Effect of the degree of template removal from mesoporous silicate materials on their adsorption of heavy oil from aqueous solution

• Published in: Frontiers of chemical science and engineering Vol. 8; no. 4; pp. 488 - 497
• Main Authors: Twaiq, Farouq, Nasser, M. S., Onaizi, Sagheer A.
• Format: Journal Article
• Language: English
• Published: Heidelberg Higher Education Press 01.12.2014
• Subjects: Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Nanotechnology; Research Article; adsorption; template removal; heavy oil; kinetics; mesoporous silicate material
• ISSN: 2095-0179; 2095-0187
• DOI: 10.1007/s11705-014-1459-1

The key aim of this study is to evaluate the adsorption of heavy oil from aqueous solutions with different oil contents over mesoporous silicate materials having different surfactant template contents. The mesoporous silicate materials have been synthesized from tetraethylorthosilicate as a silica precursor and cetyltrimethylammonium bromide as a template using the sol-gel technique. Four samples were prepared by (1) totally removing the template using the calcination process, (2) partially removing the template via ethanol extraction, (3) partially removing the template via water extraction, and (4) keeping the template as synthesized, respectively. These four samples have been characterized using X-ray diffraction, nitrogen adsorption, thermal gravimetric analysis and Fourier transformed infrared. The effect of the degree of template removal of these mesoporous materials for the oil removal has been investigated. The oil removal is inversely proportional to the surfactant content in the mesoporous material, being highest for the calcined sample but lowest for the as-synthesized sample. The kinetic of oil adsorption over the calcined material has been also studied and the data obtained fit well a second-order model.