SOL-GEL SYNTHESIS AND CHARACTERIZATION OF MACRO-MESOPOROUS TITANIA MONOLITH AND ITS APPLICATION IN CHROMATOGRAPHIC SEPARATION OF CARBOXYLATES

Abstract

Monolithic titania materials with macro-mesoporous skeleton were prepared through a template-free sol-gel synthesis route, based on the reaction of hydrolysis and polycondensation of titanium isopropoxide. Acetic acid (HAc), hydrochloric acid (HCl), and redistilled H2O were utilized as the starting reagents, without the addition of otherwise commonly used chemical modifier such as poly(ethylene oxide) and formamide. The synthesis method applied herein was economical and convenient, which allowed synthesizing titania monolith with bimodal macro-mesoporosity directly. The titania monolith with more than 10 cm in length, possessed a specific surface area of 88 m2/g (calcined at 350°C), a narrow pore size distribution, an anatase crystallite structure and great mechanical strength, and the porosity texture could be controlled by adjusting the starting composition. Using synthesized titania monolith as HPLC stationary phase, the mixture of carboxylates was successfully separated.