Zn Oxide Nanoparticles Research Articles

Ecotoxicological evaluation of sewage sludge contaminated with zinc oxide nanoparticles.

The objective of this work was to evaluate the ecotoxicological qualitative risk associated with the use of sewage sludge containing Zn oxide nanoparticles (ZnO-NPs) as soil amendment. A sludge-untreated soil and two sludge-treated soils were spiked with ZnO-NPs (0-1,000 mg/kg soil). Soil ecotoxicity was assessed with Eisenia fetida (acute and sublethal end points), and the unfilterable and filterable (0.02 μm) soil leachates were tested with a battery of biomarkers using Chlorella vulgaris, Daphnia magna, and the fish cell line RTG-2 (Oncorhynchus mykiss). The production of E. fetida cocoons in sludge-treated soils was lower than that in sludge-untreated soils. The highest effect in the algal growth inhibition test was detected in sludge-untreated soil, most likely caused by the loss of organic matter in these samples. The D. magna results were always negative. Toxic effects (lysosomal cell function and production of reactive oxygen species) in RTG-2 cells were only observed in sludge-treated soils. In general, the toxicity of ZnO-NPs in sludge-treated soils was similar to that of sludge-untreated soil, and the filterable leachate fraction [Zn salt (Zn(2+))] did not produce greater effects than the unfilterable fraction (ZnO-NPs). Thus, after the addition of ZnO-NP--enriched sewage sludge to agricultural soil, the risk of toxic effects for soil and aquatic organisms was shown to be low. These findings are important because repeated use of organic amendments such as sewage sludge may cause more and more increased concentrations of ZnO-NPs in soils over the long-term.

In–Ga–Zn oxide nanoparticles acting as an oxide semiconductor material synthesized via a coprecipitation-based method

Indium–gallium–zinc oxide (IGZO) nanoparticles that can act as an oxide semiconductor were successfully synthesized using a coprecipitation method via the hydrolysis of urea in aqueous media containing ethylene glycol. The resulting IGZO precursor nanoparticles contain crystalline indium hydroxide and zinc–gallium carbonate. Sintering the precursor nanoparticles at temperatures higher than 300 °C provides amorphous IGZO nanoparticles, while poly-crystalline IGZO nanoparticles are obtained at temperatures above 700 °C. Poly-crystalline IGZO ink was prepared using the IGZO nanoparticles for the fabrication of a thin film transistor (TFT). Annealing at temperatures higher than 400 °C for 30 min gives the desired TFT switching properties due to the removal of the organic fraction contained in the ink.

Effect of Curing Conditions on the Fabrication of Zn-oxide Nanoparticles Dispersed in a Polyimide Film

Zinc oxide nanoparticles were formed by reacting polyamic acid (PAA) with Zn during curing. In this paper, we investigated the effect of curing conditions on the zinc oxide nanoparticle formation. The polyimide (PI) precursors used in this study were biphenyltetracarboxylic dianhydride- p-phenylene diamine (BPDA-PDA) type and oxydiphthalic dianhydride 3-sulful dianhydride (ODPA-3SDA) type PAAs. Zn thin films were deposited on silicon substrates by DC magnetron sputter. PAA was then spin-coated onto Zn thin films and the PAA/metal films were cured at various conditions. The characterization using transmission electron microscope observation was carried out to investigate the size and distribution of zinc oxide particles. Zinc oxide nanoparticles were formed in the PI film regardless of the curing conditions. The size, distribution and density of zinc oxide particles were strongly dependent on the curing conditions..