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941.
942.
Adsorption of ciprofloxacin and its role for stabilizing multi-walled carbon nanotubes and characterization 总被引:1,自引:0,他引:1
S. Ashok Kumar 《Materials Letters》2009,63(21):1830-1833
In this study, multi-walled carbon nanotubes (MWCNTs) were dispersed in an aqueous solution using ciprofloxacin (CF) without chemical modification. We found that CF is a useful stabilizer for MWCNTs and the dispersions were stable for more than one month. Scanning electron microscopy, Uv-visible spectroscopy and cyclic voltammetry (CV) showed MWCNTs coated with CF molecules. Dry film of MWCNTs/CF was prepared and characterized by SEM, Uv-vis and CV. MWCNTs/CF dry film can be used as a biocompatible platform for other applications including protein and enzyme immobilization. 相似文献
943.
Yang Yang 《Materials Letters》2009,63(2):331-333
Mesoporous W6+-doped TiO2 thin films photocatalysts were prepared via electrospinning and sol-gel chemistry, employing a triblock copolymer as structure-directing agent, and were characterized by SEM, TEM, XRD as well as N2 adsoption/desorption isotherm. The photocatalytic activity of the films was investigated by employing the methylene blue (MB) as probe. In this study, 3% was the most suitable content of W6+ in TiO2, at which the recombination of photoinduced electrons and holes could be effectively inhibited. In the mean time, making the photocatalysts at nanoscale and with mesopores in the films could produce more reactive sites to adsorbe and oxidize pollutants. 相似文献
944.
Nuria Hidalgo Mauricio E. Calvo Hernán Míguez 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(20):2309-2315
A synthetic route is presented to attain high‐optical‐quality multilayered structures that result from coupling ordered mesoporous titanium oxide thin films to the surface of a dense one‐dimensional photonic crystal. Such architectures present spectrally well‐defined photon resonant modes localized in the outer coating that finely respond to physicochemically induced modifications of its pore volume. The potential of these porous coatings in detection of environmental changes through variations of the photonic response of the ensemble is demonstrated by performing isothermal optical reflectance measurements under controlled vapor‐pressure conditions. 相似文献
945.
946.
Gil-Sung Kim Mi-Ri Lee Seung-Yong Lee Jung-Hwan Hyung No-Won Park Eun Sun Lee Sang-Kwon Lee 《Nanoscale research letters》2013,8(1):371
We prepared two-dimensional Bi thin films with high-density ordered nanoscopic pores by e-beam evaporation of Bi metal. For this structure, we used polystyrene beads ranging from 200 to 750 nm in diameter as an etch mask. The typical hole and neck sizes of the Bi thin films with approximately 50 nm in thickness on SiO2/Si substrates were in the range of 135 to 490 nm and 65 to 260 nm, respectively. By measuring the thermal characteristics through a 3ω technique, we found that the thermal conductivities of nanoporous Bi thin films are greatly suppressed compared with those of corresponding bulk materials. With a decrease in pore size to approximately 135 nm, the thermal conductivity decreased significantly to approximately 0.46 W/m·K at 300 K. 相似文献
947.
Thin films can make a useful link between single crystal and supported vanadium oxide. The deposition of vanadium oxide thin films with physical vapour deposition techniques ensures clean and highly controllable synthesis. The resulting material is easily accessed with surface sensitive techniques. On flat TiO2 anatase substrates, XPS–XPD and UPS indicated that the vanadia deposition was epitaxial, and fully oxidised if performed in situ. A step closer to typical industrial catalysts was achieved by sputter deposition onto sub-millimetre inert particles. In addition to surface characterisation, these model particle catalysts allow use in reactors for catalytic testing under relevant process conditions. On both silica and titania supports, sputter deposited vanadia of varying thickness proved to be equally well dispersed. Oxidative dehydrogenation (ODH) activity was higher over vanadia/titania (anatase) than over vanadia/silica, demonstrating the synergetic interaction between anatase and vanadia. Highest activity in alkane ODH was observed for vanadia a few monolayers thick, supported on titania-coated particles. 相似文献
948.
Copper (Cu)-doped ZnO thin films were grown on unheated glass substrates at various doping concentrations of Cu (0, 5.1, 6.2 and 7.5 at%) by simultaneous RF and DC magnetron sputtering technique. The influence of Cu atomic concentration on structural, electrical and optical properties of ZnO films was discussed in detail. Elemental composition from EDAX analysis confirmed the presence of Cu as a doping material in ZnO host lattice. XRD patterns show that the films were polycrystalline in nature with (002) as a predominant reflection of ZnO exhibited hexagonal wurtzite structure toward c-axis. From AFM analysis, films displayed needle-like shaped grains throughout the substrate surface. The electrical resistivity was found to be increased with increase of Cu content from 0 to 7.5 at%. Films have shown an average optical transmittance about 80% in the visible region and decreased optical band gap values from 3.2 to 3.01 eV with increasing of Cu doping content from 0 to 7.5 at% respectively. Furthermore, remarkably enhanced photoluminescence (PL) properties have been observed with prominent violet emission band corresponding to 3.06 eV (405 nm) in the visible region through the increase of Cu doping content in ZnO host lattice. 相似文献
949.
Octadecylamine (ODA) film assisted with the preferential adhesion of poly‐DOPA was prepared on copper substrates by dip‐coating method. The DOPA self‐polymerized and adhered membrane was firmed to the copper substrate in mild aqueous alkaline environments. By immersing the substrate coated with poly‐DOPA in its absolute ethyl alcohol solution, ODA was adsorbed onto the substrate to give a hydrophobic surface. The formation and surface structure of the film were characterized by water contact angle measurement (DA), and scanning electron microscopy. The corrosion behavior of the functional hybrid films was evaluated by electrochemical impedance spectroscopy. Experimental results show that the impedance of the composite films reaches to 106 Ω, enhancing anti‐corrosion property of copper surface greatly. 相似文献
950.
Seyed Fakhreddin Hosseini Masoud Rezaei Mojgan Zandi Farhid Farahmand Ghavi 《Food chemistry》2013,136(3-4):1490-1495
With the goal of improving the physico-chemical performance of fish gelatin-based films, composite films were prepared with increasing concentrations of chitosan (Ch) (100G:0Ch, 80G:20Ch, 70G:30Ch, 60G:40Ch and 0G:100Ch, gelatin:Ch), and some of their main physical and functional properties were characterised. The results indicated that the addition of Ch caused significant increase (p < 0.05) in the tensile strength (TS) and elastic modulus, leading to stronger films as compared with gelatin film, but significantly (p < 0.05) decreased the elongation at break. Ch drastically reduced the water vapour permeability (WVP) and solubility of gelatin films, as this decline for the blend film with a 60:40 ratio has been of about 50% (p < 0.05). The light barrier measurements present low values of transparency at 600 nm of the gelatin–chitosan films, indicating that films are very transparent while they have excellent barrier properties against UV light. The structural properties investigated by FTIR and DSC showed a clear interaction between fish gelatin and Ch, forming a new material with enhanced mechanical properties. 相似文献