Synthesis of Zinc Carbonate Hydroxide Nanoparticles Using Microemulsion Process

In order to control the particle size and morphology, zinc carbonate hydroxide Zn5(CO3)2(OH)6 nanoparticles have been synthesized using a reverse microemulsion technique. The pseudo-ternary phase diagrams of the two microemulsion systems, prepared using CTAB/1-butanol/n-octane/aqueous phase system with the aqueous phase comprised of either zinc nitrate (Zn(NO3)2) or sodium carbonate (Na2CO3), were experimentally constructed. The nanoparticles synthesized by mixing of the two emulsion systems were further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The nanoparticles were further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Several important experimental parameters have been investigated for the ability to control particle size and morphology as the function of water/surfactant molar ratio (ω), water/oil molar ratio (S) and the initial concentration of reactants in the aqueous phase. Results indicate that ω values have the ability to affect the particle size and levels of aggregation, while S values had no apparent effect. In addition, the initial concentration of reactants in the aqueous phase was considered to be an important parameter as raising its values from 0.1 M to 0.5 M produced an unknown phase of zinc carbonate, exhibiting larger particle size with a unique flake like morphology.