Preparation And Hydrophobic Properties Of Leymus Chinensis Cellulose Aerogels

Natural cellulose is a kind of green material with wide distribution and large reserves in nature.The cellulose aerogels prepared by freeze-drying technology with cellulose as matrix not only have the three-dimensional structural characteristics of silica aerogels,but also have excellent properties such as biocompatibility,biodegradability and adsorption.Leymus chinensis is an important forage resource in Inner Mongolia and western northeast China.The cellulose of Leymus chinensis was extracted by sodium hydroxide-sodium chlorite method from natural Leymus chinensis(LC).The cellulose aerogel was prepared by freeze-drying with low temperature alkali system.The structural properties of the samples were investigated by comparing cotton velvet with coniferous wood pulp.Cellulose from natural leymus chinensis and the thermal decomposition temperature of the cellulose from Leymus chinensis reached 350℃and the average yield is about 25.34%.The cellulose aerogels with in Li OH、urea and water at 7:12:81.N,N-methylene bisacrylamide was used as crosslinking agent to prepare cellulose aerogel with 2%mass fraction.Add to 0.06 g,to crosslinker the cellulose aerogels with excellent structural properties were prepared when the cleaning solvent was water.Lt CA density up to 0.135 g/cm~3,18.96 m~2/g surface area density of wood pulp cellulose aerogel up to 0.147 g/cm~3,18.10 m~2/g,surface area a density of 0.157 g/cm~3,for LCCA18.35 m~2/g.Surface area at the same time,the water absorption of LCCA in the three raw materials reached 29.24 g/g up to 21.64 g/g of Lt CA and 25.57 g/g of WPCA.The hydrophobic cellulose aerogels of three raw materials were prepared by hydrophobic modification of cellulose aerogels by chemical vapor deposition,and the hydrophobic angles of Lt CA,WPCA and LCCA were 110°,115°and 122°respectively.At the same time LCCA after a week,the surface static contact could still reach 110°.After silanization,the thermal decomposition temperature of LCCA reached 250℃and the thermal stability was relatively good.Hydrophobicity LCCA the highest adsorption capacity for petroleum ether,cyclohexane,chloroform,pump oil,silicone oil was 28.42 g/g、26.95 g/g、23.46 g/g、48.55 g/g、55.63 g/g,and both reached swelling equilibrium within 12 minutes.The first adsorption reached 64.13%in ten repeated adsorption,which was better than the other two cellulose aerogels,showing excellent adsorption ability and repeated adsorption ability.