咪唑类[PF_6]^-型离子液体萃取苯胺

研究了以咪唑类[PF6]-型室温离子液体1-丁基-3-甲基咪唑六氟磷酸盐（[Bmim][PF6]）、1-己基-3-甲基咪唑六氟磷酸盐（[Hmim][PF6]）和1-辛基-3-甲基咪唑六氟磷酸盐（[Omim][PF6]）对苯胺水溶液的萃取平衡。实验结果表明：pH值对分配系数的影响很大,在碱性条件下,分配系数较高;萃取过程属于吸热过程;经过四级错流萃取,废水可达到排放标准,萃取相中的苯胺回收率在90%左右,离子液体回收率〉90%,离子液体可以循环利用。     

疏水性离子液体用于萃取酚类物质

测定了苯酚、苯基酚、苯二酚等几种不同取代基的酚类物质在疏水性离子液体[bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐)和[dmim]PF6(1-癸基-3-甲基咪唑六氟磷酸盐)与水两相中的分配系数. 实验结果表明,萃取过程很快可以达到平衡. 与传统有机溶剂相比,分配系数处在同一个数量级. 分配系数随温度升高而降低,离子液体对不同取代基的酚类萃取能力有很大差异,咪唑基团上取代烷基链的长度对不同酚类物质的分配系数有很大影响,因此可以通过调节离子液体结构使其适用于不同成分的含酚废水.     

咪唑类离子液体高效吸收二氯甲烷

合成了一系列常规离子液体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-丁基-3-甲基咪唑双三氟甲磺酰亚胺盐([Bmim][NTf2])、1-丁基-3-甲基咪唑双氰胺盐([Bmim][DCA])、1-丁基-3-甲基咪唑硫氰酸盐([Bmim][SCN])、1-乙基-3-甲基咪唑硫氰酸盐([Emim][SCN])和N-丁基吡啶硫氰酸盐([BPy][SCN]),用智能重量分析仪(IGA)测定不同温度和分压下离子液体吸收二氯甲烷(DCM)的容量。结果表明,[Bmim][SCN]具有最高的二氯甲烷吸收容量(1.46 g/g, 303.15 K, 60 kPa),5次循环后吸收能力无明显下降,[Bmim][SCN]基本可完全再生,能循环使用。量化计算结果表明[SCN]?可与二氯甲烷形成氢键,增强其对二氯甲烷的吸收能力。     

疏水性离子液体为溶剂对Co2+和Cd2+废水的萃取性能

研究了疏水性离子液体[Bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐)、[Hmim]PF6(1-己基-3-甲基咪唑六氟磷酸盐)和[Omim]PF6(1-辛基-3-甲基咪唑六氟磷酸盐)对Co2+和Cd2+的萃取性能. 结果表明,未加入螯合剂时,离子液体对Co2+和Cd2+的萃取率都很低. 螯合剂的加入大大提高了离子液体对重金属离子的萃取性能,Co2+和Cd2+的萃取率分别由原来的2.06%和1.82%提高到96.37%和93.68%. 不同螯合剂对离子液体萃取Co2+和Cd2+有一定的影响. 离子液体碳链长度的增加有利于Co2+和Cd2+的萃取. 与传统有机溶剂相似,离子液体萃取重金属离子过程中具有很强的pH摆动效应,当pH<2时,Co2+和Cd2+的萃取率几乎为0,而当pH>6时,Co2+和Cd2+的萃取率均大于90%. 运用萃取过程中的pH摆动效应对Cd2+进行反萃取,实现了离子液体的回用.     

1-丁基-3-甲基咪唑六氟磷酸盐离子液体合成

按照两步法合成了离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6),探讨了时间、温度、溶剂、反应物配比等对中间体1-丁基-3-甲基咪唑溴盐([Bmim]Br)以及离子液体[Bmim]PF6产率的影响。结果表明,反应物配比为(1∶1.1)~(1∶2),温度70℃,反应30 h,中间体产率为95.91%;中间体中加入等摩尔KPF6,25℃下反应10 h后,离子液体产率为97.26%。     

咪唑类离子液体的合成及其对氯苯的吸收-解吸性能研究

以溴代正丁烷、Ⅳ甲基咪唑为原料,合成了咪唑类离子液体1丁基3甲基咪唑六氟磷酸盐([Bmim] PF6)和1-丁基-3-甲基咪唑四氟硼酸盐([Bmim] BF4),通过红外光谱和核磁共振氢谱表征了离子液体结构;以离子液体为吸收剂进行氯苯气体吸收实验,考察了吸收温度、吸收时间、进气氯苯浓度等对离子液体吸收氯苯气体性能的影响...     

离子液体介质中微波辅助制备锌掺杂纳米TiO2及光催化活性

在1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)离子液体中,用微波干燥法制备了锌掺杂的纳米TiO2-Zn光催化荆;以甲基橙为模拟污染物,紫外灯为光源,考察了离子液体[Bmim]PF6加入量、锌掺杂量、微波干燥功率、微波干燥时间、焙烧温度和焙烧时间等因素对TiO1-Zn光催化活性的影响.结果表明,在离子液体加入量...     

[bmim][PF6]-DMF-水三元体系的液液相平衡测定

为得到含N,N-二甲基甲酰胺(DMF)废水中萃取回收DMF工艺所需的基础数据,用液液平衡釜常压下测定了1-丁基-3-甲基咪唑六氟磷酸盐([bmim][PF6)离子液体-DMF-H2O三元体系在283.15～323.15 K下的液液分层曲线和液液相平衡数据.在此基础上,考察了三元体系中DMF和[bmim][PF6]离子液体的含量以及温度对[bmim][PF6]的选择性系数的影响.实验结果表明,液液平衡相图中两相区面积随温度升高而减小;相同温度下,[bmim][PF6]的选择性系数随着三元体系中DMF的含量增加而减小,随着离子液体用量增加而增大;溶液组成一定时,[bmim][PF6]的选择性系数随着温度升高而减小;当DMF的含量大于10％时,温度对选择性系数影响不大;283.15 K,三元体系中DMF的质量分数为2.04％时,选择性系数可达33.62,[bmim][PF6]用于萃取分离水中的DMF可行.     

功能离子液体[NH_2ebim][PF_6]的合成及其吸收CO_2的研究

采用两步法合成了离子液体1-胺乙基丁基咪唑六氟磷酸盐([NH2ebim][PF6]),进行吸收CO2的研究。结果表明,CO2与离子液体[NH2ebim][PF6]的反应摩尔比介于0.5~1.0,模拟[NH2ebim][PF6]的溶解度参数为18.09 MPa0.5,比常规离子液体的溶解度参数更接近CO2的溶解度参数,说明[NH2ebim][PF6]与CO2有更好的互溶性,利于对CO2的吸收。     

双硫腙-Bmim[PF6]对水中Pb2+的萃取分离性能初探

采用双硫腙-离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim][PF6])对水中Pb2+的萃取性能进行了考察.探究了络合剂含量、萃取温度、料液相pH、萃取体系与水相体积比及干扰离子对Pb2+萃取率的影响;此外,在最佳萃取条件下,进行了反萃剂的筛选,考察了反萃剂浓度及反萃温度对反萃率的影响.结果表明,在萃取温度为35...     

Modified g-C3N4 derived from ionic liquid and urea for promoting visible-light photodegradation of organic pollutants

In this work, modified g-C₃N₄ was fabricated successfully by calcination of ionic liquid (IL) and urea. The addition of IL changed the polymerization mode of urea, induced the self-assembly of urea molecules, modified the morphological structure of the tightly packed g-C₃N₄, and extended the electron conjugation system. When using 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) as a modifier, the heteroatom Cl could be inserted into the g-C₃N₄ to optimize the electronic structure. The results of characterizations indicate that the unique structure of modified g-C₃N₄ has an expanded electron delocalization range, introduces an interlayer charge transmission channel, promotes the charge transmission, reduces the band gap, enhances the absorption of visible light, and inhibits electron-hole recombination. Modified g-C₃N₄ showed excellent photocatalytic performance for the degradation of rhodamine B and tetracycline. Furthermore, the effect of different anions in 1-butyl-3-methylimidazolium salts ([Bmim]Cl, [Bmim]Br, [Bmim][BF₄], and [Bmim][PF₆]) on the structure and function of g-C₃N₄ are discussed.     

Insight into the behavior at the hygroscopicity and interface of the hydrophobic imidazolium-based ionic liquids

How to completely remove the water from ionic liquids(ILs) is difficult for researchers because of the hygroscopicity of ILs. In order to study the hygroscopicity of ILs, two kinds of ILs, 1-Butyl-3-methylimidazolium hexafluorophosphate([Bmim][PF_6]) and 1-Butyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)([Bmim][NTf_2]) were investigated by molecular dynamics simulations. Although[Bmim][PF_6] and [Bmim][NTf_2] are hydrophobic, both of the ILs could absorb water molecules from the vapor. In this work, the process of absorbing water from the vapor phase was studied, and the water molecules could disperse into the IL. Aggregation was observed with increasing the water concentration.Although the absorbed water increases obviously, the amount of free water and small cluster in the ILs does not change significantly and always stays at a certain level. The amount of free water and small cluster in [Bmim][PF_6] is more than that in [Bmim][NTf_2], which is consistent with their hydrophobicity. In addition, the liquid-vacuum and liquid–liquid interfaces of the ILs were simulated and analyzed in detail.The number density distribution and angle distribution indicated that [Bmim]+cations arrangement regularly at the IL-vacuum interface. The butyl chain point to the vacuum, while the imidazlium ring is close to the IL phase region and perpendicular to the interface. While at the IL-water interface, the cations and anions are disordered.     

Efficient recovery of ionic liquid by electrodialysis in the acid hydrolysis process

Electrodialysis (ED) has been recently known as a highly effective technique to remove and recover ionic liquids from aqueous solution. When a conventional electrolyte solution for the ED process containing Na₂SO₄ was used, a recovery ratio of an acidic IL, 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim][HSO₄]), was 90%. On the other hand, the value clearly increased to 96% when we employed [Bmim][HSO₄] as the electrolyte solution. In an acid hydrolysis of bagasse using the IL under microwave irradiation, the recovery ratio maintains 96%, irrespective of reaction time. This demonstrates the applicability of the proposed ED system in biomass processing.     

Desulfurization of Diesel Fuel by Extraction with Lewis-Acidic Ionic Liquid

Abstract

Ionic liquids were found to be highly selective for the extractive removal of aromatic sulfur compounds from fuels at room temperature. The efficiency of ionic liquids for the removal of aromatic sulfur compounds is dependent on the properties and structure of the ionic liquids. In this work, the Lewis-acidic ionic liquid 1-butyl-3-methylimidazolium tetrahalogenoferrate(III) ([BMIM] [FeCl₄]) was synthesized and demonstrated to be more effective for the removal of aromatic sulfur compounds from diesel over ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM] [BF₄]) because of its Lewis-acidic property. The ionic liquids favorably extracted organic compounds with a higher density of aromatic π-electrons. [BMIM][FeCl₄] ionic liquid can be regenerated through reextraction by hexane, and could be used in multiple steps for the removal of sulfur compounds from diesel.     

Solubility of CO2 in three cellulose-dissolving ionic liquids

The solubility of CO₂ in three cellulose-dissolving ionic liquids (1-ethyl-3-methylimidazolium diethylphosphate, [Emim][DEP], 1-allyl-3-methylimidazolium chloride, [Amim][Cl], and 1-butyl-3-methylimidazolium chloride, [Bmim][Cl]) at temperatures within 298 and 356 K and pressures up to 6.5 MPa was determined using a Van Ness-type apparatus (static isochoric). It was demonstrated that this device can work in isothermal and isoplethal modes, being the latter faster and more precise. Moreover, it was possible to determine CO₂ solubilities in metastable liquid [Bmim][Cl]. Experimental data were modeled using the Extended Henry's law correlation and the group contribution equation of state. New parameters for the binary interaction of CO₂ with ionic liquid groups were calculated.     

甲基丙烯酸甲酯和苯乙烯在离子液体中的自由基聚合

甲基丙烯酸甲酯和苯乙烯经4,4’-偶氮-双(4-氰基戊酸)引发,分别在离子液体([C4mim][PF6])和苯中进行了自由基聚合反应,比较了相同引发剂和单体投料比下,2种介质体系中的聚合速率、相对分子质量和分子量分布,得出2种单体在[C4mim][PF6]中的聚合速率、相对分子质量明显高于苯中的产物,且[C4mim][PF6]经多次重复使用,均能得到性能稳定的聚合产物。     

1-丁基-3-甲基咪唑表面活性离子液体的界面膨胀流变行为研究

研究了1-丁基-3-甲基咪唑十二烷基硫酸盐([bmim][DS])和1-丁基-3-甲基咪唑二(2-乙基己基)磺基琥珀酸酯盐([bmin][AOT]两种表面活性离子液体在正庚烷/水界面的动态界面张力和膨胀特性。比较了[bmim][DS]或[bmin][AOT]和传统表面活性剂十二烷基硫酸钠(SDS)或二(2-乙基己基)磺基琥珀酸酯钠(Na[AOT])之间的膨胀弹性,并且考察了1-丁基-3-甲基咪唑阳离子之间静电相互作用对界面膜特性的影响。另外,通过对比[bmim][DS]和[bmim][AOT]在不同浓度下的膨胀弹性,验证了烷基链数量的改变对界面膨胀流变行为的影响。     

Partitioning Behavior of Tetracycline in Hydrophilic Ionic Liquids Two-Phase Systems

Ionic liquids-based aqueous two-phase system (ILs-ATPS) offers an alternative approach for the extraction of tetracycline (TC) through their partitioning between two phases. The procedure was composed of 1-butyl-3-methylimidazolium halide ([Bmim]X(X = Cl, Br)) and K₂HPO₄ using a liquid-liquid extraction technique. The influence factors on partition behavior of TC were optimized systematically, including the quality of salts and IL, the amount of TC, pH value, and temperature. The maximum extraction efficiency of TC could reach 99%. The interactions between the ATPS and TC have been examined by isothermal titration calorimetry. Extraction of antibiotics TC using ILs-ATPS could achieve nearly complete extractions in a single-step by way of the proper tailoring of their concentrations in the aqueous media.