Preparation, Characterization and Infrared Emissivity of ZnO Nanorod/Mica Composites

ZnO nanorod/Mica composite powders were successfully fabricated with chemical liquid deposition (CLD). The composite powder consisting of mica and ZnO nanorod was fabricated via a two-step process: (1) The ZnO colloid particles were absorbed on the surface of sheetlike mica particles via electrostatic interaction, and then heat-treatment was used to attain mica particles with ZnO nanocrystals loaded on the surface; (2) Precursor solution prepared with zinc sulfate heptahydrate, ethanolamine and ammonia was used to load ZnO nanorods on the surface of mica. The resultant composite particles were characterized by XRD, Zeta potential analyzer, scanning electron microscope (SEM) and spectral radiometer. The results showed that the zeta potential of mica in the ethanol/water solution (1:1, V/V) was -37 mV, while the zeta potential of ZnO colloidal particles was 16 mV. Thus the ZnO colloidal particles can be absorbed on the surface of mica particles via electrostatic interaction. As increased deposition density of ZnO nanorod on the surface of mica particles, the emissivity of the particles in 8 similar to 14 mu m region increased from 0.800 to 0.863. Compared with the rodlike ZnO particles, the aggregation of structural unit had no obvious effect on the infrared emissivity of the particles.