TiO2 pure phase brookite with preferred orientation,synthesized as a spin-coated film

An oriented titania (brookite) film containing neither anatase nor rutile was synthesized by a new modified sol–gel method. The precursor was TiCl₄ with cellulose and oxalic acid as complexing agent. The XRD results show oriented pure brookite titania thin film. The SEM micrograph shows square particles on the crack free continuous film. A diffusion of sodium from the substrate was detected by XPS. It was found that the nature of complexation, the concentration of the precursors, the polymer additive, solution media (low pH, solvent-EG) and the substrate were significant of the oriented brookite TiO₂ films obtained.     

超声波作用下炭黑的亲水性高分子聚合接枝

在超声波辐射作用下,用自由基聚合方法在炉法炭黑表面上接枝了聚丙烯酸及含磺酸基高分子的共聚高分子,并获得了相应炭黑接枝的优化条件（pH值、引发剂量、丙烯酸加入量和反应时间等）.借助XPS、FTIR及SEM等分析了炭黑接枝前后官能团的差异.结果表明：超声波作用下炭黑的聚丙烯酸接枝反应时间大大减少;接枝后获得的炭黑与水的亲合力、炭黑粒子之间的静电斥力都得到了很大提高,同时由于高分子的空间位阻,炭黑在水性体系中的分散稳定性得到了明显的改善.     

Gemini表面活性剂气液界面吸附过程的焓熵补偿

对季铵盐Gemini表面活性剂气液界面吸附的热力学参数进行研究,发现焓变(ΔH)和熵变(ΔS)呈线性关系,表明表面活性剂的气液界面吸附过程与其胶团化过程一样存在焓熵补偿现象,补偿温度为303 K左右,为熵驱动过程。联接链的长度越长焓变越小,即气液界面吸附越稳定。     

有机中间体2-溴噻吩的合成研究

分别采用冰乙酸溶剂法、四氯化碳溶剂法、直接溴化法合成了2-溴噻吩,重点考察了加溴方式、加溴时间、原料配比、反应温度等影响因素对直接溴化法生产2-溴噻吩工艺的影响,并对三种生产工艺的生产成本进行了对比分析.实验结果表明:冰乙酸溶剂法和四氯化碳溶剂法不适合工业化生产,而直接溴化法是比较理想的生产工艺.将溴以蒸汽状态通入液体噻吩中进行反应产率较高,且副产物最少.溴是否预热和溴蒸汽通入时间对2-溴噻吩产率影响比较明显;直接溴化法的最佳工艺条件为:原料配比为0.55∶1-0.6∶1;反应温度为65℃-75℃;加溴时间为6-8 h.     

Selective catalytic reduction of NO with propene over Au/CeO2/Al2O3 catalysts

Selective catalytic reduction of NO by propene under an oxygen-rich atmosphere has been investigated over Au/ CeO₂, Au/CeO₂/Al₂O₃ and Au/Al₂O₃ catalysts prepared by deposition-precipitation. The results demonstrated that Au/16%CeO₂/Al₂O₃ had good low-temperature activity, selectivity towards N₂ and stability, which is superior to that of Pt/Al₂O₃. It was also found that adding 2% water vapour to the feed stream enhanced the NO conversions at low temperatures while the presence of 20 ppm SO₂ increased NO conversions at higher temperatures. It is particularly interesting that under the simultaneous presence of 2% water vapour and 20 ppm SO₂, the NO conversions to N₂ were significantly increased and the temperature window was widened significantly. The catalysts were characterized by Xray diffraction (XRD), high resolution transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (HRTEM-EDX) and temperatureprogrammed reduction (H2-TPR) techniques. Both XRD and HRTEM revealed that CeO₂ was highly dispersed on the alumina support, and HRTEM combined with EDX showed that gold particles were preferentially deposited on those highly dispersed CeO₂ particles. The gold deposition made CeO₂ more reducible and interaction between gold and those highly dispersed CeO₂ particles became stronger than that with the bulk CeO₂, and this interaction is probably responsible for the superior catalytic performance of the Au/CeO₂/Al₂O₃.     

Optimal unit sizing for a hybrid wind/photovoltaic generating system

The application of a hybrid wind/photovoltaic (PV) power generating system for utilization as a stand-alone or a network connected system is investigated. The optimum combination of wind and PV generation coupled with battery storage for a stand-alone system has been obtained for a hypothetical site in Montana. Generation and storage units for the hybrid system are properly sized in order to meet the annual load and minimize the total annual cost to the customer. The optimal solutions are found by a numerical study using the hourly load demand for a typical residential home in the Northwestern US. Hourly wind speed and approximate solar radiation data have been used.     

Suitability of polyethylene terephthalate heavy-ion track membrane for protecting the environment in clean rooms and sterile closed apparatus

In this paper the method of recirculative recovery of the air in different closed apparatus and clean rooms is proposed. The method is based on diffusive gas exchange through polyethylene terephthalate heavy-ion track membrane. Tests with the membrane process were carried out to provide sterility inside a fermenter and to create normal conditions required for the vital activity of the staff in a closed clean room.