Effect of WO3 Nanoparticle Loading on the Microstructural, Mechanical and Corrosion Resistance of Zn Matrix/TiO2-WO3 Nanocomposite Coatings for Marine Application

In this study, for marine application purposes, we evaluated the effect of process parameter and particle loading on the microstructure, mechanical reinforcement and corrosion resistance properties of a Zn-TiO2-WO3 nanocomposite produced via electrodeposition. We characterized the morphological properties of the composite coatings with a Scanning Electron Microscope （SEM） equipped with an Energy Dispersive Spectrometer （EDS）. We carried out mechanical examination using a Dura Scan hardness tester and a CERT UMT-2 multi-functional tribological tester. We evaluated the corrosion properties by linear polarization in 3.5% NaCl. The results show that the coatings exhibited good stability and the quantitative particle loading greatly enhanced the structural and morphological properties, hardness behavior and corrosion resistance of the coatings. We observed the precipitation of this alloy on steel is greatly influenced by the composite characteristics.

Preparation of Long Afterglow Photoluminescent Material SrAl_2O_4:Eu^(2+), Dy^(3+) and Its Luminescent Property

Long lasting strontium aluminate phosphors were synthesized by means of coated precipitation in the experiment. SrAl 2O 4 monoclinic phase with long afterglow was synthesized at 1 100 ℃ with the aid of H 3BO 3, and the synthetic temperature decreased about 100 ℃—150 ℃ than in solid state reaction. The process of heat treatment was studied by TG-DTA. The phase compositions of powders were analyzed by XRD. The micrographs of the samples were investigated by SEM and the luminescent properties were researched by optical spectrum. The effects of H 3BO 3 on the phase composition and microstructure of the calcined powders were investigated. The results indicated that H 3BO 3 accelerated the formation of SrAl 2O 4 by consuming the intermediate phase. The addition of Dy 2O 3 stimulated the afterglow property due to the increase in the depth of the trap center in the materials.

Uptake and Speciation of Inorganic Arsenic with Cellulose Fibre Coated with Yttrium Hydroxide Layer as a Novel Green Sorbent

A novel adsorbent was developed by coating yttrium hydroxide precipitate layer on cellulose fibre. This material takes up ca. 98% of 5 μg·L 1 As（Ⅲ） and As（V） at low pH （pH〈7）, while a favorable selectivity for As（V） was achieved within pH 11--12. In practice, a mini-column packed with Y（OH）3 precipitate layer coated cellulose fibre particles was incorporated into a sequential injection system for selective uptake of arsenate at pH 11.5. The retained arsenate was afterwards recovered with 50μL of 0.8 mol.L l NaOH solution as eluent, followed by hydride generation in a reaction medium of 2.0 mol·L-1 HCl and 1.0% NaBH4 solution （W/V, in 0.5% NaOH） after pre-reduction of arsenate to arsenite by KI-ascorbic acid （5%, W/V）, with detection by atomic fluorescence spec- trometry. Total inorganic arsenic was quantitatively taken up at pH 6.0 by following the same procedure and arsenic speciation was performed by difference. With a sample volume of 1.0 mL, an enrichment factor of 16.4 was derived with a detection limit of 17 ng.L-1 within a linear range of 0.05--2.0μg.L ]. A relative standard deviation （RSD） of 2.6% （0.5 μg·L-1, n= 11） was achieved. The procedure was validated by analyzing arsenic in a certified refer- ence material GBW 09101 （human hair）, and speciation process requires no organic solvents, thus Y（OH）3 coated of inorganic arsenic in natural water samples. The entire cellulose fibre provides a green adsorbent.