Applied Mechanics and Materials Vols. 217-219

Abstract: Magnetorheological elastomers air spring, a practical new paten t is introduced, which is composed of magnetorheological elastomers, up-board, down-board and control system. The control system adjusts air pressure and real time stiffness. The air spring can enhance car capability of shock absorption, riding ride and steering stabilization, which can be applied to car’s suspension system.

Abstract: Along with the GIS(Gas insulated metal enclosed switch equipment) miniaturization and three-phase common box, GIS disk insulator electrical properties are getting more and more attention of designers. In order to provide the necessary data and the theoretical support to the insulation coordination design of the disk insulator in engineering, the electric field and the potential distribution on the disc insulator surface of 126 kV GIS isolation grounding module are carried out numerical simulation by using the finite element method. And the maximum field strength of simulation are compared to the allowable field strength values of insulators in engineering in order to see whether it has certain insulation margin, thus put forward the improvement scheme of disc insulator structure.

Abstract: Polyaniline nanorods, nanoplates and urchin-like structures have been synthesized successfully by the template-free method of aniline and peroxo–polytungstic acid using ammonium persulphate as the oxidant in aqueous solution. The peroxo–polytungstic acid concentration and reaction temperature play important role in the formation process of polyaniline nanostructures. As the precursor concentration increased to 0.29mol/L, nanorods and urchin structures were obtained. With the decrease of temperature, the amount of PANI nanoplates with radially aligned dendritic surface structures will increase. The radially aligned dendritic surface is probably due to the molecular structures of the dopant, the linear nature of PANI chains and the second nucleation formation.

Abstract: High-performance membranes for protein separation are of great interest. In this study, new type of polysulfone (PSf) composite ultrafiltration membranes are created by blending PSf with polyaniline (PANi) nanofibers and functionalized multi-walled carbon nanotubes (MWNTs) and then casting the mixture solutions via a well-developed non-solvent/solvent induced phase separation technique, using deionized water as the coagulation bath. The compositions, morphologies and properties of as-formed membranes are fully investigated. We demonstrate that membrane characteristics such as porosity, hydrophilicity, conductivity and thermal stability for PSf can be significantly enhanced with the incorporation of hydrophilic and conductive compositions of functionalized-MWNTs and PANi nanofibers. The composite membranes exhibit comparable bovine serum albumin (BSA) selectivities (89-93 vs. 92%) but much improved water fluxes (31.5-88.9 vs. 9.2 gfd/psi) against pure PSf membranes.

Abstract: Membrane technology is been widely used in drinking water treatment in order to meet the stringent water quality standards. Among the membrane processes, hydrophilic and charged modification of Ultrafiltration(UF) membranes with high filtration efficiency and antifouling properties are being paid more attention. In this work, sulfonated polysulfone (SPSf) with different degree of sulfonation(DS) was used as the modifier to improve the hydrophilic and charged properties of PVDF blend membranes. FTIR and SEM were used to investigate the chemical structure, polymorphism and morphology of the membranes. The charged and hydrophilic properties of the membranes were investigated by zeta potential analyzer and water contact angle instrument. It was found that, for all the investigated cases, the sulfonic acid groups of SPSf could migrate onto the surface of the membranes by surface segregation, which made SPSf/PVDF blend membranes have good charged and hydrophilic properties. DS of polysulfone(PSf) also affected the morphology of the membranes, a tendency toward regular granular structure, larger average pore size and porosity with the addition of SPSf in the membranes was observed. These phenomena all suggested that SPSf/PVDF blend membranes might have a potential application in the drinking water treatment.

Abstract: Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis（TGA）. The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.

Abstract: The surface modification process for polyacrylonitrile fiber which was hydrolyzed first, and then grafted with collagen was studied. The optimum process was as follows: concentration of alkaline 12%, time 10min, temperature 80°C, ratio of water and PAN fiber was 100:1. The method for surface modification of polyacrylonitrile fiber was determined from comparative analysis, and the optimum process: collagen solution concentration at 5%, pick-up at 900%, pre-baking 15min at 70°C, baking 15min at 110°C. Compared with original polyacrylonitrile fiber，the breaking strength and elongation of collagen modified polyacrylonitrile fiber decreased, while the moisture regain increased from 2% to 6.1%.

Abstract: The authors use the semi-infinite objects unsteady heat conduction theory analysis of the dry thermal conductivity of wood-plastic raw materials.The correspondence between theoretical calculations obtained wood-plastic material thickness and heating time, to determine the impact of wood-plastic raw materials in the water on the thermal diffusivity. ANSYS software material preheating and drying heat transfer to simulate the process to draw the curve of the relationship between temperature and time of the temperature rise process of wood-plastic raw materials, raw material moisture content of wood-plastic temperature changes. The comparative analysis of experimental results and simulation results are similar, and provides a reference for the study of predrying of wood-plastic raw materials.

Abstract: A series of castable polyurethane elastomers, based on polytetramethylene glycol as soft segments and toluene diisocyanate, 4, 4’-diphenylmethane diisocyanate, P-phenylene diisocyanate as diisocyanates respectively, were synthesized. The dynamic mechanical analysis method was utilized to determine tan delta property (tanδ). Also the influence of diisocyanates on the dynamic mechanical properties of castable polyurethane elastomers was analyzed. It can be concluded that the P-phenylene diisocyanate system elastomers have the most excellent dynamic mechanical properties.

Abstract: Polyacrylonitrile（PAN）/multi-walled carbon nanotubes (MWNTs) composite fibers were prepared by melt spinning using ionic liquids (ILs) as a plasticizer. The effects of different MWNTs contents on the morphology, mechanical and conductive properties of the composite fibers were discussed. The results showed that property improvements have occurred with the adding of MWNTs. When the content of MWNTs reached 10%, the conductivity of PAN/MWNTs was 8.65×10-3 S/cm.