Study of Low\nTemperature-Treated Aldolized Cellulose\nNanocrystals for Enhancing Dye Separation and Self-Healing Properties\nof Graphene Oxide Membranes

Graphene oxide (GO) membranes with\na 2D layered structure\nand nanoscale\nchannels have great application prospects for dye wastewater purification.\nIn this paper, ethylenediamine (EDA) was grafted onto the surface\nof GO nanosheets at 70 °C and aldolized cellulose nanocrystals\n(ICNC) were introduced to form EDA-ICNC hydrogel structures between\nthe GO nanosheets by Schiff base reaction. The interlayer structure\nof the membrane was determined by adjusting the amount of ICNC added\nand the degree of aldolization, and the EGOICNC-24 membrane with the\nbest performance was prepared. The water flux is not only 12 times\nhigher than that of GO membrane but also has a good separation ability\nfor dye molecules with a molecular weight around 300. Following the\nEDA-ICNC-24 hydrogel cross-linking process, the tensile strength of\nthe EGOICNC-24 membrane exhibited a 173% increase relative to that\nof the GO membrane. Additionally, the dye rejection rate reached 97.16%\nafter 130 h of dye separation. When the surface of the membrane was\ndamaged, it was self-healed by regulating the repair temperature and\nadding a very small amount of ICNC to undergo a dynamic Schiff base\nreaction and a synergistic effect of hydrogen bonding.