Performances of clay aerogel polymer composites for oil spill sorption: Experimental design and modeling

Recently developed montmorillonite clay-based aerogels have attracted an attention owing to their highly porous internal structure. This study deals with the design of experiments applied for preparation of clay aerogel polymer composites and their testing and optimization for oil spill sorption. Three design variables have been chosen for experimentation, i.e. the amounts of montmorillonite (MMT), polyvinyl alcohol (PVA) and sodium dodecyl sulfate (SDS). Based on the experimental design the response surface models have been constructed. The objective for optimization was to maximize the performances of materials for sorption of dodecane and motor oil. To this end, the multi-objective optimization problem has been solved using NSGA-II optimization algorithm. The aerogel sorbent prepared under the optimal conditions of 2.109% w/v PVA, 2.678% w/v MMT and 0.210% w/v SDS bestowed the best sorption performance for both dodecane (23.63 g/g) and motor oil (25.84 g/g). Finally, the hydrophobic aerogel sorbent has been prepared using trimethoxy(octadecyl)-silane TMOS (C21H46O3Si). The modified material with TMOS disclosed good sorption capacities for dodecane (10.55 g/g) and motor oil (12.25 g/g). The retention profile test has revealed that about 1.06-14.91% of liquid hydrocarbons can be recovered by free drainage. The advanced recovery of oily liquids has been achieved by centrifugation technique being of 42.29-66.02%. Likewise, the hydrophobic aerogel (modified with TMOS) has showed a good sorption capacity for dodecane (9.24 g/g) in the presence of water (W-test). In addition, the clay aerogel polymer composites have been characterized by means of scanning electron microscopy (SEM), Fourier transform infrared (FOR) spectroscopy and X-ray diffraction (XRD) technique. (C) 2014 Elsevier B.V. All rights reserved.