Advanced Materials Research Vols. 239-242

Abstract: A fragrance, jasmine was encapsulated into β-cyclodextrin to prepare microcapsules that can sustain the release of the fragrance and potentially be bound to textile material. This study examined the structures, thermal properties, partied size distributions, and release behaviors of the microcapsules. The release of jasmine was examined in air at elevated temperature. The experiments showed that β-cyclodextrin could efficiently sustain the delivery of jasmine.

Abstract: The theoretical decomposition voltage (EMF) for substances in FeS-CaCl₂-NaCl-KCl system was figured out. The results indicate that the EMF increases in sequence of FeS, CaCl₂, NaCl and KCl with inert anodes, and it drops with rising of temperature, increases with decreasing of FeS concentration. Under a lower FeS concentration, as a result, the anode effect can occur. Fe would be separated out from cathode and Cl₂ would be separated out from anode first in electrolytic desulfurization process.

Abstract: The effect of discharge parameters (the electrode distance, the electrolyte volume) of the plasma electrolytic oxidation on the magnesium alloy films’ surface morphology were investigated. The results show that the appropriate electrode distance is 30 mm, which exhibits a better PEO surface morphologies. The electrolyte volume should not be too large or too small, in the paper, the appropriate electrolyte volume is between 250-350 mL.

Abstract: Ni-Al intermetallic compound coatings no visible cracks, pores or inclusions are prepared on mild steel substrate by Laser- cladding in situ synthesis with mixed powders of nickel-coated aluminum, Ni-based alloy and Al. The results show that the microstructure of the coating consists mainly of two phases of NiAl and Ni₃Al, and the former amount is more than the latter, with NiAl being uniformity and staggered fine dendrites which are surrounded continuously by Ni₃Al, and the atom ratios of Ni∶Al∶Fe∶Si in NiAl and Ni₃Al are respectively 54∶39∶2∶5 and 70∶21∶3∶6. Compared with cladding nickel-coated aluminum, the coatings quality are improved, and the dilution of iron from substrate into coating are greatly reduced, as a result of lower cladding powers due to self-fluxing of Ni-based alloy and exothermic reaction between Ni and Al. The hardness of coatings are up to HV490-HV540.

Abstract: Cu₂ZnSnS₄ (CZTS) prepared by sol-gel spin-coating deposition was treated with post-sulfurization in a sulfur vapor atmosphere. The crystallinity degree of the CZTS could be significantly improved through post-sulfurization treatment. Granular structures of the CZTS as synthesized at a temperature of over 240 °C and treated with post sulfurization were obtained. The composition ratios of the as-sulfurized CZTS were close to the composition stoichiometry of CZTS with an electrical resistance of ~ 1.7 Ω cm. An as-prepared CZTS based solar cell shows an open-circuit voltage of 300 mV, and a short-circuit current of 2.48 mA cm^-2.

Abstract: Taking β-Ni(OH)₂ powder as raw material and K₂S₂O₈ as oxidant, β-NiOOH was prepared through chemical oxidation process, then which was used as cathode material to assemble nickel-zinc cell. Effects of reaction time, reaction temperature, NaOH concentration, Ni(OH)₂ concentration and mass ratio of K₂S₂O₈ and Ni(OH) ₂ on 1^st discharge specific capacity of cells were studied. XRD result indicates that the crystal structure of β-NiOOH is disordered in a way. TG-DTA analysis indicates that the decomposition reaction of β-NiOOH occurs at temperature of 156-280 °C, the end product is NiO.

Abstract: An important way of conservation and protection of forest resources is wood preservative treatment. Currently, chemical preservatives are always used in the wood preservative treatment. Therefore, preservatives security has become an important environmental issue. This study focuses on national wood preservation, which workers are committed on. Many studies have been directed to look for new preservatives that are harmless to humans, animals and environment. Chinese herbal medicine as a wood preservative is selected for the environmental pollution problems of inorganic preservatives. In this paper, according to the application of traditional Chinese medicine, the nature of wood preservative and a preliminary study by the relevant trial, the theory of Chinese herbal medicine wood preservative is proposed. The results showed that Chinese herbal medicine can be used as wood preservatives. Finally, the paper puts forward the potential abilities of Chinese herbal medicine as wood preservatives.

Abstract: In this work, a unique electrode based on aminopropyl-triethoxysilane ( APTS)-coated porous silicon(PS) substrate has been fabricared and used as a urea-sensitive electrode after urease immobilization. PS substrate was formed by electrochemical anodization in an etching solution composed of HF and ethanol. APTS layer was formed on the PS surface by coating and heating at 1053K in argon atmosphere. Urease immobilization was carried out by immersing the APTS/PS in urease solution. The immobilized system gives linear response for concentrations of urea ranging in values between 3.6×10⁻³ and 8.0×10⁻³ mol dm^-3, studied with voltammetry. The surface of biofunctionized porous silicon has thus provided a suitable environment for urease with 15 days retention of its activity. The molecular structure on the PS surface was characterized with infrared (IR) technique. The change in the surface morphology has been studied by scanning electron microscopy and it is observed that the immobilized system has successfully retained urease.

Abstract: The semi-solid brazing process of SiC_p/A356 composites and 2024 aluminum alloy using Zn-Al eutectic filler metal at 450 °C has been investigated. The two substrates and Zn-Al filler metal were heated up to the semisolid temperature range of Zn-Al filler metal by a resistance heating plate. In order to mix the filler metal with the base metal of both sides to be a single uniform joint, a stirrer was introduced into the weld seam. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiC_p/A356 composites and aluminum can be joining by semisolid metal. It can be found that almost half of the oxide film on the surface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials on the interface of oxide had been disrupted. Moreover, the oxide film of surface of aluminum alloy was more thoroughly disrupted and removed than that of surface of composites with existing of SiC particle.

Abstract: In this paper, Aluminum trioxide ceramic coatings were grown on surfaces of 2024 Aluminum alloys by micro-plasma oxidation in an aluminate electrolytic solution. In order to decrease the density of the pores and increase the anti-wear property of the ceramic coatings, Titania were added into the aluminate electrolytic solution. The struture and anti-wear property of the produced ceramic coatings were measured by X-ray diffraction, scanning electron microscope , hardness tester and frictionometer. The results show that the thickness of the ceramic coating is about 24±1 μm, surfaces of the ceramic coatings are very uniform. The hardness of the doped coating is up to 930 HV, and the wear property of the coating is the more excellent than that of undoped coating.