Electrospun nanofiber membrane for membrane adsorption, membrane contactor and fouling mitigation in ultrafiltration

可以合理设计纳米级材料，使其表现出新颖的、显著改善的物理和化学性能。高分子纳米纤维是一类重要的纳米材料，近年来受到越来越多的关注。**特别是，电纺纳米纤维膜（ENMs）已经被证明适用于各种膜工艺的水处理，如MF、UF、NF、MD、FO、PRO、膜吸收和膜空气剥离。该项目旨在进一步扩大enm作为水和气体处理过滤膜的适用范围。enm的水处理现在已经接近商业化。有些公司的目标是将纳米纤维膜用于水处理的商业化（例如，2010年在美国北卡罗来纳州成立的Xanofi）。拟议的项目将通过展示各种新能源能源的应用，为能源能源未来的商业化做出贡献。* *因此,本研究的目的是：*1)制造和测试金属氧化物纳米颗粒结合电纺纳米纤维膜（ENMs）（以下称为混合基质ENMs （MMENMs)），通过膜吸附（MA）去除水中的砷*2）制造和测试ENMs在膜接触器（MC）中的应用，用于从CO2/N2气体混合物中捕获CO2 *3)制造平行排列的ENMs，用于超滤应用中的污染缓解和洗涤增强***近几十年来，天然水中的砷污染因其高毒性、在人体内蓄积和致癌性引起了重大的环境和公共卫生问题。近年来，亲和膜的发展为低压除砷提供了一种有效的方法。由于孔隙度和连通性非常高，因此在MA中使用enm时，预计会有更高的通量。**膜接触器（MC）是一种气体和液体在多孔膜的两侧流动的过程；气体组分通过膜孔从气相扩散到液相，其中气体被液体中的吸收剂吸收。它的应用之一是从天然气和烟道气中去除二氧化碳。膜接触器单位体积的接触面积是传统分离塔的4 ~ 30倍。ENM因其高孔隙率和疏水性而成为MC膜的理想候选材料。**最近在开发金属氧化物掺入聚合物膜的过程中进行了观察；即聚合物结节平行排列，原子力显微镜（AFM）在膜表面观察到非常清晰的图案。*还发现，当进料流方向与图案线垂直时，膜污染可以大大减少，而当进料流方向与图案线平行时，膜洗涤是有效的。纳米纤维在ENM中的平行排列将在膜表面提供一个完美的图案，从而增强上述效果。

Nano-scale materials can be rationally designed to exhibit novel and significantly improved *physical and chemical properties. Polymer nanofibers, an important class of nano-materials, have attracted increasing attention during the past decade.**In particular, electro-spun nanofiber membranes (ENMs) have already been proven to be applicable in a variety of membrane processes for water treatment, such as MF, UF, NF, MD, FO, PRO, membrane absorption and membrane air stripping in the laboratory scale. The proposed project aims to widen the scope of the applicability of ENMs as filtration membrane for water and gas treatment even further. Water treatment by ENMs is now on the verge of commercialization. There are companies who are aiming at the commercialization of nanofiber membranes for water treatment (e.g. Xanofi, founded in 2010 in NC, USA). The proposed project will contribute to the future commercialization of ENMs by demonstrating a variety of novel applications of ENMs.**Thus, the objectives of this research are:*1) To fabricate and test the metal oxide nanoparticles incorporated electro-spun nanofiber membranes (ENMs) (hereafter called Mixed Matrix ENMs (MMENMs)) for the removal of arsenics from water by membrane adsorption (MA)*2) To fabricate and test ENMs in membrane contactor (MC) application for capturing CO2 from CO2/N2 gas mixtures*3) To fabricate ENMs aligned parallel for fouling mitigation and washing enhancement in ultrafiltration applications ***In the last few decades, arsenic contamination in natural water has raised significant environmental and public health concerns because of its high toxicity, accumulation in human body and carcinogenicity. Recently, the development of affinity membrane provided an effective method for arsenic removal under low pressure. In view of very high porosity and interconnectivity, a much higher flux is expected by ENMs when they are used in MA.**Membrane contactor (MC) is a process in which gas and liquid flow on the opposite sides of a porous membrane; a gaseous component diffuses through the membrane pore from the gas to liquid phase where the gas is absorbed by the absorbent in the liquid. One of its applications is CO2 removal from natural and flue gas. Membrane contactor can provide contact area per unit volume 4 to 30 times higher than the conventional separation columns. ENM is an excellent candidate for membranes for MC for its high porosity and hydrophobicity.**An observation was made recently during the development of metal oxide incorporated polymeric membranes; i.e. polymer nodules were aligned parallel, and very clear patterns were observed by the Atomic Force Microscopy (AFM) at the membrane surface.*It was also found that the membrane fouling could be reduced substantially when the feed flow was oriented perpendicular to the patterned lines, while membrane washing was effective when the feed flow was oriented parallel to the patterned lines. Parallel alignment of nanofibers in ENM will provide a perfect pattern at the membrane surface and thus enhance the above effects.