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超声化学法在纳米材料制备中的应用及其进展 总被引:1,自引:0,他引:1
介绍了运用超声化学法制备纳米材料的基本原理及其相对于其它传统的方法所具有的优势,综述了超声化学沉淀法、超声喷雾热分解法和超声电化学法等在纳米材料制备中的应用及其进展。最后对超声化学法制备纳米材料的发展方向提出了展望。 相似文献
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Ⅱ-Ⅵ族半导体纳米材料具有特殊的物理化学性质,在光学、电学和光电子等领域都有着巨大的应用前景,因此是纳米材料制备领域的研究热点之一。文章主要综述了近年来溶液相中Ⅱ-Ⅵ族半导体纳米材料制备方法的若干进展情况,并展望了其发展趋势。 相似文献
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银纳米材料粉由于具有很高的表面活性和优良的导电性能而被广泛应用于电子陶瓷、导电涂料、催化剂等领域。目前,银纳米材料的制备方法有很多,然而对银纳米材料的制备的探讨仍是人们研究的热点。本文对近五年国内外银纳米材料的制备方法及原理进行论述。 相似文献
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利用热重技术对寻甸褐煤的催化多段加氢热解过程进行了研究,考察了不同的催化剂制备方式对该过程的影响,并在固定床上研究了产物的分布和焦油组成.结果表明:催化剂的存在明显增加了自由基的生成及其被氢化饱和的速率,从而导致了总转化率的提高;与不加催化剂相比,当Mo负载量为0.2%时, 350 ℃的停留过程使转化率从26%激增到50%;不同Mo负载量下的停留对加氢热解过程中的低温峰和高温峰的影响不同;经超声处理催化剂制备的煤样,其加氢热解在任何温度下的转化率均高于用电磁搅拌制备的结果,而且热解温度越高其效果越明显;超声负载催化剂的多段催化加氢热解的总转化率远远高于通过电磁搅拌制备的煤样;催化条件下的多段加氢热解过程改变了产物的分布,并明显提高了焦油中轻质组分的含量,苯类、酚类和萘类收率分别增加了42%、37.8%和115.4%. 相似文献
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介绍了纳米磁流体、纳米磁性颗粒、纳米磁性微晶及纳米磁性复合材料的制备方法并比较了各种方法的优缺点。并对纳米磁性材料的应用进行了概述,对其研究前景进行了展望。 相似文献
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采用超声法合成铝镁水滑石,并通过X射线衍射(XRD)、红外光谱(FT-IR)、透射电镜(TEM)、热分析(DSC)、粒度分析等手段对合成的水滑石进行表征,研究超声法合成的水滑石和进口水滑石的结构及热性能。TEM测试结果表明超声法制备的水滑石晶型为絮状;物理吸附仪测试结果表明超声法制备的水滑石比表面积非常大;粒度测试结果表明超声法制备的水滑石和进口水滑石粒径分布基本相同。研究结论是超声制备的水滑石比进口样品晶粒更细、更小,比表面积更大。 相似文献
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Julio C. Bonnet Jos A. Sorrentino 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,61(3):201-207
An ultrasonic technique developed by Bonnet and Tavlarides for dispersed phase holdup determination in liquid–liquid contactors has been applied in a 0·10 m diameter Scheibel extraction column. The column consists of three alternate mixing and packing sections of 0·03 and 0·055 m in height, respectively. The packings were built with polypropylene mesh with 96% voidage. The liquid–liquid systems were toluene (dispersed)/water (continuous) and MIBK (dispersed)/water (continuous); the Rushton-type impellers were operated at 400, 500 and 600 rpm, and with four dispersed and continuous phase flow rates. In one of the mixing chambers two different holdup measuring devices were installed: two ultrasonic transducers and one controlled dispersion sampler. The values of dispersed phase holdup obtained by both methods were compared using statistical methods. It was found that at low agitation and for high interfacial tension, conditions for which the dispersion is not completely uniform, the difference was significant, whereas at high agitation and low interfacial tension the values obtained through both methods were statistically equal. This work demonstrates the applicability of the ultrasonic technique for holdup measurements to Scheibel columns, in which the only technique used so far was sampling. This ultrasonic technique allows us to solve the axial monitoring and control problems of these columns. 相似文献