Advanced Materials Research Vol. 650

Abstract: This work use the D-gun system to spray the WC-17Co coating. analyzed the microstructure and performance of the coating by SEM, EDAX, XRD, HAXD. It gave a basis for the next research work for the anti-wear coating on aluminum alloy. The hardness of the WC-17Co coating is about HV1100~1300, the average porosity less than 1%. And the max diameter of the single hole is less than 0.012mm. There are no apparent oxide in the coating. The WC particles occurred decarburization during the spraying process and deposited the coating that composed with W2C and Co3W3C phases. The corrosion resistance of the coating is more ideal. But the phase distribution in the coating is not enough uniform.

Abstract: The effect of the annealing temperature (390°C, 410 °Cand 430°C) on the stress relaxation of air side and tin side of ion exchanged glasses was investigated. The annealing time dependence of stress at different temperature can be well fitted by a second order exponential function. The stress relaxation rate on tin side is larger than air side at the ion exchange temperature (410°C) or below (390°C) but smaller above the ion exchange temperature (430°C). The depths of stress layer (DOL) of all ion exchanged glasses increase with the increasing of annealing time and the DOL on air side is always larger than tin side. These provide useful information for subsequent treatment of ion exchanged glasses.

Abstract: BMI composite is important class of material use in aerospace industry. In this paper we have fabricate glass fiber reinforced composite using DABA/BMI/KH550 matrix, And characterize the mechanical and thermal properties accordingly, Mechanical and thermal properties results shows that newly developed composite has better properties than that composite made from DABA/BMI matrix.

Abstract: The silver nanoparticles (Ag NPs) were loaded into pH sensitive polymer microspheres by in-situ reduction method, which are composed of linear poly(acrylic acid) (PAA) and cross-linked poly(N-isopropylacrylamide) (PNIPAM). The morphological structure of the formed composite microspheres and the particle diameter of the embeded Ag NPs were characterized by field emission transmission electron microscopy, their weight content by thermogravimetric analysis, and the pH sensitivity of the microspheres by dynamic light scattering. The absorbance spectra of the composite microspheres dispersed in the aqueous media with different pH values were measured by ultraviolet-visible spectrometry, and the obtained results show that the remarkable dependence relationship exists between the optical property of localized surface plasmon resonance (LSPR) of the loaded Ag NPs and the pH value, indicating that their LSPR property can be tuned by environmental pH value.

Abstract: The modified carboxymethyl cellulose(CMC) was prepared and explored to adsorb uranium(Ⅵ) ions from aqueous solution in a batch system. The experimental results showed that on the condition of reaction temperature 70~80°C, CMC 30%-35% (w/w), CMC to AA (w/w) of 10:2.5 and reaction time 3.5-4 h, the modification effect was the best. High removal efficient of U(Ⅵ) was obtained 97.1% at temperature of 25°C, pH value of 5.0, dosage of modified CMC 0.1 g/L and contact time of 60 min. It was found that the adsorption process was best described by Freundlich model and pseudo-first-order kinetic model (R2=0.9618), indicating that the adsorption is mainly on the surface of the modified CMC. Thermodynamics parameters of negative value of ΔG0 and positive value of ΔH0 revealed the spontaneity and endothermic nature of the adsorption. The adsorption is primarily due to physical adsorption.

Abstract: To study photo-oxidation behavior of PVC-coated membrane material under different UV radiation intensities, three intensities of Ultraviolet (UV) irradiation were carried out. The yellowness indexes under different weathering conditions were measured, as well as UV-Vis spectrometry. Result shows that the photo-oxidation mechanism doesn’t change under different UV intensities, but the photo-oxidation reaction rates are not equal when the cumulative UV radiation energy is same. A conclusion is obtained that photo-oxidation reaction rate under different intensities is out of proportion to UV intensity. And according to Schwarzschild’s law, an equation form is established to predict material’s life.

Abstract: Nano-PLLA/chitosan scaffolds were prepared through thermally induced phase separation(TIPS). With incorporation of chitosan fibers, composites not only improved the mechanical properties of nano scaffolds, but also reduced the degradation rate of mechanical properties which deepen the applications of scaffolds better.

Abstract: Polyaniline(PANI) doped by natural acid(citric acid, salicylic acid or rosin acid)solutions was synthesized using aniline as monomer and ammonium peroxydisulfate ((NH₄)₂S₂O₈) as oxidant. The antibacterial activities of the PANI against Gram positive bacteria(Bacillus megatherium, Bacillus subtilis, Bacillus cereus and Staphylo-coccus aureus) and Gram negative bacteria(Bacillus coli) were investigated. It was shown that PANI doped by citric acid possessed the better antibacterial activity against the selected species of Gram positive bacteria and Gram negative bacteria than PANI doped by rosin acid. PANI doped by salicylic acid exhibited ascendant antibacterial activities against Gram positive bacteria, but it has little antibacterial activity against the Gram negative bacteria.

Abstract: Terahertz ray (T-ray) imaging has been emerged as one of the most promising new powerful nondestructive evaluation (NDE) techniques, and new application systems are under processing development for the area applications. The terahertz time domain spectroscopy (THz TDS) can be considered as a useful tool using general non-conducting materials; however it is quite limited to conducting materials. In this study, a new time-domain spectroscopy system was utilized for detecting and evaluating layup effect and flaw in FRP composite laminates. In order to solve various material properties, the index of refraction (n) and the absorption coefficient (α) are derived in reflective and transmission configuration using the terahertz time domain spectroscopy. However, the T-ray is limited in order to penetrate a conducting material to some degree. So, investigation of terahertz time domain spectroscopy (THz TDS) was made and reflection and transmission configurations were studied for a 48-ply thermoplastic PPS (poly-phenylene sulfide)-based CFRP solid laminate.

Abstract: The leaching experiments of finished pigskin, finished cowhide and finished sheepskin are conducted in this essay with liquor of different pH to research the leaching performance of chrome. After continuous leaching of 120 hours, it turns out that chrome is leached out most under the effect of the liquor whose pH is 2, and it is intermittent. Comparing the content of extracted chrome, it turns out those samples, treated with liquor whose pH is 2, has increased values, which proves that the stability of chrome in leather declines.