Effect of vitamin C template on morphology and structure of alumina: emerging application in enantiomer separation

Abstract

Mesoporous nano-aluminas were prepared using aluminium isopropoxide, vitamin C (VC as a chiral template and a co-struc- tural directing agent with molar ratios of 50:50 and 90:10) and water. These compositions when dried at 120 °C and calcined at 250, 350 and 500 °C for 8 h under air atmosphere transformed to boehmite and γ-alumina depending on the concentration of VC. The influence of vitamin C and its degradation products on the morphology and texture of alumina was investigated by the means of XRD, FT-IR, SEM, EDX, TEM, TGA, DSC, BET and N2 adsorption–desorption isotherm. Mesoporous aluminas possess excellent characteristics such as large surface area (ca. 394 m2/g), 0.4 cm3/g pore volume and narrow pore size distributions that can be synthesized through a facile and green procedure. In addition, the enantiomers of pro- pranolol hydrochloride were successfully resolved from its racemate using Al50VC50T350 (AlMolar ratio of the Aluminium isopropoxide, VCMolar ratio of the Vitamin C, TTemperature) (Rs = 2.5) as chiral stationary phase. The synthesis of chiral stationary phase was accom- plished in a green, facile and inexpensive procedure that is of paramount importance in food and pharmaceutical