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Hydrogen bonding mediated ion pairs of some aprotic ionic liquids and their structural transition in aqueous solution

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Science China Chemistry 2017年第7期60卷 970-978页

作者： Huiyong Wang Miao Liu Yuling Zhao xiaopeng xuan Yang Zhao Jianji Wang Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals School of Chemistry and Chemical EngineeringKey Laboratory of Green Chemical Media and ReactionsMinistry qf EdueationHenan Normal UniversityXinxiang 453007China

Ion pair speciation of ionic liquids(ILs) has an important effect on the physical and chemical properties of ILs and recognition of the structure of ion pairs in solution is essential. It has been reported that ion pairs of some ILs can be formed by hydrogen bonding interactions between cations and anions of them. Considering the fact that far-IR(FIR) spectroscopy is a powerful tool in indicating the intermolecular and intramolecular hydrogen bonding, in this work, this spectroscopic technique has been combined with molecular dynamic(MD) simulation and nuclear magnetic resonance hydrogen spectroscopy(~1H NMR) to investigate ion pairs of aprotic ILs [Bmim][NO_3], [BuPy][NO_3], [Pyr_(14)][NO_3], [PP_(14)][NO_3] and [Bu-choline][NO_3] in aqueous IL mixtures. The FIR spectra have been assigned with the aid of density functional theory(DFT) calculations, and the results are used to understand the effect of cationic nature on the structure of ion pairs. It is found that contact ion pairs formed in the neat aprotic ILs by hydrogen bonding interactions between cation and anion, were still maintained in aqueous solutions up to high water mole fraction(say 0.80 for [BuPy][NO3]). When water content was increased to a critical mole fraction of water(say 0.83 for [BuPy][NO3]), the contact ion pairs could be transformed into solvent-separated ion pairs due to the formation of the hydrogen bonding between ions and water. With the further dilution of the aqueous ILs solution, the solvent-separated ion pairs was finally turned into free cations and free anions(fully hydrated cations or anions). The concentrations of the ILs at which the contact ion pairs were transformed into solvent-separated ion pairs and solvent-separated ion pairs were transformed into free ions(fully hydrated ion) were dependent on the cationic structures. These information provides direct spectral evidence for ion pair structures of the aprotic ILs in aqueous solution. MD simulation and ~1H NMR results support

关键词： ionic liquids ion pair hydrogen bonding far infrared spectroscopy solution

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Anisotropic thermal conductivity of magnetic fluids

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Progress in Natural Science:Materials International 2009年第2期19卷 205-211页

作者： xiaopeng Fang,Yimin xuan,Qiang Li School of Power Engineering,Nanjing University of Science & Technology,Nanjing 210094,China School of Power Engineering Nanjing University of Science & Technology Nanjing 210094 China

Considering the forces acting on the particles and the motion of the particles,this study uses a numerical simulation to investigate the three-dimensional microstructure of the magnetic fluids in the presence of an external magnetic field. A method is proposed for predicting the anisotropic thermal conductivity of magnetic fluids. By introducing an anisotropic structure parameter which characterizes the non-uniform distribution of particles suspended in the magnetic fluids,the traditional Maxwell formula is modified and extended to calculate anisotropic thermal conductivity of the magnetic fluids. The results show that in the presence of an external magnetic field the magnetic nanoparticles form chainlike clusters along the direction of the external magnetic field,which leads to the fact that the thermal conduc-tivity of the magnetic fluid along the chain direction is bigger than that along other directions. The thermal conductivity of the magnetic fluids presents an anisotropic feature. With the increase of the magnetic field strength the chainlike clusters in the magnetic fluid appear to be more obvious,so that the anisotropic feature of heat conduction in the fluids becomes more evident.

关键词： Magnetic fluids Anisotropic thermal conductivity Maxwell formula

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Controllable synthesis and spontaneous phase transition of photonic coordination polymer to produce a strong second-harmonic generation response

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Science China Materials 2020年第7期63卷 1272-1278页

作者： Jun Zhang Maierhaba Abudoureheman Xiaofan Ma Weili Kong xiaopeng xuan Shilie Pan School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China College of Chemistry and Chemical Engineering Key Laboratory of Coal Clean Conversion&Chemical Engineering ProcessCollege of Chemistry and Chemical EngineeringXinjiang UniversityUrumqi 830046China School of Chemistry and Chemical Engineering Key Laboratory of Green Chemical Media and ReactionsMinistry of EducationCollaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsHenan Normal UniversityXinxiang 453007China CAS Key Laboratory of Functional Materials and Devices for Special Environments Xinjiang Technical Institute of Physics&ChemistryCASXinjiang Key Laboratory of Electronic Information Materials and DevicesUrumqi 830011China

Herein,a novel photonic coordination polymer material was constructed by aggregation-induced emission luminogen(AIEgen)containing a tripyridyl moiety used as the linking *** displayed a spontaneous direct centrosymmetric to noncentrosymmetric phase transition in a single *** two crystals,before and after the phase transition,were both controllably synthesized and characterized by single-crystal X-ray *** being exposed to air,the centrosymmetric metastable phase(1-α)transitioned to a new stable phase with a noncentrosymmetric structure(1-β).Interestingly,the 1-βstructure exhibited a strong phasematching second-harmonic generation(SHG)response,about4.5 times higher than that of KH2PO4(KDP).In order to better understand the relationship between the structure and the nonlinear optical properties,the dipole moments were calculated and ***,the noncentrosymmetric phase with high thermal stability for 1-βretained and improved the initial photoluminescent properties of the AIEgen ligand after the structural phase transition from 1-α,and simultaneously produced the excellent SHG property,which are beneficial for the design and construction of excellent optical materials.

关键词： second-harmonic generation controllable synthesis phase transition crystal structure single-crystal X-ray diffraction

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应力多轴效应对316不锈钢蠕变设计准则的影响

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机械强度 2016年第5期38卷 1087-1092页

作者：沈孝鹏轩福贞华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室上海200237

ASME NH高温结构设计标准中对结构的非弹性应变提出了限值,但该应变限值存在诸多争议,如未考虑应力多轴效应的影响,且对所有材料设定统一的设计容限值等。对550℃下承受内压的316不锈钢弯头进行了蠕变模拟,主要研究应力多轴效应对蠕变... 详细信息

ASME NH高温结构设计标准中对结构的非弹性应变提出了限值,但该应变限值存在诸多争议,如未考虑应力多轴效应的影响,且对所有材料设定统一的设计容限值等。对550℃下承受内压的316不锈钢弯头进行了蠕变模拟,主要研究应力多轴效应对蠕变设计中应变容限的影响。使用含有损伤参量的本构方程,并根据延性耗竭模型定义了新的损伤参量。当弯头的薄膜应变和弯曲应变达到ASME NH中相应限值时,考察各损伤参量是否达到相应的临界值,以确定该应变限值是否保守。结果显示,当弯头的薄膜应变达到1%的限值时,弯头中的各损伤参量远小于相应的临界值。这说明对于316不锈钢,ASME NH中的非弹性应变的限值在多轴效应存在的情况下仍然是保守的,可以用于该温度下含多轴应力状态结构的设计和校核。

关键词： 316不锈钢 ASME NH 应力多轴度应变线性化蠕变延性

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Thermal Stability and Thermal Decomposition Kinetics of 1-Butyl-3-methylimidazolium Dicyanamide

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Chinese Journal of Chemical Engineering 2010年第5期18卷 736-741页

作者：梁蕊杨美荣轩小鹏 School of Chemistry and Environmental Sciences Henan Normal University Xinxiang 453007 China

Thermal stability and thermal decomposition kinetics of 1-butyl-3-methylimidazolium dicyanamide ([bmin+][N(CN) ]2-) were investigated using both isothermal and non-isothermal thermogravimetric analyses (TGA) under high pure nitrogen as carrier gas. The long-term thermogravimetric studies revealed that the highest temperature used should be 110 °C, at which [bmin+][N(CN)2-] lost less than 10% by mass in 10 hours. The non-isothermal activation energy values determined using Friedman and ASTM methods were (150±13) and (147±2) kJ·mol –1 , respectively. Multivariate non-linear-regression methods showed that expanded Fn and CnB models were the best fit models with highest correlation coefficient of 0.9994, and the apparent activation energies were consistent with iso-conversional methods.

关键词： ionic liquids long-term thermal stability kinetics of thermal decomposition iso-conversional method

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室温离子液体混合物的相平衡研究进展

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化学进展 2006年第5期18卷 670-679页

作者：张虎成王键吉轩小朋赵扬卓克垒河南师范大学化学与环境科学学院新乡453007

室温离子液体混合物的相平衡数据是设计和优化涉及离子液体的化学反应与分离工程的重要基础。本文综述了近年来室温离子液体混合物,特别是室温离子液体+有机物体系的气-液平衡、液-液平衡和固-液平衡的研究进展,总结了这些混合物相行为... 详细信息

室温离子液体混合物的相平衡数据是设计和优化涉及离子液体的化学反应与分离工程的重要基础。本文综述了近年来室温离子液体混合物,特别是室温离子液体+有机物体系的气-液平衡、液-液平衡和固-液平衡的研究进展,总结了这些混合物相行为的基本热力学规律以及对萃取分离工程的指导作用。

关键词：离子液体相平衡热力学混合物

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1-乙基-3-甲基咪唑甘氨酸离子液体与水的相互作用研究

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中国科学：化学 2022年第5期52卷 743-751页

作者：闵照军李志勇赵玉灵王慧勇轩小朋赵扬王键吉河南师范大学化学化工学院绿色化学介质与反应教育部重点实验室新乡453007

氨基酸离子液体因具有生物相容性、可降解性和易于合成等特点,在许多领域具有重要的应用前景.由于不同程度的吸湿性,水对氨基酸离子液体的结构和性质的影响不可忽略,因此深入研究氨基酸离子液体的微观结构及其与水分子间相互作用的本质... 详细信息

氨基酸离子液体因具有生物相容性、可降解性和易于合成等特点,在许多领域具有重要的应用前景.由于不同程度的吸湿性,水对氨基酸离子液体的结构和性质的影响不可忽略,因此深入研究氨基酸离子液体的微观结构及其与水分子间相互作用的本质具有重要意义.本文以1-乙基-3-甲基咪唑甘氨酸离子液体([C_(2)mim][Gly])为例,通过核磁共振波谱、二维红外光谱、量化计算、分子模拟等手段系统地研究了氨基酸离子液体与水的相互作用.结果表明,在25.0℃时,向[C_(2)mim][Gly]中加入水后,水分子优先与甘氨酸阴离子发生作用,破坏阴阳离子间的氢键.随着水分子数目的增加,部分甘氨酸阴离子水解为甘氨酸分子.当一个[C_(2)mim][Gly]分子周围至少有8个水分子时,阴阳离子间的氢键会被完全破坏,形成溶剂化的自由离子.

关键词：氨基酸离子液体水溶液氢键离子溶剂化

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地方师范院校化学专业中优秀中学化学教师培养的研究与实践——以河南师范大学化学化工学院为例

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科教导刊 2019年第23期 84-86,129页

作者：王海霞轩小朋曹锟祁巧艳河南师范大学化学化工学院

在我校'省部共建'背景下,化学学科作为我省A类优势学科,如何更好的彰显师范专业的'化学特色',是提高人才培养质量的迫切要求。化学化工学院以河南省教师教育改革为契机,在化学专业小班化的框架下进行了优秀中学化学教师培养模式的初步... 详细信息

在我校'省部共建'背景下,化学学科作为我省A类优势学科,如何更好的彰显师范专业的'化学特色',是提高人才培养质量的迫切要求。化学化工学院以河南省教师教育改革为契机,在化学专业小班化的框架下进行了优秀中学化学教师培养模式的初步探索和实践,明确了地方师范院校中学化学教师培养的目标,夯实化学师范生知识体系的理论基础的同时,多方位的实践过程有效地提高了师范生的综合教师素养,构建了高校与中学间的校地协同育人模式。

关键词：省部共建化学教师校地协同

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物理化学教学中思政元素的分类与融合

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科教导刊 2022年第4期 79-81,84页

作者：轩小朋裴渊超李志勇赵玉灵赵扬河南师范大学化学化工学院河南新乡453007

根据思政元素所表达的主题和育人意义,把“物理化学”课程教学中存在的思政元素划分为家国情怀、社会责任、科学态度三个类别,并对其关系进行了探讨,有助于把握好课程教学内容与思政元素的关系,能够更加有效地提炼和应用课程思政元素,... 详细信息

根据思政元素所表达的主题和育人意义,把“物理化学”课程教学中存在的思政元素划分为家国情怀、社会责任、科学态度三个类别,并对其关系进行了探讨,有助于把握好课程教学内容与思政元素的关系,能够更加有效地提炼和应用课程思政元素,全方位落实课程的培养目标。

关键词：物理化学思政元素分类与融合课程思政

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Distributing disciplinarian of ground motion parameters on an earth fissure site during strong earthquakes

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Earthquake Engineering and Engineering Vibration 2020年第3期19卷 597-610页

作者： Xiong Zhongming Zhang Chao Huo xiaopeng Chen xuan J.Jorge Ochoa College of Civil Engineering Xi'an University of Architecture and TechnologyXi'an 710055China College of Civil Engineering Inner Mongolia University of Science and TechnologyBaotou 014010China School of Natural&Built Environments University of South AustraliaAdelaide 5108Australia

To investigate the distributing disciplinarian of ground motion parameters on the earth fissure site during strong earthquakes,a series of shaking table tests were designed and conducted based on 1:15 scaled *** results showed significant differences in the ground motion parameters(including ground motion intensity indices,spectrum characteristics and strong motion duration)between the hanging-wall and footwall caused by the earth *** response,displacement response and Arias Intensity response on both sides of earth fissure indicated that the earth fissure site on the hanging-wall was destroyed more *** distributing disciplinarian of amplification factors showed clear"hangingwall and footwall effects",which were more remarkable nearby the fissure *** low-frequency component of the seismic wave was richer after selectively filtering in the soil *** comparing the predominant period and mean period of the hanging-wall and footwall,it was found that vibration frequency on the hanging-wall was greater than that on the *** values of strong motion duration were recorded on the hanging-wall close to the fissure and increased from the fissure to both sides.

关键词： earth parameters shaking

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