Ionic liquid crystal-based electrolyte with enhanced charge transport for dye-sensitized solar cells

A room temperature ionic liquid crystal, 1-dodecyl-3-ethylimidazolium iodide （C12EImI）, and an ionic liquid, 1-decyl-3- ethylimidazolium iodide （Cl0EImI）, have been synthesized, characterized and employed as the electrolyte for dye-sensitized solar cells （DSSC）. The physicochemical properties show that a smectic A （SmA） phase with a lamellar structure is formed in CIzEImI. Both C^2EImI and Cl0EImI have good electrochemical and thermal stability facilitating their use in DSSC. The steady-state voltammograms reveal that the diffusion coefficient of I3- in C^2EImI is larger than that in CmEImI, which is at- tributed to the existence of the SmA phase in Ca2EImI. Because the iodide species are located between the layers of imidazo- lium cations in CjzEImI, exchange reaction-based diffusion is increased with a consequent increase in, the overall diffusion. The electrochemical impedance spectrum reveals that charge recombination at the dyed TiOJelectrolyte interface of a C12EImI-based DSSC is reduced due to the increase in I3- diffusion, resulting in higher open-circuit voltage. Moreover, both short-circuit current density and fill factor of the Cl2EImI based DSSC increase, as a result of the increasing transport of I3 in C^2EImI. Consequently, the photoelectric conversion efficiency of C^2EImI-based DSSC is higher than that of the Cl0EImI-based DSSC.

Mesomorphous structure change by tail chain number in ionic liquid crystalline complexes of linear polymer and amphiphiles

Three polymer-amphiphile complexes were prepared by combining poly（allylamine hydrochloride）（PAH） with the potassium salt of mono-,di-,and trisubstituted benzoic acid dendrons（4-octyloxybenzoic acid,3,5-dioctyloxybenzoic acid,and 3,4,5- trioctyloxybenzoic acid）.The solid structure and properties were monitored with FT-IR,XRD,TG,DSC,and polarized optical microscope（POM）.Difference in the tail chain number of the dendritic amphiphile induced two different mesomorphous structures： lamella for the mono-,disubstituted dendron containing complexes and hexagonal column for the trisubstituted dendron containing complexes.These corresponded to the ionic thermotropic liquid crystal SmA andΦ_h phases,respectively.This finding is significant for design of functional nanostructures based on the ionic complexation of polymers and amphiphiles.

Solvent-free Synthesis,Crystal Structure and Thermal Stability of Ionic Liquid 1-Hexadecyl-3-methylimidazolium Bromide

Ionic liquid 1-hexadecyl-3-methylimidazolium bromide [C16mim]Br was synthesized by solvent-free alkylation of N-methylimidzole with hexadecyl bromide. A large transparent single crystal of 1-hexadecyl-3-methylimidazolium bromide monohydrate （[C16mim]Br·H2O）, 4 mm in length, was firstly obtained in the water-trichloromethane-toluene growth system （Vwater＇Vtrichloromethane＇Vtoluene = 0.1：1：2）. The crystal structure was determined by single-crystal X-ray diffraction method. It crystallizes in the triclinic system, space group P1, with a = 5.4962（15）, b = 7.839（2）, c = 27.279（8） A, α = 94.375, β = 91.500, γ = 101.999°, Z = 2, V = 1145.2（5） A3, C20H41BrN2O, Mr = 405.46, Dc = 1.176 Mg/m3, μ = 1.804 mm^-1, F（000） = 436, the final R = 0.0523 and wR = 0.1345. The 3D supramolecular structure is constructed through weak interactions between imidazolium cations, Br- anions and lattice water molecules. The long alkyl chain to the imidazolium ring and lattice water molecules play an important role in the self-assembly process. Moreover, it is proposed that [C16mim]Br in water has aggregation behavior and the possible self-assembled structure is the interdigitated pattern. Finally, thermal stability of [C16mim][Br]·H2O was also studied by DSC and TGA analysis.

The Effect of Ionic Liquids on the CaCO_3 Crystal Growth

In this paper, the effect of ionic liquids on the CaCO3 crystal growth has been studied for the first time. The obtained CaCO3 crystals were charactered by the X-ray diffraction and scanning electron micrographs. The results showed that the control ability of ionic liquids for CaCO3 crystals growth was dependent on the counter anion very much.

Aminopropyl-containing ionic liquid based organosilica as a novel and efficient adsorbent for removal of crystal violet from wastewaters

Herein a novel aminopropyl-containing ionic liquid based organosilica(ILOS-NH_2) is prepared, characterized and applied as effective adsorbent for removal of crystal violet(CV) dye from wastewater. The ILOS-NH2 material was synthesized by hydrolysis and co-condensation of 1,3-bis-(3-trimethoxysilylpropyl)-imidazolium chloride(BTMSPIC) under acidic conditions followed by treatment with 3-aminopropyl-trimethoxysilane in toluene under reflux conditions. This material was characterized using scanning electron microscopy(SEM), diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS), thermal gravimetric analysis(TGA) and energy dispersive X-ray analysis(EDAX). The material was effectively used in the removal of crystal violet at ambient temperature and showed high capacity and stability under applied conditions. The efficacy of p H, contact time, adsorbent dose, initial dye concentration, temperature, and isotherm studies and the applicability of pseudo-first, second order and Elovich kinetic models have also been investigated.

Oscillating Frequency Response of a Langasite Crystal Microbalance in Liquid Phase

The frequency responses of a langasite crystal microbalance （LCM） in liquid phase were investigated. It was shown that the LCM possessed much stronger oscillating ability in liquid phase than that of the commonly used quartz crystal microbalance （QCM）. The frequency shifts of the LCM to the changes in mass loading, as well as viscosity and density of the liquid were measured. The LCM was applied to monitor the adsorption process of an ionic liquid film to ethanol vapor.

Correlation between Structure and Thermal Properties of N-vinyl-3-alkylimidazolium Magnetic Ionic Liquids

Influence of structural variations of N-vinylimidazolium tetrahalogenidoferrate(III) magnetic ionic liquids(MILs) on thermal properties was investigated. Using Gaussian09/B3 PW91/6-311 G(2d, p) density functional methods, the microstructure of the MILs were analyzed. With differential scanning calorimeter(DSC) and thermogravimetric analysis(TGA), the thermal properties of the MILs were performed. The results showed that the interaction energies of ion pairs decreased, the crystallization temperature increased first and then decreased, and the surfusion first decreased and then increased with the elongation of the alkyl chain length on cation;with the increase of Br atom, the interaction energies of ion pairs increased;the interaction energies of ion pairs increased in the MILs with the same cation or anion, the nature of polarity of MILs increased and the melting point rose;as the cation or anion in MILs had a smaller size, it could have the solidsolid transition temperature. The results indicated that the decomposition temperature with the same type of MILs increased with the interaction energies of ion pairs. The interaction energy of ion pairs can be used to illuminate the correlation between the thermal properties and the structure of MILs. ILs possesses the properties of macromolecular.

Crystal structure and thermal decomposition kinetics of1-(pyridinium-1-yl)propane-(1-methylpiperidinium)bi[bis(trifluoromethanesulfonyl)imide], [PyC_3Pi][NTf_2]_2

The structure of a room temperature asymmetrical dicationic ionic liquid （ADIL）, 1-（pyridinium-l-yl） propane- （1-methylpiperidinium） bi[bis（tfifluoromethanesulfonyl）imide] （[PyC3Pi][NTf2]2）, was studied by the X-ray difo fraction method. Meanwhile, thermal analysis of [PyC3Pi][NTf2]2 was also studied using non-isothermal thermo- gravimetric analysis （TGA）. The title crystal belongs to the triclinic with space group Pi and unit-cell parameters a ： 0.95217 （8） nm, b = 1.05129 （11 ） nm, c = 1.70523 （14） nm, ct = 89,759 （8）°,β = 80.657 （7）°, γ=68.007 （9）°, and F（000） = 792. Thermal stability and thermal decomposition kinetics of the title compound were also investigated using TGA under the atmosphere of highly pure nitrogen. Heating curves at different rates were cor- related with kinetic equations Friedman and ASTM （also called iso-conversion method）. The values of average activation E （kJ·mol^-1 ） and pre-exponential constant lgA are 149.58 kJ. mol- 1 and 8.83, respectively, which were obtained by the two methods. The kinetic model function, activation energy and pre-exponential constant of this reaction using the multivariate non-linear-regression method were f（a） = （1 -a）（1 ＋ 4.1870a）, 151.04 kJ·mol^-1 and 8.81, respectively, which were basically consistent with iso-conversion methods.

Synthesis and Crystal Structure of 2-(1-Naphthalenylamino)-4-thiazolidinone

The compound 2-（1-naphthalenylamino）-4-thiazolidinone was synthesized by the reaction of 1-（naphthalene-1-yl）thiourea with ethyl chloroacetate in an ionic liquid, and its structure was characterized by IR, 1H NMR and single-crystal X-ray diffraction. The crystal of the title compound belongs to monoclinic, space group P21 /c with a=10.0081（3）, b=14.5312（4）, c=7.8739（2） , β=99.425（3）°, Z=4, V=1129.64（5）3 , Dc=1.425 g/cm3 , μ=0.269 mm-1 , F（000）=504, the final R=0.0519 and wR=0.1507. X-ray analysis indicated that the five-membered ring is essentially planar in this molecule, and intermolecular hydrogen bonds N（1）-H（1）…N（2）, C（3）-H（3）…O（1）, C（4）-H（4）…O（1） and C（12）-H（12a）…O（1） were observed. π-π Stacking interactions contribute to the stability of the structure. DSC-TG analysis showed that the title compound experienced a phase change at 190 ℃ and began to decompose above 240 ℃.

液晶电解质在锂离子电池中的研究进展

液晶电解质作为新型电解质材料,具有高离子导电性、优异的力学性能和热稳定性等优点,成为近年来锂离子电池领域研究的热点之一。液晶电解质可以通过自组装形成柱状相、近晶相或双连续立方相等结构,为锂离子的传输提供高效的离子传输通道。综述了液晶电解质在锂离子电池中的应用及研究进展,主要包括液晶电解质的基本概念和在锂离子电池中的研究进展,主要从离子电导率、电化学稳定性和充放电循环这3个方面来叙述。最后,对液晶电解质在锂离子电池领域未来的发展进行了展望。

Crystal Structures, Thermal Analysis and Electrochemical Behaviors of Functionalized Pyridinium Ionic Liquids Comprising One 1-Ethyl Acetate Group

Pyridinium ionic liquids（ILs, 1-ethyl acetate pyridinium hexfluorophosphate [EAPy][PF6] and 1-ethyl acetate-3-methyl pyridinium hexfluorophosphate [EAMPy][PF6]）, were synthesized by a two-step process involving introduction of one ethyl acetate group and anion metathesis. Colorless single crystals of the two ILs were initially obtained using the solvent-evaporation method in mixed solvents. Single-crystal X-ray diffraction was used to deter- mine the crystal structures. [EAPy][PF6] crystallizes in the monoclinic space group C2/c with a-2.2748（16） nm, b=0.6204（4） nm, c=1.8552（12） nm and Z-8, whereas [EAMPy][PF6] crystallizes in the orthorhombic space group P212121 with a=0.7126（17） nm, b=1.2792（3） nm, c=1.5327（3） nm and Z-4. The structure of [EAPy][PF6] contains double zigzag chains formed by alternately pairing large organic cations with the octahedral anions of [P1F6]- or [P2F6] . The [P1F6] and [P2F6]- anions occupy respectively two distinct crystallographic sites in crystal packing models. The structure of [EAMPy][PF6] includes ladder-type chains constructed through pairing pyridinium cations with inorganic anions of [PF6]-. The [PF6]- anion in [EAMPy][PF6] shows a distorted octahedron structure and is sandwiched by ethyl acetate groups in crystallographic stacking. This study reveals the influence of chemical modification involving the methyl group（CH3） onto crystallographic structure of pyridinium ILs. Thermal analysis indicates that the difficult crystallization of the two 1Ls is related to the low void filling of ion pairs in crystal structure, leading to relatively low melting point and evident supercooling during the cooling process. Additionally, the experimental results indicate that the two ILs have electrochemical activity. The ethyl acetate group also allows downward shifting of electrochemical windows to less negative positions and the ionic conductivities of the two ILs follow an Arrhenius-type behavior.

离子热合成ZSM-22分子筛及其晶化机理研究

本研究选用离子液体(1-丁基-3-甲基咪唑氯盐,[BMIm]Cl)为模板剂兼溶剂,采用离子热合成法成功制备了结晶度高、孔道开放、形貌规整的ZSM-22分子筛.通过系统调控初始凝胶配比,如NH_(4)F、[BMIm]Cl、H_(2)O投料量和晶化时间,实现了对ZSM-22分子筛晶体尺寸和晶化过程的精确控制.研究发现,增加[BMIm]Cl用量、减少水含量可显著提高合成体系的粘度和过饱和度,从而有效促进大量晶核的形成,抑制晶体的生长,制备得到了晶粒长度为700 nm~800 nm,宽度为50 nm~80 nm的ZSM-22分子筛,且与常规合成路线所得分子筛晶粒尺寸相近.经对晶化过程考察认为,[BMIm]Cl和合成温度是缩短ZSM-22分子筛诱导期,加速其成核和晶体生长过程的关键因素.本研究为ZSM-22分子筛的绿色可持续合成提供了新的思路,为其在催化、吸附、分离等领域的应用开辟了广阔前景.

Enhanced Crystallization Kinetics of PLLA by Ethoxycarbonyl Ionic Liquid Modified Graphene

To investigate the performance of graphene(Gra) modified with ethoxycarbonyl ionic liquid(IL), chain mobility and crystallization kinetics of poly(L-lactic acid)(PLLA), a series of PLLA nanocomposites have been prepared using solution-cast method.IL can improve the dispersion of Gra in PLLA matrix and the samples containing IL have higher growth rate of PLLA spherulite than neat PLLA does. PLLA/IL/Gra and PLLA/2 Gra exhibit the same relaxation strength and time of αN relaxation that corresponds to the longest normal mode motion at 110-140 °C. PLLA/IL/Gra shows a faster crystallization rate than PLLA/2 Gra does, which might be attributed to the Gra-imidazolium cation interaction in IL modified Gra, the significant dispersion effect of IL at Gra surface, and the increase of nuclei density of PLLA/IL/Gra.

基于离子液晶的钙钛矿界面工程提升开路电压

钙钛矿器件衬底至关重要。自组装小分子层[2-(3,6-二甲氧基-9H-咔唑-9-基)乙基]膦酸修饰氧化镍后,表面与钙钛矿失配。通过离子液晶1-十二烷基-3-甲基咪唑四氟硼酸盐修饰埋底界面,改善界面接触,与碘化铅相互作用,提升晶体质量和极小化电压损失。钙钛矿太阳电池开路电压从1.10 eV提升到1.15 eV,光电转换效率从19.48%提升到20.81%。这为反型钙钛矿太阳电池的埋底界面工程提供了新的思路。

Hydrothermal Syntheses of CuO, CuO/Cu2O, Cu2O, Cu2O/Cu and Cu Microcrystals Using Ionic Liquids

In this paper, CuO, CuO/Cu2O, Cu2O, Cu2O/Cu and Cu microcrystals were synthesized via a hydrothermal method by mixing Cu（NO3）2·3H2O and NaOH together in the presence of an ionic liquid l-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]BF4） or 1-butyl-3-methylimidazolium chloride（[BMIM]Cl）. The structures and the morphologies of the obtained products were characterized by means of X-ray diffractometer（XRD）, field-emission scanning electron microscopy/energy-dispersive spectroscopy（FESEM/EDS）, transmission electron microscopy/selected area electron diffraction（TEM/SAED） and Raman spectroscopy. The result of XRD indicates that Cu2O and Cu microcrystals are cubic phase and the Raman spectra confirm the presence of carbon. The results of FESEM and TEM images show Cu2O microcrystals as rule cubes of 2μm in length and Cu particles of 5 μm in diameter. According to the difference between crystal structures, bi-eomponent and single component products were synthesized by adjusting the reaction conditions. A possible formation mechanism of Cu2O and Cu was proposed in [BMIM]BF4.

Novel redox-active ionic thermotropic liquid crystalline complexes of polyelectrolyte and ferrocenyl surfactants

Redox-active polyelectrolyte-surfactant complexes（PSC） were prepared via the ionic self-assembly of sodium poly（styrenesulfonate） （PSS） and ferrocenyl surfactant,（11-ferrocenylundecyl）trimethylammonium bromide（FTMA） in aqueous solution. The PSS-FTMA complex exhibited an ordered interdigitated monolayer mesomorphous structure with the long period of d = 3.13 nm,and was in the ionic thermotropic liquid crystal SmA state at room temperature.Interestingly,in the solid complex, the ferrocenyl moieties formed H-aggregation showing an increase in theπ-π~＊ energy transfer of cyclopentadienes in the ferrocene moieties as known from the blue-shift in the UV spectrum.The complexes showed higher thermal stability compared with their components due to the ionic interaction.The PSS-FTMA film had a good redox reversibility,which promised to be used in electrochemical sensors.

Stereoselective Photochemical Reaction of Cyclohexyl Phenyl Ketone within Lytropic Liquid Crystals Formed by Chiral Ionic Liquids

Irradiation of cyclohexyl phenyl ketone （1） results in either intra- or intermolecular hydrogen abstraction to af- ford compounds 1-phenylhept-6-en-l-one （2） and a-cyclohexyl benzyl alcohol （3） as photoproducts, in which 3 has a pair of enantiomers. Herein, two types of chiral hexagonal liquid crystals were prepared to direct the enantioselec- tive photochemical reaction of 1. One of the hexagonal liquid crystals is composed of 1-tetradecyl-3-methyl- imidazolium bromide/p-xylene/H2O with the modification by a chiral inductor. The other one is formed by chiral （S）-3-hexadecyl-1-（1-hydroxy-propan-2-yl）-imidazolium bromide/p-xylene/H2O. The product analysis shows that the latter one can be used as a microreactor to achieve stereoselective photochemical reaction, while the former one produced compound 3 with no enantioselectivity at all.

Polycaprolactone Grafting of Cellulose Nanocrystals in Ionic Liquid[BMIM]CI

A polycaprolactone-graffed cellulose nanocrystal （PCL-g-CN） was prepared in ionic liquid and characterized by Fourier transform infrared spectrum （FT-IR）, X-ray diffraction （XRD）, and transmission electron microscopy （TEM）. A peak assigned to the carbonyl group appears at 1 730 cm-1 in the FT-IR of PCL-g-CN, which confirms that the grafting reaction is suc- cessfully completed. The morphologies of PCL-g-CNs still main- tain rod-like structure according to the TEM images. XRD results show that the crystal type of the PCL-g-CNs changed from cellu- lose I to cellulose II. The reasons for crystal transition of CNs turn out to be combined effects of anion and cation in ionic liquid with CNs.

离子液法脱硫工艺在磷石膏制酸联产水泥装置中的应用

介绍了离子液法脱除炉窑尾气中SO_(2)工艺在磷石膏制酸联产水泥熟料装置中的应用情况。针对装置运行过程中存在的脱硫溶液中SO_(4)^(2-)含量高,pH值下降和运行能耗高的问题提出相应的解决措施并进行优化改造,取得了明显的效果。

离子液体[bmim]PF_6对聚乳酸的增塑作用

合成了离子液体[bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐),并对其进行了表征。用TG、DSC和偏光显微镜等手段研究了[bmim]PF6对聚乳酸的增塑作用,并比较了它与聚乙二醇300(PEG300)的增塑效果。热重分析结果表明,PEG300作增塑剂时,由于其热降解温度较低,聚乳酸热稳定性变差;离子液体[bmim]PF6作增塑剂时,由于其热失重温度高于聚乳酸热降解温度,用其增塑的聚乳酸热稳定性变好。当[bmim]PF6的质量分数从2%增加到10%时,聚乳酸材料的玻璃化转变温度(Tg)随之降低,当加入质量分数为10%的[bmim]PF6时,聚乳酸材料的Tg降至40℃。偏光显微镜观察看出,加入[bmim]PF6后聚乳酸分子链段的活动能力增强,促进了聚乳酸的结晶,且随其用量增加,结晶度增加。该文报道工作的新颖性,已为教育部科技查新工作站(Z12)于2008年2月26日出具的第ZDT2008017号《科技查新报告》所证实。