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本文研究气液并流向上兰相流化床的一般流体流动性质。阐明了不同性质及粒度的固体颗粒、流化床静止床高、气体及液体的表观线速、气体分布板结构等参数对床层的均匀性、气体及液体滞留量、床层膨胀高度及气泡形态及大小等影响的一般规律。提出了在液固两相流化床中通入气体后,床层膨胀比随着气体速度的增大而变化的规律具有五种不同类型。用气泡上升的平均真实速度V_g/ε_g作为V_g及V_L的函数作图,可以表明气体及液体的表观线速对气体滞留量及气泡大小的影响,并用在流化床上部的照片直观地表明了这一点。最后用关联式将本文数据进行关联,误差在±10%以内。 相似文献
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液体橡皮泥是指空气环境中被颗粒包裹的以可塑性和复杂形状为特征的液体系统,目前已被成功应用于气体传感、蛋白质分析、光催化等领域,并展现出了很多独特优势。这是一种新兴的软物质体系,与被颗粒包裹的形状为类球形的液体弹珠组成相似,但打破了后者的形状单一性。本文从裸液滴和液体弹珠出发,通过对液体形状和颗粒堵塞问题的分析,梳理了液体橡皮泥技术的建立过程。随后,论述了国内外的研究进展,对不同种类液体橡皮泥的制备、特性及应用进行了概括和分析,重点讨论了单层纳米颗粒结构液体橡皮泥的系列研究。最后,围绕液体橡皮泥的概念内涵、制备方法、特性对比、功能应用等问题进行了总结和探讨,并就未来发展方向和研究思路提出了建议。 相似文献
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本文用沉淀法制备了羧基功能化离子液体表面修饰半导体TiO2纳米颗粒, 并用FTIR, TEM, XRD和XPS对其结构进行了表征. 初步探讨了羧基功能化离子液体修饰TiO2纳米微粒的形成机理. 相似文献
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离子液体具有良好的溶解能力、稳定性、结构可调性、无明显的蒸汽压等优点,使其可以作为良好的有机反应介质和催化剂,但由于其价格昂贵且不易从反应体系中分离,应用受到限制。以超顺磁性纳米颗粒作为催化剂载体,利用其所提供的磁学特性,可通过外磁场对催化剂进行简单有效的分离。不过,超顺磁性纳米颗粒具有的高比表面能以及粒子间的偶极距作用,使其容易团聚,不能稳定分散于反应体系。若在磁性纳米颗粒表面包裹一层有机物或无机物形成核-壳结构复合材料,就既可以阻止其团聚又可以对其进行表面功能化。因此,将离子液体固载到核-壳结构磁性纳米颗粒表面,制备可回收并循环使用的多相催化剂的工作受到广泛关注。本文综述了近十年来核-壳结构磁性纳米颗粒负载离子液体催化剂的制备方法及其在有机合成方面的应用,并对其未来的应用前景进行了展望。 相似文献
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有机液体吸附功能纤维是一类可吸附自身重量数十倍有机液体的新型纤维材料,具有吸附速率快、吸附量高、易回收及可重复使用等特点,在环境保护、水处理、有机液体分离与回收等领域具有广阔的应用前景,已成为近年来吸附材料研究领域的热点。本文回顾了有机液体吸附功能纤维的发展历史,介绍了所用聚合物种类、单体选用及其制备方法,分析比较了几种有机液体吸附功能纤维的纺丝成形原理,讨论了纺丝过程中各种参数对纤维结构与性能的影响,总结了有机液体吸附功能纤维的再生与应用等方面的研究进展,并对其发展趋势进行了展望。 相似文献
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CO2膨胀液体热力学特性及在化学反应中的应用 总被引:2,自引:0,他引:2
二氧化碳膨胀液体被认为是环境友好的绿色溶剂,具有良好的气体溶解度、传质特性、低黏度、条件温和以及有机溶剂用量少等突出特点,受到化学家和化学工程学家们越来越多的重视。本文详细介绍了二氧化碳膨胀液体的体积膨胀度、相平衡热力学、传递特性、酸性以及导电性等理论研究成果;在此基础上,分析讨论了这些性质变化的内在原因;总结了目前为止利用二氧化碳膨胀液体所开发的化学反应研究现状,包括加氢、醛化、氧化及其它反应等;对存在的问题和今后应该致力于解决的技术性难题进行了讨论,指出了今后重点发展的方向。 相似文献
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《Solid State Sciences》2000,2(3):313-334
The latest developments in inorganic membranes are closely related to recent advances in solid state science. Sol–gel processing, plasma-enhanced chemical vapor deposition and hydrothermal synthesis are methods that can be used for inorganic membrane preparation. Innovative concepts from material science (templating effect, nanophase materials, growing of continuous zeolite layers, hybrid organic–inorganic materials) have been applied by our group to the preparation of inorganic membrane materials. Sol–gel-derived nanophase ceramic membranes are presented with current applications in nanofiltration and catalytic membrane reactors. Silica membranes with an ordered porosity, due to liquid crystal phase templating effect, are described with potential application in pervaporation. Defect-free and thermally stable zeolite membranes can be obtained through an original synthesis method, in which zeolite crystals are grown inside the pores of a support. Hybrid organic–inorganic materials with permselective properties for gas separation and facilitated transport of solutes in liquid media, have been successfully adapted to membrane applications. Potential membrane developments offered by CVD deposition techniques are also illustrated through several examples related to the preparation of purely inorganic and hybrid organic–inorganic membrane materials. 相似文献
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Interfacial synthesis of hollow TiO2 microspheres in ionic liquids 总被引:15,自引:0,他引:15
An interfacial sol-gel synthesis of inorganic hollow microspheres in room-temperature ionic liquids is newly developed. When metal alkoxides such as titanium tetrabutoxide, Ti(OBu)4, are dissolved in anhydrous toluene and injected into 1-buthyl-3-methylimidazolium hexafluorophosphate ([C4mim]PF6) under vigorous stirring, hollow titania microspheres are formed. The present technique is widely applicable to the reactive metal alkoxides such as Zr(OBu)4, Hf(OBu)4, Nb(OBu)4, and InSn3(OR)x, giving a general route to the metal oxide microspheres. When gold nanoparicles and carboxylate-containing dyes such as fluorescein isothiocyanate (FITC) are dissolved in the toluene microdroplets, they are stably immobilized in the microsphere shells. Calcination of the titania gel microspheres gives anatase TiO2 microspheres. The present method provides the first example of inorganic hollow microspheres formed in ionic liquids, and the ability to modify microspheres with metal nanoparticles or functional organic molecules would be widely applied to the design of smart organic/inorganic hybrid materials. 相似文献
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Theo Fromme Lucie K. Tintrop Dr. Sven Reichenberger Prof. Dr. Torsten C. Schmidt Prof. Dr. Stephan Barcikowski 《Chemphyschem》2023,24(11):e202300089
Laser ablation in liquids has been established as a scalable preparation method of nanoparticles for various applications. Particularly for materials prone to oxidation, it is established to suppress oxidation by using organic solvents as a liquid medium. While this often functionalizes the nanoparticles with a carbon shell, the related chemical processes that result from laser-induced decomposition reactions of the organic solvents remain uncertain. Using a systematic series of C6 solvents complemented by n-pentane and n-heptane during the nanosecond laser ablation of gold, the present study focuses on the solvent-dependent influence on gas formation rates, nanoparticle productivity, and gas composition. Both the permanent gas and hydrogen formation was found to be linearly correlated with ablation rate, ΔHvap, and pyrolysis activation energy. Based on this, a decomposition pathway linked to pyrolysis is proposed allowing the deduction of first selection rules for solvents that influence the formation of carbon or permanent gases. 相似文献
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This review discusses briefly the preparation, electrochemistry, and electrogenerated chemiluminescence (ECL) as well as spectroscopic properties of organic nanoparticles. Organic nanoparticles, ranging from several tens of nanometers to hundreds of nanometers in diameter, were successfully prepared by various methods. Using a simple reprecipitation method, organic nanoparticles of a very small size can be prepared and show unique electrochemical and ECL characteristics. As with inorganic nanoparticles, organic nanoparticles suggest possible applications, like labels for the analysis of biological materials with ECL. 相似文献
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This review discusses briefly the preparation, electrochemistry, and electrogenerated chemiluminescence (ECL) as well as spectroscopic properties of organic nanoparticles. Organic nanoparticles, ranging from several tens of nanometers to hundreds of nanometers in diameter, were successfully prepared by various methods. Using a simple reprecipitation method, organic nanoparticles of a very small size can be prepared and show unique electrochemical and ECL characteristics. As with inorganic nanoparticles, organic nanoparticles suggest possible applications, like labels for the analysis of biological materials with ECL.
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离子液体是由阴、阳离子组成的低温熔融盐,几乎没有蒸汽压,具有稳定性好、溶解能力强、结构可设计、导电性好等优良性能.离子液体作为一种广受关注的新型“绿色溶剂”,具有代替传统有机溶剂的潜力,其制备方法和应用范围研究日趋完善和多样,已广泛应用于催化化学、光电化学、材料化学和分析化学等领域.离子液体通过功能化导向设计后,可以将... 相似文献
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GAO Yong-bo LIU Ming-xia SUN Zhi-qiang ZHANG Kai DONG Feng-xia SUN Hong-chen YANG Bai 《高等学校化学研究》2012,28(5):916-920
Determining the microstructure in human cementum might help us design new kinds of replacement materials for the treatment of teeth injury and disease. The authors characterized the nanostructures in the cementum of health human teeth via scanning electronic microscopy(SEM). It was found that the acellular cementum is mainly composed of two kinds of nanostructures―inorganic nanoparticles and organic nanofibers. And the inorganic nanoparticles show a tendency to arrange along the organic nanofibers. Based on the micro-molding in capillary strategy, the distribution of organic component in acellular cementum was copied with UV curable resin. After removing the inorganic nanoparticles by acid etching, many isolated spindle shape nanopores were left in polymer, which su- ggested that the inorganic nanoparticles should have been isolated by the organic component in cementum, and should be oval or nanosheet in shape. We hope the present work could provide reference for the biomimetic preparation of tissue engineering materials, and help us design new types of tooth implant. 相似文献
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Yuung‐Ching Sheen Yuan‐Chang Huang Chun‐Syong Liao Hisn‐Yi Chou Feng‐Chih Chang 《Journal of Polymer Science.Polymer Physics》2008,46(18):1984-1990
Superoleophobic surfaces possessing static contact angles greater than 140° with organic liquids are extremely rare. A simple approach has been developed to fabricate an extremely superamphiphobic coating material based on fluorinated silica nanoparticles resulting contact angles of water and diiodomethane at 167.5° and 158.6°, respectively. The contact angle of diiodomethane at 158.6° is substantially higher than the highest literature reported value we know of at 110°. In addition, this developed film also possesses extremely high contact angles with other organic liquids such as soybean oil (146.6°), decahysronaphthalene (142.5°), diesel fuel (140.4°), and xylene (140.5°). This developed superamphiphobic organic–inorganic hybrid film possesses unique liquid repellency for both water and organic liquids that can be used as functional coatings on numerous substrates by a simple coating process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1984–1990, 2008 相似文献