Preparation And Adsorption Properties Of Cellulose Sponge Based On Viscose Technology

As a lightweight and porous material,polymer sponges,which have the structural characteristics of low density,high porosity and high specific surface area,has become the research focus of many investigators.However,the excessive use of petroleum-based polymers has caused serious environmental pollution and lack of resources.As the most abundant natural polymer in nature,cellulose has the characteristics of renewable,biodegradable and non-toxic.It is a suitable material for preparing sponges.In our work,we prepared functional cellulose sponges based on viscose technology,and investigated the properties of cellulose viscose sponge in the two aspects of oil-water separation and dye adsorption.The main contents are listed as following:In view of the serious threat to the ecological environment and water resources caused by the discharge of oily wastewater,low-cost modified cellulose sponge was developed for oil-water separation.Cellulose sponges were prepared by hydrothermal method by adding P-toluene sulfonyl hydrazine as foaming agent into viscose,and hydrophobic and oil-wet sponges were prepared by silane modification.The study showed that silane was successfully modified to cellulose sponge.The modified sponge with good mechanical properties can maintain good resilience after repeated compression for 60 times.The hydrophobicity was obtained on the surface and inside of the sponge channel,which showed that the hydrophobicity of the sponge hydrophobic layer was stable.The modified sponges with good reuse have good adsorption performance to different oils and organic solvents,including silicone oil,edible oil and carbon tetrachloride,with the absorption capacity up to 33.89 g g^-1,29.86g g^-1 and 31.72 g g^-1,respectively.In view of the complex components in the dye waste solution,difficult to purify,and the complex treatment process,which will seriously damage the water ecosystem,chitosan was used to modify the cellulose sponge,and the designed chitosan/cellulose composite viscose sponge has the advantages of multiple dyes adsorption ability and low price.The results showed that the modified chitosan/cellulose sponge had xanthate and amino groups at the same time,and the viscose solution and additives were uniformly dispersed without aggregation,which could realize good adsorption of cationic dye methylene blue（MB）and anionic dye Congo red（CR）at the same time.The effects of pH value,adsorption time and chitosan ratio on the adsorption capacity of composite sponge dyes were systematically studied in this paper.The adsorption kinetics results were in line with the pseudo-second-order kinetic model,and the adsorption isotherm research results had a good correlation with Langmuir（R²>0.983/0.99）.At room temperature,the maximum dye adsorption capacity of 50 mg L^-1 dye solution was about 120 mg g^-1.