Shen Ying, Li Dawei, Wang Lanlan, Zhou Yuqi, Liu Feng, Wu Huiping, Deng Bingyao, Liu Qingsheng
Key Laboratory of Eco-Textiles (Ministry of Education), Nonwoven Technology Laboratory, Jiangnan University, Wuxi 214122, China.
ACS Appl Mater Interfaces. 2021 May 5;13(17):20489-20500. doi: 10.1021/acsami.1c01136. Epub 2021 Apr 27.
Nanofiber membranes via electrospinning with layered structures are frequently used for oil/water separation, thanks to their unique properties. However, challenges that involve nanofibrous membranes still remain, such as high energy consumption and unfavorable transport properties because of the densely compact structure. In this study, superelastic and robust nanofiber-based aerogels (NFAs) with a three-dimensional (3D) structure as well as tunable porosity were prepared using polyimide (PI) nanofibers via a freeze-drying process followed by the solvent-vapor treatment. The porous NFAs were further modified using trichloromethylsilane (TCMS) to generate silicone nanofilaments (SiNFs) on the surface of the PI nanofibers, which could enhance the hydrophobicity (water contact angle 151.7°) of the NFAs. The corresponding superhydrophobic NFAs exhibited ultralow density (<10.0 mg m), high porosity (>99.0%), and rapid recovery under 80% compression strain. SiNFs-coated NFAs (SiNFs/NFAs) could also collect a wide range of oily solvents with high absorption capacities up to 159 times to their own weight. Moreover, surfactant-stabilized water-in-oil emulsions could also be efficiently separated (up to 100%) under the driving force of gravity, making it a promising energy-efficient technology. Additionally, SiNFs/NFAs maintained high separation efficiency throughout five separation-recovery cycles, indicating the potential of SiNFs/NFAs in the field of oil/water separation, sewage treatment, as well as oily fume purification.
通过静电纺丝制备的具有层状结构的纳米纤维膜因其独特性能而常用于油水分离。然而，涉及纳米纤维膜的挑战仍然存在，例如由于结构致密紧凑而导致的高能耗和不利的传输性能。在本研究中，使用聚酰亚胺（PI）纳米纤维通过冷冻干燥过程并随后进行溶剂蒸汽处理，制备了具有三维（3D）结构以及可调孔隙率的超弹性和坚固的纳米纤维基气凝胶（NFA）。多孔NFA进一步用三氯甲基硅烷（TCMS）改性，以在PI纳米纤维表面生成硅纳米丝（SiNF），这可以提高NFA的疏水性（水接触角151.7°）。相应的超疏水NFA表现出超低密度（<10.0 mg/m）、高孔隙率（>99.0%）以及在80%压缩应变下的快速恢复。涂覆SiNF的NFA（SiNFs/NFAs）还可以收集各种油性溶剂，吸收容量高达自身重量的159倍。此外，在重力驱动下，表面活性剂稳定的油包水乳液也可以有效分离（高达100%），使其成为一种有前景的节能技术。此外，SiNFs/NFAs在五个分离-回收循环中保持了高分离效率，表明SiNFs/NFAs在油水分离、污水处理以及油烟净化领域具有潜力。
