Advanced Materials Research Vol. 158

Abstract: Using Octadecyltrimethylammonium (OTA) cations with long carbon chain to intercalate into Na-montmorillonite samples, the change of adsorption amount and adsorption state of OTA with the retention time was investigated. The sdudy on the reaction kinetics for the alkylammonium adsorption in the montmorillonite interlayers showed that the isothermal adsorption behavior fit in with a second order reaction kinetics equation. Reaction rate constants had great differences with application force of adsorption process. OTA in the montmorillonite interlayers through re-arrangement constantly at different time, adsorption state of OTA are analysised by XRD and FTIR. The interlayer spacing and diffraction peak relative intensity of montmorillonite/OTMA complexes shows a dynamic change, the alkyl chain conformations can change from “liquid-like” to “solid-like” with the reaction time. The arrangement of alkylammonium cations are more orderly.

Abstract: The hydrotalcite was synthesized using brucite as the source of magnesium by the method of coprecipitation. The effect of synthesis parameters, such as Mg2+ concentration of solution, crystallizing time and temperature on their crystal structure were studied. The surface morphology was characterized by SEM, and the structure was characterized by XRD. Characterization of hydrotalcite showed that the particle size of the hydrotalcite with high degree of crystallinity was 10.0～0.1μm, and the Mg2+ concentration of solution, crystallizing time and temperature influenced the crystal structure. The proper Mg2+ concentration was 0.12M, and the optimal crystallizing time and temperature were 8h and 80°C, respectively.

Abstract: Al3+/clay ratio is one of the important factors influencing microstructure of Al-pillared montmorillonite. Microstructure variation laws of Al-pillared montmorillonite prepared under the condition of different Al3+/clay ratio are systematically studied by XRD, FTIR, specific surface area and pore size analysis. The results show that the interlayer spacing and BET specific surface area of Al-pillared montmorillonite are remarkably affected by the Al3+/clay ratio. The interlayer spacing d(001) value and BET specific surface area of Al-pillared montmorillonite increase firstly and then decrease with the increases of the Al3+/clay ratio, and they reach to maximum when the Al3+/clay ratio is 10mmol/g. Besides, the BJH porous volume distribution of Al-pillared montmorillonite is the most probable distribution, and the most probable pore size is about 2 nm, which is attributed to mesopore. The porous structure of hydroxy-Al pillared montmorillonite is characterized as parallel plate slit or “house-of-cards” wedge-shaped pore which is formed by novel meso-microporous delaminated structure and fragments. With the increase of the Al3+/clay ratio, BJH total porous volume and mesoporous volume of hydroxy-Al pillared montmorillonite decreases, while the proportion of microporous volume in the total porous volume increases. The proportion of microporous specific surface area of all the hydroxy-Al pillared montmorillonite samples is about 62% and is much larger than that of Na-M and those of mesopore and macropore, indicating the main action of intercalation of hydroxy-Al pillaring solution into montmorillonite interlayer is to increase the micropore amount.

Abstract: Ternary lithium-ion battery is currently one of the hot cathode materials. In this paper, with acetate of nickel, manganese and cobalt as raw materials and lithium hydroxide as precipitation agent, LiCo1/3Mn1/3Ni1/3O2 was prepared by chemical coprecipitation method. LAND charge-discharge testing was used to study the electrochemical performance of materials at different rates (0.5C, 1C, 2C), and AC impedance spectroscopy was employed to study the rate performance and reasons of cyclical stability. The results showed that the stable SEM film formed under high rate was the main reason for the increased rate.

Abstract: A mixture of Li2CO3, NiO, Co2O3 and MnO2 with a molar ratio was introduced in the mixed high energy ball milling, LiNi1/3Co1/3Mn1/3O2 was prepared by solid state phase using mechanochemical activation which has highly reactive materials. The structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 were analisised by employing X-ray diffraction(XRD), scanning electron microscopy(SEM) and galvanotactic charge-discharge test. Charge-discharge test results show that when the the LiNi1/3Co1/3Mn1/3O2 cathode was prepared by wet milling 10h between 2.8 V and 4.4V at a current of 0.5C rate, the initial discharge capacity is 135.1mAh/g, the capacity retention rate of 93.26% after 20 cycles. When nLi: n (Ni + Co + Mn) = 1.1, the samples sintered 20h at 850 °C, the first discharge capacity is 148.5 mAh/g, and the capacity retention rate is 94.88% after 40 cycles.

Abstract: In order to study the phase of Fe and Ti in a beach placer , different methods such as the X-ray diffraction analysis, chemical analysis, scanning electron microscopic , electron probe microanalysis are used to study the characteristics of the beach placer . The research results show the major metallic mineral in the beach placer is titanic magnetite, EDS and energy spectrum map features of which indicate that the vast majority of titanic magnetite contain a certain amount of Ti , the two elements of Fe and Ti take on closely symbiosis and distribute more evenly in titanic magnetite. The Ti exists in the Magnetite lattice in form of isomorphism. The theoretical highest grade of Fe and Ti in the separated Magnetic concentrate are 66.02per cent and 4.86 per cent respectively. In addition, the beach placer contains a small quantity of Ilmenite which is hysterogenic and exists in the form of fine solid solution separation structure in the titanic magnetite

Abstract: Nano calcium carbonate (CaCO3) of good evenness and narrow particle size range were synthesized by controlling conditions and adding agents to improve the evenness and reduce particle surface strength. It was shown that the evenness degree was improved by all additives used, and the particle size was decreased only by additive B. The organic additive A had some influence on the evenness degree and the particle size, but they couldn’t be improved at the same time. The inorganic additive C and D could improve the evenness degree, but couldn’t make the particle size better. The inorganic additive B played a important role in the evenness degree and the particle size, and the nanometer CaCO3 whose size was 19.6nm and the evenness degree was 3.4 could be gained at 0.6 wt.% calcium hydroxide (Ca(OH)2) using B as additive.

Abstract: For a long time, the mineral additive was regarded as inert filler which had no reaction with the asphalt, so does the concrete mix. But some research conducted in the recent year proved that was not the case. In this study, four types of mineral materials (diatomite, kaolin (China Clay), Na-bentonite and Ca-bentonite) were selected out to investigate their effect on the asphalt mastics. The high temperature performance, low temperature performance and the temperature susceptibility of the asphalt mastics were evaluated. The result showed the diatomite rank first of the four minerals. The porous structure, huge specific area, mineralogical surface characteristic and the irregularity might be the reason for its positive effect. The bentonite, especially Na-bentonite is unfavorable to the asphalt modification.

Abstract: A bentonites in liaoning province was high quality calcium-group bentonites by acid ,the main component was montmoronite and the content of impurity was less. The activation and organise and so on experiment were carried about. The high quality activated bleaching clay was made of bentonites on the condition of acidity being 15%-25%, activation time being over 4h.The excellent organic bentonites preparation was fulfilled under the condition temperature being 60°C, slurry concentration being 5%, organise time being 1h and the dosage of dosage being 35g/100g using appropriate flowsheet, inorganic mineral gelatin was made by bentonites and its capability was measured.