Hydrophobic channels produced by micelle-structured CTAB inside MCM-41 mesopores: A unique trap for the hazardous hormone ethinyl estradiol

In this work, mesoporous hydrophobic cavities produced by a micelle structured CTAB (cetyl trimethylammonium bromide) trapped inside MCM-41 pores were used for the efficient removal of the hazardous hormone contaminant ethinyl estradiol (EE) present in water. The MCM-41 structure was prepared using different CTAB/Si molar ratios, i.e. 0.07, 0.12, 0.17, and 0.27. TG, SEM, TEM, BET, IR, elemental analysis, contact angle and positron annihilation spectroscopy showed that the MCM-41 silica structure is completely filled with trapped CTAB molecules (47-58wt%) which results in no porosity and very low surface areas of 1-5m2g-1. These materials showed high efficiency to remove EE from aqueous solution whereas pure MCM-41 (without CTAB) with high porosity and a surface area of 1333m2g-1 showed no adsorption. These results are discussed in terms of EE sorption into the hydrophobic environment created by the CTAB trapped molecules inside the mesoporous cavities of MCM-41.Fil: Ribeiro Santos, Tatiana A.. Universidade Federal de Minas Gerais; BrasilFil: Henriques, Fernando Fulgêncio. Universidade Federal de Minas Gerais; BrasilFil: Villarroel Rocha, Jhonny. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: de Castro, Mateus Carvalho Monteiro. Universidade Federal de Minas Gerais; BrasilFil: Magalhães, Welington Ferreira. Universidade Federal de Minas Gerais; BrasilFil: Windmöller, Dario. Universidade Federal de Minas Gerais; BrasilFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Lago, Rochel Montero. Universidade Federal de Minas Gerais; BrasilFil: Araujo, Maria Helena. Universidade Federal de Minas Gerais; Brasi