Advanced Materials Research Vols. 239-242

Abstract: This study aims at analyzing the chemical resistance of a wide range additives in air curing fluorocarbon coatings. Scanning Electron Microscope (SEM) and Immersion tests are used to detect coatings performances. The results showed that the surface state of coating does not affect the chemical resistance. While fumed SiO₂ content in the coating is lower than 5.2%, chemical resistance are enhanced as the increasing of fumed SiO₂ content, then maintained stability as content is more than 5.2%. Chemical resistance is increased gradually while the rutile TiO₂ content of coating is less than 3.1%, and essentially unchanged while greater than 3.1%. As wax powder content increases, chemical resistance of coating decreased. Coupling agent content increases, leading to enhanced chemical resistance of the coating when coupling agent content is less than 5.8% and maintained stable while greater than 5.8%. So fumed SiO₂, rutile TiO₂, and coupling agent would inhance chemical resistance for coating to a certain extent, and wax powder would weaken the chemical resistance.

Abstract: In this study, 1-phenyl-3-(1-aniline)-1-propene (PAP) was synthesized by aniline and Cinnamaldehyde, and its inhibitive effect on N80 steel in 15% HCl solution was investigated by using weight loss and electrochemical techniques (such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization). The chemical structure of PAP was confirmed by Fourier transform infrared spectroscopy (FTIR). The results were shown that, the inhibition efficiency of PAP could exceed 99%. Polarization measurements indicated that, the inhibitor acted as mixed type.

Abstract: The Ni-P/SiC composite coating was prepared by chemical deposition technique. The micro-structure and wear behavior of electroless Ni-P/SiC composite coating was investigated. The results show that the composite coating was dense and no any defects at the interface between substrate and electroless composite coating. Its thickness could reach 40 μm. Wear resistance was increased with the increasing content of SiC particles for single composite coating when the SiC concentration was less than 6g/L, then decreased with the increased SiC concentration. The wear resistance of gradient composite coating was improved above 16% comparing with the single composite coating. The wear resistance of T₁ gradient coating was best for all electroless Ni-P/SiC composite coatings because the bonding strength was improved owing to the gradient change of SiC content.

Abstract: The core-shell structure’s synthesis process by one-step hydrothermal method has remarkable peculiarities, such as simple procedures and short production cycles. In order to get the precursor with the core-shell structure, it’s important to study the technological parameters. In this paper, the pH value, the concentration of AlCl₃,the mass ratio of core and shell , the hydrothermal temperature and time were detailed discussed. In order to get well-coated core-shell material, the technological parameters were the pH value=8.5-9.8, the concentration of AlCl₃ 0.040－0.050g/ml, Al₂O₃：TiO₂=10％－28.5％, the hydrothermal temperature 200°C and the hydrothermal time 3 hours.

Abstract: Bacterial induced infection is a major complication associated with the use of medical implants. Degradable antibacterial ciprofloxacin-polyurethanes (CFPU) have been synthesized in attempts to address this problem. It is supposed that the material may be sensitively hydrolyzed by inflammatory enzyme, cholesterol esterase (CE), and the drug could be released according to the state of infection. The enzyme biodegradation experiments showed an extra release of ciprofloxacin when CFPU was incubated by enzyme solutions than by phosphate-buffer saline (PBS). Results showed that the drug release was enhanced as the concentration of the enzyme increased. The antimicrobial activities of degradation solutions were tested by broth dilution assay. The enzyme degradation solutions exhibited an ability to kill bacteria. The cell cytotoxicity assay indicated that the degradation products were hypotoxicity to human beings according to the cytotoxicity grade of United States Pharmacopoeia (USP).

Abstract: The FeAl/Al₂O₃ composites were fabricated by pressureless sintering process. The FeAl intermetallics compounds powders were fabricated by mechanical alloying and heat treatment process. The FeAl intermetallics compounds powders and Al₂O₃ powders were mixed and the FeAl/Al₂O₃ composite powders were prepared. The FeAl/Al₂O₃ composites bulks were fabricated by pressureless sintering process at 1600°C for 2h. The phase composition and microstructure of FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition and microstructure of the FeAl/Al₂O₃ composites sintered bulks were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were fabricated by mechanical alloying for 60h. The FeAl intermetallics compounds powders were fabricated by heat treatment at 800°C, 900°C and 1000°C. The microstructure showed that the mean particles size of the FeAl intermetallics compounds powders produced by mechanical alloying and heat treatment process was rather fine and about 4-5μm. The XRD patterns results showed that there existed the FeAl phase and Al₂O₃ phase in sintered composites. The FeAl/Al₂O₃ composites bulks exhibited the homogenous and compact microstructure. The mean particles size of FeAl was about 4-5μm and the mean particles size of Al₂O₃ was about 5-10μm. The density and relative density of the FeAl/Al₂O₃ composites increased gradually with the increase of FeAl content.

Abstract: The thermal and electrical transport properties of carbon micro-coils under the condition of common use were measured and discussed. The temperature-dependence, the load-bearing stability, the explicit and implicit values of those properties were brought forward to provide the references for their reliable industrial design and high efficient service.

Abstract: The optical fiber corrosion sensor was applied to measure the steel corrosion based on Fe-C corrosion-sensitive metal film, the sensing principle of which was introduced. Because corrosion was a complex random phenomenon and the corrosion surface of Fe-C alloy film of the optical fiber corrosion sensor possessed fractal characteristics, the image fractal dimensions was as a quantitative index of the sensor corrosion degree. The experimental results showed that the complexity level of the sensor surface morphology increased and the optical output power increased along with the increase of fractal dimensions. Therefore, a new method was provided for the research of the optical fiber corrosion sensor.

Abstract: Two camouflage paints were developed respectively on the surface of concrete and metal surface for getting high weather resistance. Different materials and their ratios especially those used in anti-aging agents, pigments and fillers were studied. Results indicated the prepared compound formula could significantly improve the properties of camouflage paints. The useful lives of products were extended and could meet the requirement of military.

Abstract: The effect of load on the friction and wear behavior of NBR and FPM was investigated using a ring-on-block tester under dry sliding. The hardness and morphology of worn surface were measured using Shore Hardness and stereo microscope, respectively. The results showed that at the load of 50, 100 and 150N, the wear loss of NBR was lower than that of FPM and the frictional coefficient of NBR was the same as that of FPM. While at the load of 175, 200 and 225N, the wear loss and frictional coefficient of NBR were higher than that of FPM. The reason for the variation of friction and wear behavior of NBR and FPM under different load was discussed preliminarily.