。所以在其表面固定電解質溶液(KCl、NaCl),製備較佳的感濕膜。電解質溶液在濕度改變時因吸水解離會提升離子導電,故可以得到高的濕度感應性,由實驗結果可知在相對濕度35~95%阻抗測量變化範圍為4 order。但此相對濕度感測器在一般環境下可長時間放置,但因電解質遇水易解離無良好的抗水洗但其抗水洗還是不佳,所以利用e-PTFE膜之疏水性,將感測原件包覆水洗,可以期待膜具有耐抗水性質。
In this study, the humidity sensors can be improved by plasma enhanced chemical vapor deposition (PECVD), in which, organic thin film was deposited on the electrode activated surface. Base on this process, polymer is anchored at the interface and free radicals were provided. Then grafting polymerization of anion monomer such as Acrylamide, was carried out by UV-light. It is accepted that the conductivity of the sensor can be improved due to the dissolution of the water molecules. In this study, grafted copolymeric membranes of poly(vinyl alcohol) with acrylamide (PVA-g-AAm) were developed and used in the pervaporation separation of water–dimethylformamide mixtures by varying the amount of water in the feed from 0 to5%. and then seus the immobilized electrolyte solution (Nacl、Kcl) on the comb-shape type electrode followed by UV-graft polymerization was performed to make water-resistive and the sensitive humidity sensor. As a result of, the input treat for HMDSZ-plasma and then grafting polymerization by PVA-g-AAm UV-light and addition different electrolyte solution. Between 35 and 95%RH, the impedance not only has linear response with %RH, but also high sensitivity(impedance from 108 to 104).