共查询到20条相似文献,搜索用时 187 毫秒
1.
以N-甲基咪唑、烯丙基氯为原料,采用回流法制备中间体氯化-1-烯丙基-3-甲基咪唑离子液体([AMIM]Cl),进而采用水相法,通过离子交换制备了疏水型离子液体1-烯丙基-3-甲基咪唑六氟磷酸盐([Amim]PF6),考察了合成温度、中间体与六氟磷酸钾的摩尔配比对其产率的影响,以红外光谱、核磁共振波谱进行结构表征。结果表明,水相法能够有效地合成目标产物,大大缩短合成时间;当温度为30℃,物料比n([Amim]Cl)∶n(KPF6)为1∶1.2,反应10min可以得到产率为87%的[Amim]PF6。 相似文献
2.
3.
4.
5.
在微波辐射下,1-甲基咪唑分别与有机卤盐(1-溴丙烷、1-溴丁烷、1-溴己烷)在80℃回流加热10min,可制得咪唑类离子液体的中间体溴代1-丁基-3-甲基咪唑([BMIm]Br)、溴代1-丙基-3-甲基咪唑([PMIm]Br)、溴代1-己基-3-甲基咪唑([C6MIm]Br),进一步与HPF6在室温搅拌反应4h,制得憎水性的咪唑类离子液体[BMIm]PF6,[PMIm]PF6和[C6MIm]PF6。对这3种离子液体及其在不同有机溶剂如丙酮、甲醇、乙酸乙酯中的电导率进行测定,发现离子液体的电导率受咪唑上取代基种类、溶剂种类、浓度和温度的影响,取代基的链越长,体积越大,离子液体的电导率越小。并且随温度升高和浓度的增大,离子液体的电导率也增大。 相似文献
6.
7.
合成了溴代-1-丁基-3-甲基咪唑([Bmim]Br)离子液体,并配制成聚丙烯腈(PAN)/[Bmim]Br溶液。利用AR-1000型流变仪对PAN/[Bmim]Br溶液的静态和动态流变性能进行了研究,结果表明,8%(质量分数)的PAN/[Bmim]Br溶液接近牛顿流体,12%的溶液为假塑性流体;该体系的损耗模量和储存模量随溶液浓度的增大而增大,随温度的升高而减小。该研究为制定PAN的纺丝工艺提供了理论依据。 相似文献
8.
9.
以离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)为改性剂,分别采用玉米淀粉(S)、羧甲基淀粉(CMS)和羟丙基淀粉(HPS)制备了淀粉/聚丁二酸丁二醇酯(PBS)共混材料,利用红外光谱、扫描电镜、X射线衍射、热重分析、差式扫描量热分析及力学性能测试等方法研究了共混材料的结构与性能.结果表明,[BMIM]... 相似文献
10.
以3-溴噻吩、正丁基锂和1,6-二溴己烷为原料,经过改良的Li-Br交换反应、溴化反应、GRIM法成功合成了聚[3-(6-溴己基)噻吩]。通过傅里叶变换红外光谱(FT-IR),核磁共振波谱(1 H-NMR)、GPC、紫外吸收分光光谱(UV-Vis)及荧光发射光谱(PL)对中间产物及聚合物进行了结构和性能表征。结果表明,所合成聚合物与目标产物的结构一致。聚合物的数均分子量为5725,多分散系数为1.39,在氯仿溶液中最大吸收波长在398nm,最大发射波长在553nm。 相似文献
11.
A. P. Fröba M. H. Rausch K. Krzeminski D. Assenbaum P. Wasserscheid A. Leipertz 《International Journal of Thermophysics》2010,31(11-12):2059-2077
This study reports thermal-conductivity data for a series of [EMIM] (1-ethyl-3-methylimidazolium)-based ionic liquids (ILs) having the anions [NTf2] (bis(trifluoromethylsulfonyl)imide), [OAc] (acetate), [N(CN)2] (dicyanimide), [C(CN)3] (tricyanomethide), [MeOHPO2] (methylphosphonate), [EtSO4] (ethylsulfate), or [OcSO4] (octylsulfate), and in addition for ILs with the [NTf2]-anion having the cations [HMIM] (1-hexyl-3-methylimidazolium), [OMA] (methyltrioctylammonium), or [BBIM] (1,3-dibutylimidazolium). Measurements were performed in the temperature range between (273.15 and 333.15) K by a stationary guarded parallel-plate instrument with a total measurement uncertainty of 3 % (k = 2). For all ILs, the temperature dependence of the thermal conductivity can well be represented by a linear equation. While for the [NTf2]-based ILs, a slight increase of the thermal conductivity with increasing molar mass of the cation is found at a given temperature, the [EMIM]-based ILs show a pronounced, approximately linear decrease with increasing molar mass of the different probed anions. Based on the experimental data obtained in this study, a simple relationship between the thermal conductivity, molar mass, and density is proposed for the prediction of the thermal-conductivity data of ILs. For this, also densities were measured for [EMIM][OAc], [EMIM][C(CN)3], and [HMIM][NTf2]. The mean absolute percentage deviation of all thermal-conductivity data for ILs found in the literature from the proposed prediction is about 7 %. This result represents a convenient simplification in the acquisition of thermal conductivity information for the enormous amount of structurally different IL cation/anion combinations available. 相似文献
12.
Solvent extraction of sr2+ and cs+ based on room-temperature ionic liquids containing monoaza-substituted crown ethers 总被引:2,自引:0,他引:2
A series of N-alkyl aza-18-crown-6 ethers were synthesized and characterized by NMR spectroscopy and mass spectrometry. These monoaza-substituted crown ethers in ionic liquids were investigated as recyclable extractants for separation of Sr(2+) and Cs(+) from aqueous solutions. The pH-sensitive complexation capability of these ligands allows for a facile stripping process to be developed so that both macrocyclic ligands and ionic liquids can be reused. The extraction efficiencies and selectivities of these monoaza-substituted crown ethers for Na(+), K(+), Cs(+), and Sr(2+) were studied in comparison to those of dicyclohexano-18-crown-6 under the same conditions. The extraction selectivity order for dicyclohexano-18-crown-6 in the ionic liquids investigated here was K(+) > Sr(2+) > Cs(+) > Na(+). The extraction selectivity order for N-alkyl aza-18-crown-6, in which the alkyl group is varied systematically from ethyl to n-dodecyl, was Sr(2+) > K(+) > Cs(+) > Na(+) in 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide and K(+) > Sr(2+) > Cs(+) > Na(+) in 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl] amide and 1-octyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]amide. The strong dependence of selectivity on the type of ionic liquid indicates an important role played by solvation in solvent extraction processes based on ionic liquids. The optimization of macrocyclic ligands and ionic liquids led to an extraction system that is highly selective toward Sr(2+). 相似文献
13.
The viscosity of imidazolium-based ionic liquids with four different cations and three different anions was measured to pressures
of 126 MPa and at three temperatures (298.15 K, 323.15 K, and 343.15 K). The high-pressure viscosity of 1-ethyl-3-methylimidazolium
([EMIm]), 1-n-hexyl-3-methylimidazolium ([HMIm]), and 1-n-decyl-3-methylimidazolium ([DMIm]) cations with a common anion, bis(trifluoromethylsulfonyl)imide ([Tf2N]), was measured to determine the alkyl-chain length effect of the cation. An increase in the alkyl-chain length increased
the viscosity at elevated pressures. [DMIm] exhibited a larger nonlinear increase with pressure over the shorter alkyl substituents.
Anion effects were investigated with [HMIm] as a common cation and anions of [Tf2N], hexafluorophosphate ([PF6]), and tetrafluoroborate ([BF4]). [HMIm][PF6], with the highest viscosity, demonstrated a very nonlinear pressure dependence even at relatively moderate pressures (to
30 MPa), similar to the results for [BMIm][PF6]. A combined Litovitz and Tait equation was utilized to describe the viscosity of the ionic liquids with pressure and temperature
and demonstrated good correlation with the experimental data. 相似文献
14.
Xiaodi Liu 《Materials Letters》2009,63(8):673-675
Wurtzite CdSe nanoparticles-assembled microspheres with macropores have been successfully synthesized through a modified hydrothermal method with Cd(NO3)2 and Na2SeO3 as precursors and hydrazine hydrate as a reductant in the presence of 1-n-butyl-3-methylimidazolium bromide ([Bmim]Br). The crystalline structure and morphology of the resulting samples were investigated by means of X-ray powder diffraction (XRD) and scanning electron microscope (SEM). The results indicated that the CdSe microspheres have an average size of about 3 μm and were assembled by CdSe nanoparticles with size ranging from 20 to 40 nm. It was found that the pH and [Bmim]Br have influence on the morphologies of the products, and the potential formation mechanism of CdSe was discussed. 相似文献
15.
Pure hexagonal phase of ZnO nanoparticles have been successfully synthesized via microwave assisted decomposition of zinc
acetate precursor in a green solvent, the ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide in a
very short time scale. The ZnO nanoparticles were characterized by powder X-ray diffraction, scanning electron microscopy,
transmission electron microscopy, and selected area electron diffraction. 相似文献
16.
Daisuke Tomida Satoshi Kenmochi Takao Tsukada Kun Qiao Quanxi Bao Chiaki Yokoyama 《International Journal of Thermophysics》2012,33(6):959-969
Viscosity and thermal conductivity values are reported for a series of 1-alkyl-3-methylimidazolium tetrafluoroborate compounds with hexyl (1-hexyl-3-methylimidazolium tetrafluoroborate) and octyl (1-octyl-3-methylimidazolium tetrafluoroborate) groups. The viscosity was measured with a rolling-ball viscometer at 293.15 K to 353.15 K and pressures up to 20.0?MPa. The experimental values were correlated with a hybrid VFT–Tait equation. The thermal conductivity was measured using the transient short hot-wire method at 294 K to 335 K and pressures up to 20.0?MPa. The experimental values at 293.15 K and 0.1?MPa agreed with the predicted values proposed by Fr?ba et?al. 相似文献
17.
Rahmat Sadeghi Hemayat Shekaari Rahim Hosseini 《International Journal of Thermophysics》2009,30(5):1491-1509
Density and speed-of-sound data for 1-propyl-3-methylimidazolium bromide ([C3mim][Br]) + acetonitrile (MeCN), [C3mim][Br] + dimethylformamide (DMF), and [C3mim][Br] + dimethylsulfoxide (DMSO) binary mixtures in the dilute concentration region are reported at T = (288.15 to 308.15) K. From these data, apparent molar volume, isentropic compressibility, excess molar volume, and isentropic
compressibility deviation values have been calculated. Negative deviations from the ideal behavior of both molar volume and
isentropic compressibility have been observed for all systems investigated in this study. It has been found that deviations
from ideal behavior for the [C3mim][Br] + MeCN system are larger than those for the [C3mim][Br] + DMF system which, in turn, are larger than those for the [C3mim][Br] + DMSO system. The results have been interpreted in terms of ion–dipole interactions and structural factors of the
ionic liquid and investigated organic solvents. 相似文献
18.
为了减少钢铁冶金酸洗过程中酸液对不锈钢或碳钢的过腐蚀,得到高效的新型缓蚀剂材料,利用失重法、电化学法及扫描电子显微镜(SEM)等研究了不同浓度离子液体[HMIM]BF_4对HP13Cr不锈钢以及A3碳钢在1 mol/L盐酸溶液中的缓蚀特性和吸附行为。失重试验得出,试样在1 mol/L盐酸溶液中的腐蚀速率随离子液体添加浓度的增大而减小,即离子液体缓蚀效率随其浓度增加而增大;SEM结果显示,盐酸溶液中离子液体的添加对不锈钢HP13Cr以及碳钢A3均能起到显著的保护作用。电化学测试表明,该离子液体对这2种钢材的缓蚀作用均属于混合型抑制,但阳极抑制作用表现更强。离子液体对金属的防护作用与其在金属表面的吸附行为有关;[HMIM]BF_4在2种钢材表面的吸附行为符合Langmuir吸附等温线,兼具物理、化学吸附特性,热力学参量表明吸附过程为自发、吸热的熵增过程。相比于双咪唑季铵盐,[HMIM]BF_4离子液体缓蚀剂保护性能更优异,而且对于A3碳钢更为有效。 相似文献
19.
Mesoporous Al-MCM-41 materials were synthesized using room temperature ionic liquid 1-cethyl-3-methylimidazolium bromide ([C16mim]Br) as a single template and characterized by X-ray diffraction, N2 adsorption-desorption, ICP-AES, 27Al MAS NMR and TEM technique. These mesoporous materials exhibit hexagonal p6m pore architectures, and possess high surface area and narrow pore distribution. All aluminum in as-synthesized samples exists in tetrahedral coordination. Upon calcination nearly all aluminum still remains the tetrahedral coordination even when the Si/Al ratio is as low as 15. This indicates that the tetrahedral aluminum of Al-MCM-41 is stable. 相似文献
20.
F. J. V. Santos C. A. Nieto de Castro P. J. F. Mota A. P. C. Ribeiro 《International Journal of Thermophysics》2010,31(10):1869-1879
The electrical conductivity and viscosity of 1-hexyl-3-methylimidazolium bis(trifluorosulfonyl)imide, [C6mim] [(CF3SO2)2N], were measured at atmospheric pressure, between 270 K and 350 K, for samples with an amount of water not exceeding 200 ppm,
as part of International Union of Pure and Applied Chemistry Project 2002-005-1-100. Water content was monitored before and
after measurements, by coulometric Karl–Fisher titration. Special care was taken with ionic liquid manipulation in view of
the measurement uncertainty budget. The uncertainties of the electrical conductivity measurements and of the viscosity measurements
are estimated to be better than 2.0 % and 0.5 %, respectively. Results were compared with data from other authors, and all
data were correlated as a function of temperature. 相似文献