四乙氧基矽烷/聚碳酸酯電漿披覆膜應用於滲透蒸發分離四氟丙醇水溶液

Plasma deposition of tetraethoxysilane onto polycarbonate membrane for Pervaporation of aqueous tetrafluoropropanol mixture

羅嘉豪(Chia-Hao Lo)

指導教授 ： 賴君義

中原大學/工學院/化學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500617

摘要

隨著資訊膨脹CD-R儲存容量已不敷使用，使得高儲存記憶體之DVD-R產能快速激增，在DVD製程上需要使用四氟丙醇溶劑（TFP）進行染料分散，而目前大陸產製之四氟丙醇，其含水率高（約20~50wt%），不符合DVD製程使用（含水率需小於0.5wt%），加上生產過程中會有大量TFP有機廢氣產生，其經過冷凝回收後含水率約為20wt%，因此若能利用滲透蒸發分離技術進行四氟丙醇之純化及回收，除了可降低生產成本外亦能減少環境污染。
本研究擬以電漿輔助化學氣相沉積法（Plasma enhanced chemical vapor deposition, PECVD）製備二氧化矽/聚碳酸酯（PC）複合膜作為滲透蒸發薄膜，主要是利用二氧化矽所擁有極佳的熱穩定性及耐有機溶劑特性，過程中利用電漿功率及沉積時間之變化，以控制SiOxCyHz沉積層厚度及化學結構組成，藉此可獲得高度自由體積之SiOxCyHz薄膜，以期運用於滲透蒸發分離四氟丙醇水溶液時，能獲得高透過量及高選擇比之分離效能。
實驗結果發現隨著電漿功率及沉積時間的上升，導致基材表面溫度隨之上升，使得離子轟擊（Ion bombardment）及蝕刻效應（Etching）增強，因此沉積速率隨之下降，由XPS及FT-IR圖譜顯示，當電漿功率及沉積時間上升，SiOxCyHz沉積層內C/Si的比例下降而O/Si的比例增加，表示其結構隨之緻密化，膜材性質則由”有機性質”轉變為”無機性質”所主導。從膜厚隨電漿功率的變化，可發現當電漿功率增加時，隨著沉積時間增長膜厚增厚的幅度明顯變小，表示碳-氫物種不易吸附於基材薄膜表面上，使得沉積層結構中碳-氫的含量變少，結構堆疊的更緻密，因此對滲透蒸發效能的提昇，由一開始的”膜厚”影響轉為”結構變化”主導，於滲透蒸發分離80wt%四氟丙醇水溶液應用上，隨著電漿功率及沉積時間的上升，其透過量下降而選擇比上升，當電漿功率50W、沉積時間3小時，薄膜具有最佳之分離效能其為透過量442±83(g/m2hr)、透過水濃度99.4±0.4(%)。研究中證明藉由電漿聚合法所製備SiOxCyHz/PC複合膜，確實能有效提昇滲透蒸發分離四氟丙醇水溶液之效能。

關鍵字

滲透蒸發 ； 二氧化矽 ； 電漿化學氣相沉積 ； 四氟丙醇

並列摘要

The production of highly storage memory, DVD-R, was increases resulted from the insufficient storage capacity of CD-R for the expansion of information. The tetrafluoropropanol（TFP）was necessary to disperse the dyestuff in the fabricated procedure of DVD. While the water content in the China’s made TFP was too high（20~50%）to use for the fabrication of DVD（the water content should be lower than 0.5 wt%）. Moreover, large amount of TFP waste gas can be created in the process of DVD fabrication, which can be condensed and reused. The utilization of pervaporation to purify and reuse the TFP can reduce the production costs and environmental pollution.
In this study, the pervaporation membranes, SiOxCyHz/ polycarbonate（PC） composite membranes, were fabricated by using the plasma enhanced chemical vapor deposition（PECVD）method to deposit the tetraethoxysilane (TEOS) on the surface of PC membrane to investigate the effects of plasma power and deposition time on the deposition layer thickness and chemical structure of SiOxCyHz and hope to obtain highly free volume SiOxCyHz layer with excellent pervaporation performances for the separation of aqueous TFP solution.
The results show that the deposition rate decreases with increasing the RF power and deposition time due to the enhancement of ion bombardment and etching effect results from the increasing temperature of substrate surface. The XPS and FT-IR data reveal that the C/Si ratio of composite membrane decreases while the O/Si ratio increases with increasing the RF power and deposition time and lead the property of membrane can be changed from organic property to inorganic property. It means that the packing density of SiOxCyHz layer increases with decreasing the C/Si ratio. Nevertheless, the change of deposition layer thickness at higher RF power would drop off as increasing the deposition time. It also can be proved that the packing density of SiOxCyHz layer increases with increasing RF power and deposition time. An optimum pervaporation results, permeation rate of 442 g/m2hr and 99.4 wt% water concentration in permeate, was obtained with the SiOxCyHz/PC composite membrane prepared by 50W plasma power and 3 hr deposition time.

並列關鍵字

SiO2 ； pervaporation ； plasma polymerization ； tetrafluoropropanol

參考文獻

7. 張秋萍“微波電漿輔助化學氣相沉積法合成碳奈米管之研究”私立中原大學化學工程學系碩士學位論文 (2003).

3. S. P. Nunes and K.-V. Peinemann (Eds.), “Membrane Technology in the Chemical Industry”, Wiley-VCH, Germany, (2003).

5. N. Inagaki, “Plasma Surface Modification and Plasma Polymerization”, Technomic Publication, (1996).

8. I. Gancarz, G. Poźniak, and M. Bryjak, “Modification of polysulfone membranes 1. CO2 plasma treatment”, Euro. Polym. J., 35 (1999) 1419-1428.

9. I. Gancarz, G. Poźniak, and M. Bryjak, “Modification of polysulfone membranes 3. Effect of nitrogen plasma”, Euro. Polym. J., 36 (2000) 1563-1569.