Abstract: In order to reduce the adherence of platelets to the pyrolytic carbon surface of cardiac valve prosthesis, micro patterns are textured on the surface by nanosecond laser. As the basement, the textured pyrolytic carbon then reacts with formamide and zinc by hydrothermal method for preparation of globular ZnO film. In the process, the formamide concentration should be 10%, temperature at 70°C and the time lasts for 24 hours. Subsequently, scanning electron microscope (SEM) is employed for observation of its characteristics and morphologies and Optical Contact Angle Measuring Device (OCA) for measurement of contact angles. The experimental results indicate that the ZnO film produced on the textured pyrolytic carbon surface is a globular structure, similar to dandelions and the contact angle with super-hydrophobicity feature is 155 o. So it is concluded that globular ZnO film makes the rough pyrolytic carbon surface endowed with the characteristic of super-hydrophobicity.
Abstract: Six multilayered films with overall compositions of Co10Zr80Nb10, Co10Zr70Nb20, Co20Zr70Nb10, Co30Zr60Nb10, Co20Zr60Nb20 and Co10Zr60Nb30 were first prepared by alternatively depositing high pure metals onto the NaCl single crystal substrates and then irradiated by 160 keV xenon ions with the doses ranging from 2×1014 Xe+/cm2 to 9×1015 Xe+/cm2. It turns out that several metastable phases, e.g. amorphous phase, were formed in these metallic multilayered films upon irradiation. Meanwhile, some interesting phase transformations were also observed with increasing irradiation doses. Besides, the phase formation and transformation mechanism of non-equilibrium alloy phases are discussed in terms of thermodynamics of solids and atomic collision theory.
KEYWORDS: Zr-Co-Nb system, metastable alloys, phase transformation, ion beam irradiation
Abstract: Magnetic Fe3O4 nanobubbles surrounded by nanoparticles are prepared by adopting microwave assisted reflux method. The nanomagnetic particles surrounded by small beads like particles are fabricated by irradiating the prepaperd sample solutions by microwave radiations coupled with reflux method simultaneously at 90°C for 45 mins. The characterization of the prepared Fe3O4 particles are carried out by using x ray diffraction, scanning electron microscopy and transmission electron microscopy. The instrumentations shows the morphology that is thick walled bubble like with approximate diameter of about 300 nm to 400 nm surrounded by small nanoparticles of 5 nm to 30 nm in range. The particles are bubbles like and some broken bubbles showed that these might be hollow from inside.
Abstract: The structural and electronic properties of fully-relaxed thin-film SrTcO3 are investigated using first-principles method. In contrast to the insulating property of the bulk SrTcO3, the thin-film SrTcO3 with a thickness of 8.06 Å is found to be nearly metallic with a very small band gap of 0.17 eV. Its band structure meets the demands of being thermoelectric material. Moreover, thin-film SrTcO3 is found to retain its bulk high magnetic ordering temperature(TN) property, which suggests that it is applicable in high ambient temperatures. Comparison of the electronic/magnetic property of thin-film and bulk SrTcO3 is performed to explore the origins of their different electrical properties.
Abstract: This paper presents the investigation of cyproconazole,namely2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol,ascorrosion inhibitor for copper in synthetic seawater (3.5% NaCl solution).The inhibition action of cyproconazole on the corrosion of copper was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization.The selective desorption of Cyproconazole from copper surface was also studied by the differential polarization curves.EIS indicates that the inhibition formed an adsorption film on copper surface.The inhibition efficiency increases with increasing concentration.Polarization curves show that Cyproconazole acts as mixed-up inhibitor.
Abstract: Reactive ion etching (RIE) of bismuth zinc niobate (BZN) thin films using an SF6/Ar plasma has been studied. An optimum process parameters was obtained according to the highest etch rate of 90nm/min. Under this etching condition, the crystal structural properties and surface morphology of the BZN film before and after etching were characterized using X-ray diffraction (XRD), the film showed a surface reconstruction after etching, a cubic pyrochlore structure orientation transition was observed from preferential (222) to (400), and ZnF2 phases were detected. The film surface was chemically analyzed by X-ray photoelectron spectroscopy (XPS) to investigate the reactive ion etching mechanism. A zinc-rich surface was formed because low-volatile ZnF2 residues were difficult to remove.
Abstract: Sonochemical degradation of the antibiotics chloramphenicol in aqueous solution with sodium peroxydisulfate sulphate (SPDS) enhancement was investigated. The preliminary studies of optimal degradation methodology were conducted with sole SPDS, cobalt activated SPDS (SPDS/Co2+), ultrasonication with SPDS (SPDS/US) and ultrasonication with cobalt activated SPDS (SPDS/Co2+/US). The effect of the initial pH values of the aqueous solution on the sonochemical degradation rate of chloramphenicol was also investigated. The results showed that the sonolysis of chloramphenicol can be accelerated remarkably by adding SPDS and the efficient treatment method for treating the chloramphenicol wastewater was ultrasound coupled cobalt activated SPDS. The ultrasonic degradation rate constants in acidic water are higher than those obtained in neutral or basic aqueous solutions.
Abstract: Chiral fluorinated side-chain liquid-crystalline elastomers (LCEs) IP - IVP were graft copolymerized by hydrosilylation reaction. The chemical structure, liquid-crystalline behavior and polarization property were characterized by use of various experimental techniques. The effective crosslink density of the chiral LCEs was studied by swelling experiments. All the samples IP - IVP displayed chiral smectic C mesophase (SC*) on heating and cooling cycles. With increasing chiral crosslinking units in the elastomer systems, the glass transition temperature and chiral smectic C mesophase-isotropic phase transition temperature of fluorinated elastomers increased slightly, indicating that the temperature range of SC* mesophase became narrow with increase of chiral crosslinking agents for all the chiral fluorinated elastomers. All the samples IP - IVP showed 0.12-0.16 μC/cm2 of spontaneous polarization.
Abstract: Sodium hyaluronate / konjac glucomannan (SH/KGM) porous scaffolds were prepared via blending sodium hyaluronate and konjac glucomannan. The ammonia was used as cross-linker in blending process. The SH/KGM scaffolds were soaked into calcium nitrate solution and then followed by immersing into simulated body fluid to get SH/KGM/HAP porous scaffolds. X-ray diffraction and fourier transform infrared spectroscopy (FTIR) were used to characterize the crystallization and chemical structure of SH/KGM and SH/KGM/HAP scaffold materials. The scanning electron microscope (SEM) was used to analysis the morphology of SH/KGM/HAP scaffold and BMSCs on surface of the scaffold. The results show that hydroxyl-apatite produced on the surface of the SH/KGM, which appears as spherical particles in the SH/KGM/HAP scaffold surface, and the SH/KGM/HAP porous scaffold possesses good biocompatibility with cell.