Abstract: Type-A zeolite was synthesized in hydrothermal condition with stellerite obtained from Guangxi. The influences of raw material modification, crystallization temperature, crystallization time and particles’size of stellerites were discussed on preparing zeolite molecular sieve. It is shown that A-type zeolite was synthesized in crystallization time of 6 hours, crystallization temperature of 90-100 °C according to certain proportion with stellerite modified by hydrochloric acid of 15%. The crystallinity of A-type zeolite is 98%, whiteness 95%, average particle size 3.72 µm and more than 90% particles’size are less than 10μm. These meet the zeolite standards of Q / Chalco A021-2004. Type-A zeolite is widely used in detergent industry, petrochemical industry, chemical industry, environmental protection and development of new functional materials fields as it has many excellent performance, such as good ion exchange, adsorption and catalysis, due to its unique crystal structure[1-4]. Because the synthesis of type-A zeolite based on chemical materials costs too much and is also restricted by chemical materials, which can not meet the needs of zeolite application. Therefore, researchers have become focus on preparing type-A zeolite with cheap mineral- materials[5-8]. In this research, we prepared type-A zeolite through Hydrothermal method with stellerites obtained from Guangxi.
Abstract: One-dimensional titanate nanotubes and nanowires were synthesized by hydrothermally treating TiO2 nanoparticles (P25) with an aqueous NaOH solution in a revolving autoclave. The effect of the reaction temperature and time on the morphology and crystal structure of titanate nanomaterials was systematically studied. When the hydrothermal treatment was carried out in a revolving autoclave, nanotubes with NaxH1-xTi2-x/4Υx/4O4•H2O crystal structure were obtained and favor to self-assemble in shape of clusters and bundles, and nanotube bundles tended to transform into nanowires with the crystal structure transforming into NaxH2-xTi3O7 within 48 h at a hydrothermal temperature higher than 130 °C. Based on the experimental results, a possible mechanism for the formation of titanate nanotube by wrapping of nanosheets and nanowires formed via the cooperation of oriented attachment and Ostwald ripening was proposed.
Abstract: Efficient integration of synthetic nanotubes/nanowires into functional nanodevices by bottom-up approaches is the key of mass production of nanodevices, and is still a big challenge. Here we present a simple microfluidic method of patterning and aligning a large scale of carbon nanotubes by hydrodynamic focusing: the sample solution carrying carbon nanotubes were hydrodynamically controlled by the sheath flows. This method can be used to align and position both a large scale of nanotubes and a few lines of nanotubes to designated positions, offering a general pathway for assembly of nanosystems.
Abstract: Soybeans and soy products are the main source of isoflavones. Soy isoflavones are phytochemicals of intense interest due to their association with a variety of health protective effects. The objective of this study was to identify, characterise, and to evaluate the soybean extracted powder . The extraction of soybean was prepared in dry powder by using spray drying technique. The powder was then investigated for their stability for 1 year. The studied parameters were identification of isoflavone by TLC and HPLC and some physicochemical properties such as moisture content, wettability and thermogram. The result showed that both genistein and daidzein were stable for 1 year of study whereas the extract form was not stable.
Abstract: As a new kind of materials, nanoscale zero-valent iron which had excellent adsorption ability and high chemical reactivity had been widely applied in advanced wastewater treatment. In this paper, the preparation of nanoscale zero-valent iron particles was liquid phase reduction ,and then iron nanoparticles were characterized by scanning electron microscope and X-ray diffraction. Also the application of nanoscale zero-valent iron in the difficult degradation coking wastewater treatment was discussed.
Abstract: SnO2/Al2O3 nanofibers have been fabricated from a suitable inorganic–organic composite solution via a simple electrospinning method and followed by calcination treatment of the electrospun polymer/inorganic composite fibers. The effect of voltage, tip-to-collector distance and calcining temperature on the morphology and crystal structure of nanofibres was investigated by scanning electron microscope (SEM), X-ray photoelectron spectra (XPS) and X-ray diffraction (XRD). The diameter and diameter distribution of nanofibers can be controlled by controlling the electrospinning parameters and the more ideal diameter is 200-350nm. The formation of phase identified by XRD indicated the existence of tetragonal rutile tin oxide crystals and amorphous alumina. This paper provides a new method for the preparation of the SnO2/Al2O3 catalysts for NOX reduction.
Abstract: The microwave permittivity and permeability of Carbon Nanotubes (CNTs)/paraffin and CNTs-Co(C)/paraffin were measured respectively and their differences were discussed in detail. Furthermore, the reflection losses for double-layer CNTs (CNTs-Co(C))/epoxy coatings, with the thickness ranged from 1.6-2 mm, were practically tested through Arc Method in 2.6-18 GHz frequence range. The results indicated that the reflection loss peak shifted towards low frequency and the peak value decreased with the coating thickening and possible mechanisms for the phenomena were given.
Abstract: The spinel nanocrystalline Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was prepared by polyacrylamide gel method. Influences of Nd3+ ions substitution on the microstructural and electromagnetic properties for the Co0.5Zn0.5Fe2O4 ferrites had been systematically investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and wave-guide method. The results showed that the Nd3+ ions can replace Fe3+ ions and adjust lattice parameters. The average size of the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 particles were identified to be about 50nm and 60nm by TEM, respectively. The complex permittivity (=ε′-jε″) and complex permeability (=μ′-jμ″) for the composites had been measured in the frequency range of 8.2-12.4GHz. The results showed that the Co0.5Zn0.5Fe2O4 and Co0.5Zn0.5Nd0.05Fe1.95O4 ferrites had both dielectric loss and magnetic loss. The dielectric loss tangent (tgδε) and magnetic loss tangent (tgδm) for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite were obviously higher than those of the Co0.5Zn0.5Fe2O4. The maximal value of tgδε and tgδm for the Co0.5Zn0.5Nd0.05Fe1.95O4 ferrite was around 0.30 at 12.4GHz and 0.16 at 10.8GHz, respectively.
Abstract: Ni-Al2O3 nanocomposite coating, which was fabricated by eletrodeposition technique with the aid of ultrasonic and agitation. The effect of ultrasonic and agitation on the characteristics of the deposits was investigated by scanning electron microscopy (SEM) and microhardness tester. The results shows that ultrasonic and agitation result in decreasing of Al2O3 nanoparticles aggregation and increasing of Al2O3 nanoparticles uniformly dispersed on the matrix of the composite coating. The ultrasonic and agitation improved the Ni crystallization in the Ni-Al2O3 nanocomposite electroforming coating. Compared to the process of without ultrasound, the nanocomposite is prepared with ultrasonic and agitation, which has a higher stiffiness by the same current density and electrolyte. The average microhardness of the deposit reaches to 461.9 HV with ultrasonic and agitation, which is double of the conventional electroforming coating.
Abstract: Relative permeability is an important magnetic characteristic for ferrofluid to exhibit its magnetized potential during the magnetization process. To understand above physical property varying with field intensity, a popular analytic model, based on Langevin theory, has been usually considered and widely used. Unfortunately, an implicit model, derived from above hypothesis, for solving the instantaneous magnetization of ferro-particle will be carried out unless the determination of saturated magnetization should be conducted in advance. Just for the study dealing with magnetic property of testing ferro-sample is concerned, the previous acquisition of magnetization curve is impossible and unpractical without the precise measurement of magnetization-degree. On the other hand, required experimental expense is still so costly that it seems to be unaffordable for general laboratory. Thus a self-designed electromagnetic mechanism with special facility of smaller size, economical cost and efficient operation to quantify the reduced gravity of ferro-sample attracts our interest and is set up in this study. Meantime, an auxiliary numerical method, Newton interpolatory divided-difference formulas in trapezoidal rule, involved in this study successfully avoids the essentiality of saturated magnetization determined previously, and which also provides a numerical approximation through the weight loss of ferrofluid experienced by the designed experimental system. As compared with the result measured by VSM (vibration sample magnetometer) method, the estimated profile shows an excellent agreement except the extraordinary outcome occurring at B=6 mT, where a drastic increase of relative permeability will be evaluated due to the faster magnetization starts.