[BMIM]ClO4离子液体的热力学性质

在273.15～353.15K范围内测定了[BMIM]ClO4离子液体的密度和表面张力。根据Glasser理论讨论了该离子液体的热力学性质,估算出其晶格能和标准熵。根据离子液体的空隙模型计算了离子液体的恒压热膨胀系数α=6.27×10-4 K-1,与实验值α=5.46×10-4 K-1基本一致。     

离子液体[Amim]PF_6的水相法合成与表征

以N-甲基咪唑、烯丙基氯为原料,采用回流法制备中间体氯化-1-烯丙基-3-甲基咪唑离子液体([AMIM]Cl),进而采用水相法,通过离子交换制备了疏水型离子液体1-烯丙基-3-甲基咪唑六氟磷酸盐([Amim]PF6),考察了合成温度、中间体与六氟磷酸钾的摩尔配比对其产率的影响,以红外光谱、核磁共振波谱进行结构表征。结果表明,水相法能够有效地合成目标产物,大大缩短合成时间;当温度为30℃,物料比n([Amim]Cl)∶n(KPF6)为1∶1.2,反应10min可以得到产率为87%的[Amim]PF6。     

Cu纳米颗粒添加体的[BMIm]NTf_2离子液体法制备及其摩擦学性能

用离子液体法制备Cu纳米颗粒并将其用于摩擦学研究优于常用的方法,以往对此报道不多。通过微波辐射合成了1-丁基-3-甲基咪唑双三氟甲基磺酰亚胺{[BMIm]NTf2}离子液体,利用化学还原法分别在水溶液和[BMIm]NTf2中制备了Cu纳米颗粒,采用XRD,TEM,TG和DTA对其结构进行了表征;将2种纳米Cu颗粒溶于N68基础油中,采用四球摩擦磨损试验机对2种纳米Cu添加体的摩擦学性能进行了试验,并对磨痕表面进行了SEM分析。结果表明:[BMIm]NTf2离子液体中制备的Cu纳米颗粒为面心立方结构,粒径为3～25nm,能够显著改善N68基础油的抗磨减摩性能;与水溶液中制备的纳米Cu添加体相比,其摩擦系数下降了24.6%,钢球磨斑直径下降了18.8%,PB值提高了16.4%。     

[BMIM]Cl离子液体中壳聚糖/纤维素纤维的制备及性能

以[BMIM]Cl离子液体为溶剂,在可控的条件下,将棉纤维与壳聚糖进行共混,采用湿法成型技术,制备了不同质量比的壳聚糖/纤维素纤维复合材料.并通过力学测试、红外光谱(FT-IR)和扫描电镜(SEM)等手段对其结构、性能进行了分析.结果表明,随着壳聚糖加入量的增加,纤维的取向度和结晶度下降,纤维的断裂强度下降,复合纤维表...     

BMIC-AlCl3离子液体的电化学性能

研究了酸性BMIC-xAlCl3(氯化-1-丁基-3-甲基咪唑-AlCl3)离子液体的电化学性能。结果表明,x(AlCl3)(AlCl3的摩尔分数)对离子液体的电化学性能有着较大的影响。当0.50.667时,随着x(AlCl3)进一步增大,电导率开始下降,阴极电流密度减小,阴极电流效率减小。沉积层随着x(AlCl3)的增大变得平整致密。此外,红外光谱研究发现,随着x(AlCl3)的增大,AlCl4-的吸收峰逐渐减弱,Al2Cl-7的吸收峰增强,但当x(AlCl3)>0.667时,Al2Cl-7的吸收峰又稍有减弱。     

室温离子液体辅助制备中孔γ-Al2O3

液相反应条件下,以薄姆石溶胶为铝源,室温离子液体1-甲基-3-丁基咪唑四氟硼酸盐([BMIM][BF4])存在下制备了晶态结构中孔γ-Al2O3.采用N2物理吸附,X射线衍射,透射电子显微镜,27Al魔角固体核磁共振对所制备的样品进行了结构表征.结果表明:通过调节[BMIM][BF4]的用量,得到了孔道结构呈脚手架状、比表面积较大、平均孔径在12nm左右、孔容在1.0cm3/g以上,孔径分布较宽的介孔氧化铝;[BMIM][BF4]加入能够明显改善氧化铝的孔道结构.     

基于离子液体电解质的柔性电化学O2传感器性能研究

氧气是人类和其他大部分生命体赖以生存的物质基础,环境中过低和过高的氧气浓度都会影响人的身体健康,甚至危及生命安全。因此,针对未知环境空气中氧气浓度的监测对于保障作业人员的生命安全尤为必要。近年来,随着智能穿戴产业的迅速发展,柔性氧气传感器由于结构适应性强、可共形设计以及轻量等特点越来越受到学术界与产业界的关注。本工作采用1-丁基-3-甲基咪唑六氟磷酸盐[BMIM]PF₆离子液体作为电解质,聚对苯二甲酸乙二醇酯(PET)为柔性衬底,通过蒸镀金电极并采用柔性封装工艺,制备了一种柔性电化学氧气传感器,并系统研究了其应用性能。所制备的氧气传感器在0%～60%的氧气浓度范围内表现出了良好的线性度(R²=0.974)、T₉₀响应时间(约为20 s)、灵敏度(0.534)。该柔性电化学氧气传感器在智能穿戴、工业安防等领域显示出广阔的应用前景。     

一类新型绿色环保的介质材料--咪唑类离子液体

室温离子液体已成为绿色环保材料领域研究的热点之一.本文简述了咪唑类室温离子液体的制备方法,分析了结构与性能的关系,介绍了咪唑类离子作为液体绿色环保介质材料在化学反应、分离过程和电化学领域中的一些应用.     

离子液体[BMIM][BF_4]中CdS纳米棒的合成与表征

以室温离子液体1-甲基-3-丁基咪唑四氟硼酸盐为介质制备了CdS纳米棒,采用X射线衍射和透射电镜对样品进行了结构表征。结果表明所制备CdS纳米棒具有六方相结构,直径为30nm左右,长度为300nm左右。离子液体和长链烷胺的双重作用促使了CdS一维棒状结构的形成。离子液体同时起到了修饰剂和导向剂的作用。     

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。     

1-丁基-3-甲基咪唑碘对液体、凝胶电解质及染料敏化太阳电池性能的影响

采用季铵化反应成功合成了[Bmim]I，并制备了含有[Bmim]I、KI和I2的离子液体液体电解质和凝胶电解质。通过对比[Bmim]I浓度对液体和凝胶电解质电导率的影响及液体、凝胶电解质DSC的各项光电性能，发现液体电解质有更高的电导率，其组装的DSC的光电性能均高于凝胶电解质体系，通过对DSC稳定性的对比，发现离子液体凝胶电解质显示了更好的长期稳定性。     

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。     

1-己基-3-甲基咪唑六氟磷酸盐离子液体的微波辅助合成与结构表征

采用1-溴代己烷和N-甲基咪唑为原料,微波辅助快速合成了溴化1-己基-3-甲基咪唑([HMIM]Br)中间体,此步反应产率可达到95%。通过将中间体和六氟磷酸钾进行离子交换,制备了离子液体1-己基-3-甲基咪唑六氟磷酸盐([HMIM]PF6),产率约为48%。与传统方法相比,反应时间极大地缩短。产物的结构经傅立叶变换红外光谱(FT-IR)、超导脉冲傅立叶变换核磁共振氢谱(1HNMR)和超导脉冲傅立叶变换核磁共振碳谱(13CNMR)确认,纯度经高效液相色谱法(HPLC)分析达到99.0%以上。     

Effect of ionic liquid dispersion on performance of a conducting polymer based Schottky diode

The effect of ionic liquid (IL) dispersion on the performance of Schottky diode fabricated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been investigated. Two kinds of ILs including 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6, hydrophobic IL) and 1-butyl-3-methylimidazolium chloride (BMICL, hydrophilic IL) were dispersed to the PEDOT:PSS by mechanical stirring and sonication processes. Schottky diodes were fabricated with these mixtures. The forward current of Schottky diodes fabricated with PEDOT:PSS dispersed BMI PF6 (SD-BMIPF6)/BMICL (SD-BMICL) by mechanical stirring is slightly reduced compared with that of Schottky diodes fabricated with pristine PEDOT:PSS (SD-PEDOT). However, SD-BMIPF6 and SD-BMICL by sonication technique show higher forward current with respect to SD-PEDOT. Compared with SD-BMIPF6 and SD-BMICL, the forward current of SD-BMICL is much higher than that of SD-BMIPF6. Since the BMICL has hydrophilic nature, the enhancement of forward current might be due to the uniform dispersion of the BMICL on the PEDOT:PSS matrix.     

Crystal structure and aggregation behavior in water of ionic liquid 1-hexadecyl-3-methylimidazolium Bromide

A large-transparent single crystal of 1-hexadecyl-3-methylimidazolium bromide monohydrate ([C₁₆mim]Br·H₂O) with 4-mm length was firstly obtained in the water-trichloromethane-toluene growth system (V_water:V_{trichloromethane}:V_toluene = 0.1:1:2). The crystal structure was determined by single crystal X-ray diffraction method. It crystallizes in the triclinic system, space group P-1, with unit cell parameters a = 5.4962(15) Å, b = 7.839(2) Å, c = 27.279(8) Å, α = 94.375°(4), β = 91.500°(5), γ = 101.999°(4), Z = 2, V = 1145.2(5)ų, Dc = 1.176 Mg/m³, μ = 1.804 mm^− 1, F(000) = 436, the final R1 = 0.0497, wR2 = 0.1154. The 3D supramolecular structure is constructed through the weak interactions between imidazolium cations, Br⁻ anions and lattice water molecules. The long alkyl chain to imidazolium ring and lattice water molecules play an important role in the self-assembled process. Moreover, it is proposed that [C₁₆mim]Br has the aggregation behavior in water at the higher concentration and the possible self-assembled structure is the interdigitated pattern.     

BaTiO3填充PEO基复合聚合物电解质厚膜的制备与性能研究

采用溶液铸膜法制备PEO基复合聚合物电解质(CPE)厚膜,利用XRD、SEM、DSC、FTIR分析等多种结构测量技术对CPE的性能进行了表征和分析.本文研究的是在(PEO)6:NaPO3基导电聚合物电解质中加入质量分数为3～10 wt％ BaTiO3填料,从而分析性能的变化.(PEO)6:NaPO3在加入填料后玻璃化转...     

Mechanical properties of a TiAl-based alloy at room and high temperatures

Intermetallic titanium aluminides have attracted considerable industrial interest for aero and automotive applications owing to their specific strength. These alloys are candidates for high-temperature applications such as turbine blades and turbocharger turbine wheels. In this work, the mechanical behaviour of an as-cast Ti–47Al–3Cr–3Nb (at.-%) alloy was studied. Four-point bending tests were performed to determine the mechanical properties of the alloy at both room and high temperatures. Microhardness and Young’s modulus were evaluated by dynamic indentation tests at room temperature. Analyses of the as-cast alloy showed that, with the selected production process conditions, it has a duplex microstructure. Tests revealed that, while at room temperature the alloy is brittle, between 700 and 900°C it exhibits good ductility and mechanical properties.     

新型蓝色电致发光材料——联苯乙烯衍生物的合成及发光性质研究

首次合成了一种新型的蓝色电致发光材料－联苯乙烯衍生物，4，4′-双[2,2(2-萘基，苯基）]苯乙烯基）－1，1‘－联苯（NPVBi)，由于材料有较高的玻璃化转变温度，使它具有较好的热稳定性，制备了结构为ITO／TPD／NPVBi/Alq/LiF/Al的电致发光器件，研究了其电致发光性质，得到了色纯度较好的蓝色发光，特别是器件在不同的工作电流下，色坐标基本不变，色度相当稳定，研究表明NPVBi有望成为一种良好的蓝色发光材料。     

SiC_W含量对SiC_W/Si_3N_4复合陶瓷力学及高温微波性能影响

以α-Si_3N_4粉、β-SiC_W为原料,Al_2O_3、Y_2O_3为烧结助剂,采用凝胶注模工艺制备了SiC_W/Si_3N_4复合陶瓷材料,烧结温度为1 650℃,保温1.5h。研究了SiC_W加入含量对SiC_W/Si_3N_4复合陶瓷的微观结构、力学及常温/高温微波吸收性能的影响。结果表明:随着SiC_W含量的增加,SiC_W/Si_3N_4复合陶瓷的抗弯强度和断裂韧性都有先増后减的趋势,当含量为10wt%时,抗弯强度达到最大值505MPa,断裂韧性达9.515MPa·m1/2。常温介电常数在SiC_W含量为10wt%时,实部达最大值12,在12GHz最大吸收值为-21dB。高温介电常数随着SiC_W含量的增加有先增后减的趋势,在含量为10wt%时,实部达到最大值12.5。相比于纯Si_3N_4陶瓷,当SiC_W含量为10wt%时,SiC_W/Si_3N_4复合陶瓷在11.7GHz左右最大吸收可达-27dB,有效吸收频带(小于-5dB)为11.2~12.3GHz。     

Room temperature ionic liquid (RTIL)-decorated mesoporous silica SBA-15 for papain immobilization: RTIL increased the amount and activity of immobilized enzyme

Mesoporous materials, especially functionalized ones, have become a promising carrier for enzyme immobilization. We synthesized room temperature ionic liquid-decorated mesoporous SBA-15 (RTIL-SBA-15) for papain immobilization. The results of powder XRD, IR and N₂ adsorption-desorption isotherms have confirmed that ionic liquid [Simim⁺][Cl⁻] was successfully grafted on the surface of SBA-15. As a consequence of the electrostatic attraction between the cation [Simim⁺] and the negatively charged papain, RTIL-SBA-15 had an advantage over SBA-15 when papain was immobilized at pH = 9.00. The kinetic study showed that the interaction between papain and the carrier was stronger after ionic liquid modification. In the casein hydrolysis, the papain immobilized on RTIL-SBA-15 showed a higher specific activity than that on SBA-15, implying that the ionic liquid [Simim⁺][Cl⁻] was beneficial to improve the activity of the immobilized papain. The optimum pH of the immobilized papain was shifted to higher than that of free enzyme.