電紡絲與表面改質法製備具疏水性聚二氟乙烯/二氧化矽複合纖維膜及其於二氧化碳捕捉之應用

Electrospinning preparation and hydrophobic modification of composite PVDF/silica nanofiber membranes for membrane contactors used for carbon dioxide capture

王麒森(Chi-Sen Wang)

指導教授 ： 林義峰

中原大學/工學院/化學工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200651

摘要

本研究旨在將具有高孔隙度、高比表面積以及高機械強度的有機無機複合奈米纖維膜製備成薄膜接觸器，並應用於二氧化碳捕捉，文中將探討電紡絲參數影響後的纖維型態以及薄膜表面疏水程度對二氧化碳回收效能之影響。
本研究先以不同的電紡絲參數製備奈米纖維，結果發現在可紡絲範圍中，電壓越大，纖維直徑越細。工作距離越長，纖維直徑則略為減少，但變化不大。最後溶液流量與纖維直徑呈現了一個非線性的關係。由實驗結果得知一參數：20kV、15cm以及1.5ml/hr可使製備出的奈米纖維直徑最細，纖維型態均勻，具有高孔隙度以及高比表面積。
因此，本研究便將纖維膜覆蓋在陶瓷薄膜上並進行二氧化碳捕捉，但純的有機纖維膜疏水性不足，造成吸收通量迅速下降，故在製備過程中加入了TEOS，製備成PVDF/silica的複合奈米纖維膜，並且利用FAS作疏水改質提升其接觸角達到140°，實驗結果證明疏水改質後的複合纖維膜應用在薄膜接觸器中其吸收通量提升且長時間操作下仍具有穩定的通量。
最後，我們將陶瓷基材更換為PVDF商業膜以及二氧化矽氣凝膠，實驗結果證實有機無機複合薄膜不但可以有效提升二氧化碳捕捉效果，也改善了PVDF商業膜無法長時間操作的缺點。

關鍵字

有機無機複合 ； 薄膜接觸器 ； 奈米纖維膜 ； 二氧化碳捕捉

並列摘要

The purpose of this study is the preparation of an organic-inorganic composite nanofiber membranes with high porosity, specific surface area and mechanical strength as a membrane contactor for the capture of carbon dioxide. In this paper, we will explore the carbon dioxide removal efficient with degree of hydrophobic of membrane surface and the morphologies of nanofiber efficient with electrospinning parameter.
First of all, we prepared nanofiber by different electrospinning parameter. The results showed that in a spinning range, the voltage increases, and the diameter become small. The work distance increase, and the fiber diameter slightly decreases. The solution flow rate and the fiber diameter had a nonlinear relation. The results showed that a suitable parameter: 20kV, 15cm and 1.5ml/hr to prepare the thinnest nanofiber, that had uniform morphology, high porosity and high specific surface area.
Therefore, we mantle the fiber over the ceramic membrane and make carbon dioxide capture. Because the pure organic nanofiber membrane have insufficient hydrophobic, the carbon dioxide absorption flux decrease quickly. We added TEOS in the solution to prepare composite PVDF/silica nanofiber membrane and used the fluoroalkylsilanes(FAS) to modify the surface of fiber in order to raise contact angles to 140°, the results showed that the nanofiber membrane after hydrophobic modified used in membrane contactors and the absorption flux enhanced. The fiber membrane has high porosity in order to gas through the membrane and had steady flux after long-time test indicated the fiber has high degree of hydrophobic and it can effectively slow down the liquid into the pores.
Finally, ceramic substrate change for PVDF commercial membrane and silica aerogel, and the results show that the composite nanofiber not only raise carbon dioxide capture effect, but also improve the defect of PVDF commercial membrane can not be a long-time test.

並列關鍵字

organic-inorganic composite ； nanofiber membrane ； carbon dioxide capture ； membrane contactor

參考文獻

張昊崴(2008)，平板式氟碳薄膜親疏水性對二氧化碳回收效能影響之研究，私立中原大學化學工程學系碩士論文

陳建樺(2011)，製備多孔疏水性二氧化矽薄膜及其於二氧化碳捕捉之應用，私立中原大學化學工程學系碩士論文

Aaron D. and C. Tsouris (2005). "Separation of CO2 from Flue Gas: A Review." Separation Science and Technology 40 321-348.

Atchariyawut S., C. Feng, R. Wang, R. Jiraratananon and D.T.Liang (2006). "Effect of membrane structure on mass-transfer in the membrane gas-liquid contacting process using microporous PVDF hollow fibers." Journal of Membrane Science 285: 272-281.

Baker R. W. (2004). "Membrane Technology and ApplicationsS." John Wiley & Sons Ltd.