Synthesis And Adsorption Properties Of Cattail Based Cellulose Aerogel

Cattail is rich in cellulose and widely distributed in nature,but its application is limited.The cattail not properly used will not only cause environmental pollution but also cause human allergies.In this study,cattail cellulose aerogel was successfully prepared by freeze-drying method with cattail as raw material,and its adsorption properties were studied.This study explores the application potential of cattail cellulose aerogel in the field of sewage treatment and turns waste into treasure.The results show that:1.The effects of NaClO2 and KOH on the microstructure and chemical composition of cattail fiber were investigated.NaClO2 and KOH treatments are necessary steps to prepare cattail cellulose aerogel.NaClO2 removed the waxy layer and transformed the cattail from hydrophobic to hydrophilic,which laid a foundation for the preparation of cattail cellulose aerogel by forming uniform and stable suspension in solution.The lignin and xylan in cattail were removed by KOH,and cattail cellulose was further purified.2.The influence of freezing process and the content of cellulose and polyvinyl alcohol(PVA)on the molding and properties of cattail cellulose aerogels were studied.Liquid nitrogen freezing(-196℃)and cold trap freezing(-55℃)are suitable for the preparation of pure cattail cellulose aerogel and polyvinyl alcohol(PVA)/cattail cellulose aerogel,respectively.The cross-linking between cellulose and PVA constitute the skeleton of cattail cellulose aerogel.The density and compressive strength of cattail cellulose aerogel increased with the increase of cellulose and PVA contents.In addition,the cattail cellulose aerogel shows a low thermal conductivity(～26.4 mW·m-1·K-1),which makes it expected to be applied in the field of thermal insulation.3.The adsorption properties of cattail cellulose aerogel to organic liquid and oil before and after modification were also analyzed.After modified by the method of vapor phase deposition with methyltrimethoxysilane(MTMS),cattail cellulose aerogel changed from hydrophilic to hydrophobic with contact angle of 140°.The static adsorption experiments indicated that the cyclic adsorption capacity of cattail cellulose aerogel to organic liquids will be improved after hydrophobic modification and the introduction of PVA,and the adsorption capacity of cattail cellulose aerogel to organic liquids and oil was 76.5～119.3 g/g.Dynamic adsorption experiments showed that the adsorption behavior of cattail cellulose aerogel to oil was in accordance with the pseudo-first-order,which belonged to physical adsorption and surface adsorption.