CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China.
Environ Int. 2019 Jul;128:37-45. doi: 10.1016/j.envint.2019.04.019. Epub 2019 Apr 25.
Oil contamination will seriously affect the health of water environment, so it is necessary to design ideal oil absorbents with large absorption capacity and high selectivity for effectively purify the oil contaminated water. Preparing high performance carbon aerogel for oil absorption has attracted growing attention, but challenges remain. Here we report a facile approach to fabricate mechanical strength enhanced three-dimensional (3D) nanofibrous aerogel principally through supporting agent liquid assisted collection-electrospinning technology, in which the immersion work was applied to measure the immersion capacity of nanofibers according to liquid-solid interfaces theory. Particularly, electrospun polyacrylonitrile (PAN) nanofibers (NFs) were collected directly in graphene oxide (GO) aqueous dispersion, and the continuous fibrous skeleton assembled with two-dimensional (2D) GO sheets to form open porous networks during the electrospinning process, which basically avoided the tedious preparation steps (nanofiber membrane cutting and re-crosslinking) that have been used previously. Due to the open porous networks promising structure stability of the aerogel, the GO sheets content required in the aerogel stacking process was largely reduced, and there was no strict requirement on the pre-freezing temperature and manner in the subsequent freeze-drying process. Furthermore, followed by thermal treating the PAN NFs/GO composite aerogel, fluffy carbon nanofibers/GO aerogels (CNF/GOAs) were obtained, which exhibited ultra-low density (2-3 mg/mL) and great compressibility (80%). After hydrophobic modification of polydimethylsiloxane by vapor deposition, the CNF/GOAs performed high absorption capacity (120-286 wt/wt) toward diverse oils. Owing to the fire-resistance and great elasticity, the CNF/GOAs could be recycled simply by combustion or mechanical squeeze, and still showed great absorption capacity after 10 cycles, which were feasible for large scale application.
油污会严重影响水环境健康，因此有必要设计具有大吸收容量和高选择性的理想吸油剂，以有效地净化含油污水。用于吸油的高性能碳气凝胶的制备引起了越来越多的关注，但仍存在挑战。在这里，我们报告了一种通过支撑剂液体辅助收集-静电纺丝技术制备机械强度增强的三维（3D）纳米纤维气凝胶的简便方法，其中浸渍工作根据固液界面理论用于测量纳米纤维的浸渍容量。特别地，通过将聚丙烯腈（PAN）纳米纤维（NFs）直接收集在氧化石墨烯（GO）水溶液中，并且在静电纺丝过程中，连续的纤维骨架与二维（2D）GO 片组装以形成开放多孔网络，这基本上避免了以前使用的繁琐的制备步骤（纳米纤维膜切割和再交联）。由于气凝胶具有开放多孔网络的结构稳定性，在气凝胶堆叠过程中所需的 GO 片含量大大减少，并且在随后的冷冻干燥过程中对预冷冻温度和方式没有严格的要求。此外，通过对 PAN NFs/GO 复合气凝胶进行热处理，得到蓬松的碳纳米纤维/GO 气凝胶（CNF/GOAs），其表现出超低密度（2-3mg/mL）和高可压缩性（80%）。通过气相沉积对聚二甲基硅氧烷进行疏水处理后，CNF/GOAs 对各种油表现出高吸收能力（120-286wt/wt）。由于防火性和高弹性，CNF/GOAs 可以通过燃烧或机械挤压简单地回收，并且在 10 次循环后仍显示出高的吸收能力，这对于大规模应用是可行的。
