Zhou Lijie, Zhai Shengcheng, Chen Yiming, Xu Zhaoyang
College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
Polymers (Basel). 2019 Apr 18;11(4):712. doi: 10.3390/polym11040712.
Under the current situation of frequent oil spills, the development of green and recyclable high-efficiency oil-absorbing aerogel materials has attracted wide attention from researchers. In this study, we report a high-strength, three-dimensional hydrophobic cellulose nanofiber (CNF)/polyvinyl alcohol (PVA)/graphene oxide (GO) composite aerogel with an anisotropic porous structure, which was fabricated by directional freeze-drying technology using anisotropically grown ice crystals as a template, followed by hydrophobic treatment with a simple dip coating process. The prepared composite aerogel presented anisotropic multi-level pore microstructures, low density (17.95 mg/cm) and high porosity (98.8%), good hydrophobicity (water contact angle of 142°) and great adsorption capacity (oil absorption reaching 96 times its own weight). More importantly, the oriented aerogel had high strength, whose compressive stress at 80% strain reached 0.22 MPa and could bear more than 22,123 times its own weight without deformation. Therefore, the CNF/PVA/GO composite aerogel prepared by a simple and easy-to-operate directional freeze-drying method is a promising absorbent for oil-water separation.
在当前石油泄漏频繁的形势下，绿色可回收高效吸油气凝胶材料的开发引起了研究人员的广泛关注。在本研究中，我们报道了一种具有各向异性多孔结构的高强度三维疏水纤维素纳米纤维（CNF）/聚乙烯醇（PVA）/氧化石墨烯（GO）复合气凝胶，它是以各向异性生长的冰晶为模板，通过定向冷冻干燥技术制备而成，随后采用简单的浸涂工艺进行疏水处理。所制备的复合气凝胶呈现出各向异性的多级孔隙微观结构，低密度（17.95毫克/立方厘米）和高孔隙率（98.8%），良好的疏水性（水接触角为142°）以及巨大的吸附容量（吸油率达到自身重量的96倍）。更重要的是，定向气凝胶具有高强度，其在80%应变下的压缩应力达到0.22兆帕，并且能够承受超过自身重量22123倍的重量而不变形。因此，通过简单易操作的定向冷冻干燥方法制备的CNF/PVA/GO复合气凝胶是一种很有前景的油水分离吸附剂。
