Research on Adsorption of Methylene Blue onto the Mesoporous Silica Microspheres

Abstract

Mesoporous silica microspheres (MSM) with diameter about 100 nm were prepared by hydrothermal synthesis using cetyl trimethyl ammonium bromide(CTAB) as template agent and tetraethyl orthosilicate(TEOS) as silica source. And they were characterized byscanning electron microscopy (SEM) , N2 adsorption-desorption analysis , infrared spectroscopy (FT-IR). Then methylene blue adsorption test was investigated. Effect of pH, temperature of the adsorption of methylene blue onto MSM were studied. The adsorption amount onto MSM increased with the initial pH-value of the solution in the range of 3~10. Alkaline was more favorable to adsorption. The adsorption amount onto MSM decreased with the initial temperature of the solution at 22 °C~ 45 °C. low-temperature was more favorable to adsorption. The adsorption isotherm of methylene blue on MSM could be described by the Langmuir model.