1-乙基-3-甲基咪唑四氟硼酸盐[Emim]BF_4离子液体的制备和表征

以N-甲基咪唑、溴乙烷和四氟硼酸钠为原料,按照两步法制备了离子液体1-乙基-3-甲基咪唑四氟硼酸盐([Emim]BF4),考察了反应时间、温度、溶剂等对中间体[Emim]Br以及离子液体[Emim]BF4产率的影响,结果表明,反应物N-甲基咪唑与溴乙烷的摩尔比1∶1.5,温度70℃,反应8 h,中间体产率为87.4%;中间体中加入等摩尔NaBF4,25℃下反应10 h,离子液体产率为91.1%。     

1-乙基-3-甲基咪唑四氟硼酸盐的合成研究

以溴乙烷和N-甲基咪唑为原料合成了中间体溴化1-乙基-3-甲基咪唑,以中间体与NaBF4进行复分解反应制备了离子液体1-乙基-3-甲基咪唑四氟硼酸盐。探讨了投料比、反应时间、反应温度对中间体和1-乙基-3-甲基咪唑四氟硼酸盐产率的影响,确定了最佳合成条件。在此工艺条件下,1-乙基-3-甲基咪唑四氟硼酸盐产率可达94%以上。     

系列室温离子液体1-烷基-3-甲基咪唑四氟硼酸盐性质的研究

合成了系列1-烷基-3-甲基咪唑四氟硼酸盐([C2-7mim]BF4)室温离子液体,并通过核磁氢谱、红外光谱、质谱等手段对其进行了结构表征。采用Wilhelmy白金板法在室温(25℃)测定了离子液体的表面张力,测试结果显示,随着1位氮上取代基碳链的增长,其表面张力γ呈现出下降的趋势,且变化范围较宽,如从[C2mim]BF4的表面张力值50.4 mJ/m2到[C7mim]BF4的36.1 mJ/m2。吸水性能测试结果表明,随着氮取代基碳链的增长,其饱和吸水量逐渐减少。     

离子液体1-乙基-3-甲基咪唑四氟硼酸盐对化学镀铜的影响

在甲醛化学镀铜镀液中加入离子液体1-乙基-3-甲基咪唑四氟硼酸盐,研究了对化学镀铜的影响。结果表明,随着离子液体质量浓度的增大,化学镀铜溶液的沉积速率降低,铜层晶粒细化,电阻增加。环境扫描电镜和X-射线衍射观察测试表明,镀层表面分布均匀,且在铜(111)晶面成核的趋势增加。电化学测试表明,随着离子液体质量浓度的增大,阳极氧化峰电位负移,氧化峰电流密度减小,进一步显示ρ(1-乙基-3-甲基咪唑四氟硼酸盐)对甲醛化学镀铜溶液沉积速率有抑制作用。     

1-丁基-3-甲基咪唑四氟硼酸盐的合成研究

以1-溴丁烷和N-甲基咪唑为原料合成了中间体溴化1-丁基-3-甲基咪唑,以中间体与NaBF4进行复分解反应制备了离子液体1-丁基-3-甲基咪唑四氟硼酸盐。探讨了投料比、反应时间、反应温度对中间体和1-丁基-3-甲基咪唑四氟硼酸盐产率的影响,确定了最佳合成条件。在此工艺条件下,1-丁基-3-甲基咪唑四氟硼酸盐产率可达85%以上。     

1-乙基-3-甲基咪唑四氟硼酸盐离子液体的合成及溶解性能的研究

以N-甲基咪唑和溴乙烷为原料,合成中间体[Emim]Br,讨论原料配比、溶剂、反应时间和反应温度对[Emim]Br产率的影响,最高产率为94.63%。四氟硼酸钠与中间体[Emim]Br以等摩尔比进行反应,确定最优的合成条件,在最佳合成条件下目标离子液体的转化率为94.45%。浊点法测定溶解度表明甲苯等溶剂在[Emim]BF4离子液体中有较好的溶解性能。     

间苯二甲酸在[Emim]BF4-H2O溶液中的溶解度及介稳区

研究采用动态法测定了间苯二甲酸在离子液体(1-乙基-3-甲基咪唑四氟硼酸盐,[Emim]BF4)-水二元混合溶剂中的溶解度曲线和超溶解度曲线,并且采用经验方程、理想溶液模型及λh方程对溶解度数据进行了关联,经验方程和λh方程的关联结果较好。实验结果表明,间苯二甲酸在[Emim]BF4-H2O体系中的溶解度均随温度的升高而增大,且随二元混合溶剂中1-乙基-3-甲基咪唑四氟硼酸盐([Emim]BF4)含量的增加而增大。测得的超溶解度曲线与溶解度曲线基本平行,介稳区宽度均随温度的增加而变窄。     

聚乳酸/1-乙基乙基醚-3-甲基咪唑四氟硼酸盐共混物等温结晶动力学研究

利用差示扫描量热仪(DSC)和偏光显微镜(POM)研究了聚乳酸/1-乙基乙基醚-3-甲基咪唑四氟硼酸盐(PLA/[EOEIM]BF4)共混物的等温结晶行为。由等温结晶动力学分析可知,[EOEIM]BF4含量不同时,共混物的Avrami指数n基本保持在2.5左右,表明[EOEIM]BF4对PLA的成核及生长机理影响不大。然而,共混物的半结晶时间t1/2随[EOEIM]BF4含量的增加而增大,说明[EOEIM]BF4的加入对PLA的结晶有阻碍作用,这可能是由于[EOEIM]BF4与PLA分子间的相互作用所造成的。X射线衍射测试结果表明,所有样品在120℃下等温结晶所得的晶型为α晶型。     

辛基甲基咪唑四氟硼酸盐的微波合成及对钒的萃取

以1-甲基咪唑与1-溴辛烷为主要原料,采用微波法合成1-辛基-3-甲基咪唑溴盐,再以其为中间体,进行离子交换得到1-辛基-3-甲基咪唑四氟硼酸盐离子液体。将产物进行提纯处理后,研究其对钒的萃取性能。并取样对其进行红外光谱、表面张力测试等一系列性质及结构检测。结果表明:甲基咪唑与溴辛烷及NaBF_4合成的离子液体对钒的萃取效果良好,萃取率达到80%。     

离子液体合成含溴1，3，4-噻二唑的研究

采用无溶剂一锅法合成了1-丁基-3-甲基咪唑四氟硼酸盐离子液体([bmim]BF4),反应原料N-甲基咪唑、溴代正丁烷和四氟硼酸钾在水浴中搅拌反应3 h,收率为91.8%。然后以1-丁基-3-甲基咪唑四氟硼酸盐离子液体催化合成含溴1,3,4-噻二唑类化合物,反应条件为:反应温度95～100℃,反应时间2 h,收率为58.3%。用减压蒸馏的简单方法将离子液体分离出来。研究结果表明,用离子液体[bmim]BF4合成含溴1,3,4-噻二唑的方法比传统方法即用浓硫酸作催化剂的方法的收率高6.7%。     

1-丁基-3-甲基咪唑四氟硼酸盐离子液体的合成与表征

以N-甲基咪唑为原料,正丁基溴为烷基化试剂,合成中间体[Bmim]Br,然后与醇钠溶液及氟硼酸反应,制备[Bmim]BF4。结果表明,反应温度80℃,反应24 h,中间体产率为83.7%;目标离子液体的转化率为98.6%。差式扫描量热(DSC)显示,离子液体具有较低的熔点。     

1-丁基-3-甲基咪唑四氟硼酸盐离子液体的合成与表征

以N-甲基咪唑和1-溴代正丁烷为原料,两步合成法制备了离子液体[bmim]BF4。考察了反应时间、反应温度、原料配比对中间体1-丁基-3-甲基咪唑溴盐[bmim]Br收率的影响和离子交换时间和离子交换温度对目标产物[bmim]BF4产率的影响。结果表明:①合成中间体[bmim]Br的最佳条件为:反应温度65℃,反应时间16 h,N-甲基咪唑与1-溴代正丁烷的摩尔比为1∶1.1,产品收率可达94.8%;②合成离子液体的最佳条件为:反应温度65℃,反应时间24 h。     

Electrodeposition of tin and antimony in 1-ethyl- 3-methylimidazolium tetrafluoroborate ionic liquid

The electrodepositions of Sn(II) and Sb(III) were studied in the [EMIm]BF₄ ionic liquid at ambient temperature. Linear sweep voltammetry (LSV) results indicated that the reductions of Sn(II) and Sb(III) on Pt electrode are electrochemically irreversible. The diffusion coefficients of Sn(II) and Sb(III) in the ionic liquid electrolyte were determined in terms of the LSV data. Tin and antimony ions form simpler Sn(II) chlorocomplex species and higher Sb(III) chlorocomplexes, respectively present in the ionic liquid electrolyte. Energy dispersive X-ray spectroscopy (EDX) analysis revealed that tin and antimony alloys can be electroplated in the ionic liquid electrolyte.     

[Bmim]BF4离子液体在甲醇中的体积和黏度性质

在298.15 K和常压下,测定了1-丁基-3-甲基咪唑四氟硼酸([Bmim]BF4)离子液体+甲醇体系的密度和黏度。由密度计算了体系的表观摩尔体积,并采用Redlich-Mayer方程关联了体系的表观摩尔体积与组成的关系,得到了[Bmim]BF4在甲醇中的标准偏摩尔体积。由Jones-Dole方程对体系的黏度随组成的变化进行了拟合,获得了[Bmim]BF4在甲醇中的黏度B系数。结果表明:[Bmim]BF4+甲醇体系的表观摩尔体积和黏度均随[Bmim]BF4浓度的增加而增加,[Bmim]BF4在甲醇中的标准偏摩尔体积和黏度B系数分别为155.72×10-6m3/mol和0.282 9。     

Electrodeposition of palladium-indium from 1-ethyl-3-methylimidazolium chloride tetrafluoroborate ionic liquid

Voltammetry at a glassy carbon electrode was used to study the electrochemical co-deposition of Pd-In from a chloride-rich 1-ethyl-3-methylimidazolium chloride/tetrafluoroborate air-stable room temperature ionic liquid at 120 °C. Deposition of Pd alone occurs prior to the overpotential deposition (OPD) of bulk In. However, underpotential deposition (UPD) of In on the deposited Pd was observed at the potential same as the deposition of Pd. The UPD of In on Pd was, however, limited by a slow charge transfer rate. Samples of Pd-In alloy coatings were prepared on nickel substrates and characterized by energy dispersive spectroscope (EDS), scanning electron microscope (SEM) and X-ray powder diffraction (XRD). The electrodeposited alloy composition was relatively independent on the deposition potential within the In UPD range. At more negative potentials where the OPD of Pd-In has reached mass-transport limited region, the alloy composition corresponds to the Pd(II)/In(III) composition in the plating bath. The Pd-In alloy coatings obtained by direct deposition of Pd and UPD of In on the deposited Pd appeared to be superior to the Pd-In alloys that were obtained via the co-deposition of Pd and bulk In at OPD potentials.     

Preparation and electrochemical properties of composite polymer electrolytes containing 1-ethyl-3-methylimidazolium tetrafluoroborate salts

The effects of room-temperature molten salt addition on the micro-structure and electrochemical properties of composite electrolytes (CEs) based on poly(ethylene oxide) (PEO)/ethylene carbonate (EC)/LiBF₄ were studied. Additional salt, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF₄), was found to influence the crystalline structure and heterogeneous morphology, resulting in changes to the ionic conductivity of the CE. The CE containing 0.2 mol of EMIBF₄ showed a small crystallinity, 27.9%. These CEs showed the highest ion conductivity, 3.1 × 10⁻⁴ S/cm, five times higher than that of the pristine PEO/EC/LiBF₄. This enhanced conductivity originated from the decreased crystallinity and improved ion transference due to a Lewis acid-base interaction. The CE containing 0.3 mol of EMIBF₄ showed decreased conductivity due to the lower mobility, reflecting the high viscosity of the molten salt.     

Isobaric vapor-liquid equilibrium for methanol+benzene+1-octyl-3-methylimidazolium tetrafluoroborate

Isobaric vapor-liquid equilibrium (VLE) data for {methanol (1)+benzene (2)+1-octyl-3-methylimidazolium tetrafluoroborate (3)} where 3 is an ionic liquid ([OMIM]⁺[BF₄]^?) at atmospheric pressure (101.32 kPa) were measured with a modified Othmer still. The results showed that the ionic liquid studied can transfer the azeotropic point and eliminate the azeotropic phenomena when its concentration is up to x₃=0.30. This means that [OMIM]⁺[BF₄]^? can be used as a promising entrainer in the application of extractive distillation. The measured ternary data were correlated using the NRTL model.     

Physical and electrochemical properties of 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium iodide,and 1-butyl-3-methylimidazolium tetrafluoroborate

The density, viscosity, refractive index, heat capacity, heat of dilution, ionic conductivity, and electrochemical stability of 1-butyl-3-methylimidazolium bromide ([bmim][Br]), 1-butyl-3-methylimidazolium iodide ([bmim][I]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]) were measured at room temperature or over a temperature range of 293.2 to 323.2 K. The density and refractive index values of [bmim][I] appeared to be the highest among three ionic liquids (ILs). However, the experimental viscosity values of [bmim][Br] were higher than those of [bmim][BF₄], while the heat capacities and heats of dilution of [bmim][BF₄] were higher than those of [bmim][Br]. The cyclic voltammogram of [bmim][br] and [bmim][BF₄] indicated electrochemical windows in the stability range from 2.7 V of [bmim][[Br] to 4.7 V of [bmim][BF₄].     

Diffusion coefficient of ferrocene in 1-butyl-3-methylimidazolium tetrafluoroborate - concentration dependence and solvent purity

The ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate is used as electrolyte in the electrochemical determination of the diffusion coefficient of ferrocene as a function of concentration by cyclic voltammetry and chronoamperometry. An improved synthesis of the room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate is described, which yields a product of high purity suitable for electrochemical purposes. A qualitative color test is discussed which allows the simple detection of silver ion contaminations. The diffusion coefficient of ferrocene appears to be concentration dependent in the solvent chosen.