Exploring Qualitative and Quantitative Decoration on Amine-Modified Mesoporous Silica for Enhance Adsorption Performances

Abstract

Using the triblock copolymer Pluronic F127 as a surfactant, tetraethyl orthosilicate (TEOS) as a silica source, and hydroxylamine hydrochloride as an amine source, a group of amines-modified mesoporous silica Santa Barbara Amorph-16 (SBA-16) materials with different template withdrawal methods and amine loading concentrations were prepared through sol-gel conditions. The investigation will provide qualitative and quantitative information on amine-modified SBA-16 decoration with a brief overview of the non-destructive analysis methods for advanced materials as adsorbent candidates. Highly ordered mesostructured amine-modified SBA-16 materials were prepared using high-temperature (or calcination) and solvent extraction de-templating methods. Mesostructured amine-modified SBA-16 has been successfully examined using a Synchrotron Radiation Low-Angle X-ray Diffraction (SR-LXRD) instrument for phase identification, Small-Angle Synchrotron X-rays Scattering (SAXS) for identifying structural changes in a porous material, Fourier Transform Infrared (FTIR) for identifying functional groups, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) elemental analyzer for determining the number of silica, oxygen, and nitrogen elements, and a Specific Surface Area (SSA) analyzer for measuring the specific surface areas. The SR-LXRD and SAXS results demonstrated that the synthesized novel materials were defined unambiguously as a bi-continuous cubic body center Im3m mesostructured. FTIR and SEM-EDS analyses verified that the amine groups were uniformly deposited on the SBA-16 surface. The SSA analyzer results also clarified that the novel materials exhibited ordered and meso-framework amine-modified SBA-16 with a large surface area. Novel materials can be considered high-potential uranium adsorbent candidates. Preliminary adsorption investigations have shown that the amine-modified SBA-16 materials can adsorb uranium in natural seawater showing an uptake capacity of as much as 24.48 mg-U/g-adsorbent.