Wu Han, Shi Jia, Ning Xin, Long Yun-Ze, Zheng Jie
Industrial Research Institute of Nonwovens & Technical Textiles, College of Textiles & Clothing, Shandong Center for Engineered Nonwovens, Qingdao University, Qingdao 266071, China.
Collaborative Innovation Center for Nanomaterials & Devices, College of Physics, Qingdao University, Qingdao 266071, China.
Polymers (Basel). 2022 Feb 5;14(3):621. doi: 10.3390/polym14030621.
A simple and novel strategy of superhydrophilic-superhydrophobic Janus membrane was provided here to deal with the increasingly serious oil-water separation problem, which has a very bad impact on environmental pollution and resource recycling. The Janus membrane of cPVA-PVDF/PMMA/GO with opposite hydrophilic and hydrophobic properties was prepared by layer-by-layer electrospinning. The structure of the Janus membrane is as follows: firstly, the mixed solution of polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA) and graphene oxide (GO) was electrospun to form a hydrophobic layer, then polyvinyl alcohol (PVA) nanofiber was coated onto the hydrophobic membrane by layer-by-layer electrospinning to form a composite membrane, and finally, the composite membrane was crosslinked to obtain a Janus membrane. The addition of GO can significantly improve the hydrophobicity, mechanical strength and stability of the Janus membrane. In addition, the prepared Janus membrane still maintained good oil-water separation performance and its separation efficiency almost did not decrease after many oil-water separation experiments. The flux in the process of oil-water separation can reach 1909.9 L m h, and the separation efficiency can reach 99.9%. This not only proves the separation effect of the nanocomposite membrane, but also shows its high stability and recyclability. The asymmetric Janus membrane shows good oil-water selectivity, which gives Janus membrane broad application prospects in many fields.
本文提出了一种简单新颖的超亲水-超疏水Janus膜策略，以应对日益严重的油水分离问题，该问题对环境污染和资源回收产生了非常不利的影响。通过逐层静电纺丝制备了具有相反亲水和疏水性质的cPVA-PVDF/PMMA/GO Janus膜。Janus膜的结构如下：首先，将聚偏氟乙烯（PVDF）、聚甲基丙烯酸甲酯（PMMA）和氧化石墨烯（GO）的混合溶液进行静电纺丝形成疏水层，然后通过逐层静电纺丝将聚乙烯醇（PVA）纳米纤维涂覆在疏水膜上形成复合膜，最后，将复合膜交联得到Janus膜。GO的加入可以显著提高Janus膜的疏水性、机械强度和稳定性。此外，制备的Janus膜仍保持良好的油水分离性能，经过多次油水分离实验后其分离效率几乎没有下降。油水分离过程中的通量可达1909.9 L m h，分离效率可达99.9%。这不仅证明了纳米复合膜的分离效果，还显示了其高稳定性和可回收性。不对称Janus膜表现出良好的油水选择性，这使得Janus膜在许多领域具有广阔的应用前景。
