Applied Mechanics and Materials Vol. 161

Abstract: The adsorption performance of mercury ion onto activated carbon prepared from rice husk with NaOH was carried out at initial concentration of 100 mg/L. The activated carbon obtained at 800 °C possessed the outstanding specific surface area of 2786 m²/g. And the results showed that the maximum adsorption capacity of Hg²⁺ was recorded as 342.0 mg/g due to abundant micropores of 1.076 nm. In addition, the adsorption data were well explained by the Langmuir model with the monolayer adsorption capacity of 555.6 mg/g.

Abstract: A coating was made by electrostatic spraying of epoxy resin / TiO₂ particles for the purpose of suppressing audible noise caused by corona discharge on high-voltage transmission lines. Wetting property of the coating was improved by oxygen plasma treatment. It was found that the coating became more wettable as the increase of TiO₂ content during electrostatic spraying process. With respect to the coating for suppression of audible noise from transmission lines, the optimal mass ratio of TiO₂ particles (diameter:5-10μm ) to epoxy resin was 30%, and the contact angle was 73°on the epoxy / TiO₂ coating surface which could be reduced to less than 5°after oxygen plasma treatment for 20s.

Abstract: In this paper, the performance of alkylphenol polyoxyethylene ether sulfosalt that were specially APESO and AESO was evaluated from CMC, interfacial tension, foamability and adsorption. Then these features were analyzed at different conditions, including temperature, time and concentration.

Abstract: m-β-hydroxyethylsulfonyl aniline is one of the important reactants in synthesizing reactive black KNB. In order to recovery m-β-hydroxyehylsulfonyl aniline from reactive dye wastewater, two separation units including tributyl phosphate/petroleum ether extraction and sodium hydroxide solution stripping were studied. It is found that the single stage extraction rate was 85% when extraction phase ratio of organic to aqueous phase (O/A) was 2:1, while the single stripping rate was higher than 50% when 0.5M sodium hydroxide solution was selected and the stripping phase ratio of aqueous to organic phase (A/O) was 2:1.

Abstract: The organic–inorganic hybrid catalyst [(CH2)5NH2]4SiW12O40 was prepared by matrix acid and piperidine. The matrix acid was synthesized by sodium molybdate and sodium silicate, and the piperidine was organic ligand. The proposed composition and structure of the catalyst were evidenced by XPS, FT-IR, XRD, TG-DTA and elemental analysis. The results indicated that the heteropoly anions still reserved their Keggin structure in the compound. Its catalytic performance was evaluated in the oxidation of benzaldehyde to benzoic acid. Various reaction parameters were changed to attain the optimal conditions. The optimal reaction conditions were found to be: n(catalyst): n(benzaldehyde)=3.1×10-3:1; n(H2O2)： n(benzaldehyde)=4.5：1; reaction temperature was 80°C; reaction time was 4h. The yield of benzoic acid achieved above 85%.

Abstract: On condition that the surface of 304 stainless steel has formed passive film, we have done research on the impact that the change of concentration of Cl- and Na+, the temperature, pH of Na+, on 304 stainless steel properties. This experiment is preceded studied with electrochemical method. The results show that along with the increase of temperature, pH improves the repairing capacity of passive film on the surface of 304 stainless steel. However, its stability decreases. Meantime, the pitting corrosion will happen become easier, when the repairing capacity of passive film and stability have been weakened because of the concentration of Na+, Cl- increases.

Abstract: Pure CeO₂ and a series of (x %) K-CeO₂ (x=1, 2, 3, 4) catalysts were respectively prepared by the precipitation and incipient wetness impregnation methods, and characterized by means of XRD, BET and H₂-TPR techniques. The catalytic activity was investigated by the gas-solid reaction with methane in the absence of gaseous oxidant in a fixed bed reactor at 800 °C. The XRD measurement showed that doping of K₂CO₃ did not change the structure of CeO₂ with the addition of K₂CO3 without formation of Ce-K-O solid solution in these materials. Surface area of catalysts was _{Subscript text}decreased with the impregnation amount of K₂CO₃. Reducibility of catalysts was obviously enhanced by the addition of K₂CO₃ as shown in H₂-TPR tests. The catalysts activity tests indicated that adding K₂CO₃ to CeO₂ could promote the oxygen storage capacity of catalysts. K species in CeO₂ could affect the CO formation in methane oxidation.

Abstract: Acid solution and copper-containing acid mine drainage (AMD) was treated by neutralization-adsorption process. The results showed that pH can be adjusted to 4.0 by adding 10g·L^-1 calcite in acid solution with pH=1.0. Adsorption and desorption performance of poly(hydroxamic acid) (PHA) resin for Cu²⁺ and Fe³⁺ ions were investigated by column tests. The results showed that adsorption capacities of PHA for Cu²⁺ and Fe³⁺ ions were satisfying, and the metals adsorbed on PHA can be eluted by sulfuric acid solution effectively. AMD of Dexing copper mine of Jiangxi was treated as a sample. The results showed that 1.5g·L^-1 calcite can remove almost all of the Fe³⁺ ion, and Cu²⁺ ion can be removed by PHA and then be eluted by sulfuric acid solution with adsorption ratio of 98.95% and elution ratio of 98.50%, separately.

Abstract: A computer simulation model was established to analyze the curing and cooling of reaction injection molding process of nylon 6 based on theory of balance equation of energy, reaction kinetics and crystallization kinetics. The reasonable assumptions and simplifications were introduced in the model, and an explicit finite difference method with MATLAB software was applied to calculate and predict the conversion and temperature distribution within a plate type mold. The results show that the center position reaches the peak temperature about 45s. The effects of the feed temperature, wall temperature, and reaction rate constant on the temperature and conversion were discussed for searching the optimum processing conditions. The results suggests that the effect of reactive rate on crystallization, molecular weight and phase structure is decided by the value of reaction constant; the influence of the mold wall temperature on reactive rate and temperature near the boundary was great; and the control of feed temperature is important in condition of low mold temperature.

Abstract: Cationic native starch (CNS) and cationic hydrolyzed starch (CHS) were investigated in physical modification of cotton to realize salt-free dyeing of reactive dyes and their application properties were compared. Adsorption isotherm studies of C.I. Reactive Red 2 on the modified cotton presented the dyeing followed Langmuir-type model. The dyeing properties of the fibers modified with CNS and CHS were investigated and compared. The results showed the dye fixation and fastness properties of both C.I. Reactive Red 2 and C.I. Reactive Blue 19 on CNS modified cotton were inferior to that on the untreated and CHS modified ones.