Localized hydrogels based on cellulose nanofibers and wood pulp for rapid removal of methylene blue

Abstract

Access to clean water has become increasingly difficult, motivating the need for materials that can efficiently remove pollutants. Hydrogels have been explored for remediation, but they often require long times to reach high levels of adsorption. To overcome this limitation, we developed a rapid, locally formed hydrogel that adsorbs dye during gelation. These hydrogels are derived from cellulose—a renewable, nontoxic, and biodegradable resource. More specifically, we found that sulfated cellulose nanofibers or sulfated wood pulps, when mixed with a water‐soluble, cationic cellulose derivative, efficiently remove methylene blue (a cationic dye) within seconds. The maximum adsorption capacity was found to be 340 ± 40 mg methylene blue/g cellulose. As such, these localized hydrogels (and structural analogues) may be useful for remediating other pollutants.Access to clean water has become increasingly difficult, motivating the need for materials that can efficiently remove pollutants. In this work, locally formed hydrogels made from mixing anionic and cationic cellulose derivatives are developed, which rapidly adsorb cationic dye during the gel formation process. A maximum adsorption efficiency of 340 ± 40mg methylene blue/g cellulose was observed, rivaling comparable cellulose‐based gels reported. These localized hydrogels (and structural analogues) may be useful for remediating other pollutants.