咪唑基离子液体对聚丙烯抗静电性能的影响

以咪唑基离子液体(im i-IL)为抗静电剂与聚丙烯(PP)熔融共混制备出PP/im i-IL共混复合材料,并对材料的抗静电性能、抗静电耐擦洗性能和力学性能进行了测试。结果表明,咪唑基离子液体在显著提高PP的抗静电性能和抗静电剂耐擦洗性能的同时,材料的冲击强度虽略有下降,但拉伸强度提高。     

磷酸酯基离子液体对木质素的溶解性能

合成表征了5种磷酸酯类离子液体,并将其用于溶解木质素。结果表明,离子液体1,3-二甲基咪唑磷酸甲酯盐[Mmim]DMP对木质素的溶解性能最佳,在70℃搅拌120 min,木质素溶解度可达45%。扫描电镜(SEM)、X射线衍射(XRD)和红外光谱(FT-IR)表征结果显示离子液体在木质素溶解过程中并未使木质素发生衍生化反应,但经离子液体溶解再生后,木质素的形貌均发生了显著变化,离子液体溶解性能越强,所得再生木质素颗粒越均匀、分散性越好且弥散衍射特征越强烈。此外,回收所得离子液体重复使用5次后,对木质素仍有较好的溶解性能。     

烯丙基咪唑离子液体的合成与溶液性能

室温离子液体氯化1-烯丙基-3-甲基咪唑被合成,利用质谱和NMR对其结构进行了表征。该离子液体与水或乙醇的二相混合液在293.2K的粘度被测定并计算了该混合体系的过量粘度,建立了过量粘度与水或乙醇的摩尔分数的关系。另外,电导率随组分及温度的变化以及电导活化能也被测定,溶液的电导率随温度的升高及溶剂量的增加而增大。     

DMSO对纤维素在咪唑型离子液体中溶解性能的影响

本文通过向传统离子液体中添加助溶剂DMSO来增强离子液体对纤维素的溶解效果。系统研究了DMSO添加量对纤维素溶解性能的影响,结果表明50℃下随着DMSO添加量的增大,纤维素的溶解程度增加,当DMSO添加量为50%时溶解效果最佳。采用电导率测试研究了DMSO与离子液体的作用机理,并通过FT-IR、XRD、TGA、SEM以及力学性能测试等方法对添加不同量DMSO溶剂溶解再生后的纤维素膜进行了分析,结果表明添加DMSO后溶剂仍为纤维素的直接溶剂,溶解再生后纤维素晶型由Ⅰ转变为Ⅱ型,并且随着DMSO添加量的增加,溶剂对纤维素分子链及结晶区的破坏能力增大,从而导致再生纤维素结晶度、抗拉强度及聚合度相对纯离子液体再生的有所降低。     

氯化1-羧甲基-3-甲基咪唑对PLA/POE-g-GMA共混物结构演化与性能的影响

通过熔融共混法制备了聚乳酸、甲基丙烯酸缩水甘油酯接枝乙烯-辛烯共聚物与氯化1-羧甲基-3-甲基咪唑离子液体的共混物(PLA/POE-g-GMA/ILs),并使用差示扫描量热仪(DSC)、热重分析仪(TG)、扫描电子显微镜(SEM)、电子万能试验机等研究了ILs对PLA/POE-g-GMA共混体系结构演化与性能的影响.T...     

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。     

胍盐离子液体的合成及其对钢/钢摩擦副的摩擦性能研究

采用先溴化再置换的方法合成了两种胍盐离子液体,利用热重分析仪评价了离子液体的热稳定性。研究了这两种胍盐离子液体的摩擦学性能,在扫描电子显微镜下观察了磨斑表面形貌,并与膦嗪以及全氟聚醚和烷基咪唑离子液体进行对比。用X射线光电子能谱仪(XPS)分析了润滑机理。结果表明:与膦嗪、全氟聚醚以及烷基咪唑离子液体相比,胍盐离子液体对钢/钢摩擦副具有非常好的润滑作用,其承载能力最强,摩擦系数最小,磨痕最浅,并且增长链长可以有效地提高其减摩抗磨效果。     

聚离子液体/三聚氰胺碳基材料的制备及电化学性能

将三聚氰胺和聚[3-氰甲基-1-乙烯基咪唑双(三氟甲磺酰基)酰亚胺]（PCMVImTf2N）以不同质量比原位复合作为前驱体,经高温煅烧制备得到多孔碳基催化剂。研究结果表明：当三聚氰胺与聚离子液体PCMVImTf2N的质量比为1:7时,制得的NC-7在0.5 mol/L硫酸（H2SO4）电解液中显示出最佳的电催化析氢能力;在电流密度为10 mA/cm2时,其过电位为117 mV,对应的Tafel斜率为46 mV/dec,性能优于众多无金属电催化剂。     

离子液体[Emim]Ac对甘蔗渣纤维素溶解性能的研究

采用两步法合成离子液体1-乙基-3-甲基咪唑醋酸盐([Emim]Ac),研究其在微波加热下对甘蔗渣纤维素的溶解作用,考察温度对离子液体的剪切粘度以及甘蔗渣纤维素溶解时间、再生得率的影响,并采用FT-IR、TGA、XRD、SEM等测试手段对溶解再生前后甘蔗渣纤维素的结构特性进行分析。结果表明:随着温度逐渐升高,[Emim]Ac的剪切粘度显著降低,甘蔗渣纤维素的溶解时间不断缩短,再生得率不断升高;但温度超过100℃后,甘蔗渣纤维素的再生得率急剧下降。溶解再生后的甘蔗渣纤维素未发生衍生化,但晶型由纤维素Ⅰ型转变为纤维素Ⅱ型,结晶指数急剧减小,热稳定性略有下降,表面形态粗糙多孔。     

离子液体的设计合成

离子液体具有非常好的物理、化学性质 ,正引起人们越来越多的重视。作为一种可设计溶剂 ,可以调整离子液体的结构 ,设计出一些有独特功能的任务适应性离子液体。本文就目前发展的一些特殊用途的离子液体合成设计进行了介绍 ,为人们更好的应用与设计提供参考。     

烷基咪唑离子液体插层高岭石的制备与表征

为研究离子液体插层高岭石复合材料的性能,利用三步插层法合成离子液体1-乙基-3-甲基咪唑溴盐/高岭石(K-[Emim]Br)、1-丁基-3-甲基咪唑溴盐/高岭石(K-[Bmim]Br),采用X射线衍射(XRD)、红外光谱(FTIR)、差热分析法(TG-DSC)、扫描电镜(SEM)及紫外吸收光谱(UV)等技术对产物进行表征.结果表明:离子液体分子已经进入到高岭石层间,将片层撑开,增大了层间距,说明其插层成功;离子液体与高岭石内表面羟基形成氢键;离子液体插层后,高岭石的脱羟基温度由492℃分别上升到501和494℃,热稳定性能得到提升;插层复合物的形貌较原始高岭石有了明显改变;复合物在紫外区域具有良好的紫外吸收性能.     

1,3-二正丁基咪唑六氟磷酸盐离子液体的微波辅助合成与结构表征

以三甲基硅烷咪唑和1-溴代正丁烷作为原料,采用未经改装的家用微波炉在无溶剂条件下经季铵化反应合成了中间体溴化1,3-二正丁基咪唑([DnBIM][Br]),此步反应产率可以达到92%.再将第一步制得的中间体与六氟磷酸钾经复分解反应,得到1,3-二正丁基咪唑六氟磷酸盐离子液体([DnBIM][PF6]),收率为68%.提...     

Toxicity and biodegradability of imidazolium ionic liquids

Several bioassays have been carried out to analyze the toxicity and biodegradability of several imidazolium ionic liquids (ILs) in aqueous phase. The synthetized compounds consist of an imidazolium cation with two alkyl substituents in positions 3 (R1) and 1 (R2) and a counter-ion. The alkyl substituent R1 has been fixed as a methyl group and the effect of the alkyl chain length (C1-C8) of the other substituent (R2) has been tested. Moreover, the influence of diverse counter-ions A- (Cl-, PF6, XSO4-) has been analyzed. Acute toxicity and EC50 values of each compound in the aqueous solution have been determined by using the Microtox standard procedure. Biodegradability of IL has been determined by measuring BOD5 of aqueous samples containing IL and/or D-glucose and the IL residual content and/or d-glucose concentration after this assay. The viability of the microorganisms used in the BOD5 has been related to the ATP in the samples, measured by a bioluminescence assay. All the ILs tested were not biodegradable in the considered conditions. Besides, it was found that the shorter the chain length of side chain R2, the lower the toxic effect is. On the contrary, the anion has a little effect on the IL toxicity.     

Development of conducting polychloroprene rubber using imidazolium based ionic liquid modified multi-walled carbon nanotubes

A simplified and an eco-friendly approach to develop polychloroprene rubber composites with high electrical conductivity is reported. The usage of room temperature ionic liquid, 1-butyl 3-methyl imidazolium bis(trifluoromethylsulphonyl)imide and a low concentration (5 phr) of commercial grade multi-walled carbon nanotubes (MWCNTs) in polychloroprene rubber exhibited an electrical conductivity of 0.1 S/cm with a stretchability >500%. The physical (cation-pi/pi-pi) interaction between the ionic liquid and the MWCNTs is evidenced by Raman spectroscopy. Transmission electron microscopy images exhibit an improved dispersion of the BMI modified tubes in matrix at various magnification scales. The dependency of dynamic properties on the concentration of ionic liquid at constant loading of nanotubes supports the fact that ionic liquid assists in the formation of filler-filler networks. The tensile modulus of 3 phr loaded modified MWCNT/CR composite is increased by 50% with regard to that of the unmodified MWCNT/CR composite. Mooney-Rivlin plot displays the existence of rubber-filler interactions.     

离子液体中氧化锌纳米结构的合成

以离子液体为介质，采用一步化学热分解反应制备出直径为10nm左右，长度达40-110nm的氧化锌纳米棒。利用IR，XRD，TEM以及SAED等测试手段对其进行了表征。实验结果表明：体系中离子液体的加入对产物形貌有着重要的影响。同时讨论了氧化锌纳米结构的生长机理。     

Synthesis of mesoporous Co-B alloy in room-temperature ionic liquids and its electrochemical properties

Co-B alloy with mesoporous structure was firstly synthesized using room-temperature ionic liquids as templates and investigated as an anode for secondary alkaline batteries. Investigations indicate that such mesoporous structure facilitated the electrochemical hydrogen storage. It maintained 94% of the initial capacity (336 mA h/g) after 50 cycles. The excellent cycling performance is most likely due to the stable structure during cycling. Meanwhile, it exhibited an excellent rate capability. The results demonstrated that the prepared Co-B-mesoporous is capable of serving as a high power capability anode for the rechargeable alkaline batteries.     

离子液体与杉木粉对酚醛胶粘剂性能的影响

制备了离子液体/杉木粉/酚醛树脂的复合胶粘剂,用DSC、FTIR和TGA分别对其固化温度、化学结构及热稳定性进行测试分析,研究了木粉和离子液体对复合胶粘剂性能的影响.结果表明,木粉能有效降低胶粘剂的游离醛含量,离子液体可以大幅度提高胶粘剂的胶合性能.与普通酚醛胶相比,当离子液体与木粉质量比为10:1时,复合胶粘剂游离醛从1.76%降低到0.24%,拉伸剪切强度从2.16 MPa提高到5.39 MPa,且固化后不龟裂,透明度较高.TGA结果表明复合胶的热分解温度提高,但残碳率降低.分析了被离子液体溶解的木粉对游离醛的捕捉作用及离子液体对胶合性能的贡献.     

Synthesis of PbS nanocubes using an ionic liquid as the solvent

Lead sulfide (PbS) is a major ore mineral of lead and an important semiconductor. The small band gap and large exciton Bohr radius make PbS an interesting system for studying the effect of size confinement. The precise control of their size and size distribution is an important goal of modern materials chemistry. In this work, lead sulfide (PbS) nanocubes have been successfully synthesized in an ionic liquid 1-n-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF₆) (ILs). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed the cubic morphology of the synthesized nanocrystals with the length about 100 nm. X-ray powder diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) showed the nanocubes were cubic PbS with a lattice constant of 5.93 Å.