Abstract
We employed polymer functionalized silica gel as an adsorbent for the removal of Cr(vi) from water. The chains of 2-aminoethyl methacrylate hydrochloride (AEMA·HCl) polymer were grown from the surface of silica gel via surface-initiated conventional radical polymerization and the resulting hybrid material exhibited high affinity for chromium(vi). To investigate the adsorption behavior of Cr(vi) on diverse polymer based hybrid materials, the removal capacity of (SG-AEMH) was compared with our previously reported branched polyamine functionalized mesoporous silica (MS-PEI). The adsorption capacities of polymer based materials were also compared with their respective monolayer based platforms comprising a 3-aminopropyltriethoxysilane (APTES) functionalized silica gel (SG-APTES) and mesoporous silica (MS-APTES). The polymer based systems showed excellent Cr(vi) adsorption efficiencies compared to monolayer counterparts. The structural characteristics and surface modification of these adsorbents were examined by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The experimental data were analyzed using the Langmuir and Freundlich models. Correlation coefficients were determined by analyzing each isotherm. The kinetic data of adsorption reactions were described by pseudo-first-order and pseudo-second-order equations. Thermodynamic parameters, i.e., change in the free energy (ΔG°), the enthalpy (ΔH°), and the entropy (ΔS°), were also evaluated. The synthesized hybrid materials exhibited a high adsorption capacity for chromium ions. Furthermore, they could be regenerated and recycled effectively.
Highlights
Sana Nayab,†ab Humaira Baig,†ac Abdul Ghaffar,c Eylul Tuncel,d Zehra Oluz,d Hatice Duran d and Basit Yameen *a
The structural characteristics and surface modification of these adsorbents were examined by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA)
It was observed that best desorption results for SG-AEMH were obtained by using NaNO3 and for SG-APTES were obtained by using NaOH, while for mesoporous silica tethered with a branched polymer (MS-PEI) and MS-APTES the best desorption results were obtained by using NaOH
Summary
Sana Nayab,†ab Humaira Baig,†ac Abdul Ghaffar,c Eylul Tuncel,d Zehra Oluz,d Hatice Duran d and Basit Yameen *a. Simple and low cost adsorbents have been synthesized by several researchers for an effective removal of heavy metals including Cr(VI) even at low concentration.[10,11,12,13,14,15,16,17] Li et al, demonstrated the preparation of chitosan nano bers with an average diameter of 75 nm and cross linked with glutaraldehyde for the removal of Cr(VI).[18] Aboutorabi et al, employed TMU-30 based metal–organic framework (MOF) containing isonicotinate N-oxide as adsorptive sites for the adsorption of Cr(VI) from aqueous solution.[19] Recently, Dong et al, prepared the ionic liquid functionalized cellulose (ILFC) through the gra ing of glycidyl methacrylate onto cellulose microsphere followed by reaction with ionic liquid 1-aminopropyl-3-methyl imidazolium nitrate for the adsorptive removal of Cr(VI).[20] Table 1 gives
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
