title: Surface modification of pyrophyllite with amino silane coupling agent for the removal of 4-nitrophenol from aqueous solutions.
abstract: The surface of naturally hydrophobic mineral pyrophyllite was modified to hydrophilic by treatment with prehydrolyzed N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (APEO) coupling agent to prepare a novel and effective adsorbent for the removal of 4-nitrophenol (4-NP) from aqueous solutions. XRD, FTIR, and SEM analyses were used to characterize the surface modification. It was found that after the grafting procedure, heat treatment at 110 degrees C results in condensation reaction between the OH groups of the APEO molecule and the hydroxyl groups and/or oxygen atoms on the pyrophyllite surface and the adsorption of 4-NP by APEO-modified pyrophyllite involves interactions between dissociated 4-NP molecules and protonated amine groups of APEO molecules attached to the mineral surface. Adsorption equilibrium data for 4-NP adsorption on APEO-treated and untreated pyrophyllite were most satisfactorily fitted using the Freundlich adsorption isotherm and adsorption capacity was found to be 0.268 mg/g for modified pyrophyllite whereas it was only 0.105 mg/g for untreated pyrophyllite.
authors.affiliation: Department of Science Education, Inönü University, 44280 Malatya, Turkey.
authors.forename: H
authors.initials: H
authors.lastname: Sayilkan
authors.forename: S
authors.initials: S
authors.lastname: Erdemoğlu
authors.forename: S
authors.initials: S
authors.lastname: Sener
authors.forename: F
authors.initials: F
authors.lastname: Sayilkan
authors.forename: M
authors.initials: M
authors.lastname: Akarsu
authors.forename: M
authors.initials: M
authors.lastname: Erdemoğlu