首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
离子液体具有稳定性高、溶解性好和电化学宽窗口等优点,是理想的电解液。在离子液体中,可以得到在水溶液或其他有机电解液无法沉积的半导体材料,并且离子液体电沉积方法简便灵活,可以控制半导体材料的形貌和尺寸,在制备纳米半导体的领域中具有非常重要的现实意义。本文介绍了离子液体的性能特点,并综述了几种离子液体中电沉积半导体材料。其中包括单质半导体薄膜材料(S、iGe、Te、灰Se等),以及在光电子领域具有广阔应用前景的各种直接带隙的半导体化合物(GaAs、InSb、ZnTe等)。最后,提出离子液体电沉积方法与模板法相结合,制备Si、Ge纳米线,并可以辅助胶体晶体模板法制备光子晶体,为获得完全带隙的光子晶体材料提供了新的技术路线。  相似文献   

2.
本文综述了离子液体在气相色谱固定相中的发展过程。为提高固定相的使用温度、选择性和色谱柱效,离子液体先后经历多次制备方法的改善,本文主要介绍了小分子离子液体、大体积离子液体、柱内烯基咪唑聚合离子液体、物理混配离子液体和化学键合离子液体等非手性离子液体的合成进展;同时综述了由手性氨基酸、手性胺和键合环糊精合成的手性离子液体的研究进展;并比较各种离子液体用作色谱固定相时的稳定性及选择性差异。另外,对离子液体在二维气相色谱和快速气相色谱中的应用扩展作了总结,并展望离子液体作为新型分离材料在气相色谱固定相中的研究和应用前景。  相似文献   

3.
离子液体作为潜在的“绿色”溶剂,具有许多传统溶剂无法比拟的优异性能,在有机合成、催化、液液分离和萃取等领域引起了广泛的研究。而在离子液体领域无机材料的制备是一个较新的发展分支,现已利用其合成出多种具有独特结构和性能的无机材料。本文就离子液体在无机材料制备方面的应用及发展趋势进行了综述。目前,对于制备无机材料,离子液体主要是作为电解液、表面活性剂或溶剂,本文介绍了其在应用中的优缺点,并指出该领域未来的发展趋势是离子热合成和集模板-溶剂-反应物于一身的离子液体反应。  相似文献   

4.
离子液体作为一类新型绿色介质,具有低熔点、难挥发、宽电化学窗口、结构可调等特性.负载型离子液体将离子液体与不同种类载体结合,维持其流动或结构特性,具有高活性、高选择性、易回收、降低工艺能耗等优点,突破传统离子液体在工业应用中的限制,为实现离子液体规模化应用提供新方法.本文总结了负载型离子液体近年来的研究进展,介绍了负载型离子液体的分类及浸渍法、键合法、溶胶-凝胶法等常用的制备方法;阐述了其筛选预测模型及在模拟计算中的研究进展;论述了负载型离子液体在催化、分离中的应用进展;讨论了负载型离子液体未来的发展趋势.  相似文献   

5.
总结了作者及其团队近10年来在离子液体萃淋树脂的制备方法及其在稀土分离中的应用研究进展。离子液体萃淋树脂是一种新型的高效固体分离材料,其制备方法有物理负载法、化学负载法、溶解凝胶法和膜负载法等,所用载体一般为高比表面多孔的高分子树脂、SiO_2等。离子液体萃淋树脂具有离子液体的可设计性,可根据不同的结构需求设计合成出不同性能的离子液体萃淋树脂,同时可以减少萃取剂的流失,适用于高效和高选择性的分离和纯化稀土离子,是溶剂萃取法萃取分离稀土的有效补充和完善。  相似文献   

6.
佟国宾  鄂雷  徐州  马春慧  李伟  刘守新 《化学进展》2019,31(8):1136-1147
离子液体因其熔点低、液态温域宽、蒸气压低、热稳定性高、电导率高、电化学窗口宽、结构可设计及对许多化合物的亲和性等系列性能而引起人们广泛关注。离子液体在炭材料制备、改性领域展示出了良好的前景及巨大的应用潜力,可直接作为碳源,经过高温炭化实现杂原子掺杂制备多孔炭材料;离子液体也可充当反应介质和致孔剂,将生物质转化为多孔炭材料;此外,由于离子液体与炭材料相容性较好,可以用于多孔炭材料改性制备炭复合材料。基于离子液体的炭材料在电催化、超级电容器、吸附分离及生物医学等领域具有潜在的应用价值。本文总结了基于离子液体炭材料的制备、改性及应用最新研究进展,并着重介绍了其在能源和环境相关领域的应用。  相似文献   

7.
石墨烯需求量日益增加,有关其制备方法的研究已有大量文献报道.咪唑类离子液体与石墨烯间的特殊作用,使得离子液体参与制备石墨烯成为很有潜力的方法.本文对离子液体参与石墨烯及其复合物制备的研究进展进行了综述.在论述了制备机理的基础上,系统总结了离子液体参与的各种制备方法,评判了各种方法的优缺点,重点关注了离子液体在其中所起的作用,指出了最有潜力的离子液体应具备的结构特点,对开发基于离子液体的石墨烯及其复合物制备方法的研究具有一定的指导作用.  相似文献   

8.
离子液体及其在环境污染物分离分析中的应用   总被引:1,自引:0,他引:1  
介绍了离子液体的制备方法和重要性能,综述了近年来离子液体在环境污染物分离分析领域中的应用情况。引用文献45篇。  相似文献   

9.
二维钙钛矿作为一种新型光电材料,既具有二维材料的可溶液加工、柔性、可穿戴性以及廉价容易制备等特点,又具备钙钛矿材料结晶度高、载流子迁移率高、激子束缚能低、量子效率高、吸收光谱宽、光吸收系数高和能耗损失低等特性,已经成为材料研究领域的热点而受到广泛关注。本文深入分析了二维钙钛矿材料的组成特点及结构构建规则,探究了其光电特性、能带性质以及非线性光学性质等,对二维钙钛矿光电材料常见的两大类制备方法液相法和气相法进行了归纳,总结了二维钙钛矿材料在太阳能电池、光电探测器、发光二极管、场效应晶体管和激光等光电器件领域的应用现状,最后对该类材料目前存在的主要问题及未来发展前景进行了展望,以期为设计制备高性能二维钙钛矿光电材料提供参考。  相似文献   

10.
离子液体在生物柴油合成中的应用进展   总被引:5,自引:0,他引:5  
介绍了合成生物柴油常用的酯交换方法以及离子液体的定义、结构、性质和制备方法, 简单描述了酸性离子液体作为催化剂在酯化反应中的应用, 综述了离子液体在生物柴油合成中的应用进展并展望了其应用前景.  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

13.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

14.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

15.
16.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

17.
The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m2g-1 instead of aerosil with one of 175 m2g-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
小环化合物中饱和碳质子化学位移的计算   总被引:3,自引:0,他引:3  
小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:  相似文献   

19.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

20.
结合实际发展电化学科学─—武汉大学电化学研究室工作简介查全性,陆君涛(武汉大学化学系电化学研究室,武汉430072)在物理化学的众多分支学科中,电化学长期保持良好的发展势头。除了电化学所研究的体系(溶液、电极/溶液界面等)具有广泛的基础意义外,促使电...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号