沉降速度表征氢氧化镁阻燃剂改性效果的研究

在改性研究中,通过沉降速度对改性前后的氢氧化镁粉体进行表征和测试,以确定最佳的表面改性剂和最佳的改性工艺条件。研究结果表明最佳的表面改性剂为硬脂酸锌;最佳的改性工艺条件为:改性温度为85℃,改性剂用量为5%,改性时间为0.5h。     

氢氧化镁粉体的表面改性研究

主要研究了氢氧化镁的湿法表面改性的工艺过程，用浊度分析方法对改性效果进行了比较，确定了最佳工艺条件。实验结果表明：最佳改性剂为硬脂酸钠，改性剂用量为6％（质量分数），改性温度为85℃，改性时间为20min。同时，最佳条件下改性样品的红外光谱分析表明：最佳改性条件下，硬脂酸钠有效包覆在氢氧化镁粒子表面，使氢氧化镁表面有机化，增强了氢氧化镁粉体与有机体的亲和性，这对于制取添加型的氢氧化镁阻燃剂具有指导意义。     

工艺参数对TiO_2粉体表面有机改性效果的影响

利用两种溶胶-凝胶工艺制备了TiO_2粉体,并对TiO_2表面进行有机改性。结果表明:Ⅰ号工艺更好,在实验范围内,适宜的有机改性条件为:改性剂为月桂酸钠,改性时间为30 min、改性温度为40℃、有机改性剂的用量为10%、在环己烷中的亲油化度值为0.61 g。     

月桂酸有机化改性纳米二氧化钛工艺研究

文章采用月桂酸作为改性剂对纳米二氧化钛粉体进行了有机表面改性。研究了在改性过程中,改性剂用量、改性时间、改性温度、溶液的pH对二氧化钛粉体表面改性的影响,通过对比试验,并对每组实验做了亲油化度的测定。实验结果表明,工艺条件为:改性剂用量5%、改性时间1.5小时、改性温度80℃、溶液的pH=5时,可以获得较好的改性效果。最后对改性前后的纳米二氧化钛作了红外光谱(IR)和热重分析(TGA)测试,证明了月桂酸有机化改性纳米二氧化钛的可行性。     

Mg(OH)_2阻燃剂的表面改性及其在软质PVC中的应用

通过TEM、BET、IR对改性前后的Mg(OH)2粉体进行表征和测试,确定了最佳表面改性剂和最佳改性工艺条件。结果表明,改性后的Mg(OH)2比表面积由原来的21.5760m2/g增加到29.8008m2/g,颗粒之间的团聚被打开;红外分析进一步说明,表面改性后Mg(OH)2表面有新的化学键形成;最佳改性工艺条件为:改性温度85℃,改性剂用量5%,改性时间0.5h。改性Mg(OH)2阻燃剂和软质PVC有较好的相容性和分散性。     

氢氧化铝阻燃剂的表面改性

为改善氢氧化铝阻燃剂与聚合物间的相容性,对氢氧化铝进行了改性研究,确定了量佳工艺条件,并对改性后的氢氧化铝粉体进行了性能测试。结果表明,最佳改性剂为硬脂酸,改性剂的量佳用量为1.5%。改性后的氢氧化铝粉体的表面性质发生了明显变化,沉降速度减慢,吸油值降低,活化指数增大,分散性好。     

纳米氢氧化镁表面改性研究

主要研究了纳米氢氧化镁湿法表面改性的工艺过程,将改性前后的粉体添加到软质PVC体系中测定该体系的氧指数、拉伸强度和断裂伸长率,同时与普通氢氧化镁粉体进行了比较。实验结果表明：在本实验条件下最佳的改性剂为硬脂酸锌,改性时间为0．5h,改性温度为85℃,改性剂用量为5％(质量分数);改性纳米氢氧化镁粉体比普通氢氧化镁和未改性纳米氢氧化镁粉体提高了软质PVC体系的阻燃性能,同时降低了对体系机械力学性能的影响。     

粉体撞击流超细粉碎与表面改性研究

采用撞击流技术 ,实现粉体的超细粉碎与表面有机化改性工艺于一体。阐述撞击流超细粉碎与表面改性装置的流程特点及工作机理。用硬脂酸作为改性剂 ,对重质碳酸钙进行超细粉碎与表面改性研究 ,研究系统中工质压力、加料速度、改性剂用量等参数对改性粉体性能的影响。通过测定改性粉体的活化指数、红外图谱及其在液体石蜡中的粘度变化 ,证明改性粉体的改性效果良好 ,试验流程及装置具有可行性。     

硬脂酸镁改性碳酸钙研究

采用硬脂酸镁对碳酸钙进行表面改性处理,考察了改性剂用量、改性温度、改性时间对粉体改性效果的影响。通过对改性前后碳酸钙粉体的活化度、吸油值、沉降体积以及黏度等性能的测试,从而确定最佳的改性条件。结果表明,最佳的改性工艺条件为：改性剂用量为2%,改性温度为70℃,改性时间为30min。由红外光谱分析可知,硬脂酸镁与碳酸钙之...     

无机粉体表面改性技术发展现状与趋势

表面改性是无机粉体的主要加工技术之一,对提高无机粉体的应用性能和应用价值有着至关重要的作用。从粉体表面改性方法、工艺、设备、表面改性剂及其配方等方面综述了无机粉体表面改性技术现状;从表面改性工艺与设备、改性剂及其配方、层状硅酸盐矿物粉体的插层以及表面无机复合改性等方面综述了非金属矿物表面改性技术的新进展;并对无机粉体表面改性技术的发展前景和发展趋势进行了展望。     

钛基二氧化铅电极的制备、改性及应用现状

概述了近年来国内外钛基二氧化铅电极的研究进展,主要涉及钛基二氧化铅电极的制备方法(包括中间层和活性层的制备方法)、改性(包括掺杂离子、颗粒和表面活性剂)及应用现状等。指出了现阶段二氧化铅电极存在的问题,并对其发展前景进行了展望。     

BaTiO3超细粉体的溶胶-沉淀法制备及其表征

采用溶胶-沉淀工艺制备BaTiO3纳米粉体,探讨了沉淀剂NaOH溶液浓度对制备BaTiO3粉体相组成的影响,提出了溶胶-沉淀法合成纯相BaTiO3的反应机理,并对沉淀水洗后的湿凝胶进行表面改性.探讨了添加表面活性剂及有机溶剂脱水过程对粉体团聚程度的有效控制.     

钛基二氧化铅电极的应用与改性研究进展

介绍了钛基二氧化铅电极在无机化工、有机化工和环境保护领域的应用进展,并分析了电极应用中存在的问题,提出对电极进行改性是提高电极性能的途径,并对中间层制备、掺杂离子和掺杂颗粒等电极改性方法进行了系统阐述,指出了今后的研究发展方向.     

Electrochemical degradation of phenol in aqueous solution on bismuth doped lead dioxide: a comparison of the activities of various electrode formulations

This paper describes the development of electrochemical processes for the oxidative degradation of toxic organic chemicals in waste waters. Doped bismuth lead dioxide anodes have been tested by the kinetic study of phenol anodic oxidation in aqueous solution. The main products during oxidative degradation of phenol are 1,4- benzoquinone, maleic acid and carbon dioxide. Several deposits of Bi2O5–PbO2 on Ti/(IrO2–Ta2O5) substrates have been prepared by anodic oxidation of Pb2+ and Bi3+ in aqueous solutions containing perchloric acid to increase the solubility of bismuth. To study the effect of perchlorate ions, the efficiency of the PbO2 deposit prepared from lead nitrate in an aqueous solution (pure PbO2) was compared with that of a deposit prepared from perchloric acid solution (perchlorate doped PbO2). Although the phenol is oxidized at the same rate on the two deposits, the charge corresponding to the total elimination of 1,4-benzoquinone is three times higher for perchlorate doped PbO2 than for pure PbO2. Phenol degradation is more efficiently carried out on a PbO2 anode doped with perchlorate and with bismuth than on the same electrode doped only with perchlorate. Among the electrodes tested in this work, the pure PbO2 anode is the most efficient for phenol degradation. It is assumed that certain active sites on the anode occupied by perchlorate ions do not participate in the transfer of oxygen atoms and that for the PbO2 electrode doped with bismuth, oxygen evolution is favoured to the detriment of oxygen atom transfer.     

抗紫外纳米ZnO/TiO_2粉体的氧化铝表面改性

用液相沉积法对纳米ZnO/TiO2进行了表面改性。用TEM、XRD和FTIR对产物进行了结构表征,用静态沉淀法分析了改性前后纳米ZnO/TiO2的分散稳定性,用紫外-可见分光光度计对其紫外屏蔽性能进行了检测。结果表明,改性纳米ZnO/TiO2表面存在致密的氧化铝膜,产物经充分分散后在有机介质中或水中的稳定时间分别由改性前的2 m in和5 m in提高到2 h和1 d,紫外线透过率由改性前的大于8.5%降低到小于7%。     

Low-Temperature Synthesis of Nanocrystalline Zinc Titanate Materials with High Specific Surface Area

Nanocrystalline zinc titanate (ZnTiO₃) was synthesized at low temperatures through the combination of a sol–gel processing and a polymer binder method. ZnTiO₃ powders of ∼5 nm in size were obtained by heating pastes, which were composed of a Zn-Ti methanolic solution containing acetylacetone and an organic polymer binder, at 500°C in air. Thermal decomposition behavior of the pastes was analyzed by thermogravimetry-differential thermal analysis. Crystallinity of ZnTiO₃ was examined by transmission electron microscopy. The BET measurement revealed that the powders had a relatively high specific surface area of 106 m²/g.     

单晶硅表面微结构调节技术的改进

提出改变碱液腐蚀单晶硅表面特性的一个简单方法,即在碱液中加入活性剂改变碱液在硅表面的润湿性能从而改变其腐蚀特性。分别采用普通碱液、四甲基氢氧化铵（tetramethylammonium hydroxide,TMAH）溶液和加入阴离子有机氟表面活性剂的普通碱液腐蚀硅表面。结果发现：普通碱液和TMAH腐蚀液腐蚀的硅表面的金字塔大小差异大、有许多蜂窝状的小金字塔,反射率较高;用加入阴离子有机氟表面活性剂的普通碱液腐蚀的单晶硅表面,能形成比较规则的金字塔,金字塔尺寸为4～6μm、均匀性好、覆盖率高、表面反射率下降到12．65％。有机氟表面活性剂能提高硅在碱中腐蚀速率,有效调控单晶硅金字塔形貌、大小与分布,为精确调控单晶硅表面微结构提供了可能。     

Preparation of nanometer-sized barium titanate powders by a sol-precipitation process with surfactants

Nanometer sized barium titanate powders can be obtained by adding surfactants to titanyl acylate precursors in a strong alkaline solution (pH>13). FTIR, TGA, SEM and XRD were used to investigate the effects of the surfactants influence on the morphology of the obtained titanate powders and their sinterability. In a pre-added surfactant process (i.e. surfactant added before precipitation in alkaline solution), a slower rate of hydrolyzation is observed, and the shift rate in the condensation is slower. Less crosslinking of smaller particles is observed. The addition of anionic surfactant (LAS) in general leads to the formation of micelles, which control the nucleation and crystal growth of the titanate powders. This micelle formation results in a smaller particle size (30–90 nm), and a larger surface area of 60.5 m²/g for BaTiO₃ powders was obtained. The nanometer-sized barium titanate powders were readily sintered at 1100–1200 °C.     

Tailoring of the Lead Metaniobate Ceramic Processing

The processing of a PbNb₂O₆ (PN) ceramic was investigated and optimized. Through thermal gravimetric and X-ray diffraction analysis the optimal calcination condition and the starting firing temperature were estimated. The powders were submitted to thermal treatments to obtain PN ceramic powders with an orthorhombic ferroelectric phase. The effect of PbO excess addition to compensate the PbO losses, during the calcination and the firing, was also studied. The highest density value was found to be 96% of the theoretical density. The temperature dependence of the dielectric properties, for samples sintered at different temperatures, allowed the study of the sintering kinetic.     

最新一代的Gemini表面活性剂在有机颜料生产中的应用（二）

有机颜料在合成过程,分散过程和表面改性处理中,需要各类具有润湿,分散功能的助剂。由于有机颜料本身的特殊性,对助剂的要求很高,目前市场上供应的助剂不能完全满足要求。Gemini表面活性剂由于独特的性能,优异的表面活性;大大超过传统的表面活性剂,赋予低表面张力,有利于有机颜料的润湿;超低的临界胶束浓度和降低表面张力效力,有利于有机颜料的分散稳定性。它在有机颜料领域的应用正在开始,期待进一步的开发。