Advanced Materials Research Vols. 148-149

Abstract: In this study, the commercial titanium dioxide (P25) was used to prepare titania aggregates with different morphologies The preparation procedure included the alkali treatment, hydrothermal with different reaction temperature and time, and sequentially spray drying. The results show that the hydrothermal temperature and time have a great influence on the morphology of primary titania particles. The results show that the one-dimensional nanotube, nanorod, and nanowire titania are obtained at T=140°C for t=24h, T=180°C for t=24h, and T=180°C for t=72h, respectively. Moreover, the obtained titania with different primary shapes are successfully applied to prepare the titania secondary particles with various morphologies, i.e., ring-like net structure, bird nest-like porous structure, and dense spherical structure. The optical absorption spectra also show that the titania aggregates obtained after spray drying have a higher optical absorbance in a range of ultraviolet and visible regions.

Abstract: The special electric characteristic of nanomaterials is one of their spectacular features. To fully explore the electric excellence of nanomaterials, it is mandatory that we assemble and connect the nanomaterials into a closed circuit and test its electric property preliminarily. Here, we design, fabricate and characterize an economic microfluidic device for a simple way to manipulate and align silver nanowires onto electrode arrays, and thus test its electric characteristics easily. This approach provides a feasible way to characterize nanomaterials in large scale and also an efficient method for mass integration of nanodevices.

Abstract: Silver slurry was used as conducting material, and the improved silver cathode electrode was fabricated. The CNT paste formed as field emitters was screen-printed on the surface of silver cathode electrode. The diode FED panel with CNT field emitters was sealed, and the fabrication of cathode substrate and anode substrate was described. The screen-printing technology and the sintering process were employed in the course of device fabrication for the silver cathode electrode. The field emission current was measured and the emission image was presented. The packaged FED showed good field emission characteristics and better field emission uniformity, which the manufacture process was also low-cost, feasible and simple.

Abstract: Defect segmentation has been a focal point in fabric inspection research, and it remains challenging because it detects delicate features of defects complicated by variations in weave textures and changes in environmental factors. According to the different features between the normal fabric image and defect image, this paper presents an adaptive image segmentation method based on a simplified region growing pulse coupled neural network (SRG-PCNN) for detecting fabric defects. The validation tests on the developed algorithms were performed with fabric images, and results showed that SRG-PCNN is a feasible and efficient method for defect detection.

Abstract: Carbon nanotube used as the cathode material, the diode-type field emission display panel was developed with low-cost screen-printing method and precise photolithography process. The modified CNT field emitter was fabricated for improving the field emission characteristic, and the detailed fabrication process was also presented. The indium-tin-oxide film on the cathode back-plane was divided to form the CNT cathode electrode, and the insulation slurry was screen-printed to form the insulation layer. Field emission characteristic of whole display device was measured. The sealed field emission display panel showed good emission properties and high display image brightness.

Abstract: Monoclinic scheelite BiVO4 was synthesized from a mixture of aqueous Bi(NO3)3 and NH4VO3 solutions by hydrothermal method. Then using successive coating of BiVO4 with a carbon layer and a ZrO2 layer followed by heat treatment to remove the carbon layer prepared a core-shell(ZrO2@void@BiVO4) nanoparticles with a void layer between the BiVO4 core and the ZrO2 shell. TG-DTA and IR suggest that BiVO4 was coated with ZrO2. TEM shows that there was a void space between the BiVO4 core and the ZrO2 shell. The samples were characterized by XRD and the peaks of ZrO2@void@BiVO4 suits well with the pure phase monoclinic scheelite BiVO4. And its visble-light photocatalytic activity was evaluated by the photodegradation of methylene blue(MB). The results indicated that the photocatalytic activity of ZrO2@void@BiVO4 is similar to that of pure phase BiVO4, which makes it can be used for preparing liquid-gas phase boundary visble-light photocatalyst.

Abstract: Gelcasting is widely used in ceramic material preparation. A disadvantage of this technology is inhomogeneous structure and inner stress caused by temperature gradient owing to the heating of slurry. Theoretical analysis and experiments prove that gelling process of ultrafine ZrO2 can be completed at room temperature. When premixed solution/initiator/catalyst ratio is 100/1/0.5 (by volume), the gelcasting ZrO2 body with homogeneous structure and bending strength of 50.09MPa is prepared.

Abstract: The corrosion inhibition of copper in 3% NaCl solution by 3-amino-1, 2, 4-triazole (ATA) has been studied in relation to the concentration of the inhibitor using electrochemical (AC impedance and dc polarization) techniques. The results indicate that ATA has good corrosion inhibition for copper in 3% NaCl solution. The inhibition efficiency attains the maximum value of 97.65% when the concentration of ATA is 20 mg•L-1.Polarisation curves show that ATA behaves as a type of cathodal inhibition in 3% NaCl solution. Adsorption of the ATA is found to follow the Langmuir’s adsorption isotherm, and the adsorption mechanism is typical of chemisorption.

Abstract: Silicon nitride nanowires have been synthesized by mechanosynthesis method. The silicon powders were first milled for 160 hours under the presence of ammonia gas with 300kPa. And then they were heat-treated at 1250 for 2 hours in the pure nitrogen gas. The phase and the microstructure of the as-prepared product were detected by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The results showed that the product consisted of α-Si3N4 nanowires. The nanowires had the length of tens of millimeters and the diameters of 50～100nm. The vapor-solid (VS) mechanism was employed to interpret the nanowires growth.

Abstract: The inhibition action and adsorption behavior of an environment-friendly inhibitor polyepoxysuccinic acid (PESA) on copper in aqueous NaCl (0.02%) solution was investigated by means of electrochemical techniques. The results indicated that the best inhibition efficiency of PESA was 69.5% with the concentration of 12 mg/L at 20 . The adsorption of PASP prevented Cu from being corroded. The adsorption behavior of PASP followed Langmuir isotherm, it was spontaneous, and belonged to chemical adsorption.