Cellulosic supergel for oil and water dual absorption and remediation

An oil-water absorbing binate cellulosic supergel was developed for dual remediation of oil as well as water contamination. Scaffold for supergel was developed using high internal phase emulsion (HIPE) templating of an interpenetrating network of wood pulp cellulose (WPC) and hydroxyethyl cellulose (HEC) with polyacrylic acid (PAA). The HIPE was formed by dispersing dodecane in a continuous aqueous phase of WPC, HEC, and acrylic acid (AA) stabilized using sodium dodecyl sulfate (SDS). Micron-sized, interconnected pores were uniformly formed within the scaffold thereby achieving a remarkable porosity of 96.5 ± 4.8 % and a density of 0.054 ± 0.015 g/cm³. Combining emulsion templating with formation of inter-penetrating network (IPN) provided a unique approach to tailor pore size of the scaffold which unconventionally turned out to be smaller than the droplet size of the emulsion. The scaffold showed a significantly higher oil sorption value of 29.8 ± 2.9 g/g because of enhanced filling and trapping mechanism of oil in the porous structure of the scaffold. The scaffold showed persistent water or oil sorption for ten sorption-desorption cycles and successfully used to sorb both aqueous as well as oil media together thereby offering remediation for both in a single step from toxic wastes such as dyes.