- 學位論文
靜電紡絲法製備超疏水性聚二甲基矽氧烷/聚苯乙烯奈米纖維膜及其於二氧化碳捕捉之應用
Electrospinning Preparation of Superhydrophobic Polydimethylsiloxane/Polystyrene Nanofibrous Membranes for Carbon Dioxide Capture
摘要
在眾多二氧化碳之分離與捕捉技術中，薄膜因規模容易放大、低能源消耗及節省空間等優點，故於氣體分離技術上備受矚目。近年來，奈米纖維薄膜因具備高孔隙度、高比表面積等特點，故若將其作為薄膜接觸器(membrane contactor)系統之氣液接觸介面，將可有效提升二氧化碳之吸收通量。在製備奈米纖維薄膜的技術之中，靜電紡絲(electrospinning)是一種製造奈米級纖維薄膜的高分子加工技術，其製程簡單、材料來源多元且所製備出來的靜電紡絲薄膜具備多功能特性，因此，本實驗首先將探討靜電紡絲過程參數包括溶劑組成、高分子溶液濃度、進料流速、噴絲頭與收集板間之工作距離及電場強度對聚苯乙烯(polystyrene, PS)奈米纖維結構造成之影響，而後將所製備之PS奈米纖維薄膜應用於薄膜接觸器系統並進行二氧化碳捕捉之測試。由實驗結果證明，PS奈米纖維薄膜雖具備超疏水(152.1°)特性，然而其仍會於二氧化碳薄膜接觸器系統中發生薄膜潤濕(wetting)之現象。本研究為增加薄膜之耐溶劑性，將於PS溶液中加入一具有疏水性之聚二甲基矽氧烷(polydimethylsiloxane, PDMS)進行混合紡絲。與PS奈米纖維薄膜相比，PDMS/PS奈米纖維薄膜因具備較高之耐溶劑性及疏水性，故其更適合使用於二氧化碳薄膜接觸器系統中。此外，本實驗所製備之PDMS/PS-40wt%奈米纖維薄膜可進行長時間與再生之二氧化碳吸收實驗連續操作，故對於未來氣體分離應用上將具備極大之發展可能性。
並列摘要
Among the various CO2 capture methods, the membrane technology has proven to be highly efficient in capturing CO2 due to the ease at which this technology can be scaled up, its low energy consumptions and small area requirements for use by the gas separation. In recent years, nanofibrous membranes exhibit the unique advantages at the high porosity and high specific surface area. If the nanofibrous membranes as a membrane contactor system's gas-liquid interface, it'll effectively enhance the carbon dioxide absorption flux. Various nanofibrous membranes were successfully prepared by a simple electrospinning process. In this study, we first discuss the electrospinning process parameters, including the solvent composition, polymer solution concentration, feed flow rate, working distance and electric field strength, for the effect of Polystyrene(PS) nanofibrous structures. Then, the as-prepared water-repellent PS porous membranes were used for the CO2 capture application. Due to the PS nanofibrous membranes were wetted by the amine solutions in the CO2 membrane contactor, the hydrophobic Polydimethylsiloxane(PDMS) materials were added into the PS nanofibrous membranes to form the mixed matrix with the improvement of membranes solvent resistance. Compared with the pristine PS nanofibrous membranes, the PDMS/PS nanofibrous membranes exhibit greater solvent resistance and hydrophobic, making them more suitable for use in CO2 capture by the membrane contactor. Furthermore, the PDMS/PS-40wt% nanofibrous membranes can be a long and continuous operation of the CO2 regeneration and absorption experiments. It demonstrates the as-prepared PDMS/PS nanofibrous membranes can be used for continuous long-term CO2 absorption applications (e.g., in membrane contactors for CO2 capture) and may potentially have large-scale applications.