Superhydrophobic modification of cellulose sponge fabricated from discarded jute bags for oil water separation

Recent oil spills endanger the aquatic ecosystem besides huge loss of natural resources, hence require immediate attention. To develop economical solution for combating oil spills, discarded jute bags, with 60–65% cellulose were used to fabricate cellulose sponge using sol-gel method followed by freeze drying. The sponge surface was rendered superhydrophobic by dip coating with Tetraethyl-orthosilicate/Hexadecyltrimethoxy Silane (TEOS/HDTMS). The pristine and dip coated hydrophobic cellulose sponge (DHCS) were characterized for structure, morphology and hydrophobicity. FE-SEM confirmed the hydrophobic coating of TEOS/HDTMS on sponge surface, while superhydrophobicity was established with static contact angle of 151°. DHCS exhibited oil water separation efficiency of 98.5% and 97.2% and equilibrium adsorption efficiency of 35.55 g/g and 31.37 g/g for diesel oil and motor oil, respectively. The adsorption follow pseudo-second order kinetics with regression coefficients, R2 > 0.99. Equilibrium studies indicated that the Freundlich isotherm was best fit isotherm for oil water removal by DHCS. DHCS displayed significant recyclability with slight reduction of adsorption capacity to 85.2% for diesel oil and 82.5% for motor oil of its initial value after 10 cycles.