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911.
3‐Methacryloxypropylpolysilsesquioxane (MA‐PS) was prepared by acid‐ or base‐catalyzed hydrolytic polycondensation of 3‐methacryloxypropyltrimethoxysilane (MAS). MA‐PS coating film was prepared by dip‐coating on organic, metal and inorganic substrates, including poly(ethylene terephthalate), aluminum, stainless steel, and glass. The coating films on poly(ethylene terephthalate) and glass showed high adhesive strength. The hardness of coating films increased with increasing heat treatment temperature, whereas they decreased with increasing H2O/MAS molar ratio. The refractive index of coating films increased with increasing heat treatment temperature. In addition, flat and transparent free‐standing films (0.24–0.27 mm thickness) were prepared from MA‐PS that were crack‐free after heat treatment at 1000 °C. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
912.
Quan Chen Jason Gim Hong Tan Shou Cang Shen Yu Chan Liu Wai Kiong Ng Xian Ting Zeng 《Journal of Sol-Gel Science and Technology》2007,44(2):125-131
AlOOH boehmite nanorods, synthesized by a solid-based process, were incorporated into a sol–gel coating in which GPTS was
used as a precursor. Transparent composite coatings with nanorod content up to 40 wt% were obtained by spin coating the sol–gel
mixture on glass substrates. Nanorods in the coating were found be aligned parallel to the substrate surface. Mechanical properties,
such as modulus and hardness of the nanorod filled coating, were slightly lower than coatings of the same composition but
filled with commercially available nanosized boehmite particles. However, crack toughness was greatly improved, as supported
by nanoindentation test results. The improvement in crack toughness was attributed to the high aspect ratio of the rigid nanorods,
in addition to the fact that the nanorods were aligned within the composite parallel to the surface. 相似文献
913.
The piezoelectric film electro-deposition for optical fiber sensor with ZnO coating is studied. The zinc oxide plating film is made on the copper surface directly by cathodic electro-deposition in the Zn(NO3)2 single salt aqueous solution systems. The influences of main experimental conditions on the properties of ZnO thin film in the electro-deposition processes are analyzed and a stable, practical and economic technique is obtained. 相似文献
914.
We developed a facile method of enzyme-mediated conversion of 6-tuliposide to α-methylene-γ-butyrolactone (tulipalin). We used a tuliposide-converting enzyme for the conversion of 6-tuliposides extracted from tulip tissues into the corresponding tulipalins in high yields within 2 h at pH 7.0. The resulting tulipalins were selectively extracted by using several organic solvents. 相似文献
915.
Reine Nehmé Catherine Perrin Vincent Guerlavais Jean‐Alain Fehrentz Hervé Cottet Jean Martinez Huguette Fabre 《Electrophoresis》2009,30(21):3772-3779
The diastereoisomeric separation of peptidomimetics of hexarelin, a strong growth hormone secretagogue, in CE has been studied. Highly sulfated‐γ‐CD was found to be an appropriate selector for the separation of the stereoisomers. However, non‐repeatable analyses were obtained on bare fused silica capillary due to the progressive adsorption of the analytes on the capillary wall. Two types of polyelectrolyte coating agents were tested to prevent this phenomenon. Coating with neutral polyethylene oxide was found to be efficient but resulted in a very long analysis time (about 40 min). Coating with cationic poly(diallyldimethylammonium) chloride was found both to prevent analyte adsorption, reduce analysis time and alter separation selectivity. EOF measurement revealed that the highly sulfated‐γ‐CDs were strongly adsorbed on the poly(diallyldimethylammonium) chloride coating surface yielding a stable strong cathodic EOF, which considerably reduced analysis time (about 12 min). Very good repeatability of analysis was obtained (RSDmigration time<1%). 相似文献
916.
Jiangang Li Maosong Fan Xiangming He Rusong Zhao Changyin Jiange Chunrong Wan 《Ionics》2006,12(3):215-218
TiO2-coated LiNi1/3Co1/3Mn1/3O2 materials were prepared by the hydrolyzation of Ti(OBu)4. The impact of TiO2 coating on the structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 was investigated using X-ray diffraction, scanning electron microscope, and charge–discharge tests. The results indicated that TiO2 coating did not affect the lattice of LiNi1/3Co1/3Mn1/3O2, but exhibited obvious effects on its discharge capacity and cycling stability. As coated TiO2 increased from 0.0 to 2.0 mol%, the initial capacity of samples decreased slightly, but the cycling stability over 2.5∼4.3 V increased remarkably. The capacity retention reached 99.5% at the 50th cycle at a coating amount of 2.0 mol%. 相似文献
917.
918.
Heinz-Dieter Kurland Janet Grabow Gisbert Staupendahl Wilfried Andrä Silvio Dutz Matthias Erich Bellemann 《Journal of magnetism and magnetic materials》2007
Magnetic iron oxide nanopowders were produced with the laser evaporation technique under normal process gas pressure. In addition, the generated particles were coated in situ with stearic acid and separated on magnets. The methods and the used laboratory setup are briefly described. Influences of essential process conditions, particularly the use of continuous and pulsed laser radiation as well as the properties of the process gas, were experimentally investigated. The produced nanopowders were analysed with TEM, XRD, and magnetic measurements and confirmed the in-principle suitability of the presented method. 相似文献
919.
The interface between cold gas sprayed zinc-based coatings and selected light weight alloy substrates (aluminium AA7022 and
magnesium AZ91) has been investigated by scanning and transmission electron microscopy in combination with energy-dispersive
X-ray spectroscopy. In both cases a non-uniform interfacial zone with a thickness of up to 10 microns is evident. It consists
of coating and substrate phases as well as an approximately 1 micron thick, partially whirled layer. For the AA7022 substrate
the interfacial layer contains nano and submicron sized crystallites of the binary MgZn2 phase (η) which are embedded in an aluminium solid solution matrix. In the case of AZ91 substrate two ternary phases, Mg5Zn2Al2 (φ) and Mg11Zn11Al6 (τ) with particle size smaller than 50 nm are evident. The formation of these phases during spraying cannot be explained
by diffusion process only, but a local melting is needed. Consequently, the assumption that the high kinetic energy of cold
gas sprayed particles causes an intensive mechanical mixing of coating and substrate material accompanied by a high local
temperature rise is proved. 相似文献
920.
The advantages of electroless nickel plating (EN) include excellent corrosion resistance, wear resistance, solderability, low porosity and uniform thickness even on complex parts and ability to plate on nonconductors. In the present study nano ZnO particles were synthesized by using an electrochemical technique and incorporated the particles into Ni-P plates. An alkaline bath was selected and used for nano zinc oxide incorporation. The electrochemical and metallurgical properties of the Ni-nano ZnO-P plates were evaluated and compared with that of the un-reinforced Ni-P plates. The incorporation of the nano ZnO particles resulted in improvement of metallurgical and corrosion resistance characteristics of the plates. 相似文献