不同孔结构硅胶负载强氧化性酸脱除柴油中硫化物的性能

选用不同孔结构的硅胶作为吸附剂,浓硝酸、过氧乙酸和次氯酸作为氧化剂,考察了硅胶孔结构对其负载强氧化性酸脱除含4,6-二甲基二苯并噻吩150μg/g的模型柴油中硫化物的影响,并通过红外光谱和N_2等温吸附法对硅胶进行了表征。结果表明:对于过氧乙酸,硅胶孔结构对脱硫效果无明显的影响;对于分子直径较大的无机酸(次氯酸),硅胶孔径对脱硫率有较大的影响;对于分子直径较小的无机酸(浓硝酸),硅胶孔径和比表面积对脱硫率都有较大的影响;硫化物的氧化产物与硅胶孔结构无关。

Enhancement on Synthesis of Boehmite Through a Precarbonizationassisted Hydrogen Peroxide Route in Highly Alkaline Sodium Aluminate Solutions

Hydrogen peroxide(H2O2)precipitation from sodium aluminate(SA)solution at close-ambient temperature is an efficient method to synthesize boehmite and its derived alumina with high surface area,but the precipitation yield of Al2O3 is usually below 50%in highly alkaline SA solutions.Here the synthesis of boehmite is enhanced through a precarbonization-assisted H2O2 route in highly alkaline SA solutions.It is found that the crystal structure of the precipitation product is evidently influenced by the precipitation conditions.As the precipitation temperature increases from 273 to 325 K,a small amount of gibbsite by-product is formed.As the aging temperature increases from 301 to 333 K,the crystallinity of boehmite decreases and part of the boehmite dissolves due to an increase in the pH value.Based on the above results,a precarbonization-assisted H2O2 route is proposed to obtain pure boehmite with more complete recovery of Al2O3 from highly alkaline SA solutions.The route includes a controllable precarbonization step of SA solutions with a molar ratio of Na2O to Al2O3 higher than 2:1,followed by the H2O2-precipitated step with a molar ratio of H2O2 to Al2O3 less than 7:1.Because of its facile operation conditions,no extraneous impurity,time saving and a possible recycle of the filtrate,the route has great potential to be an alternative method for preparation of boehmite and its derived alumina.

Wettability and surfactivity of sodium phosphate surfactants in strong alkali solutions

The wettability,surfactivity and the correlation between wettability and surfactivity of sodium diethylhexylphosphate,sodium diethylhexyl polyoxyethylene phosphate and their complex in NaOH solutions were studied.A complex alkali resistant phosphate surfactant with good permeability was prepared.The wettability of surfactants was investigated by measuring the immersion time,sinking time and capillary effects of nature cotton grey fabric in NaOH solutions.The surfactivity of the surfactants was characterized by measuring the surface tension.The effect of the complex on the surface appearance of cotton grey fabric was also investigated with a scanning electron microscope(SEM) .The results show that all the surfactants exhibit good wettability for cotton grey fabric in 0.5-5.0 mol/L of NaOH solutions,the complex system exhibits better wettability in 5.0-7.0 mol/L of NaOH solutions,in comparison with either corresponding single surfactant component employed,and wettability is well correlative with the surfactivities of the surfactant.SEM images indicate that the cotton grey fabric is well wetted by the alkaline surfactant solution and the quality of fabric is improved.

提高嵌件树脂结合力的工艺研究

以强氧化性酸处理CT-R及1700环氧体系浇注件中的金属嵌件，通过拉伸强度测试研究了酸浓度、温度、清洁度等工艺参数对金属嵌件树脂结合力的影响。结果表明，针对CT—R树脂体系，最优处理工艺如下：碱洗30s，320mL/L硝酸处理30s，热水洗2min，浓度110异，L的强氧化性酸酸洗15min，水洗3min。该条件下嵌件-树脂结合力达到60MPa以上，可明显提高超高压（330—1000kV）和特高压（直流电压≥±800kV，交流电压≥1000kV）电器绝缘件的质量稳定性。