Advanced Materials Research Vols. 864-867

Abstract: The goal of this article was to develop an optimum process to extract cellulose from sisal fiber and study the influence of pretreatment on the structure and property of sisal fiber. The sisal fiber was treated with 3% HNO₃ solution at 120°C for 3h, then treated with 3% sodium hydroxyl solution at 110 °C for 2h which was the optimum refining condition. The percentage of cellulose reached 97.23% after pretreatment by chemical analysis. The morphology analysis and FTIR analysis proved that hemicellulose and lignin were removed from sisal fiber. The result of XRD indicated that the crystallinity of pretreated fiber declined. The pretreated fiber presented higher thermal stability by TGA.

Abstract: This paper describes research into the usage of waste materials in newly developed industrial polymer floorings. The research outputs are presenting possibilities of replacing the commonly used natural materials by waste - without a significant change in properties of the resulting polymer flooring systems.

Abstract: A novel attapulgite clay-based composite (BiVO₄/attapulgite) was successfully prepared as a heterogeneous photocatalyst for degradation of rhodamine B (RhB) dye solution under visible light irradiation. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and microanalysis by energy dispersive spectrometry (EDS), and UV-visible diffuse reflectance spectra (DRS). The results showed that monoclinic BiVO₄ particles were loaded successfully on to the surface of attapulgite fibers and were widely dispersed. The DRS spectrum reveals that the BiVO₄/attapulgite composite had much stronger absorption in the visible light range of 420-800 nm. Correspondingly, the BiVO₄/attapulgite composite showed significantly higher activity in degrading RhB solution under visible-light irradiation compared to that of pure BiVO₄.

Abstract: To improve the quality of needled nonwoven for filtration, many companies will finish the nonwoven fabric in order to improve its performance. The process of singeing with calendering finishing is very important to improve its performance, after finishing the internal filter to a certain extent been blocked, reducing the pressure when cleaning, thereby extending the life of fabrics. We used different methods to deal with needle non-woven fabrics for filtration, which including singeing and singeing with calendering. Then we tested the strength, air permeability, weight and other properties of untreated samples, only singeing samples and singeing with calendering samples. The paper analyzed how treatments affect the properties of needle non-woven fabrics for filtration.

Abstract: The TiO₂-based photocatalysts have been synthesized by using sol-gel process and their photocatalytic activities were studied by the degradation of methylene blue (MB). It was shown that the calcination temperature has great influence on the crystalline phase transition of TiO₂. For all the samples (Ag-doped and undoped TiO₂ photocatalysts) calcined at 573K, only anatase phase was observed from XRD diffraction spectra and the intensity of peaks is weak. After the calcined at 773K, a mixture of anatase-rutile phase appeared. The contents of rutile phase were about 85% and77% for undoped and Ag-adopted TiO₂ photocatalysts.There were only rutile phases for all the TiO₂ photocatalysts calcined at 973K observed from XRD diffraction spectra. Magnetically stirring time of A solution before added B had no obvious effects on the polymorphs transition of TiO₂.

Abstract: Designing of grouting mixes for reinforcement of non-cohesive soils has to satisfy demanding needs. Grouting mix has to have good workability, volumetric stability, good penetration capability, sufficient strength and, last but not least, it should not be too expensive. For above-mentioned reasons, clay-cement suspensions seem to be an appropriate candidate, also because they can be topped up with high-temperature fly ash for even higher cost saving. The paper presents results of preliminary tests of consistency of grouting mixes with various proportions of added fly ash and cement. The tests determined particularly liquid limit and viscosity limit with Marsh funnel.

Abstract: Within the task the so called high-temperature X-ray diffraction analysis (HT-XRD) was used in the field of sulphated binders. Gypsum or calcium sulphate CaSO₄.2H₂O is the basic raw material for the sulphated binder production. As it is known by gradual warming of gypsum its different phase transformations can be obtained which significantly differ in its properties. Using this analysis identifications of temperatures of particular phase transformations in the CaSO₄·xH₂O system can be performed.

Abstract: CdO nanoparticles with different sizes were synthesized by a simple thermal decomposition reaction of the precursor CdCO₃, which was synthesized by room-temperature grinding reaction between Cd(CH3COO)₂•2H₂O and Na₂CO₃. Composition, structure and morphology of the products were analyzed and characterized by XRD, TG and FTIR spectra. Formation of CdO nanoparticles was thought that nucleation rate of the reactive system was far excess growth rate of particle. Optical properties of the products were recorded, and the UV-vis spectra exhibited the distinct blue shift in comparison with them of the bulk CdO, which was because that the quantum confinement effect of the products could be larger than the Coulomb effect. PL spectra of the products showed the emission bands around 520 and 720 nm respectively, which attributed to the quantum size effect and structural defects in the crystals.

Abstract: The technogenic fluorineanhydrite is a waste product from the production of fluoric acid. It can have binding properties after its activation by some known chemical compounds, and so it may be used as a binder for the production of construction materials, in particular, the polystyrene concrete. The article considers the fluorineanhydrite composition as well as the polystyrene concrete produced on its basis with a surface-active additive and staple basalt fibre. The results of micro-structural and chemical analyses of developed composite are given. The polystyrene concrete (D 700 density class) has been developed with the ultimate compression strength value of 1.8 MPa and the water-resistance coefficient value of 0.68.

Abstract: A Ce-Zr-Mn-O_x (CZM) catalyst has been discovered for selective catalytic reduction of NO_x with NH₃ in the presence of O₂. In this paper, The catalysts of CZM with 10~50 wt% MnO₂ content and Ce-Zr-O₂ (CZ) catalyst are prepared by hydrothermal synthesis method. The catalytic activity of CZM catalysts at different temperatures, different space velocities and different ratios of NH₃/NO are studied. The results show that the catalyst of CZM with 40 wt% MnO₂ content yields higher NO conversion at low temperature than others. This catalyst shows nearly 90% NO_x conversion in a temperature range of 150°C~250 °C at a space velocity of 53000 h^-1 .