Bilge Erdem

Removal of Orange II from Aqueous Solutions Using N-Vinyl Imidazole-based Hydrogels as Adsorbents

Poly(N-vinyl imidazole) hydrogel (p-VIm) and its partially quaternized analogue (p-VIm-Ar) were prepared and used for the removal of Orange II (OII). A fourier transform infrared spectrophotometer, scanning electron microscope with an energy dispersive X-ray spectrometer attached, thermogravimetric analyzer, zeta potential analyzer, and a drop shape analyzer were used for the characterization of the hydrogels. The influence of some experimental parameters, such as pH of the OII solution, contact time, and initial OII concentration on the adsorption process, was examined, and the obtained data were used to calculate the isotherm and kinetic parameters. Adsorption processes of OII onto adsorbents were coherent with the Langmuir isotherm and pseudo-second-order kinetic models. The quaternized analogue exhibited remarkable adsorption performance in the pH range of 2–12, while the effective adsorption with p-VIm occurred only at pH 2.0. The maximum adsorption capacity values of adsorbents were determined as 2331 (for p-VIm) and 1327 mg g−1 (for p-VIm-Ar) at pH 2.0 and 132 (for p-VIm) and 1357 mg g−1 (for p-VIm-Ar) at pH 6.0.

Synthesis, Characterization and Adsorptive Properties of Quaternized 2-Dimethylaminoethyl Methacrylate Based Polymer–Clay Nanocomposites

ABSTRACT [2-(Methacryloyloxy)ethyl]dimethylhexadecylammonium bromide (QDMA) was synthesized by means of quaternization of 2-dimethylaminoethyl methacrylate. Poly(QDMA) and poly(QDMA)-bentonite nanocomposites containing different amount of bentonite were prepared by in situ suspension polymerization and characterized. Adsorption behaviors of these materials towards acid orange 8 and p-nitrophenol were investigated with respect to solution pH. For both adsorbate, adsorption capacities of some nanocomposites were found to be higher than those of bentonite and poly(QDMA). Effects of various parameters such as contact time, initial adsorbate concentration, and temperature on the adsorption of acid orange 8 and p-nitrophenol onto NC3 from aqueous solutions were also evaluated. GRAPHICAL ABSTRACT