State Key Laboratory of Bio-fibers and Eco-textiles, School of Environmental Science and Engineering, Institute of Marine Biobased Materials, Qingdao University, Qingdao, 266071, China.
Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, China.
Chemosphere. 2023 Sep;336:139179. doi: 10.1016/j.chemosphere.2023.139179. Epub 2023 Jun 15.
Aerogel has excellent application potential in adsorption, heat preservation, and other areas due to its typical advantages of low density and high porosity. However, there are several issues with the use of aerogel in oil/water separation, including weak mechanical qualities and challenges in eliminating organic contaminants at low temperature. Inspired by cellulose Iα, which has excellent performance at low temperature, this study used cellulose Iα nanofibers extracted from seaweed solid waste as the skeleton, through covalent cross-linked with ethylene imine polymer (PEI) and hydrophobic modification of 1, 4-phenyl diisocyanate (MDI), supplemented by freeze-drying technology to form three-dimensional sheet, and successfully obtained cellulose aerogels derived from seaweed solid waste (SWCA). The compression test shows that the maximum compressive stress of SWCA is 61 kPa, and the initial performance still maintains 82% after 40 cryogenic compression cycles. In addition, the contact angles of water and oil on the surface of the SWCA were 153° and 0°, respectively, and the stable hydrophobic time in simulated seawater is more than 3 h. By combining the elasticity and superhydrophobicity/superoleophilicity, the SWCA with an oil absorption capacity of up to 11-30 times its mass, might be utilized repeatedly for the separation of an oil/water mixture.
气凝胶因其低密度和高孔隙率的典型优势，在吸附、保温等领域具有极好的应用潜力。然而，气凝胶在油水分离中的应用存在几个问题，包括机械性能较弱和在低温下去除有机污染物的挑战。本研究受低温性能优异的纤维素 Iα 的启发，以从海藻固体废弃物中提取的纤维素 Iα 纳米纤维作为骨架，通过与乙烯亚胺聚合物（PEI）共价交联和 1,4- 二异氰酸苯（MDI）的疏水性改性，辅以冷冻干燥技术形成三维片状结构，成功获得了源自海藻固体废弃物的纤维素气凝胶（SWCA）。压缩测试表明，SWCA 的最大压缩应力为 61kPa，经过 40 次低温压缩循环后，初始性能仍保持 82%。此外，SWCA 表面的水和油的接触角分别为 153°和 0°，在模拟海水中的稳定疏水性时间超过 3 小时。通过结合弹性和超疏水性/超亲油性，SWCA 的吸油能力高达其质量的 11-30 倍，可以重复用于油水混合物的分离。
