Preparation and characterization of amino or carboxyl-functionalized ionic liquids

New functionalized ionic liquids, 1-carboxylmethyl-3-methylimimidazolium hexafluorophosphate or fluoborate and 1-aminoethyl-3-methylimimidazolium hexafluorophosphate or fluoborate have been synthesized and investigated. The obtained amino or carboxyl-functionalized ionic liquids were all characterized by FT-IR, ^1H NMR and MS （ESI） and their properties such as freezing point, viscosity, solubility, specific gravity, surface tension, and interfacial tension were also determined.

Interaction Energies of Tetraalkylphosphonium Cation- and Amino Acid Anion- Based Ionic Liquids

Ab initio calculations were performed using the Gaussian 03 software package to obtain the optimized structure, interaction energy and infrared spectrum of ionic liquids （ILs） containing a tetraalkylphosphonium cation and an amino acid anion. In order to investigate the effect of the presence of nitrogen in the cation, the tetraalkylphosphonium cation was replaced by a tetraalkylammonium cation, while amino acids were retained as anions in the ionic liquid. The amino acids studied here included glycine, alanine, serine, lysine, and glutamine. Optimized structures of several ILs in the gas phase were determined at the levels of Hartree-Fock （HF/6-3＋G（d）） and 1density functional theory （B3LYP/6-3 1＋＋G（d,p））. At high-level estimations, MP2/6-31＋G（d） and MP2/6-31＋＋G（d,p）, the interaction energies between the cations and anions of the ILs were determined. In order to investigate the effect of alkyl-chain length on interaction energy, the alkyl groups were varied from methyl to ethyl and propyl in the tetraalkylphosphonium functional groups. This procedure revealed that there is a considerably stronger interaction between the alkylphosphonium cations and amino acids than between alkylammonium cations and amino acids. Vibrational spectroscopy of ILs shows that a significant -OH vibration peak occurs at 4124 cmt in serine-containing ILs, and a prominent C=O vending peak occurs at 1626 cm^-1 in amino acids.

CO₂Absorption Performance of “Dry Matter” Prepared with Amino Acid-Based Ionic Liquids

Dry Matter (DM) is a powdery substance which is composed of micro droplets and surrounding hydrophobic silica nanoparticles. Because of the much larger surface area than that of the corresponding bulk liquid, DM, which contains amino-functionalized ionic liquids (ILs), is a promising CO2 absorption material provided with quick absorption speed. In the present study, we successfully prepared powdery DMs by utilizing aqueous solutions of amino acid-based ILs (tetraethylammonium glycine [N2222][Gly], and tetraethylammonium alanine [N2222][Ala]). Although a DM with lysine-based IL (N2222) [Lys]) was also prepared, only a soufflé-like material was obtained. We measured CO2 absorption performance for the DMs to find that the mass-base absorption ability (mass-base A.A.) (CO2 mol/DM kg) and the mol-base one (CO2 mol/IL mol) of [N2222][Lys] were ca. two times of [N2222][Gly] and [N2222][Ala], while the absorption speed of the former was inferior to the latter two, i.e., ca.15 min vs. 5 min for 90% absorption. In order to improve the mass-base A.A. of [N2222][Gly], we used 10% of aqueous poly(allylamine) (PAlAm) solution instead of water. The resultant mass-base A.A. proved to be significantly larger (1.9) than either of those of the respective single component systems (1.1 and 0.75 for the bulk IL and aq. PAlAm, respectively), and comparable to the A.A. (1.6 - 2.5) of 20% - 30% monoethanolamine solution which is commonly used in industrial application.

Supported ionic liquid sorbents for CO_2 capture from simulated flue-gas

Supported ionic liquid(IL) sorbents for CO_2 capture were prepared by impregnating tetramethylammonium glycinate([N1111][Gly]) into four types of porous materials in this study. The CO_2 adsorption behavior was investigated in a thermogravimetric analyzer(TGA). Among them, poly(methyl methacrylate)(PMMA)-[N1111][Gly]exhibits the best CO_2 adsorption properties in terms of adsorption capacity and rate. The CO_2 adsorption capacity reaches up to 2.14 mmol·g-1 sorbent at 35 °C. The fast CO_2 adsorption rate of PMMA-[N1111][Gly] allows 60 min of adsorption equilibrium time at 35 °C and much shorter time of 4 min is achieved at 75 °C. Further, Avrami's fractional-order kinetic model was used and fitted well with the experiment data, which shows good consistency between experimental results and theoretical model. In addition, PMMA-[N1111][Gly] remained excellent durability in the continuous adsorption–desorption cycling test. Therefore, this stable PMMA-[N1111][Gly] sorbent has great potential to be used for fast CO_2 adsorption from flue-gas.

An ultrasonic-ionic liquid process for the efficient acid catalyzed hydrolysis of feather keratin

A novel efficient method for hydrolyzing feather keratin using an ultrasonic-ionic liquid coupling process has been developed, with reaction conditions optimized using response surface analysis of data obtained from single factor optimization studies. Ultrasonic irradiation(225 W power) of feathers in 8.4 mol·L^(-1) hydrochloric acid containing 1-butyl-3-methylimidazolium chloride as a cosolvent at 80 °C for 1.4 h, followed by heating at 110 °C for 8.3 h, resulted in hydrolysis of their keratin component in an excellent 83.1% yield. Compared with previous methods, this new method employs reduced amounts of hydrochloric acid, shorter reaction time, and affords amino acid hydrolysis products in higher yield.

A novel ligand-free palladium catalytic system with SO_3H-functional ionic liquids as cocatalyst for amidocarbonylation reaction

Effects of Lewis acid BF3·OEt2, and BrCnsted acids TsOH, CF3COOH, H3PO4, and HCIO4 as cocatalyst respectively on the ligand-free palladium-catalyzed amidocarbonylation were investigated. SO3H-functional ionic liquids 1-methyl-3-（4-sulfonic acid）butylimidazolium hydrosulfate [MIm（CH2）4803H][HSO4] and 1-methyl-3-（4-sulfonic acid）butylimidazolium triflate [MIm（CH2）4SO3H][OTf] were firstly employed as cocatalysts instead of these Lewis acid and Brφnsted acids. By using a ligand-free and weak corrosive catalyst in situ prepared form PdBr2, LiBr.H2O, and [MIm（CH2）4SO3H][OTf], the arnidocarbo- nylation of benzaldehyde, acetamide, and CO could proceed smoothly and afford N-acetyl-α-phenylglycine with yield of 58% in [C6mim]PF6 medium.

氨基改性二氧化硅固载碱性离子液体催化Knoevenagel反应

在硝酸铈铵引发下,将1-乙烯基-3-氨乙基咪唑氢溴酸盐([VAIm]Br·HBr)固载于3-氨丙基三甲氧基硅烷改性后的介孔二氧化硅(MSN-NH_(2))表面,再用KOH处理制备了MSN-NH-[VAIm]OH催化剂。并采用FTIR、TG、N_(2)吸附-脱附和XRD等方法进行了表征。实验结果表明,基于0.5g的MSN-NH_(2)载体的较优制备条件为1.4mmol[VAIm]Br·HBr、0.20g硝酸铈铵、40℃和12 h,将制备得到的MSN-NH-[VAIm]OH应用于催化苯甲醛和丙二腈的Knoevenagel反应,苯甲醛转化率和苯亚甲基丙二腈的选择性分别高达99.0%和100%,催化剂可稳定循环使用5次以上。

氨基酸离子液体在能量存储和生物质资源化中的研究进展

氨基酸作为蛋白质的基本组分,由于分子结构中同时含酸性和碱性基团(羧基和氨基),可以方便地设计以氨基酸为阴离子或阳离子的氨基酸离子液体。氨基酸离子液体具有溶解性强、低熔点和热稳定性高等优势,可以作为碳前驱体、溶剂、催化剂和吸附剂等应用到储能、生物质资源化以及碳中和等领域。本文概述了近7年氨基酸离子液体在超级电容器电极材料、生物质提取及催化转化和二氧化碳分离捕集方面的研究工作,重点综述了以氨基酸离子液体为前驱体在超级电容器碳电极材料方面的研究进展,并展望了氨基酸离子液体的应用及发展前景。

离子液体催化合成嘧啶氨基酸酯类化合物

以离子液体1-丁基-3-甲基咪唑氯盐([BMIM]Cl)为催化剂,合成了嘧啶氨基酸酯类化合物。研究了不同的常规溶剂和离子液体溶剂对嘧啶氨基酸酯类化合物产率的影响,以离子液体1-丁基-3-甲基咪唑溴盐([BMIM]Cl)为催化剂,在温度为90℃的最优反应条件下一锅法合成了8个嘧啶氨基酸酯衍生物(4a~4h),具有较高的产率(82%~93%)。通过离子液体回收利用实验结果表明,重复使用5次后活性无明显下降,此外,生物活性测试结果表明,该类衍生物对猕猴桃溃疡病菌、柑橘溃疡病菌、水稻白叶枯病菌具有一定的活性,其中,2-(((5-氯-4-甲氧基-6-甲基嘧啶-2-基)氨基)(4-氯苯基)甲基)丙二酸二乙酯对猕猴桃溃疡病菌、柑橘溃疡病菌、水稻白叶枯病菌活性分别为71.5%、63.0%、55.4%,优于对照药剂叶枯唑对3种病菌的抑制活性。

氨基离子液体聚合物抗高温抑制剂的作用机理

为解决高温地层黏土水化所引起的井壁失稳问题,合成了含双键和氨基的离子液体单体,并将其与丙烯酰胺共聚得到了一种聚合物抑制剂PAN。采用傅里叶变换红外光谱仪对PAN的分子结构进行了表征,并通过浸泡膨胀和搅拌分散、线性膨胀、热滚回收实验评价其抑制性能。结果表明:PAN抑制黏土膨胀与分散的性能优于常用抑制剂KCl、聚醚胺D230及离子液体单体,并且抗温达250℃。通过XRD、Zeta电位、润湿性分析了PAN的抑制机理。PAN通过缠绕包覆在黏土颗粒上、压缩双电层、增加黏土颗粒间胶结性及颗粒表面疏水性而起到抑制作用,为新型抗高温强效抑制剂的研发提供理论与技术支持。

胍类氨基酸离子液体捕集烟气中CO_(2)实验研究

目的通过开展胍类氨基酸离子液体捕集烟气中CO_(2)性能研究实验,找到吸收性能好、溶剂损失少和能耗低的新型CO_(2)吸收剂。方法以四甲基胍(TMG)为阳离子,赖氨酸(Lys)、丙氨酸(Ala)和天冬氨酸(Asp)为阴离子,制备了[TMG][Lys]、[TMG][Ala]和[TMG][Asp]3种低黏度胍类氨基酸离子液体,并对其脱碳性能进行评价。结果碱性较大的[TMG][Lys]具有较高CO_(2)吸收量,在常压、45℃、80 mL/min的条件下,吸收量为0.64 mol CO_(2)/mol IL。水的加入对CO_(2)的吸收有积极的影响,30%(w)[TMG][Lys]水溶液的吸收量增加到0.99 mol CO_(2)/mol IL,且经过5次吸收-解吸循环后仍能达到0.81 mol CO_(2)/mol IL。通过傅里叶红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)对[TMG][Lys]的脱碳机理进行分析,CO_(2)主要通过与阴离子上的氨基反应生成氨基甲酸酯,以实现对烟气中CO_(2)的高效捕集。结论该研究可为工业CO_(2)捕集高效低耗吸收剂的开发提供参考。

利用铁尾矿资源制备磁性纳米纤维素材料对Pb(Ⅱ)的吸附去除

为探索固废资源的高值化应用,利用铁尾矿合成磁性Fe_(3)O_(4),并通过与氨基酸离子液体和纤维素的交联,制备磁性纤维素纳米材料Fe3O4@Cellulose/AAILs,用于吸附去除重金属Pb^(2+)。应用傅里叶变换红外光谱(FTIR)、振动样品磁强计(VSM)、X射线衍射(XRD)、电镜扫描(SEM)和X射线光电子能谱(XPS)对材料微观结构进行了表征,运用Box-Behnken响应曲面法研究了吸附过程的影响因素。FTIR和XRD分析表明,氨基酸的氨基和羧基修饰改性纤维素结构。选择Pb^(2+)去除率作为响应,考察了溶液的初始pH、吸附温度及吸附剂投加量之间的相互作用。结果表明:在25℃、pH值=7和吸附剂投加量为0.2 g时,Pb^(2+)去除率可达98.296%。材料的吸附行为符合Langmiur吸附等温模型、伪二级动力学模型。XPS分析进一步揭示了其对Pb^(2+)的吸附机理,主要包括表面物理吸附、离子交换、官能团络合、静电吸引等。Fe_(3)O_(4)@Cellulose/AAILs可以作为一种高效、快速的吸附剂用于去除水体中Pb2+。

氨基酸离子液体介入的Fe-MOFs纳米棒催化氧化α-蒎烯

α-蒎烯氧化时通常用到挥发性溶剂,不够环保。而采用新型氨基酸离子液体-纳米金属有机框架Fe-MOFs协同催化体系,可实现无溶剂条件下α-蒎烯的清洁、温和转化。研究结果表明:用均苯四甲酸根(PMA)作配体时制备的Fe-PMA-60纳米棒可与氨基酸离子液体[C_(4)mim]Cys构成协同催化体系,以TBHP为氧源,在无溶剂及60℃条件下反应10h,α-蒎烯转化率为99.8%,主产物马鞭草烯酮、马鞭草烯醇的总选择性为81.0%。Fe-PMA-60重复使用8次,催化结果没有显著的变化。

Baeyer-Villiger Oxidation of Cyclic Ketones Catalyzed by Amino Acid Ionic Liquids

A series of amino-acid-based ionic liquids was synthesized via one-step protonation of the corresponding L-amiiio acid by utilizing an array of proton sources.The catalytic activity of the amino-acid-based ionic liquids for the Baeyer-Villiger oxidation of cyclic ketones was investigated using cyclopentanone as a model cycloketone.Theproline-based ionic liquid[ProH]CF3SO3 was shown to exliibit thebest catalytic activity.The reaction condition was optimized to give the following reagent ratio of h(cyclopentanone):n(catalyst):w(H2O2)=1:0.06:4,60℃and 6 h.Under the optimum conditions,the conversion of cyclopentanone was 96.57%and the selectivity forδ-valerolactone was 73.01%.The catalytic activity was shown to be constant after 4 cycles.A simple treatment was allowed for the recover and the reuse of[ProH]CF3S03.The successful utilization of[ProH]CF3SO3 to catalyze a host of cyclic ketones via Baeyer-Villiger oxidation clearly demonstrated the capacity of[ProH]CF3S03 to tolerate variation in the substrate.

The direct electrochemistry of glucose oxidase based on the synergic effect of amino acid ionic liquid and carbon nanotubes

Amino acid ionic liquids(AAILs) have attracted much attention due to their special chemical and physical properties,especially their outstanding biocompatibility and truly green aspect.In this work,a novel electrochemical biosensing platform based on AAILs/carbon nanotubes(CNTs) composite was fabricated.AAILs were used as a novel solvent for glucose oxidase(GOD) and the GOD-AAILs/CNTs/GC electrode was conveniently prepared by immersing the carbon nanotubes(CNTs) modified glassy carbon(GC) electrode into AAILs containing GOD.The direct electrochemistry of GOD on the GOD-AAILs/CNTs/GC electrode has been investigated and a pair of reversible peaks was obtained by cyclic voltammetry.The immobilized glucose oxidase could retain bioactivity and catalyze the reduction of dissolved oxygen.Due to the synergic effect of AAILs and CNTs,the GOD-AAILs/CNTs/GC electrode shows excellent electrocatalytic activity towards glucose with a linear range from 0.05 to 0.8 mM and a detection limit of 5.5 μM(S/N = 3).Furthermore,the biosensor exhibits good stability and ability to exclude the interference of commonly coexisting uric and ascorbic acid.Therefore,AAILs/CNTs composite can be a good candidate biocompatible material for the direct electrochemistry of the redox-active enzyme and the construction of third-generation enzyme sensors.

水合物抑制-缓蚀双功能抑制剂研究进展

在石油天然气开采和运输过程中,天然气水合物堵塞和井筒腐蚀是两个棘手的问题。水合物抑制剂和井筒缓蚀剂分别是解决上述两个问题的化学剂。考虑到水合物抑制剂和缓蚀剂在分子结构上具有相似点,注入具备水合物抑制-缓蚀双功能的抑制剂既可简化现场加注工艺,又能节省施工成本。然而,目前关于此双功能抑制剂的研究报道较少。为此,本文梳理了当前水合物抑制-缓蚀双功能抑制剂的研究进展,包括离子液体类、氨基酸类、生物大分子类和共聚物类四大类,总结了影响此双功能抑制剂性能的主要因素,并讨论了其未来的发展趋势。

[Phe][HSO_(4)]离子液体催化月桂酸制备生物柴油

以苯丙氨酸和硫酸为原料合成一种强酸型的氨基酸离子液体[Phe][HSO_(4)],系统探究[Phe][HSO_(4)]在甲醇与月桂酸酯化制备生物柴油反应中的催化性能,并采用响应面法对反应条件进行优化.在较佳的反应条件下,离子液体质量为2.3%(基于月桂酸)、反应时间为1 h、醇酸摩尔比为12.5∶1、反应温度为78℃时,月桂酸的转化率可达95.73%.此外,[Phe][HSO_(4)]重复使用5次后,仍保持着较佳的催化活性,月桂酸的转化率保持在94.0%左右,具有良好的稳定性,展现了较强的工业应用前景.

Ionic Liquid 1-Vinyl-3-dodecylimidazole Bromide Embedded Hybrid Monolithic Column and Its Versatile Post-modification with Amino Acids

The amino acids post-modified ionic liquids-based hybrid monolithic columns were successfully developed.For the first step,using 1-vinyl-3-dodecylimidazole bromide(VDI·Br)and polyhedral oligomeric silsesquioxane methacryl substituted(POSS-MA)as monomer and crosslinking agent,the monolithic POSS-VDI matrix material was polymerized in 100μm capillary.The prepared POSS-VDI column is of ion-exchange/reverse-phase mixed-mode retention characteristics.The column e fficiency reached 137,000 N/m for thioureas.The POSS-VDI column has also been successfully applied to recognize and analyze the eff ective components of Traditional Chinese Medicines Fangji and the Root of Kudzu Vine.Furthermore,based on its good chromatographic performances,in the second step,amino acids L-Proline(L-Pro),Glycine(Gly)or DLPhenylalanine(DL-Phe)were further exploited as the anion exchangers to post-modify the POSS-VDI column.The new POSS-VDI-Pro,POSS-VDI-Gly and POSS-VDI-Phe columns exhibited diff erent separation selectivity for the complex egg white protein sample.The present work provides a good route to fabricate versatile amino acids and ionic liquids modified monolithic columns with good separation selectivity.

Experimental and Theoretical Investigation of One-pot Synthesis of 2-Amino-4H-chromenes Catalyzed by Basic-functionalized Ionic Liquids

An efficient and environmentally benign procedure for the reactions of three components condensation of sali- cylaldehyde and two different CH acids to give 2-amino-4H-chromenes catalyzed by a series of basic-functional- ized ionic liquids was reported. The most possible reaction pathway was proposed for the first time by performing density functional theory （DFT） calculations. Both cation and anion of [Bmim]OH have a cooperative effect on the reaction. [Bmim]＋ increases the electrophilicity of salicylaldehyde via intermolecular hydrogen bonds, while OH deprives proton of two CH acids to strengthen their nucleophilic ability.

氨基酸离子液体对壳聚糖溶解性能的影响

合成了一系列氨基酸类离子液体,从中筛选出对溶解壳聚糖具有良好性能的离子液体——甘氨酸盐酸盐离子液体。在常温常压下考察了该离子液体1%～10%水溶液对壳聚糖的溶解能力,溶解壳聚糖能力最大能达到6.32%(质量分数,下同)。对离子液体重复使用5次后,溶解能力没有明显下降。采用X射线衍射(XRD)和红外光谱(FT-IR)对再生的壳聚糖进行表征,结果表明,壳聚糖在溶解过程中没有发生衍生化。甘氨酸盐酸盐离子液体水溶液是壳聚糖的良溶剂。