電漿聚合碳氮層-TPX複合膜應用於氧氮分離之研究

Plasma Polymerization of Nitrogen-Containing Monomers on TPX Membranes and Application to Oxygen/Nitrogen Separation

楊順文(Shun-Wen Yang)

指導教授 ： 魏大欽

中原大學/工學院/化學工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200241

摘要

本研究將電漿聚合反應改質TPX膜分為兩主題進行探討，首先比較純乙炔、乙炔/氮氣、乙炔/氨氣、純乙烷及乙烷/氮氣等電漿聚合物特性之差異；再探討電漿功率、腔體壓力、氣體及乙炔流量等操作參數對乙炔/氨氣電漿聚合物之影響。配合GPA、SEM、AFM、FTIR、XPS及OES等分析儀器對電漿沈積層-TPX複合膜性質、電漿沈積層性質及電漿聚合反應時電漿內物種變化情形進行量測，探討電漿物種對電漿沈積層性質之影響，以及電漿沈積層組成對氧氮分離效能之影響。
實驗結果發現以乙炔為主要進料之電漿聚合反應，其沈積速率及聚合物之密度均高於以乙烷為主要進料之電漿聚合反應，對於電漿沈積層-TPX複合膜之氧氮分離效能影響以乙炔電漿效果最佳，但因內應力效應之影響，使得純乙炔電漿聚合膜在厚度大於50 nm時產生微破裂之現象，造成氧氮分離效果急遽下降，當通入氮氣或氨氣時可降低內應力之累積，而延遲膜破裂之現象，氮氣之添加又比氨氣有更好之效果。在改變電漿功率、腔體壓力及乙炔流量等操作參數進行乙炔/氨氣電漿聚合反應中，可知增加電漿功率、腔體壓力及乙炔流量均有助於乙炔/氨氣電漿沈積層-TPX複合膜之氧氮選擇比，由OES電漿診斷發現電漿中所生成之CN物種為電漿聚合物氮官能基之重要來源。
綜合以上兩主題之結果發現影響複合膜之氧氮分離效能之主要原因以氣體分子之擴散速率差異為主，而氮官能基對氧氮分離也有少許幫助，原因應是氮官能基對氮氣分子之排斥力所造成。

關鍵字

氣體分離 ； 表面改質 ； 電漿聚合反應 ； 氧氮選擇比 ； 氧氣透過率

並列摘要

The plasma deposited nitrogen-containing polymers onto commercial poly-4-methyl-1-pentene (TPX) membrane and their application in O2/N2 separations were investigated. The first part of this study is the comparison of plasma-polymerized films from pure C2H2, C2H2/N2, C2H2/NH3, pure C2H6, and C2H6/N2 mixtures under the same operating condition. It was found that O2/N2 separation performance was drastically improved by nitrogen-containing plasma polymer. Highly cross-linked film was deposited from acetylene-based rather than ethane-based plasmas. Thus, the separation of oxygen over nitrogen in the plasma polymer is mainly determined by the diffusion rate difference of both molecules. It was also found that the addition of nitrogen into hydrocarbon plasmas enhanced the deposition rate and reduced the internal stress of plasma-polymerized film.
In the second part of the study, the effects of operating parameters on C2H2/NH3 plasma polymer were investigated. It was found that the O2/N2 selectivity of the plasma polymer increases with plasma power, chamber pressure, and C2H2 flow rate. OES spectrum indicated that stronger emissions of CN (388.3 nm) radicals appeared in higher plasma power, higher chamber pressure, and lower monomer flow rate conditions. It is proposed that CN radical is the main resource of nitrogen-containing bondings in the plasma polymer.

並列關鍵字

selectivity ； modification ； gas separation ； plasma deposition ； permeability

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