Ionic liquid groups modified 3D porous cellulose microspheres for selective adsorption of AO7 dye

In this study, a three-dimensional porous cellulose-based microsphere material modified with ionic liquid functional groups was prepared. Seven kinds of cellulose microspheres with different ionic liquid groups were successfully produced and were used for the adsorption of Acid Orange 7 dye. Cellulose microsphere modified with 4-methylimidazole, named as CMs4, had the greatest adsorption capacity of 218.6 mg/g and the fastest adsorption rate. CMs4 reached an adsorption capacity of 100 mg/g after only 10 min. Compared with materials in other literatures, CMs4 had an excellent Acid Orange 7 dye adsorption rate. According to the zeta potential analysis, the surface potential of CMs4 depended on the pH. Exploiting this property, cationic and anionic dyes can be separated using CMs4 by changing the pH. Since cellulose materials are renewable and widely available, CMs4 is a promising environmentally friendly material for dye adsorption applications.