Anodic ZrO2 Nanotube Arrays Formation by Anodisation in Ethylene Glycol with Varying Amount of Water

Anodisation of zirconium, Zr at 40 V for 60 min in 0.1 wt.% NH4F/ethylene glycol (EG) added to it 1 ml, 2 ml or 3 ml of water resulted in the formation of self-aligned ZrO2 nanotube (ZNT) arrays. Water content did not affect the length and diameter of the ZNTs but was influencing surface etching whereby better surface etching was observed for sample anodised in 3 ml-water/NH4F/EG. From transmission electron microcopy (TEM) image, the ZNTs were found to have an outer diameter of ~ 40 nm and wall thickness of 10 nm. Annealing at 400 °C was resulted in monoclinic (M-ZrO2) and tetragonal (T-ZrO2) formation, but at 600 °C M-ZrO2 dominates. Cr(VI) reduction is higher for ZNTs annealed at 400 °C compared to 600 °C sample.

QDs-Epoxy Resin for Strain Monitoring

The discovery of the variation of the photoluminescence (PL) intensity of quantum dots (QDs) with mechanical deformation has stimulated the interest of developing QDs-based structures for the measurement and monitoring of stress or strain. In this work, tensile bars with the coating of QDs-epoxy composite are subjected to cyclic loading and unloading tests, and the PL intensity of the coating of QDs-epoxy composite is measured as a function of mechanical strain. There are four types of responses in the PL intensity, depending on the loading condition. Transmission electron microcopy is used to examine the rearrangement of QDs in the coatings before and after the tensile tests for understanding the change in the PL response.

Synthesis and Characterization of CdSe Nanocrystal Quantum Dots by Solution-Liquid-Solid Method

The present work describes a solution-liquid-solid (SLS) synthesis route for the preparation of CdSe nanocrystal quantum dots using the low-melting-point Bi nanoparticles as catalysts. UV-vis absorption spectra were used to determine the growth of CdSe cluster. The shape and size distribution of the CdSe QDs were determined by analysis of Transmission electron microcopy (TEM) images. A peak wavelength of 399nm in the absorption spectra on day 5 indicated that the CdSe cluster formed. TEM micrographs showed that CdSe QDs had a relatively narrow distribution of QD size, and the diameter of CdSe QDs was about 4 nm. Our preliminary results illustrated that smaller size of CdSe QDs could be prepared by SLS method and it was small enough for bioimaging applications.

Nanotwins in Copper Nanowires Controlled by Laser Assisted Electrochemical Deposition

Nanotwins in metallic nanowires can improve mechanical strength and maintain high electrical conductivity. We demonstrated a method of pulse laser assisted electrodeposition, which can generate dense nanotwins with different directions in copper nanowires of uniform length. Transmission electron microcopy characterization shows at lower electrochemical potential of −0.2 Volt, nanotwins tend to align along the longitudinal direction of the nanowires whereas at the high potential −0.8 Volt, nanotwins of {111}/<112> type that cross the width of the wire are formed. We investigated the two types of nanotwins by comparing the microstructures under different electrochemistry and laser setting. Two different mechanisms are proposed for two kinds of nanotwin — annealing twins and growth twins.

Synthesis of CdMoO4 Microcrystals by a Molten Salt Method

Cadmium molybdate (CdMoO4) nanoparticles, cube-like crystallites and octahedral microparticles have been successfully synthesized by a molten salt method at 270°C. The structure, morphology and luminescent property of the resultant powders were characterized by X-ray diffraction (XRD), transmission electron microcopy (TEM), scanning electron microcopy (SEM), and photoluminescence (PL), respectively. The resultant samples are a pure phase of CdMoO4 and without any impurities. PL spectra results show that the optical properties of CdMoO4 particles are strongly relied on their morphologies.