Advanced Materials Research Vols. 750-752

Abstract: Mesoporous carbons were prepared by one step method using hard coal pitch as carbon source, in which magnesium oxide was adopted as template. The adsorption value of vitamin B₁₂, specific surface and pore size distribution, surface topography of mesoporous carbons were tested by spectrophotometer, specific surface analyzer and scanning electron microscopy. The results showed that the vitamin B₁₂ absorption value on mesoporous carbon could be improved with suitable carbonization temperature and mass ratio of template agent to carbon source. The maximum value achieved to 103.82mg/g when the mass ratio of MgO to modified pitch was 8:2.

Abstract: During the exploitation and utilization of the mineral resources, varieties of pollutants have been produced, which would impact the natural environment inevitably and bring many adverse effects to ecological environment and the human health. Its worth noting that the wastewater from copper mineral processing (WCMP) is one of the main source of mine environmental pollution. The WCMP is characterized by large quantity and containing large numbers of suspended solids, residual flotation reagents and heavy metals, etc. Wastewater can be discharged and realized reuse only after effective treatment. Recently, natural sedimentation, neutralization, flocculation, oxidation and other treatment techniques by wastes are the commonly used methods to treat the mineral processing wastewater.

Abstract: The stickies in pulp and paper machinery especially in the blankets will cause a lot of problems such as paper defects, increasing the time of machine shut down . Therefore, Inhibiting the Stickies of blanket is very important to regular production. In this study,we mainly studied on the inhibition of Stickies in the blanket with enzyme. The processed blanket was treated by several kinds of enzymes. The results showed that the optimum enzyme treatment conditions were obtained as followings:PH of 7, temperature of 50°C, 2×10⁴U/g of cellulose enzyme, 2×10³U/g of amylase and 10⁴U/g of lipase. The blankets obtained better cleaning situation under this conditions.

Abstract: Synthesis of Poly(L-lactide) (PLLA) by the ring-opening polymerization (ROP) of L-lactides in supercritical carbon dioxide (SC-CO₂) with co-solvent were studied. Effects of kinds of co-solvent on the molecular weight (MW) and the molecular weight distribution (MWD) of the resultant polymers were investigated by the gel permeation chromatography (GPC). The resultant polymers were also characterized with ¹H NMR, ¹³C NMR and FT-IR. It was found that PLLA with high purity and almost without racemization could be obtained by this technology and the acetone is the best co-solvent for this kind of polymerization. By using stannous octoate as initiator and acetone as co-solvent, PLLA having a weight-average molecular weight (M_w) near to 9×10⁴ and polydispersity index (PDI) of 1.7 was successfully synthesized.

Abstract: Biological treatment is one of the considerable choices for removing of organic pollutants present in petrochemical wastewaters. In this study, BS5, the isolate with the highest COD removal rate, was identified as Bacillus flexus, based on 16S rDNA sequences. Subsequently, the optimized COD removal conditions of BS5 were investigated. It was indicated that the optimal conditions were 35°C, pH 7.5. Under such circumstance, the removal rate of COD can reach 81.04%. The isolation of Bacillus flexus strain BS5 provided an alternative for the bioremediation of alkaline wastewater. Lastly, the study showed that consecutive disposal process may help to reducing COD of wastewater effectively.

Abstract: The influence of alkali lignin (AL) as a carbonization agent on the thermal degradation and flame retardancy of intumescent flame retardant (IFR) coating was investigated under air condition, with ammonium polyphosphate (APP) as an acid source, and melamine (MEL) as a blowing agent. Compared with a traditional APP/pentaerythritol (PER) /MEL IFR system, thermogravimetric analysis (TGA) results showed that APP/AL/MEL IFR system could induce the synergistic effect at a much boarder temperature range, and improve the thermal stabilities of the IFR coating. With the increase of AL loading, cone calorimeter test showed the peak heat release rate of the IFR coatings decreased from 54.86 MJ/m² to 41.06 MJ/m² .

Abstract: Biochar is environmental friendly materials that can be used for environmental protection. In the research, the application of biochar for phosphate adsorption and recovery from wastewater was examined. The material surface characterization analysis, include Transmission Electron Microscope with energy dispersive X-ray spectroscopy and Fourier Transform Infrared spectroscopy, was performed to characterize the prepared biochar. The application analysis, include optimal solution pH and interfering ions effect, was performed for phosphate adsorption and recovery from wastewater. The research conclusions were drawn as follow: (1) material surface characterization demonstrated the prepared biochar was coarse, unshaped, irregular, and contained a great deal of carbon; (2) application analysis indicated biochar adsorption amount for phosphate was decrease with an increase in solution pH, and biochar adsorption amount for phosphate was also decrease with an increase in interfering ions concentration.

Abstract: The dyeing properties of the polylactic acid (PLA) fiber with four different disperse dyes was studied. In the disperse dyeing process, differential scanning calorimeter (DSC) analysis was applied to test and analyze the changes of the glass-transition and melting temperature of the dyed and pure PLA fiber. The results indicated that not only the structure of the dispersed dyes and the dyeing conditions affected the dyeing performance of PLA fiber, but also the degree of the crystallinity of PLA fiber contributed to the final dyeing results. Moreover, the transformation of such crystallinity during the disperse dyeing process should be taken into account when the dyeing temperature was studied.

Abstract: Applying one-step solvothermal synthesis method, different CdS/TiO₂ nanocomposite materials are obtained by changing the ratio of sulfur and titanium sources. The composite structure and morphology are determined by XRD and TEM. Taking the degradation of methyl orange solution as a model reaction, the photocatalytic activity of CdS/TiO₂ composite materials is investigated. The results show that the amount of CdS in composite photocatalyst has great effects on the degradation efficiency of methyl orange under the irradiation of sunlight, and the lower pH of reaction system is also needed to sustain the high degradation efficiency for methyl orange.

Abstract: The nanometer TiO₂ thin membrane on different substrates doped with La³⁺ was prepared from Ti (OC₄H₉)₄ and La (NO₃)₃ by Sol-Gel processing using dipping technique. The photocatalytic activity of membrane at different doping concentration in photocatalytic methyl orange was studied. The result showed that both the degraded rate and the optimum concentration depended on the change of doping concentration and substrates. When TiO₂ thin membrane was doped with 0.5 La³⁺ on the substrates of glazed ceramic, aluminum and stainless steel, TiO₂ membrane has the maximum degradation rate.