99 resultados para ionic liquid
Resumo:
A new metal-free organic sensitizer (see figure) for high-performance and applicable dye-sensitized solar cells is presented. In combination with a solvent-free ionic liquid electrolyte, a similar to 7% cell made with this sensitizer shows all excellent stability measured under thermal and light-soaking dual stress. For the first time a 4.8% efficiency is reached for all-solid-state dye-sensitized solar cells based oil all organic dye.
Resumo:
A novel bifunctional task-specific ionic liquid (TSIL), i.e. [trialkylmethylammonium][sec-nonylphenoxy acetate] ([A336] [CA-100]) was impregnated on intermediate polarized XAD-7 resin, and the prepared solvent impreganated resin (SIR) was studied for rare earth (RE) separation. Adsorption ability of the SIR was indicated to be obviously higher than that prepared by [A336][NO3] because of the functional anion of [A336][CA-100]. Adsorption kinetics, adsorption isotherm, separation and desorption of the SIR were also studied.
Resumo:
A series of silica-based organic–inorganic hybrid materials were prepared by the sol–gel process for Cr(III) and Cr(VI) adsorption. These silica materials generally had high surface areas, good physical–chemical stability and high thermal stability. Trialkylmethylammonium bis 2,4,4-trimethylpentylphosphinate ([A336][C272]) and trihexyl(tetradecyl)phosphonium bis 2,4,4-trimethylpentylphosphinate (Cyphos IL 104) were explored as porogens to prepare porous silica and as extractants to extract chromium ions. Cyphos IL 104 and [A336][C272] functionalized silica sorbents (SG-2, SG-5) can be effectively used for the removal of Cr(III) and Cr(VI) from aqueous solutions by adjusting pH values, whereas trialkylmethylammonium chloride (Aliquat 336) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) functionalized silica sorbents (SG-3, SG-4) can only be used for the removal of the single chromium species, Cr(VI) or Cr(III).
Resumo:
Herein, we report an approach for protein detection enhanced by ionic liquid (IL) selectors in capillary electrophoresis (CE), with avidin as a model protein. Hydrophilic ILs were added into the running buffer of CE and acted as selectors for sample injection, enriching the positive target and excluding the negative from the capillary. When using 3% (v/v) IL selector, the detection sensitivity of avidin was improved by over one order of magnitude, while the interference from protein adsorption was effectively avoided, even in an uncoated capillary. The electrochemiluminescence method was initially used for IL-based CE with low noise that was independent of the IL concentration, making ILs almost transparent as additives in the electrophoresis buffer.
Resumo:
A new material (IL923SGs) composed of ionic liquids and trialkyl phosphine oxides (Cyanex 923) for Y(III) uptake was prepared via a sol-gel method. The hydrophobic ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate (C(8)mim(+)PF(6)-) was used as solvent medium and pore templating material. The extraction of Y(III) by IL923SGs was mainly due to the complexation of metal ions with Cyanex 923 doped in the solid silica. Ionic liquid was stably doped into the silica gel matrix providing a diffusion medium for Cyanex 923, and this will result in higher removal efficiencies and excellent stability for metal ions separation. IL923SGs were also easily regenerated and reused in the subsequent removal of Y(III) in four cycles.
Resumo:
A novel dissolving process for chitin and chitosan has been developed by using the ionic liquid 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) as a solvent, and a novel application of chitin and chitosan as substitutes for amino-functionalized synthetic polymers for capturing and releasing CO2 has also been exploited based on this processing strategy.
Resumo:
本文对1-辛基-3-甲基咪唑六氟磷酸盐离子液体([C8mim]PF6)在包头稀土矿分离钍以及攀西矿分离铈工艺中的应用作了初步探索。论文首先研究了伯胺N1923溶于离子液体对硫酸体系钍的萃取分离行为,考察了酸度、盐析剂浓度、萃取剂浓度等对N1923/IL萃取钍的影响,并与庚烷体系的萃取规律作了对比。在此基础上对萃取机理进行了探讨,提出了不同于分子溶剂体系的萃取机理,认为N1923/IL在水相有硫酸钠作为盐析剂时对钍的萃取为“胶束增溶”萃取机理。此外,钍对稀土的分离考察结果认为,虽然N1923/IL对钍的萃取效率降低,但在一定条件下钍对稀土仍能保持较高的分离系数。由此本文对N1923/IL应用于钍的分离实践作了初步评估。 论文的另外一部分工作研究了纯[C8mim]PF6及其与2-乙基己基膦酸二(2-乙基己基)酯(DEHEHP)的混合体系对硝酸铈(IV)的萃取性能。研究发现纯[C8mim]PF6本身对硝酸铈(IV)有良好的萃取选择性,机理考察结果认为铈(IV)的萃取是由于Ce4+离子在富硝酸根溶液中形成络阴离子Ce(NO3)62-并与离子液体的阴离子PF6—发生交换的结果。一种新型含铈离子液体[C8mim]2Ce(NO3)6的合成进一步证实了这一机理。反萃考察发现被萃入离子液相的铈(IV)用水可完全反萃,且萃取和反萃过程中因离子交换机理导致的离子液体流失可以通过添加适量离子液体组分的方法予以抑制。此外,本文考察了DEHEHP溶于[C8mim]PF6对于含氟硝酸体系铈(IV)的萃取行为,发现在一定条件下DEHEHP对铈(IV)的萃取能获得与分子溶剂中等同的萃取机理。在此基础上,采用DEHEHP/IL从氟碳铈矿分解液中进行分离铈和氟的研究,获得纯度为99.9%以上的纳米CeF3产品。由此我们提出一个将离子液体应用于攀西氟碳铈矿铈钍稀土分离流程的模型,为离子液体在稀土清洁分离流程中实现溶剂绿色化的目标提供了一个范例。
Resumo:
Low-cost excitonic solar cells based on organic optoelectronic materials are receiving an ever-increasing amount of attention as potential alternatives to traditional inorganic photovoltaic devices. In this rapidly developing field, the dye-sensitized solar cell(1) (DSC) has achieved so far the highest validated efficiency of 11.1% (ref. 2) and remarkable stability(3).
Resumo:
We report a high molar extinction coefficient organic sensitizer for high efficiency dye-sensitized solar cells. In combination with a solvent-free ionic liquid electrolyte, we have demonstrated a similar to 7% cell showing an excellent stability measured under the thermal and light soaking dual stress. This is expected to have an important practical consequence on the production of flexible, low-cost, and lightweight DSC based on plastic matrix.
Resumo:
We report two new heteroleptic polypyridyl ruthenium complexes, coded C101 and C102, with high molar extinction coefficients by extending the pi-conjugation of spectator ligands, with a motivation to enhance the optical absorptivity of mesoporous titania film and charge collection yield in a dye-sensitized solar cell. On the basis of this C101 sensitizer, several DSC benchmarks measured under the air mass 1.5 global sunlight have been reached.
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Palladium nanoparticle-loaded carbon nanofibers (Pd/CNFs) were prepared by electrospinning and subsequent thermal treatment processes. Pd/CNFs modified carbon paste electrode (Pd/CNF-CPE) displayed excellent electrochemical catalytic activities towards dopamine (DA), uric acid (UA) and ascorbic acid (AA). The oxidation overpotentials of DA, UA and AA were decreased significantly compared with those obtained at the bare CPE. Differential pulse voltammetry was used for the simultaneous determination of DA, UA and AA in their ternary mixture.
Resumo:
A new approach for fast and sensitive electrochemiluminescence (ECL) detection of narcotic drugs on a microchip after separation by micellar electrokinetic chromatography (MEKC) is presented, taking the cocaine and its hydrolysate ecgonine as the test analytes. The mixture of hydrophilic BMIMBF4 ionic liquid (IL) and sodium dodecyl sulfate (SDS) was used directly as the buffer of MEKC with less noisy baselines, lower electrophoretic current and satisfactory separation performance.
Resumo:
A series Of pyrrolidine-triazole based dendritic catalysts have been synthesized and applied directly in the asymmetric Michael addition of ketones to nitroolefins without the use of an organic solvent. Good yields (up to 99%), and high diastereoselectivities (up to syn/anti = 45:1) and enantioselectivities (up to 95% ee) have been obtained. Furthermore. the third generation catalyst can be reused at least five times without significant loss of catalytic activity. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
The extraction behavior of Ce(IV) along with Th(IV) and Ln(III) (Ln = Ce, Gd, Yb) nitrate by pure ionic liquid, [C(8)mim]PF6, was investigated. [C(8)mim]PF6 alone showed good extraction ability for Ce(IV), while it was slight for Th(IV) and negligible for Ln(III). The extraction behavior of Ce(IV) by [C(8)mim]PF6 was particularly studied, and the most probable extraction mechanism proposed was the anion exchange mechanism. Moreover, the stripping of Ce(IV) from IL phase was also investigated. The Ce(IV) in IL phase can be quantitatively recovered by water.