Adsorption equilibrium and kinetics studies of crystal violet adsorbed by anionic polymer brush functionalized mesoporous silica nanoparticles

Abstract

The removal of crystal violet (CV) dye from an aqueous solution has been investigated using anionic poly(potassium 3-sulfopropyl methacrylate) (PKSPMA) brushes grafted on mesoporous silica nanoparticles (MSNPs). Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) were used to characterize PKSPMA brushes modified MSNPs (PKSPMA@MSNPs). Surface-modified MSNPs were almost spherical shapes with sizes ranging between 190 nm and 340 nm with an average pore size of ca. 5. The adsorption process of the CV was investigated under various of testing conditions, including pH, contact duration and initial dye concentration. The maximum loading of CV onto PKSPMA@MSNPs was observed at pH 3, with approximately 91% adsorption efficiency at a concentration of 100 ppm. The removal of CV onto PKSPMA@MSNPs was best described by the Langmuir isotherm, with a maximum monolayer adsorption capacity (qmax) of 128.37 mg g−1. The kinetics of the adsorption process were best described by the pseudo-second-order model.