氧化還原技術製備薄膜應用於滲透蒸發分離乙醇水混合液之研究

Preparation Thin Film Composite Membranes via Oxidation-Reduction Method and Their Applications for Dehydration for Ethanol/Water Mixtures

本研究之目的探討氧化還原技術製備具有聚砒硌薄層之聚嗍碸非對稱薄膜並應用於滲透蒸發分離乙醇水混合液，研究中利用鐵離子起始砒硌單體於溼式相轉換形成聚嗍碸非對稱薄膜時形成聚砒硌緻密皮層，研究探討單體濃度等因素對於研究條件下所製備聚砒硌薄層聚嗍碸薄膜滲透蒸發分離性能之影響，研究中進一步對聚砒硌薄層之親疏水特性進行探討，利用離子化技術促進水分子於皮層之親和力，並比較離子化效應對於滲透蒸發分離乙醇／水混合液分離性能之影響，研究中發現當膜進行離子化對水分子吸附能力顯著提升，使聚砒硌薄層聚嗍碸薄膜更加親水而導致分離性能提升。結果亦顯示最佳條件下所製備之非對稱性薄膜，其影響非對稱薄膜滲透蒸發之因素在於濕式成膜過程中鑄膜溶液產生薄層剝離，導致緻密層缺陷，無法有效阻隔乙醇水溶液，因而不能更進一步有效提升滲透蒸發分離性能。

The purpose of this study is to prepare polypyrrole thin film composite membranes for dehydration of water/ethanol mixtures by pervaporation. The ferrate ion was used as the initiator of polymerization of polypyrrole during the phase inversion process of polysulfone membrane. The dense skin layer on the supported polysulfone membrane was form by suitable reaction conditions. The effect of monomer concentration on the skin layer formation was investigated and applied for dehydration of ethanol/water mixtures by pervaporation. The hydrophilicity of the composite membrane is one of the important factors to dominate the separation performance of pervaporation membranes. The ionization of polypyrrole was processed to obtain a hydrophilic surface of composite membranes. It was found that the enhancement in hydrophilic properties of composite membrane was improved by ionization via hydrochloride solution. The separation performance was improved with improving the hydrophilicity of composite membranes. The over dosage of monomer in polymerization caused defects of the thin film on the supported membranes and then declined the separation performance of composite membranes.