Shape Controlled Synthesis of Barium Carbonate Microclusters and Nanocrystallites using Natural Polysachharide – Gum Acacia

Abstract

Different morphosynthesis strategies for BaCO3 using natural polysaccharide-gum acacia (GA) as templating species are presented. The influence of GA with different functionalities such as -OH, -COOH and -NH2 on the crystalli- zation and structure formation was investigated. Some interesting morphologies, including rods, dumbbell, double-dumbbell and flower like clusters, can be readily generated by using GA as cooperative modifier in the mineralization process, under the conditions of 0.5%, 1% of templating species and at ambient temperature. The modifier GA and its concentration is the key factor in this system. In continuation, morphology was also examined for mixed metal carbonates (Ba-LaCO3, Ba-TbCO3). The possible formation mechanism of the nanocrystallites is discussed. Structural characterization of the syn- thesized materials was investigated by Powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis (EDAX), Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA) coupled Mass (MS) and Fourier Transform Infrared spectroscopy (FT-IR).