二氧化矽沉積塗層與矽烷偶聯劑改質之薄膜蒸餾技術應用之研究

Surface n-Alkylsilane hydrophobic grafting of SiO2 plasma-induced coating layer on PVDF membrane surface applied in membrane distillation

李珊寧(SHAN-NING LI)

指導教授 ： 游勝傑 ； 王雅玢

中原大學/工學院/環境工程學系/碩士(2024年)

https://doi.org/10.6840/cycu202400516

摘要

本研究主要目的是透過結合電漿和接枝等兩種改質方法，來提高聚偏二氟乙烯 (PVDF)薄膜的疏水性，然後研究應用改質膜於薄膜蒸餾(MD)系統中之性能。PVDF 薄膜以氧電漿進行改質後，再以一種二氧化矽沉積與二種烷基矽烷化學物質進行接枝：四乙氧基矽烷、辛基三氯矽烷和癸基三氯矽烷。研究經由孔徑、孔隙率、水接觸角 (WCA)、掃描電子顯微鏡 (SEM)、衰減式全反射傅立葉轉換紅外光譜儀 (ATR-FTIR) 和原子力顯微鏡 (AFM)、X 射線光電子能譜儀(XPS)對改質膜進行特性分析。本研究評估了接枝劑化學結構中碳鏈長度和二氧化矽沉積塗層對薄膜表面疏水性的影響。研究於空氣間隙式薄膜蒸餾 (AGMD) 系統中分析應用改質薄膜之效果，進料溶液為 7%、10% 和 15% wt 氯化鈉合成廢水，透過脫鹽率和水通量等兩個參數，評估改質薄膜之適用性，在 AGMD 操作期間並持續監測電導度變化，以確保薄膜沒有破裂現象。
經過連續 24 hr 操作結果顯示 10%TEOS、10%Octyl 和 15%Decyl 具有較高的除鹽效率，其去除率皆為 100.00%。此外，5%Octyl 改質薄膜的水流通量為 5.15 kg/m2h，相較於商業 PVDF 薄膜通量高出 31%。20%Octyl 和 25%Decyl 改質薄膜，水通量值則分別為 3.93 和 3.90 kg/m2h，通量接近一般商業薄膜。原因是 20%Octyl 和 25%Decyl 改質薄膜通過高濃度的矽烷接枝反應進行改質，導致這兩種膜會比改質薄膜厚，因此降低通量。三種改質劑製造出的改質薄膜在操作 8 小時內電導度值均低於 0.05 mS/cm，可證明在 AGMD 操作過程中所有改質膜都沒有破裂的情形。

關鍵字

表面改質 ； 射頻電漿 ； 氧電漿 ； 接枝 ； 矽烷偶合劑 ； 二氧化矽沉積塗層 ； 薄膜蒸餾

並列摘要

The main purpose of this study is to improve the hydrophobicity of polyvinyl fluoride (PVDF) membrane by combining two modification methods such as plasma and grafting, and then study the performance of the modified membrane in the membrane distillation (MD) system. After the PVDF membrane is modified with an oxygen plasma, it is grafted with a silicon dioxide deposition and two alkyl silane chemicals: tetraethoxysilane, octyl trichlorosilane and decyl trichlorosilane. The modified membrane was studied by aperture, porosity, water contact angle (WCA), scanning electron microscope (SEM), attenuated all-reflection Fourier conversion infrared spectrometer (ATR-FTIR), atomic force microscope (AFM), and X-ray photoelectron spectrometer (XPS). Sexual analysis. This study evaluates the influence of carbon chain length and silica deposition coating on the hydrophobicity of the membrane surface in the chemical structure of the graft. The effect of application of modified membrane is analyzed in the air gap membrane distillation (AGMD) system. The feeding solution is 7%, 10% and 15% wt sodium chloride synthetic wastewater. Through two parameters such as desalination rate and water flux, the applicability of the modified membrane is evaluated during the AGMD operation period. Continuously monitor the changes in conductivity to ensure that the membrane does not rupture.
After 24 hr continuous operation, the results show that 10% TEOS, 10% Octyl and 15% Decyl have high salt removal efficiency, and their removal rate is 100.00%. In addition, the water flow of 5% Octyl modified film is 5.15 kg/m2h, which is 31% higher than that of commercial PVDF membrane. 20% Octyl and 25% Decyl modified membrane, the water flux values are 3.93 and 3.90 kg/m2h respectively, and the flux is close to that of ordinary commercial membranes. The reason is that 20% Octyl and 25% Decyl modified membrane are modified by high-concentration silane grafting reaction, resulting in these two membranes being thicker than modified films, thus reducing the flux. The conductivity value of the modified membranes produced by the three modifiers is less than 0.05 mS/cm within 8 hours of operation, which can prove that all the modified membranes did not break during AGMD operation.

並列關鍵字

surface modification ； radio frequency plasma ； oxygen plasma ； grafting ； silane coupling agent ； silicon dioxide deposition coating ； membrane distillation

參考文獻

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