Preparation Of Cellulose Acetate Composites And Study On Dye Removal

Dye wastewater is one of the main industrial wastewater in China.Dye wastewater seriously damages the ecological environment and endangers human health and safety.It is one of the pollutants that need to be controlled in China.Cellulose derivatives have good biocompatibility,strong reproducability,non-toxic and harmless,environment-friendly properties,etc.Compared with natural cellulose,they are more soluble in general organic solvents,and have been widely used in medical treatment,environmental protection,food packaging,textile and other fields.In this paper,cellulose acetate was used as the raw material to prepare composite aerogel and composite microspheres.The materials were characterized by scanning electron microscopy,X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis and other equipment,and the removal ability and antibacterial properties of the materials for dyes in wastewater were studied.The research contents and conclusions of this paper are as follows:(1)Cellulose acetate aerogel was prepared by thermally induced phase separation,and then soaked in zirconium based organic framework(UIO-66-NH₂)precursor solution loaded with UIO-66-NH₂ in situ to prepare UIO-66-NH₂/cellulose acetate aerogel,which was used for the adsorption of methylene blue and methyl orange.UIO-66-NH₂/cellulose acetate aerogel has a good three-dimensional channel structure.The maximum adsorption capacities of methylene blue and methyl orange under the optimum reaction conditions were 75.4mg/g and 31.6mg/g,respectively.(2)The dry UIO-66-NH₂ was uniformly mixed in the solvent by premixed method,and then the cellulose acetate aerogel was prepared by thermally induced phase separation method to obtain the composite aerogel,which was used for the adsorption of methylene blue and methyl orange.The three-dimensional pore structure of the composite aerogel weakened with the increase of the amount of UIO-66-NH₂.The maximum adsorption capacities of methylene blue and methyl orange were 103.4mg/g and 52.2mg/g,respectively,under the optimal reaction conditions(3)UIO-66-NH₂/cellulose acetate aerogel crosslinked polyethylenimine prepared by premixed method was selected.Using glutaraldehyde as cross-linking agent,polyethylenimine was cross-linked on the surface of aerogel to obtain polyethylenimine/UIO-66-NH₂/cellulose acetate aerogel.The adsorption kinetics and isothermal adsorption experiments show that the adsorption of methylene blue and methyl orange by polyethylenimine/UIO-66-NH₂/cellulose acetate aerogel conform to the quasi-second-order kinetics and Freundlich isothermal adsorption model.The maximum adsorption capacities of methylene blue and methyl orange were 129.5mg/g and 78.9mg/g,respectively,under the optimal reaction conditions.(4)Porous cellulose acetate microspheres were prepared by emulsification method,and then modified with polydopamine and Ag-Fe₃O₄ by in-situ one-pot method.A novel Ag-Fe₃O₄/polydopamine/porous cellulose acetate microspheres were obtained.The microspheres have a good spherical porous structure,and the Ag-Fe₃O₄nanoparticles are successfully uniformly loaded on the surface of the microspheres.Ag-Fe₃O₄/Polydopamine/porous cellulose acetate microspheres can rapidly catalyze the reduction of 4-nitrophenol,and at the same time have a good inhibitory effect on Escherichia coli.