| With the development of modern society,it is more and more important to use the eco-friendly cellulose materials as the sustainable natural polymer resource because of its biocompatibility,biodegradation,and reproducibility properties.Now,cellulose has become one of the most interests for many applications,such as additives for pharmaceuticals,and drug delivery,reinforcement in polymer composite,food and cosmetics additives.Especially,using cellulose as raw materials to make hydrogels and aerogels has attracted more and more interests.In this paper,cellulose aerogels have been successfully prepared by using cotton pulp cellulose as raw materials,using green non-toxic and recycling N-methylmorpholine-N-oxide monohydrate as solvent.Cellulose-graphene oxide（cellulose-GO）aerogels had been prepared by adding graphene oxide（GO）into cellulose aerogels by ultrasound assisted.The contents of this paper are as follows:（1）The cellulose aerogels were successfully prepared via using NMMO·H2O as a solvent to dissolve cellulose pulp.Then the mixture was solidified in the room temperature.After plenty of water washing,obtained samples by next freeze-drying process.The cellulose aerogel presents the interconnected sponge-like hierarchical porous structure.The density of the cellulose aerogel was low to 0.057g cm-3.The porosity,water content and swelling ratio were high to 96.2%,1450%and 96.2%.The crystalline structure of the regenerated cellulose aerogel is cellulose II.With the increase of cellulose content,the shrinkage rate of aerogel decreased,the density increases,and the pore size of three-dimensional mesh structure decreases.The initial decomposition temperature of the cellulose aerogel is about 290℃,and the thermal stability is very good.The increase of swelling ratio in the phosphate buffered saline（PBS）is more obvious when the concentration of cellulose is lower.（2）The cellulose-GO aerogels were successfully prepared via using a solution mixed with melt NMMO·H2O solution and ultrasound GO solution to dissolve cellulose pulp.Then the mixture was solidified in the room temperature.After plenty of water washing,obtained samples by next freeze-drying process.The density of the aerogel was low to 0.103g cm-3.GO was uniformly dispersed in the NMMO·H2O solution,graphene oxide.It accelerates gelation.The shrinkage rate of the cellulose-GO aerogels is lower than the pure cellulose aerogel.The structure is more stable.The addition of GO was increase swelling ratio and water content of the composite aerogels.The swelling ratio was increased from 718%to 875%.The water content is basically unchanged after recycle absorption of 5 times.The concentration of graphene oxide has little effect on the thermal stability of the composite aerogels and the swelling property of the PBS buffer.（3）The cellulose based carbon-graphite aerogels were prepared by the cellulose-GO aerogels under high temperature carbonization and reduction.The density and the shrinkage rate of the cellulose based carbon-graphite aerogels were low to 0.073g cm-33 and 52.1%.With the increase of cellulose content,the shrinkage rate of aerogel decreases.With the increase of GO content,the shrinkage rate and density of aerogel decreased.The structure of the composite aerogel has a great relationship with the temperature of the pyrolysis.The optimum preparation condition of the cellulose based carbon-graphene aerogels is 15 minutes at 600℃.The composite aerogels can be used for oil-water separation with hydrophobic and oleophylic.Oil can be removed by burning.It is stable and durable. |
