Advanced Materials Research Vols. 150-151

Abstract: CaO-B2O3-SiO2 glass ceramics were prepared by powders of different particle sizes. The relationship between CBS powder characteristics and structures was studied by XRD and SEM, and the effect of powder characteristics on sintering properties, dielectric properties at 10GHz, thermal properties (CTE) were investigated to obtain low-temperature sintered glass ceramics. The results showed that the median particle size of glass powders reduced, sintered temperature and apparent porosity decreased. But at the same time, bulk density and thermal expansivity increased. The sample with the powders of D50=2.34μm could be sintered at 850 with the density about 2.615g•cm-3 and the water absorption about 0.16%. Having a dielectric constant of 6.16 and a dielectric loss of 1.9×10-3 at 9.98GHz, the sintered sample could satisfy the requirements of the substrate materials used in LTCC in some fields.

Abstract: Self- compacting concrete (SCC) has characteristics of good flow-ability, non-vibrating and self-compacting. It is the optimum to be used in concrete members with densely distributed steel bar and concrete is inconvenient to be vibrated. The mixture ratio of design grade of C20 and C40 SCC commonly used in project is given after trial mix. The compression stress-strain relation of SCC prism is obtained by MTS. The Mechanical property indexes of SCC are got. The ultimate compression strain of the extreme fiber is acquired by testing beam made of SCC, and the relation between the ultimate compression strain of the extreme fiber in flexural member and the strain at the peak of the stress-strain curve subjected to uniaxial compression is given.

Abstract: In order to improve the flame retardancy of wood-plastic composites,a new sandwiched composite is introduced in this paper with basic magnesium sulfated whisker(MOS) filled high density polyethylene(HDPE) as skin and wood flour filled HDPE as core.The oxygen index of the skin and the mechanical properties of the whole sandwiched composite are investigated. The results show that, the flame retardancy of the skin will be improved siginicantly when much MOS is used,and the skin containing 40wt% MOS has an oxygen index of 25.6%,in addition,the sandwiched composite in which both the mass contents of MOS in the skin and wood flour in the core are 40% has better mechanical properties than the traditional wood plastic composite(WPC) without any skin,and the sandwiched WPC is more fatigue-resistant.

Abstract: In this study, an Accelerated Lithium Migration Technique (ALMT) was applied to simultaneously drive alkali out and lithium into concrete as a remedy for alkali-silica reaction (ASR) problem. The mortar specimens used in the experiments contained 2.0% Na2Oeq. Constant current denities were applied during the ALMT testing process. The anolyte and catholyte solutions consisted of LiOH．H2O and Ca(OH)2, respectively. The results show that there are a well correlated linear relationship between the applied current density and the steady flux and migration coefficient of the Li+. During the process of ionic migration, K+ was first removed completely from the specimen, followed by Na+, after which the Li+ flux remained steady. The system resistance initially decreased, and then increased gradually. The time corresponding to when the Li+ concentration in the cathode/Li+ in the source cell was equal to 0.1% indicates the time-span needed for Li+ to penetrate throughout the specimen. Furthermore, the accumulated charge carried by the cations and the accumulated charge applied during testing showed a similar in all test cases.

Abstract: The abnormal vibration of H5 mill’s gear box has influenced the implementation of the energy-saving process in the alloy bar production line of special steel branch, Baosteel limited company. The reasons of the abnormal vibration have been determined by experiment and ANSYS finite element analysis, and corresponding measures have been provided. The rigidity of the gear box has improved by reinforcing ribs. By applying the reinforced gear box, the abnormal vibration has been effectively inhibited and the implementation of the energy-saving process has been guaranteed.

Abstract: The wood-plastic composites (WPC) were prepared via compress molding by using the blends of high density polyethylene (HDPE) and modified polyethylene (MAPE) as the matrix and wood flour (WF) as filler. The effect of MAPE content in the matrix on the mechanical properties of the matrix and WPC was investigated. It was shown that the change of MAPE content in the matrix had no influence on the tensile strength of the matrix, but markedly reduced the impact strength of the matrix. Additionally, it had significant influence on the strength of WPC. When the content of wood flour and the content of the matrix remained fixed, with increasing the content of MAPE in the matrix, the tensile strength and the flexural strength of WPC tended to increase rapidly initially and then become steady. Moreover, with the increasing of MAPE concentration, the impact strength of WPC decreased when the low content of wood flour (30%) was filled, but increased at high wood flour loading (70%).

Abstract: The rod-shaped polyaniline (PANI)-barium ferrite nanocomposites were synthesized by in situ polymerization of aniline in the presence of BaFe12O19 nanoparticles with diameters of 60-80 nm. The composites obtained were characterized by infrared spectra (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The thermal stability and the composition of the composites were investigated by TG-DTG analysis. The results indicate that the thermal stability of the composites is higher than that of the pure PANI which can be attributed to the interactions existed between PANI chains and ferrite particles.

Abstract: Titania nanoparticles were anchored onto active carbon (AC) through a hydrothermal process to obtain TiO2/AC composites. The optimal TiO2 loading and hydrothermal pH were investigated. The prepared TiO2/AC composites were used as adsorbents for dibenzothiophene (DBT) from model fuel. The adsorption capacity of TiO2/AC composite in the optimal synthesis conditions has enhanced 12.4% compared with pure AC. The adsorbents were regenerated by toluene washing, and the TiO2/AC composite showed higher adsorptive capacity than AC even after three recycles. The pore structure and surface chemical proprieties of TiO2/AC composite and AC were also investigated by N2 adsorption-desorption isotherms and Beohm titration. The results indicate that the surface acidic sites of TiO2/AC may play an important role in the improved adsorption performance.

Abstract: Under vertically uniform distributive load, a safe and economical selection method for thickness of L-shaped floorslab was given through the finite element analysis for the slab having different length gaps with and without the same gap area.

Abstract: Modified membrane separators with lower cost using non-woven Polypropylene (PP) were widely used in the field of the secondary lithium batteries. Sulfonation is one of the most commonly modified methods for the surface modification of polymers. In order to make it effective in industry production, plasma surface treatment is applied to one, and it is an effective surface activation technology without changing its original properties. The characteristic properties of modified PP membrane separators have been studied by Alkali Absorption property Test, Tensile Strength Test, Fourier-Transform Infrared Measurements (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS). Sulfonic acid groups in the polymer membranes were evidenced by the FTIR and the XPS spectroscopy. The results showed that the plasma sulfonation treatment reaction was very effective to improve the surface hydrophilicity of the non-woven membranes. The suitable sulfonation process could keep the lower cost in industry production.