composite coatings have been synthesized on mild steel shafts using surfactant cetyltrimethyle ammonium bromide (CTAB) as dispersant. The effects of the surfactant on the alumina dispersion, weight fraction in coatings, and corrosion resistance of the composite coatings under salt spray test were investigated. Results showed that alumina dispersion was improved, whereas weight fraction was decreased, with the increasing concentration of the dispersant CTAB. The corrosion resistance of the composite coatings was found to increase with the increase in CTAB concentration up to a certain optimum of 20 mg/L, beyond which a decreasing trend of corrosion resistance was observed under salt spray test. Compared with Ni-P coating, all the Ni-P-Al 2 O 3 composite coatings showed improved corrosion-resistant properties.

Dense arrays of ultra-thin zinc oxide (ZnO) nanorods have been fabricated on c-oriented ZnO seed layers by hydrothermal growth, with particular emphasis on exploring the effects of annealing or plasma pre-treating the seed layer. Such pre-treatments influence the density, size and surface defects of particles within the nucleating seed layer, which impacts on the subsequent nanorod growth via sequential reaction with OH À and Zn 2+ species. Oxygen-rich defects at the seed layer surface are deduced to have particular impact -affecting both the c-axis growth rate and the photoluminescence properties of the as-grown nanorods.

A novel one-step coating and assembly approach was employed to fabricate well-defined ZnO nanodot/SiO2 nanorod arrays, which exhibit much enhanced UV emission efficiencies and excellent stability.