离子液体[BMIM]Br与[BMIM][BF4]配比浓度对Br-离子电荷转移的调节

利用X射线吸收精细结构光谱(XAFS)及紫外吸收光谱两种方法, 分析了离子液体1-丁基-3-甲基咪唑溴盐([BMIM]Br)中逐渐掺入1-丁基-3-甲基咪唑四氟硼酸盐([BMIM][BF₄])时, Br^-阴离子与咪唑阳离子之间氢键作用及电荷偏移量的改变. 随着[BMIM][BF₄]加入量增多, Br 元素XAFS近边(XANES)显示吸收峰降低, 吸收边位置向低能端位移0.9 eV; 扩展边(EXAFS)算出径向结构显示Br 与近邻原子间平均配位数降低、平均键长增长; 紫外光谱也有明显蓝移减色效应. 这些结果都表明Br₄^-的掺入改变了Br^-与阳离子间的电荷偏移量, 负电荷更多地转移到Br^-上, 量化计算的数据同样支持该结论.     

咪唑离子液体对铜在硫酸溶液中的缓蚀作用

采用动电位极化和电化学阻抗谱技术研究了三种新型烷基咪唑离子液体, 1-丁基-3-甲基咪唑硫酸氢盐([BMIM]HSO₄), 1-已基-3-甲基咪唑硫酸氢盐([HMIM]HSO₄), 1-辛基-3-甲基咪唑硫酸氢盐([OMIM]HSO₄), 对铜在0.5 mol·L_-1 H₂SO₄溶液中的缓蚀作用. 实验结果表明: 咪唑离子液体能有效抑制铜在硫酸溶液中的腐蚀, 相同浓度下的缓蚀效率大小顺序为[OMIM]HSO₄>[HMIM]HSO₄>[BMIM]HSO₄. 动电位极化表明三种咪唑化合物的加入对铜的阴阳极腐蚀过程均有抑制作用, 属于混合型缓蚀剂. 电化学阻抗谱用带两个常相位原件的等效电路对含两个时间常数的体系进行拟合, 发现咪唑化合物的添加会引起电荷传递电阻和双电层电容等阻抗参数的变化, 表明此类化合物通过吸附于铜电极与溶液界面起到缓蚀作用, 且这种吸附符合Langmuir吸附等温关系. 吸附过程热力学计算说明咪唑化合物在铜表面发生了自发的物理吸附.     

壳聚糖在4种咪唑型离子液体中溶解性的研究

研究、比较了壳聚糖在4种咪唑型离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)、1-丁基-3-甲基咪唑醋酸盐([ BMIM] Ac)、1-乙基-3-甲基咪唑醋酸盐([EMIM] Ac)和氯化1-烯丙基-3-甲基咪唑([AMIM] Cl)中的溶解性,提出了可能的溶解机理,并利用红外光谱(FTIR)、热重分析(TGA...     

离子液体在番茄红素提取中的应用研究

以1-丁基-3-甲基咪唑四氟硼酸盐([Bmim]BF4)、1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)、1-乙基-3-甲基咪唑四氟硼酸盐([Emim]BF4)、1-乙基-3-甲基溴盐([Emim]Br)、1-丁基-3-甲基咪唑硫酸一氢盐([Bmim]HSO4)离子液体为萃取剂,并用超声波辅助萃取新鲜番茄中的番茄红素.对离子液体超声波辅助萃取新鲜番茄中的番茄红素的条件进行了优化,优化后的提取条件为:以[Bmim]BF4为萃取溶剂,离子液体浓度:V乙醇/V[Bmim]BF4=3,在固定超声温度为40℃,超声萃取时间10min,超声波功率380W,料液比1:5 (g/mL)时,效果最佳.     

介孔聚离子液体的可控合成及在常压CO2环加成反应中应用

采用刚性的离子液体聚合单体双-（3-乙烯基-1-咪唑）亚甲基双溴盐（[C₁DVIM]Br）,以聚乙二醇（PEG）为溶剂,能够简单快捷制备出高比表面积的介孔聚离子液体.通过调节PEG的分子量大小,即可有效控制所得聚离子液体的孔结构.介孔聚离子液体由于具有典型的聚阳离子骨架、较高的比表面积以及丰富的卤素位,作为非金属多相催化剂在常压下氧化苯乙烯为底物的CO₂环加成反应中表现出优异的催化活性和良好的回收稳定性,循环使用5次后催化性能基本保持不变.此外,该催化材料还表现出良好的底物兼容性,可以有效转化很难反应的脂肪类环氧化合物.     

一种可高温运行的离子液体电解质燃料电池

本文采用N-甲基咪唑为原料通过溴盐的中间步骤合成了1-乙基-3甲基咪唑磷酸二氢盐([Emim]H₂PO₄)离子液体。首先利用元素分析和核磁共振确定了其组成,并测量了该离子液体的粘度和电导性能,然后使用多孔的聚偏氟乙烯作为支撑制备了离子液体电解质复合膜,120 ℃时通过交流阻抗测得其电导率为2.7×10^-2 S·cm^-1。最后将该复合膜组装在单电池中测试了不同温度下的性能,常压下120 ℃时可获得0.85 mW·cm^-2的功率密度,结果表明该复合膜的质子传导可以完全不依赖水,从而能够实现高温操作。     

一种新的离子液体表面活性剂软模板法合成碳酸锶纳米棒

在室温下,以SrCl2·6H2O和(NH4)2Co3为原料,采用咪唑季铵盐离子液体表面活性剂1-十六烷基-3-甲基咪唑溴盐[C16 mim]Br软模板法制备了SrCO3纳米棒.利用透射电子显微镜(TEM)对产物进行了表征.初步探讨了SrCO3纳米棒的形成机理.结果表明SrCO3纳米棒长度在200nm左右,由平均直径为1...     

离子液体在多水相液液平衡体系中的作用

通过用短链离子液体(1-乙基-3-甲基咪唑溴盐[C2mim]Br、1-丁基-3-甲基咪唑溴盐[C4mim]Br)部分或全部取代SDS/DTAB/PEG/NaBr/H2O多水相体系中的无机盐NaBr,用长链离子液体十二烷基-3-甲基咪唑溴盐[C12mim]Br部分取代体系中阳离子表面活性剂DTAB,系统研究了离子液体在分相体系中的作用及其对分相体系性质的影响.研究表明,SDS/DTAB/PEG/NaBr/H2O混合体系形成的四水相体系可以看作"聚合物双水相"与"表面活性剂双水相"共存的结果.短链离子液体([C2mim]Br、[C4mim]Br)较强的亲水性能赋予其较强的盐析能力,在混合体系中表现出明显的盐效应,保证了四水相体系中"聚合物双水相"的存在.短链离子液体与聚合物之间的相互作用及其对表面活性剂之间相互作用的影响均不可忽略.对混合体系的相行为,共存多相的性质有重要的影响.而长链离子液体[C12mim]Br主要通过自身的疏水作用影响"表面活性剂双水相"的性质,充当表面活性剂的角色.然而,[C12mim]Br与DTAB分子结构上的差异,导致表面活性剂分子在"表面活性剂双水相"的两相重新分配,影响了对应两相的体积及萃取能力.可见,通过调节离子液体的烷基链长、混合体系中的含量等可获得具有特定性质的多水相体系.     

离子液体中聚3-己基噻吩的制备及电致变色性质和器件的研究

以室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF₆为溶剂及支持电解质,通过电化学方法制备聚(3-己基噻吩)(PHexT)膜。采用循环伏安法和扫描电子显微镜,对膜的电化学性质及形貌结构进行表征。同时通过紫外可见光谱、计时电流、计时库仑以及计时吸收曲线等方法研究聚合物膜的光谱电化学和电致变色特性,并在此基础上制备PHexT膜的电致变色器件。实验结果表明,在离子液体中制备的PHexT膜光滑致密,掺杂态时为蓝色,脱掺杂时为桔红色,并且具有高的颜色对比度 (40%),较短的响应时间 (2.5 s) 和高的电致变色着色效率 (230cm²/C),该膜制成的固态电致变色器件具有很好的电致变色性能和长的循环寿命。     

对氨基苯酚在石墨烯-离子液体复合物修饰电极上的电化学行为研究

使用石墨烯(Graphene,GR)和离子液体1-丁基-3-甲基咪唑六氟磷酸盐([BMIM] PF6)作修饰剂,通过壳聚糖(CHIT)成膜,制备了石墨烯-离子液体复合物修饰电极([BMIM] PF6 - GR - CHIT/GCE).在0.1 mol/L磷酸盐缓冲液中,采用循环伏安和微分脉冲伏安法研究了对氨基苯酚在[...     

Improved visible light photocatalytic activity of sphere-like BiOBr hollow and porous structures synthesized via a reactable ionic liquid

BiOBr uniform flower-like hollow microsphere and porous nanosphere structures have been successfully synthesized through a one-pot EG-assisted solvothermal process in the presence of reactable ionic liquid 1-hexadecyl-3-methylimidazolium bromide ([C(16)mim]Br). The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). Possible formation mechanism for the growth of hollow microspheres was discussed. During the reactive process, ionic liquid [C(16)mim]Br played the role of solvent, reactant and template at the same time. Moreover, the photocatalytic activities of BiOBr flower-like hollow and porous structures were evaluated on the degradation of rhodamine B (RhB) under visible light irradiation. The results assumed that BiOBr porous nanospheres sample showed much higher photocatalytic activity than the conventionally prepared sample and TiO(2) (Degussa, P25). The relationship between the structure of the photocatalyst and the photocatalytic activities were also discussed in detail; it can be assumed that the enhanced photocatalytic activities of BiOBr materials could be ascribed to a synergistic effect, including high BET surface area, the energy band structure, the smaller particle size and light absorbance.     

The Synthesis of Anatase TiO2 Nanoparticles by Solvothermal Method using Ionic Liquid as Additive

The solvothermal reactions of Ti(OiPr)₄ in alcohol using ionic liquid as additive were investigated. In the presence of [BMIM][Cl], [BMIM][Br], [BMIM][NTf₂], [BMIM][SO₃Me], [BMIM][SO₄Me], or [BMIM][OTf] (BMIM = 1‐Butyl‐3‐methylimidazolium), pure anatase nanoparticles were obtained. The controlled hydrolysis of Ti(OiPr)₄ in the presence of ionic liquids to form titanium oxo clusters plays a key role in the formation of anatase nanostructures, and ionic liquids can be repeatedly used to synthesise anatase nanoparticles. However, in the presence of [BMIM][PF₆], [BMIM]₂[Ti(OH)₆] was obtained by an anion exchange reaction.     

Impact of 1-butyl-3-methylimidazolium chloride on the electrospinning of cellulose acetate nanofibers

Additives like ionic liquids (ILs) have proven to be excellent materials useful in improving the electrospinnability and conductivity of both synthetic and biopolymers. The aim of this study is to investigate the effect of 1-buthyl-3-methylimidazolium chloride [BMIM]Cl on the electrospinnability of cellulose acetate (CA). The results showed that [BMIM]Cl has the greater effect on viscosity and conductivity of the spinning solution while the morphology of the nanofibers significantly improved as the concentration of the IL increases from 0% to 12% (v/v) of [BMIM]Cl. To understand the interaction between CA and [BMIM]Cl, Fourier-transform infrared spectroscopy (FTIR) has been used. Observations by scanning electron microscopy (SEM) suggested that [BMIM]Cl significantly altered the morphology of the CA nanofibers and 12% (v/v) of [BMIM]Cl would be an ideal concentration producing uniform fibers with a mean diameter of 180nm. In addition, the membranes showed a significant increase in conductivity (from 0 to 2.21 × 10^?7S/cm) as the concentration of ionic liquid increases up to 12% (v/v) that indicates a successful loading of IL inside the nanofibers.     

离子热法制备多级孔AlPO_4-5分子筛

采用离子热法,以磷酸为磷源,γ-Al_2O_3为铝源,在1-丁基-3-甲基溴化咪唑离子液体中于320℃反应10 min内快速合成了多级孔AlPO_4-5分子筛,其结构和形貌经傅里叶红外光谱(FT-IR),X-射线衍射(XRD),扫描电子显微镜(SEM),氮气物理吸-脱附(BET)和透射电镜(TEM)表征。     

Thermodynamic analysis for solubility of pimelic acid in ionic liquids

Based on the solubilities of pimelic acid in ionic liquids [EMIM][HSO₄], [PMIM]Br, [i-PMIM][HSO₄], [BMIM]Br, and [BMIM][HSO₄], dissolution enthalpy and dissolution entropy at different temperatures have been calculated. The experimental data of solubilities are correlated with the modified Apelblat equation. The thermodynamic properties of pimelic acid in ionic liquids were discussed. The solubilities correlated by the model are in good agreement with experimental data.     

Functionalization of Carbon Nanotubes with Water‐Insoluble Porphyrin in Ionic Liquid: Direct Electrochemistry and Highly Sensitive Amperometric Biosensing for Trichloroacetic Acid

A functional composite of single‐walled carbon nanotubes (SWNTs) with hematin, a water‐insoluble porphyrin, was first prepared in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM][PF₆]) ionic liquid. The novel composite in ionic liquid was characterized by scanning electron microscopy, ultraviolet absorption spectroscopy, and electrochemical impedance spectroscopy, and showed a pair of direct redox peaks of the Fe^III/Fe^II couple. The composite–[BMIM][PF₆]‐modified glassy carbon electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) in neutral media due to the synergic effect among SWNTs, [BMIM][PF₆], and porphyrin, which led to a highly sensitive and stable amperometric biosensor for TCA with a linear range from 9.0×10^?7 to 1.4×10^?4 M . The detection limit was 3.8×10^?7 M at a signal‐to‐noise ratio of 3. The TCA biosensor had good analytical performance, such as rapid response, good reproducibility, and acceptable accuracy, and could be successfully used for the detection of residual TCA in polluted water. The functional composite in ionic liquid provides a facile way to not only obtain the direct electrochemistry of water‐insoluble porphyrin, but also construct novel biosensors for monitoring analytes in real environmental samples.     

Self-assembly and enhanced photocatalytic properties of BiOI hollow microspheres via a reactable ionic liquid

BiOI uniform flowerlike hollow microspheres with a hole in its surface structures have been successfully synthesized through an EG-assisted solvothermal process in the presence of ionic liquid 1-butyl-3-methylimidazolium iodine ([Bmim]I). The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), nitrogen sorption, and diffuse reflectance spectroscopy (DRS). A possible formation mechanism for the growth of hollow microspheres was discussed. During the reactive process, ionic liquid not only acted as solvents and templates but also as an I source for the fabrication of BiOI hollow microspheres and was vital for the structure of hollow microspheres. Additionally, we evaluated the photocatalytic activities of BiOI on the degradation of methyl orange (MO) under visible light irradiation and found that as-prepared BiOI hollow microspheres exhibited higher photocatalytic activity than BiOI nanoplates and TiO(2) (Degussa, P25) did. On the basis of such analysis, it can be assumed that the enhanced photocatalytic activities of BiOI hollow microspheres could be ascribed to its energy band structure, high BET surface area, high surface-to-volume ratios, and light absorbance.     

Properties of Ionic Liquid Confined in Porous Silica Matrix

Porous silica matrices of different pore sizes with confined ionic liquid (1‐butyl‐3‐methylimidazolium hexafluorophosphate) [BMIM] [PF₆] were prepared by sol‐gel technique using a tetraethyl orthosilicate (TEOS) precursor with an aim to study the changes in physico‐chemical properties of ionic liquid on confinement. It is found that on confinement 1) melting point decreases, 2) fluorescence spectra shows a red shift and 3) the vibrational bands are affected particularly those of imadazolium ring, which interacts more with the walls of the silica matrix. Preliminary theoretical calculations suggest that SiO₂ matrix interact more with the heterocyclic group of [BMIM] cation than the tail alkyl chain end group resulting in significant changes in the aromatic vibrations.     

Synthesis of Silver Nanoparticles Using Ionic‐Liquid‐Based Microwave‐Assisted Extraction from Polygonum minus and Photodegradation of Methylene Blue

A green biogenic, nontoxic, high‐yielding synthetic method is introduced for the synthesis of silver nanoparticles (AgNPs) using ionic‐liquid‐based, microwave‐assisted extraction (ILMAE) from Polygonum minus . The aqueous ionic liquid (1‐butyl‐3‐methylimidazolium chloride [BMIM]Cl)‐based plant extract was used as reducing agent to reduce silver ions to AgNPs. The synthesis of AgNPs was confirmed by UV–visible spectrophotometry. Fourier transforms infrared (FTIR) spectra showed that the plant bioactive compounds capped the AgNPs. The particle size and morphology of Ag NPs were characterized by dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM), respectively. Elemental analysis was carried out by energy‐dispersive X‐ray (EDX) spectroscopy. Photodegradation studies showed that the AgNPs degraded 98% of methylene blue in 12 min.