Advanced Materials Research Vols. 284-286

Abstract: Three expanded graphite/ZnO composites, marked as EG/ZnO-1, EG/ZnO-2 and EG/ZnO-3, were prepared by heating a mixture of zinc acetate and water-washed expandable graphite, dried expandable graphite and EG, respectively. The products were used for removing methyl blue (MO) in water. Under UV irradiation, the composites have the adsorption capacity of EG and the photocatalysis capacity of ZnO at the same time. ZnO-loading method influences the textural characteristics and the MO removal capacities of EG/ZnO composites. Comparatively speaking, EG/ZnO-3 is the most effective for removing MO among these composites.

Abstract: This study presents impact properties and interfacial strength of Ultra-high molecular weight polyethylene fiber plain woven fabric reinforced vinyl ester composites with different matrix volume fraction. The interfacial strength was found to be decreased by reducing the matrix volume fraction. Stress, strain and energy absorption per thickness in the impact process were evaluated and the relation between these impact parameters and interfacial strength of the laminates were investigated. The maximum stress was decreased and the maximum strain was increased with the drop of interfacial bonding strength. The experiment results also revealed that the sample with a matrix volume fraction 23% showed higher energy absorption than other ones.

Abstract: With Al-Si welding wire ER4043, lap joint between aluminium and titanium alloy was made by MIG welding-brazing process with nocolok flux aiding filler metal in promoting metal wettability. A thin intermetallic compound layer was formed at the interface between the weld metal and titanium alloy and the layer mainly consits of TiAl3 phase. The tensile strength of the joint can reach 151MPa and fracture occurred in aluminium base metal.

Abstract: Exfoliated graphite/ZnO composites (EG/ZnO) were prepared by heating a mixture of EG and zinc acetate, and under UV irradiation, used for removing methyl orange (MO) from aqueous solution. The composites synchronously have the adsorption efficiency of EG and decomposition efficiency of ZnO. The removal efficiency is influenced by the ZnO content, initial MO concentration and pH of solution. After selection of desired operation parameters, the complete MO removal can be achieved after 3 h UV irradiation.

Abstract: Three expanded graphite/ZnO composites, marked as EG/ZnO-1, EG/ZnO-2 and EG/ZnO-3, were prepared by heating a mixture of zinc acetate and water-washed expandable graphite, dried expandable graphite and EG, respectively. The adsorption capacity of the composites for spilled crude oil was measured, and under UV irradiation, the decomposition of the absorbed crude oil was investigated by oil weight loss method. The results show that the composites have adsorption and photocatalysis capacity for crude oil at the same time, and the adsorption and photocatalysis capacity are influenced by ZnO-loading method.

Abstract: An Al/Al₂O₃ gradient coating applied on a heat-resistant stainless steel was prepared through a slurry process by using aluminum and γ-Al₂O₃ powders as the transition filler material, alpha alumina as the surface coating material, aluminum dihydrogen phosphate as the binder, and sodium molybdate as the corrosion inhibitor. The effects of heat treatment temperature, adhesive/filler ratio and γ-Al₂O₃ content on the bonding strength, microhardness and thermal shock resistance were investigated. The crystal phase and microstructure were characterized by XRD and SEM. The results indicated that the composition of the coating changed continuously from surface to coating-substrate interface. The coating could offer high bonding strength and good thermal shock resistance when heat treated at 700°C.

Abstract: As a new type of building material, Basalt Fiber Reinforced Plastics is employed in concrete in place of steel reinforcement under such strongly-corrosive environment as marine engineering projects to avoid durability problem caused by corrosion. But BFRP bars’ alkali-resistance must be considered and studied. In this study, BFRP was soaked in saturated Ca(OH)2 solution and its tensile strength was measured through long-period immersion and high-temperature immersion experiments respectively. Besides, accelerated high-temperature method was adopted to detect its main ingredients: continuous Basalt fiber and resin. The results indicate that BFRP has poor alkali-resistance and its alkali-resistance must be improved if it is applied in concrete for long-term purpose.

Abstract: Acrylonitrile-butadiene-styrene (ABS) was treated with various formulations containing an intumescent fire retardant, which consists of ammonium polyphosphate (APP) and a novel char-forming agent, poly(diphenolic phenyl phosphate)(poly(DPA-PDCP)). The behaviour of this intumescent system was investigated by thermogravimetric analysis (TGA), LOI test and cone calorimeter test, respectively. The results showed that the addition of poly(DPA-PDCP) enhanced the thermal stability and flame retardancy of ABS/APP. The weight of residues improved with the addition of poly(DPA-PDCP) . SEM investigations of residual char burning after cone calorimeter test revealed that poly(DPA-PDCP) plays an stimulative role in the process of carbonization. The intumescent chars formed from ABS/APP/ poly(DPA-PDCP) composites were intact and strong. It is confirmed that the poly(DPA-PDCP) is an efficient char-forming agent for flame retardant ABS resin.

Abstract: Three natural graphite flakes (35, 50 and 80 mesh) were used as raw material. Exfoliated graphite (EG) was prepared by rapidly heating expandable graphite to 1000 °C in a muffle and by irradiating it in a microwave oven with a power of 280 W for 40 s, respectively. The EG samples were used for removing methyl orange (MO) from aqueous solution. The effect of preparation technique of EG (particle size of natural graphite and exfoliation method of expandable graphite) on MO removal properties was investigated, and a higher removal rate was achieved.

Abstract: A quantitative structure-property relationship (QSPR) model was proposed for predicting electric spark sensitivity of 39 nitro arenes. The genetic function approximation (GFA) was employed to select the descriptors that have significant contribution to electric spark sensitivity from various descriptors and for fitting the relationship existed between the selected 8 descriptors and electric spark sensitivity. The correlation coefficients (R²) together with correlation coefficient of the leave-one-out cross validation (Q²_CV) of the model are 0.924 and 0.873, respectively. The model is highly statistically significant, and the robustness as well as internal prediction capability of which is satisfactory. The results show that the predicted electric spark sensitivity values are in good agreement with the experimental data.