Preparation and characterization of zinc loaded hollow glass microspheres (HGMs) from amber coloured glass frits.

Hollow glass microspheres loaded with ZnO nano particles were fabricated from amber colored glass powder blended with zinc acetate salt, by flame spheroidisation method. The morphology and the microstructure of the samples were observed using SEM, TEM, FTIR and XRD techniques, whereas the composition of the feed glass and product HGMs were determined using EDX and ICP. The results showed that HGMs with surface coating of zinc oxide nanoparticles can be successfully synthesized using this single step process. Effect of zinc acetate percentage (0-10%) in the glass feed on the formation of zinc oxide coated HGMs and the nature of the ZnO coating were studied. A continuous thin coating of ZnO nanoparticles on the HGMs surface were obtained when the zinc acetate content in the feed glass powder was 2 - 5%. Further increase of the zinc acetate in the feed glass led to uneven coating on the surface of HGMs. A clear cut diffraction pattern for crystalline ZnO was observed at the thick patches observed on the HGMs samples with 10% loading of zinc. The thickness of the ZnO coating increased from 10 nm to 500 nm when the zinc content in the feed glass increased from 2 to 10%.