Anionic structural effect in liquid–liquid separation of phenol from model oil by choline carboxylate ionic liquids

Phenolic compounds exist in crude oil as pollutants, and their removal is vital important for the refining and further application of oils. In traditional separation approaches, strong acid and strong base have to be used to remove these compounds, which may cause serious environmental problems. In this work, 19 kinds of cholinium ionic liquids have been developed to separate phenol from model oil by liquid–liquid extraction. Structural effect of anions of the ionic liquids in the separation is systematically investigated. It is found that depending on the chemical structure of ionic liquids, phenol can be removed from toluene with single-step removal efficiency from 86 to 99% under optimal conditions. The type of substituent groups and the-CH_2 number between two carboxylates have obvious effect on the removal efficiency, and more hydrophilic ionic liquids have a stronger extraction performance for phenol. Furthermore, thermodynamic,^(13) C NMR,~1 H NMR and density functional theory calculations have been performed to characterize the extraction process and to understand the extraction mechanism. It is shown that the extraction of phenol from oil to ionic liquid is a favorable process, and this process is mainly driven by enthalpy change. The formation of the hydrogen bond between anion of the ionic liquid and-OH of phenol is the main driving force for the extraction of phenol from oil to the ionic liquids.

Electrochemical Behavior of Niobium Electrodeposited 316 Stainless Steel Bipolar Plate for PEMFC in Choline Chloride Based Ionic Liquids

Niobium was electrodeposited on 316 stainless steel bipolar plates of a fuel cell in water and air-stable choline chloride based ionic liquids. The electrochemical corruption property of bipolar plates in simulated PEMFC environment was investigated. It was showed that the plating film was distributed on the surface of 316 stainless steel like isolated islands with height less than 50 nm. The XPS, XRD results showed that a smooth and strong chemical inert film of Nb O and Nb2O5 was formed on the surface of 316 stainless steel. In simulated cathodic condition, the corrosion potential of Nb coated stainless steel was improved by 244 m V, whilst in an anodic condition, it was improved by 105 m V. The current densities for the coated 316 stainless steel were decreased to 2.479 4 μA·cm-2 from 14.810 μA·cm-2 at-0.1 V and to 0.576 μA·cm-2 from 13.417 μA/·cm-2 at 0.6 V, respectively. It was implied that the niobium coating effectively decreased the corrosion rate. The results of the electrochemical tests indicated that the corrosion resistance of stainless steel was greatly improved after coated with niobium.

CO_2/N_2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures

The high price and toxicity of ionic liquids(ILs) have limited the design and application of supported ionic liquid membranes(SILMs) for CO_2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200(PEG200) mixtures were selected to prepare novel SILMs because of their green and costeffective characterization, and the CO_2/N_2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO_2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO_2 permeability ranged in 343.3–1798.6 barrer and high CO_2/N_2 selectivity from 7.9 to 34.8.It was also found that the CO_2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to38 m Pa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control.

含铈功能离子液体导电水凝胶的制备及应用

目的:开发制备方法简单、力学性能强和导电性能好的水凝胶。方法:在聚乙烯醇(PVA)水凝胶中掺杂含铈类离子液体,用万能试验机和LCR数字电桥测试其性能。结果:在水凝胶中加入含铈类离子液体后电导率有了显著的提升,但过量的含铈类离子液体会使其力学性能下降。这表明可以通过控制含铈类离子液体的浓度来实现电导率和力学性能之间的平衡。结论:复合水凝胶中含铈类离子液体浓度越高,导电性能越好,适量的铈类离子液体同时也可以提高水凝胶的机械性能。综上所述,0.02 mol的含铈类离子液体与水凝胶以1∶100配制成的复合水凝胶平衡了导电性能和力学性能之间的关系。

不同胆碱类离子液体对豌豆蛋白功能特性的影响

豌豆蛋白水溶性、起泡性能等功能性相对较差,限制其在食品工业的深加工与开发。该文利用生物相容性好的绿色溶剂胆碱类离子液体改善豌豆蛋白溶解性,研究豌豆蛋白在浓度均为56.00%的氯化胆碱([Ch][Cl])、乙酸胆碱([Ch][Ac])、乳酸胆碱([Ch][La])、磷酸胆碱([Ch][Ph])、柠檬酸胆碱([Ch][Ci])5种溶液中功能特性的变化。结果表明:除[Ch][Ci]外,其余4种离子液体可以显著提升豌豆蛋白的溶解性(p<0.05)。[Ch][Ph]的作用效果最好,可使豌豆蛋白在水中的溶解度由4.50%提高至12.70%,泡沫稳定性达到600.00%。这与离子液体黏度大(34 mPa·s),促进豌豆蛋白α⁃螺旋与β⁃折叠结构减少从而诱导豌豆蛋白去折叠,以及破坏疏水作用力与蛋白分子链间氢键有关。综上,胆碱类离子液体是一种能够提高豌豆蛋白溶解性和泡沫稳定性的良好溶剂。

[芥酰胺苯甲酸][胆碱]离子液体表面活性剂的合成及性能研究

鉴于简单易得的原料和潜在的环境友好性,脂肪酸型离子液体表面活性剂近年来引起了人们极大的兴趣。以菜籽油加工过程中的下脚料芥酸(二十二碳-13-烯酸)为原料,制备了一种超长碳链的脂肪酸基离子液体表面活性剂[芥酰胺苯甲酸][胆碱](EABCho)。通过傅里叶红外光谱仪、核磁共振氢谱、碳谱确认了其分子结构。利用表面张力、电导率、偏光显微镜和流变研究了该离子液体表面活性剂水溶液的表面活性、胶束化热力学以及溶液的相行为等基础性能。结果表明超长碳链和苯环结构的引入赋予了EABCho极强的自组装能力。EABCho的临界胶束浓度仅为0.01 mmol/L,胶束化自由能达到了-59.852 kJ/mol,均远低于短碳链的[月桂酰胺苯甲酸][胆碱]。随着浓度的增大,EABCho水溶液依次呈现出胶束相、六方液晶相和层状液晶相,均表现出显著的类凝胶性质。

Synthesis, Characterization and Thermophysical Properties of Three Neoteric Solvents-Ionic Liquids Based on Choline Chloride

The authors prepared,characterized and preliminary studied the properties of some neoteric solvents-ionic liquids based on choline chloride,i.e.,three ionic liquids based on the eutectics of choline chloride（2-hydroxyN,N,N-trimethylethanaminium chloride） with,respectively,urea,malonic acid and citric acid.The obtained mixtures were clear and colorless ionic liquids at room temperature.The thermophysical properties,namely,density,viscosity,and electrical conductivity of these mixtures were investigated as a function of temperature within a range of 298-353 K.Correlations for the temperature dependence of the measured properties were generated and discussed in terms of Arrhenius theory.Finally the electrochemical windows of the eutectic liquids were determined.

Choline-based ionic liquids for CO_2 capture and conversion

Choline-based ionic liquids(Ch-ILs) with anions possessing interacting sites to attract CO_2 were designed, which could capture CO_2 with capacity >1.0 mol CO_2 per molar IL under ambient conditions. Moreover, this kind of ILs combining with Cu Cl could catalyze the formylation of amines with CO_2/H_2 at 120 °C. Especially, choline imidazolate showed the best performance,affording a series of N-formamides in excellent yields. It was demonstrated that the IL activated CO_2 and the synergistic effect between the IL and Cu Cl resulted in the high activity for catalysing the formylation of amines with CO_2/H_2.

Physicochemical Properties of Bi-containing Ionic Liquid Analogs Based on Choline Chloride

The preparation and characterization of homogeneous and colorless ionic liquid analogs（ILAs） containing choline chloride（ChC1）, malonic acid and bismuth chloride were investigated. The structure of the above mixture was preliminarily analyzed, and then the physicochemieal properties including viscosity, conductivity and density were investigated as functions of temperature and composition. Additionally, the thermal stability of the ILAs and the electrochemical behavior of Bi3＋ ions in the medium were studied. Structure analysis reveals that the synthesis of deep eutectic solvents（DESs） is closely related to the formation of hydrogen bonds between malonic acid and ChC1, with their viscosity, conductivity and density being greatly dependent on the temperature and composition. Thermo- gravimetric analysis demonstrates that the ILAs are very stable between room temperature and 398.15 K. And the electrochemical experiments indicate that the bismuth films can be successfully deposited from this ILAs and the deposition mechanism of bismuth is a rather irreversible process. The surface morphology of bismuth films deposited on Cu substrates was very compact and smooth. Thus, ChCl-malonic acid DESs were shown to be a good alternative to aqueous solvents for various deposition-related applications.

基于离子液体的反相液相色谱法检测胆碱和四甲基铵

本文发展了以离子液体为流动相添加剂的反相液相色谱分离和间接紫外检测胆碱和四甲基铵的方法。研究了离子液体、甲醇、紫外检测波长等因素对分离、检测胆碱和四甲基铵的影响。用普通的反相色谱柱,以甲醇/1-丁基-3-甲基咪唑四氟硼酸盐水溶液为流动相,在210 nm紫外检测波长下,实现了胆碱和四甲基铵的分离和检测。本方法对分析物的检出限低于0.5 mg/L,标准曲线具有良好的线性关系。将方法应用于植物生长调节剂和桶装水样品的分析,加标回收率为95.1%~99.6%,相对标准偏差小于2.0%。

氯化胆碱-尿素低共熔离子液体电沉积Zn的工艺改进

配制了氯化胆碱和尿素电解液(CU电解液),采用单因素试验方法,通过微观形貌观察、电化学性能测试、显微硬度测试等研究了主盐(ZnCl_(2))浓度、温度、时间、电流密度等对(锌)镀层耐蚀性的影响。结果表明:当ZnCl_(2)浓度为0.5 mol·L^(-1),温度为70℃,时间为20 min,电流密度为1.2 A·cm^(-2)时,沉积所得镀层在3.5%NaCl中的耐蚀性最优,显微硬度较高(109 HV),外观质量较好(表面粗糙度为0.498μm)。

胆碱羧酸离子液体润滑剂的毒性研究

近年来,离子液体润滑剂在各个领域运用都非常广泛,环保型的离子液体润滑剂研究也成为了润滑剂领域的重要研究方向之一,毒性的大小作为衡量离子液体是否环保的标准,更是被人们所重视。文章以水生生物海虾和绿藻为试验对象,对实验室所合成的5种胆碱羧酸离子液体的毒性大小进行研究,并与传统离子液体1-丁基-3-甲基咪唑四氟硼酸盐(L-B104)进行对比,以海虾的半致死浓度LD50和绿藻的半抑制浓度EC50评价这些胆碱羧酸离子液体毒性大小。实验结果表明,5种胆碱羧酸离子液体的毒性明显低于对照样L-B104,从而可以证明胆碱羧酸离子液体润滑剂的毒性很小,属于环保型的离子液体润滑剂。

氯化胆碱添加剂对[Bmim]Cl-AlCl_3离子液体体系电解精炼铝的影响

研究了AlCl3摩尔分数为0.667的[Bmim]Cl-AlCl3离子液体体系中氯化胆碱(ChCl)添加剂对体系电导率及电解精炼铝的影响.结果表明,当ChCl浓度小于8mmol/L时,体系的电导率随ChCl浓度增加而显著提高,但ChCl浓度进一步增加体系的电导率逐渐降低.添加少量ChCl后,阴极还原峰电位正移,还原峰电流逐渐降低.在温度373K和电流密度50A/m2条件下添加5mmol/LChCl进行恒电流电解,电解过程的槽电压显著降低,阴极电流效率显著提高(接近100%),直流电耗仅为0.611kW·h/kg,只有纯离子液体体系电解铝的50%,且在低碳钢基体上得到的铝沉积层光滑致密、晶粒细化.

[Me_3NC_2H_4OH]Zn_2Cl_5水溶液的激光光解研究

利用时间分辨激光光解技术研究了季铵盐型离子液体[Me3NC2H4OH]Zn2Cl5(简写R-Zn2Cl5)的光解行为,研究发现离子液体能被266nm激光单光子电离,生成阳离子自由基、[Zn2Cl5]?中性自由基和水合电子,观察到胆碱激发三线态的存在,并测定了离子液体光电离的量子产额为0.04.利用266nm激光对离子液体、胆碱、氯化锌、氯化钠的光解行为比较,发现胆碱阳离子的贡献很小,[Zn2Cl5]-阴离子起主要作用.采用氧化性自由基SO?4-引发离子自由基,揭示其光电离机理,测定离子液体的动力学反应速率常数,SO?4-460nm的衰减速率常数为1.3×109L?mol-1?s-1,320nm离子自由基瞬态产物的生成速率常数为1.5×109L?mol-1?s-1,两者很接近,说明SO?4-自由基的衰减与瞬态自由基的生成是同步的.

钴锌合金在氯化胆碱-尿素离子液体中的电沉积行为

为探索新型的Co-Zn合金电镀工艺,在氯化胆碱-尿素离子液体中电沉积了钴锌合金镀层,探讨了阴极电位、Co(Ⅱ)/Zn(Ⅱ)浓度比、温度及时间等工艺参数对电沉积的影响,并对合金镀层性能进行了测试。结果表明:在氯化胆碱-尿素离子液体中,控制体系的组成和沉积条件,可得到表面均匀、附着力强、有金属光泽的非晶态Co-Zn合金镀层,其中Co的质量分数可达90%。

[ChCl-3EG]/CrCl_3·6H_2O离子液体中电沉积铬镀层的研究

以氯化胆碱(ChCl)、乙二醇(EG)和CrCl3·6H2O制备的[ChCl-3EG]/CrCl3·6H2O低共熔溶剂型离子液体为电解液,在镍基阴极上电沉积出黑铬镀层.采用冰点测定仪、旋转式黏度计、电导率仪分别测定了该离子液体的熔点、黏度和电导率,以线性扫描伏安法测得[ChCl-3EG]离子液体的电化学窗口为3.22V.[ChCl-3EG]/CrCl3·6H2O离子液体的循环伏安曲线表明Cr3+的电化学还原经历Cr3+→Cr2+和Cr2+→Cr0两步还原反应,起始还原电位分别为-0.26V和-1.06V,且两步均为不完全可逆过程;以电流密度为20 mA/cm2于50℃下进行恒电流电沉积30min,对阴极沉积物的XRD和XPS测试表明,镀层成分铬原子百分比为Cr 80.94%、Cr2O319.06%.SEM和AFM测试表明,在[ChCl-3EG]/CrCl3·6H2O离子液体中可电沉积出平整、致密、无裂纹、表面粗糙度为5.56 nm的黑铬镀层,电沉积铬的电流效率约为65.8%.

低共熔离子液体催化大豆油环氧化制备增塑剂

为进一步提高环氧化效率,以氯化胆碱为氢键受体,将其与二水草酸以物质的量比为1∶1制备的低共熔离子液体作为酸性相转移催化剂,并以过氧甲酸为供氧剂,无溶剂催化大豆油环氧化合成环保型增塑剂.通过单因素实验探究了反应温度、反应时间及催化剂、双氧水、甲酸的用量对原料油环氧化率的影响.在优化条件下制得的产品色泽浅,环氧化率高达90.32%,环氧值为6.85%,产品质量优于国家标准.且催化剂易与产物分离,并能循环使用.傅里叶红外光谱(FT-IR)及核磁共振光谱(1H NMR)结果表明原料油中不饱和双键转化较为完全,环氧化率高,催化剂的选择性好;热分析(TG-DSC)表明产品环氧大豆油初始热分解温度为265℃,在高于223℃的温度下才有失重趋势,热稳定性较好.

氯化胆碱离子液体中纳米铜的电化学制备

在氯化胆碱离子液体中,采用牺牲阳极法于80℃下直接从金属铜制备了纳米铜微粒,其结构和性能经IR,XRD,SEM,TEM和TG表征。结果表明:纳米微粒大致呈球形,面心立方结构,粒径约30 nm。

羊毛角蛋白在巯基乙酸胆碱中的溶解再生

为提高废弃羊毛纤维的综合利用率,采用一种新型的还原性类离子液体巯基乙酸胆碱对羊毛进行溶解和再生,观察了羊毛纤维在其中的溶解过程。采用红外光谱仪、X射线衍射分析仪、差示扫描量热仪以及凝胶电泳仪对不同温度下提取的再生角蛋白性能进行了研究。结果表明:巯基乙酸胆碱能够有效打开羊毛角蛋白大分子之间的二硫键,从而实现对羊毛皮质层及鳞片层的高效溶解,120℃条件下,最高溶解质量分数可以达到16%;经巯基乙酸胆碱溶解再生制得的角蛋白,其蛋白主体结构得到保留,但是与原羊毛相比,再生角蛋白中的α-螺旋含量降低,分子质量降低,并且随着溶解温度提高,角蛋白大分子也发生了一定程度降解。

胆碱类低共融溶剂在CO_2捕集与分离中的应用

胆碱类低共融溶剂是一种新型的离子液体。它不仅具有传统离子液体的优点,还具有价格低廉、低毒、生物可降解等优势。对胆碱类低共融溶剂在CO2捕集与分离中所涉及的物理性质,如气体的溶解度、CO2的吸收-解吸、密度、稳定性、黏度和表面张力等进行考察,并分析了胆碱类低共融溶剂的结构对各物性的影响。通过与传统离子液体的对比,胆碱类低共融溶剂在CO2捕集与分离中的应用具有一定的优势,如CO2溶解度高,黏度低。然而,胆碱类低共融溶剂在气体的选择性分离、表面张力等的研究还不足,且热稳定性方面还存在瓶颈,因此,其在CO2捕集和分离中的应用还有待进一步探讨。