Nguyen Vy T, Ha Lam Q, Nguyen Tu D L, Ly Phuong H, Nguyen Dang Mao, Hoang DongQuy
Faculty of Materials Science and Technology, University of Science, Ho Chi Minh City 700000, Vietnam.
Vietnam National University, Ho Chi Minh City 700000, Vietnam.
ACS Omega. 2021 Dec 20;7(1):1003-1013. doi: 10.1021/acsomega.1c05586. eCollection 2022 Jan 11.
The characteristics of aerogel materials such as the low density and large surface area enable them to adsorb large amounts of substances, so they show great potential for application in industrial wastewater treatment. Herein, using a combination of completely environmentally friendly materials such as cellulose nanofibers (CNFs) extracted from the petioles of the nipa palm tree and graphene oxide (GO) fabricated by simple solvent evaporation, a composite aerogel was prepared by a freeze-drying method. The obtained aerogel possessed a light density of 0.0264 g/cm and a porosity of more than 98.2%. It was able to withstand a weight as much as 2500 times with the maximum force (1479.5 N) to break up 0.2 g of an aerogel by compression strength testing and was stable in the aquatic environment, enabling it to be reused five times with an adsorption capacity over 90%. The CNF/GO aerogel can recover higher than 85% after 30 consecutive compression recovery cycles, which is convenient for the reusability of this material in wastewater treatments. The obtained aerogel also showed a good interaction between the component phases, a high thermal stability, a 3D network structure combined with thin walls and pores with a large specific surface area. In addition, the aerogel also exhibited a fast adsorption rate for methylene blue (MB) adsorption, a type of waste from the textile industry that pollutes water sources, and it can adsorb more than 99% MB in water in less than 20 min. The excellent adsorption of MB onto the CNF/GO aerogel was driven by electrostatic interactions, which agreed with the pseudo-second-order kinetic model with a correlation coefficient = 0.9978. The initial results show that the CNF/GO aerogel is a highly durable "green" light material that might be applied in the treatment of domestic organic waste water and is completely recoverable and reusable.
气凝胶材料具有低密度和大表面积等特性，使其能够吸附大量物质，因此在工业废水处理中显示出巨大的应用潜力。在此，使用从尼帕棕榈叶柄中提取的纤维素纳米纤维（CNF）和通过简单溶剂蒸发制备的氧化石墨烯（GO）等完全环保材料的组合，通过冷冻干燥法制备了一种复合气凝胶。所得气凝胶的轻质密度为0.0264 g/cm，孔隙率超过98.2%。通过抗压强度测试，它能够承受高达2500倍的重量，最大力（1479.5 N）可压碎0.2 g气凝胶，并且在水环境中稳定，能够重复使用五次，吸附容量超过90%。连续30次压缩恢复循环后，CNF/GO气凝胶的回收率高于85%，这便于该材料在废水处理中的可重复使用性。所得气凝胶在组分相之间还表现出良好的相互作用、高热稳定性、具有薄壁和大比表面积孔隙的三维网络结构。此外，该气凝胶对亚甲基蓝（MB）的吸附速率也很快，亚甲基蓝是纺织工业污染水源的一种废物，它能在不到20分钟内吸附水中99%以上的MB。MB在CNF/GO气凝胶上的优异吸附是由静电相互作用驱动的，这与相关系数为0.9978的准二级动力学模型相符。初步结果表明，CNF/GO气凝胶是一种高度耐用的“绿色”轻质材料，可能应用于生活有机废水的处理，并且完全可回收和重复使用。
