Study On The Preparation And Adsorption Behavior Of Cyclodextrin-modified Cellulose Binary System Hydrogel

This work has investigated the preparation of carboxymethyl cellulose/microcrystalline cellulose hydrogel with ?-cyclodextrin modification(gel CMC-MCC-?-CD),and the adsorption ability of gel CMC-MCC-?-CD to an organic pollutant 3-methoxy-4-hydroxybenzaldehye(Van).This paper has discussed the practicable value of the material and looked forward to provide some theoretical meanings toward organic pollutants removal.A series of carboxymethyl cellulose/microcrystalline cellulose hydrogel particles were prepared through inverse suspension polymerization under alkaline condition,and they were modified with ?-cyclodextrin to enhance adsorption and encapsulation ability.Gel CMC-MCC-?-CD particles were characterized through FTIR,TGA and SEM,and the results showed that polymer hydrogel CMC-MCC-P-CD were crosslinked and modified successfully.We could also see the inner structure of gel CMC-MCC-?-CD is like honeycomb structure and there are many cavities inside hydrogel.This paper investigated the equilibrium swelling ratio(ESR)firstly,experiments showed gel CMC-MCC-P-CD obtained excellent ESR that could reach up to 2432%under pH value of 11.0.ESR of gel CMC-MCC-?-CD would decrease when the amount of ?-CD increases.Secondly,gel CMC-MCC-?-CD particles possessed excellent adsorption and encapsulation efficiency(VEE),maximum adsorption efficiency is 93.58%under cellulose ratio of 1:1 at low initial concentration.Moreover,VEE would increase when the amount of ?-CD increases,it proved that ?-CD can enhance the adsorption and encapsulation ability.Gel CMC-MCC-P-CD particles are also with satisfying release ability,maximum release efficiency is 94.01%under pH value of 8.0 and temperature of 80 ?.The adsorption data of G3 best fitted with Pseudo-second-order adsorption kinetic model with constants of 0.6588×10-3 L·min-1·mmol-1(K),0.3393 mmol·L-1(Qe)and correlation coefficient of 0.9959,it suggested that chemisorption dominated the process.The release data of G3 best fitted with Korsmeyer-Peppas release kinetic model with constants of 0.0531 L·min-1?mmol-1(Kkp),0.2893 mmol·g-1(Qe)and correlation coefficient of 0.9953.Diffusion constant,which can reveal the mechanism of release behavior,was found to be 0.433.According to Peppas Release Theory,the releasing process of vanillin from gel CMC-MCC-?-CD was simultaneously governed by diffusion and dissolution,and the influence of diffusion is much bigger than dissolution.In reusability research,though the VEE and VRE decreased by 1.06%and 1.13%after 5 cycles of "adsorption-release" process,it still performanced at a high level of working efficiency,its VEE and VRE could still be 92.42%and 91.43%.The encapsulation attenuation ratio(EAR)and release attenuation ratio(RAR)of gel CMC-MCC-?-CD were found to be 1.24%and 1.53%,which showed the reusability of prepared polymer hydrogel CMC-MCC-?-CD.