The Influence of Anion on the Coarsening Kinetics of ZnO Nanoparticles

Abstract

In solution phase synthesis of nanoparticles, processes such as coarsening and aggregation can compete with nucleation and growth in modifying the particle size distribution in the system. We report on the synthesis of ZnO nanoparticles from Zn(CH3CO2)2, ZnBr2, and Zn(ClO4)2 in 2-propanol. For synthesis from Zn(CH3CO2)2 and ZnBr2, nucleation and growth are fast and are followed by diffusion-limited coarsening. For synthesis from Zn(ClO4)2, diffusion-limited coarsening is observed at shorter times whereas at longer times the particle size increases more rapidly. The rate constant for coarsening at constant temperature increases in the order Br- < CH3CO2 - < ClO4 - indicating that the rate is dependent on anion adsorption. The temperature dependence of the rate constant for coarsening is due to the temperature dependence of the solvent viscosity and the temperature dependence of the bulk solubility of ZnO.

Effect of γ-Fe2O3 nanoparticles on rheological and volumetric properties of solutions containing polyethylene glycol

“…1a, b. The TEM image of cFe 2 O 3 nanoparticles taken by producer was also shown in Quantum effects like band gap enhancement with particle size decreasing are usually main reason for the blue shift of maximum absorption wavelength for particles less than about 80 Å in diameter [22,23]. Therefore, the particle size distributions for nanofluids of c-Fe 2 O 3 -PEG400 and cFe 2 O 3 -PEG400-PEG6000 have been measured in this work.…”

Ambient Degradation of ZnO Powders: Does Surface Polarity Matter?

“…This method of refluxing zinc salts and OH − in an alcoholic medium is one of the most commonly employed methods for making ZnO nanocrystals. 17,[21][22][23][24] The lower solubility of the precursor 3 ) 2 ) in alcohol relative to aqueous media would presumably lead to both faster nucleation and slower ripening, but this has not yet been studied in detail. 13 Surface characterization: short-term degradation.-Surface compositions of freshly made samples were investigated with XPS (Fig.…”

An investigation into the influence of zinc precursor on the microstructural, photoluminescence, and gas-sensing properties of ZnO nanoparticles

“…The combustion of organic species produces a high local temperature, called ''hot spots'' (Carvalho et al 2009), which induced the formation of the necks between the particles (Da Silva et al 2011). According to previous studies, the type of zinc precursors can influence the nucleation, as well as particle growth process of ZnO compound (Hu et al 2003;Singh et al 2013). In the case of acetate ions (CH 3 COO -), the nanoparticles growth was precluded by the presence of organic ions adsorbed on the nanoparticles, reducing the mass diffusion during annealing process and consequently the particle size.…”

“…Some reports in the literature have focused on the control of the materials properties by the choice of a specific synthesis method, as well as the modification on the synthesis parameters such as reaction time, pH, and precursors Du et al 2010;Golic et al 2011;Hu et al 2003;Yousefi et al 2011;Zhang et al 2012).…”