The second evolution of ionic liquids: from solvents and separations to advanced materials--energetic examples from the ionic liquid cookbook

In this Account of the small portion of the recent research in ionic liquids (ILs) by the Rogers Group, we fast forward through the first evolution of IL research, where ILs were studied for their unique set of physical properties and the resulting potential for tunable "green solvents", to the second evolution of ILs, where the tunability of the cation and anion independently offers almost unlimited access to targeted combinations of physical and chemical properties. This approach is demonstrated here with the field of energetic ionic liquids (EILs), which utilizes this design flexibility to find safe synthetic routes to ILs with high energy content and targeted physical properties.     

离子液体应用研究进展

由于离子液体具有较低的熔点、良好的导电性和可以忽略的蒸汽压等优点,引起了科学界和工业界的广泛瞩目.随着研究的日益深入,室温离子液体已经被开发和应用到诸多领域.对室温离子液体应用的研究进展进行了综述,详细介绍了离子液体在电化学、化学反应、分离过程以及在新材料等方面的应用.并对该领域的研究前景作了展望.     

离子液体在纳米ZnO材料制备中的研究进展

离子液体（ILs）具有蒸气压低、液程宽、热稳定性好、结构和性质可调节等特点, 作为反应溶剂、模板剂或结构导向剂等在纳米材料制备领域得到了广泛的应用。纳米ZnO在传感器、太阳能电池、光催化和发光二极管等领域具有广泛的应用。总结了近年来ILs在纳米ZnO材料制备中的研究进展, 重点归纳和比较了常规非质子型ILs、质子型ILs、碱性ILs和聚ILs在制备纳米ZnO中的应用,及其调控纳米ZnO形貌、尺寸和性能的作用特点, 并为今后ILs应用于金属纳米材料的制备提出了建议。     

离子液体回收循环利用的研究进展与趋势

离子液体是完全由阴阳离子组成的绿色可设计溶剂。因为其稳定性好、极低挥发性及独特的物理化学性质,使其在诸多领域具有巨大的应用潜力,近年来已成为研究热点。由于离子液体相对昂贵的生产成本,随着应用规模及范围的逐渐扩大,如何高效回收循环利用离子液体受到极大关注,成为离子液体产业化必须要解决的难题之一。本文概述了近年来在离子液体回收应用方面的研究进展,重点探讨了利用蒸馏、萃取、膜分离、吸附分离以及相分离等方法回收离子液体存在的优势及不足。分析表明,离子液体的回收和循环利用将极大促进离子液体产业的发展,但目前的规模仍然偏小且多处于研发阶段,在此基础了提出了未来拟重点开发的回收利用技术及发展趋势。     

Phosphonium cation-containing polymers: From ionic liquids to polyelectrolytes

Phosphonium cation-based ionic liquids (ILs) are a readily available family of ILs that often offer superior properties compared to ammonium cation-based ILs. Recently investigated applications include extraction solvents, electrolytes in batteries and super-capacitors, and corrosion protection. At the same time, the range of cation–anion combinations available commercially has also increased in recent years. Polymerized ionic liquids and polyelectrolytes play major roles in a broad range of biological applications including antimicrobials, non-viral gene delivery, synthetic enzymes, metal chelation, and drug delivery. Ammonium- and phosphonium-containing macromolecules will be reviewed with a focus on structure–property relationships of these polyelectrolytes and ionic liquids. Phosphonium-containing macromolecules often display enhanced performance compared to ammonium analogs.     

离子液体结构对Diels-Alder反应的影响

综述了不同结构离子液体对Diels-Alder反应的影响,总结了大量国内外有关离子液体中Diels-Alder反应. 分别从极性、酸性和黏度的角度分析了离子液体结构变化对Diels-Alder反应产物选择性或反应速率的影响. 讨论了离子液体中所能形成的氢键种类、咪唑类阳离子C(2)位取代情况、离子液体的Lewis酸性或Br?nsted酸性、离子液体黏度和反应体系黏度等因素的影响. 采用量子化学密度泛函理论计算了反应活化能、反应物的亲电性和过渡态C?C键长. 结果表明,离子液体的独特结构能降低反应活化能,同时增加反应过程中成键的不协同性. 指出未来的发展方向是通过对离子液体物理性质更深入的研究,基于反应机理合成功能化离子液体,进一步优化反应,发展新型、高效、绿色的Diels-Alder反应,从而扩大其应用.     

功能化离子液体在二氧化碳吸收分离中的应用

吸收及分离二氧化碳是降低碳排放和应对全球气候变化的主要策略之一,这就必然要求全球科技工作者注重开发具有选择性高效吸收分离二氧化碳的新材料和新路线。作为近20多年来发展的一类代表性的新材料,离子液体（尤其是功能化离子液体）具有独特的物理化学性质,例如几乎没有蒸气压、液态温度范围大、热稳定性和化学稳定性好、电化学窗口宽、不可燃、结构-性质可调控等。这些性质使离子液体在二氧化碳吸收及分离领域受到广泛关注。重点综述了近5年（2015~2019）来功能化离子液体吸收分离二氧化碳的研究进展, 主要内容包括单位点离子液体、多位点离子液体、基于功能化离子液体的混合物、功能化离子液体杂化材料对二氧化碳的吸收分离。同时, 对目前该领域的发展所面临的主要问题和进一步的研究工作进行了分析讨论。     

质量连接性指数改进的基团贡献法预测咪唑类离子液体的熔点

离子液体（ILs）由于其优越的性能目前已成为多个领域的研究热点,但热力学基础数据的缺乏是其应用的障碍之一,除实验测定外,基团贡献等思想也为设计和筛选ILs提供了重要的性质预测方法。采用相对简单的质量连接性指数区分ILs不同基团的连接方式,在考虑离子液体的结构特征基础上利用相对成熟的基团贡献思想,建立了一个新的基团贡献模型用于预测咪唑类ILs的熔点。对121种咪唑类ILs熔点的预测结果的平均相对偏差为5.15%,方差检验所得的R2和RMSD分别为0.8686和相似文献   

螯合型离子液体：合成、性质以及应用

配位型离子液体在过去一段时间内得到了广泛的关注。其中,螯合型离子液体因其存在多个配位点,因而可以通过螯合作用增强金属与配体的相互作用。根据金属在分子中所处的位置,可以将螯合型离子液体分为4种类型：阳离子螯合型离子液体、阴离子螯合型离子液体、阴阳离子螯合型离子液体和中性螯合型离子液体。对近年来报道的螯合型离子液体的合成、物理性质及其应用进行了综述,阐述了其存在的问题、面临的挑战和今后研究的方向。     

手性功能化离子液体的合成进展

手性离子液体作为功能化离子液体的一种,综合了离子液体与手性物质两方面的特性。不仅具有手性特征,而且几乎无蒸气压,无可燃性,具有很高的热力学和化学稳定性,电导率高,可以循环使用,对无机和有机物有良好的溶解性、稳定性等。手性离子液体可以作为手性溶剂,催化剂载体或手性诱导剂,应用于手性合成、手性分离和手性催化等领域。本文综述了近些年来手性离子液体合成的最新进展,结构上按阴、阳离子分类,同一离子类型中按物质种类分类。同时介绍了一些新的合成技术。最后对手性离子液体可能的发展趋势和以后的研究方向进行了展望。     

Ionic Liquids‐Based Membranes for Carbon Dioxide Separation

Ionic liquids (ILs) have gained wide‐spread focus owing to its negligible vapor pressure, low heat capacity, high thermal stability, and structural diversity. The solubility and selectivity toward carbon dioxide has made ILs a unique platform that possess the potential in gas separations. In particularly, combining functional ILs with membranes and porous supports is an efficient way to design task‐specific materials for CO₂ separations. This minireview summarizes the developments and advances of ionic liquids‐based membranes for CO₂ separations in recent three years, with an emphasis on the strategy of incorporating ionic liquids and CO₂ separation performance.     

Sugar-derived ionic liquids

Ionic liquids (ILs) are special molten salts with melting points below 100 degrees C that are typically constituted of organic cations (imidazolium, pyridinium, sulfonium, phosphonium, etc.) and inorganic anions. Due to their ionic nature, they are endowed with high chemical and thermal stability, good solvent properties, and non-measurable vapor pressure. Although the recycling of ILs partly compensate their rather high cost, it is important to develop new synthetic approaches to less expensive and environmentally sustainable ILs based on renewable raw materials. In fact, most of these alternative solvents are still prepared starting from fossil feedstocks. Until now, only a limited number of ionic liquids have been prepared from renewable sources (e.g., hydroxy acids, amino acids, terpenes), and even less from naturally occurring carbohydrates. This short review describes the synthesis and applications of chiral and achiral ILs obtained from inexpensive sugars.     

离子液体汽化焓的测量方法

离子液体具有蒸气压低、不易挥发、导电能力强、化学性质稳定、可循环利用等特点,具有以下作用：能够替代有机溶剂作为绿色环保的新型溶剂;可以作为催化剂催化化学反应;可以作为电解质溶液参与电化学反应,制作新型电池;可以作为吸附气体的吸附剂等。过去人们认为离子液体不挥发,也不能测量它们的汽化焓,回顾了近年来离子液体的相关研究成果,发现陆续有研究者提出测量离子液体汽化焓的方法,鉴于目前缺少相关总结工作,将系统性地介绍这些方法并阐述其原理,为今后的离子液体研究提供指导。     

离子液体在低碳烯烃/烷烃分离中的应用研究进展

低碳烯烃/烷烃的高效分离是石油化工领域可持续发展的关键过程之一,传统的低温精馏过程选择性低、能耗大。离子液体作为一种结构可调的绿色溶剂为低碳烃的高效分离提供了新的思路。本文综述了近年来国内外离子液体在低碳烯烃/烷烃分离中的研究进展,总结了常规离子液体、功能化离子液体以及含过渡金属的离子液体在低碳烯烃/烷烃分离中的应用,阐明了离子液体中阴阳离子、功能化基团、过渡金属与低碳烯烃相互作用的机理,着重介绍了合成金属功能化离子液体、添加金属盐、添加金属纳米粒子3种向离子液体中引入过渡金属方式的特点以及过渡金属的种类、比例,有机配体的类型对离子液体烯烃/烷烃分离性能的影响,并探讨了该方向的研究和发展趋势。     

Recent Research Progress of Ionic Liquid Dissolving Silks for Biomedicine and Tissue Engineering Applications

Ionic liquids (ILs) show a bright application prospect in the field of biomedicine and energy materials due to their unique recyclable, modifiability, structure of cation and anion adjustability, as well as excellent physical and chemical properties. Dissolving silk fibroin (SF), from different species silkworm cocoons, with ILs is considered an effective new way to obtain biomaterials with highly enhanced/tailored properties, which can significantly overcome the shortcomings of traditional preparation methods, such as the cumbersome, time-consuming and the organic toxicity caused by manufacture. In this paper, the basic structure and properties of SF and the preparation methods of traditional regenerated SF solution are first introduced. Then, the dissolving mechanism and main influencing factors of ILs for SF are expounded, and the fabrication methods, material structure and properties of SF blending with natural biological protein, inorganic matter, synthetic polymer, carbon nanotube and graphene oxide in the ILs solution system are introduced. Additionally, our work summarizes the biomedicine and tissue engineering applications of silk-based materials dissolved through various ILs. Finally, according to the deficiency of ILs for dissolving SF at a high melting point and expensive cost, their further study and future development trend are prospected.     

离子液体在纳米纤维素制备中的应用进展

纳米纤维素因其优异的性能和独特的结构在很多领域都受到了关注,其制备和应用已成为相关领域的研究热点。目前纳米纤维素的制备方法众多,但依然面临着较大的挑战。离子液体因其对木质纤维素优良的溶解性能及可回收性,在纳米纤维素制备中展现了较大的潜力。基于此,综述了离子液体在纳米纤维素制备方面的应用进展,重点介绍了离子液体作为预处理手段在纳米纤维素制备方面的应用现状,以及作为溶剂和催化剂直接水解制备纳米纤维素方面的研究进展,并对制备过程中离子液体的回收情况进行了简单概述。     

离子液体的电导性质研究进展

离子液体(ILs)具有优异的导电能力,其电导性质不仅是电化学应用的基础,而且广泛用于研究ILs溶液热力学性质与微观结构。本文首先总结了近年来实验测定法在研究纯ILs、ILs+溶剂和ILs+ILs体系电导率(κ)或摩尔电导率(Λ)等方面取得的进展,详细讨论了ILs结构、ILs浓度、温度等因素对体系κ或Λ的影响,并结合溶液热力学模型分析了ILs κ或Λ的变化规律。在此基础上,重点介绍了电导性质在研究纯ILs的离子率以及ILs+溶剂体系微观结构和相互作用方面的应用及进展。最后,对ILs电导性质研究与应用提出了几点建议。     

A new strategy for protein crystallization : Effect of ionic liquids on lysozyme crystallization and morphology

Protein crystallization is a complex physical and chemical process. The high-quality protein crystal is still a persistent bottleneck to the application of X-ray crystallography in structural biology. The additives may promote formation of crystal nucleus and subsequent growth in protein crystallization. As a distinct material, ionic liquids (ILs) have aroused great attention and interest for protein crystallization due to their unique properties. We reviewed the progress of protein crystallization and reported research about protein crystal morphology control by ILs, as crystal growth template, in aqueous solutions. ILs encourage changes in some cases in terms of growth morphology and crystal size. The effect of ILs on lysozyme growth morphology can be attributed to changing interaction among lysozyme molecules in aqueous solutions. This work can provide some initial insight into the preparation of high quality crystal and the development of new crystal form.     

基于QSAR方法的离子液体毒性预测

离子液体因其极低的蒸气压、独特的溶解催化性能而备受关注,在许多领域展现出良好的应用潜力。但实现离子液体的工业化,离子液体的潜在毒性及环境影响也是重要的指标。针对离子液体的毒性性质,采用启发式算法筛选了5个影响离子液体毒性的关键参数,以离子液体对大肠杆菌（E. coil）毒性数据 MIC值作为研究对象,建立了40种咪唑类离子液体的定量结构-活性相关（QSAR）预测模型,使用外部测试集对模型进行了外部验证。结果表明,该模型具有良好的可靠性,可用于咪唑类离子液体的毒性预测。     

The role of the symmetry and the flexibility of the anion on the characteristics of the nanostructures and the viscosities of ionic liquids☆

The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.