N-甲基-N-丁基吡咯烷溴化物和N-甲基-N-乙基吡咯烷溴化物在锌溴液流电池中的应用

在锌溴液流电池中,作为溴络合剂在电解液中使用的季铵盐对电池性能及安全性具有重要作用.本文利用循环伏安法及线性扫描伏安法研究了N-甲基-N-丁基吡咯烷溴化物和N-甲基-N-乙基吡咯烷溴化物加入到电解液后对电极反应的影响,利用交流阻抗测量了不同组成及浓度下的电解液电导率变化,测试了不同电解液对电池充放电性能的影响及溴络合能力,结果表明加入MBP的电解液具有更好的溴络合能力和电池性能.     

旋光法测定左旋N-乙基-氨甲基吡咯烷的含量

旋光法;左旋N-乙基-氨甲基吡咯烷;含量测定     

PP14TFSI离子液体在可充镁电池电解液的应用

制备了可充镁电池电解质苯酚基镁盐,以四氢呋喃（THF）与N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺（PP14TFSI）离子液体混合物代替四氢呋喃作为该电解质的溶剂. 当THF与PP₁₄TFSI体积配比为1:1时,该苯酚基镁盐电解液镁可逆溶出性能最佳,电化学窗口宽（2.7 V vs. Mg）,离子电导率高（7.77 mS·cm^-1）. 此外,热重测试表明离子液体的加入大大降低了THF溶剂的挥发性,提高了可充镁电池的安全性能. 四氢呋喃 + N-甲基-N-丁基-哌啶-双三氟甲基磺酰胺混合溶剂有望作为可充镁电池电解液的首选溶剂.     

离子色谱法分析盐酸头孢吡肟成品中的N-甲基吡咯烷

建立了外加水模式抑制电导检测的离子色谱法定性定量分析盐酸头孢吡肟中的N-甲基吡咯烷。色谱条件:色谱柱为Ion Pac CS12A阳离子交换柱(250 mmx4 mm i.d.)及其相应的CS12A保护柱(50 mmx4 mm i.d.),流动相为20 mmol/L甲基磺酸-20%乙腈水混合溶液(体积比为87∶13),流速为1.0 mL/min,自再生微膜阳离子抑制器,外加水模式,电导检测。N-甲基吡咯烷在0.38-60.8 mg/L时,峰面积和峰高与样品质量浓度均有良好的线性关系(r2=0.998);检测     

C60-N-甲基吡咯烷衍生物直接进样电喷雾离子阱质谱表征

通过直接进样方式,采用电喷雾电离质谱技术分析了8个合成的富勒烯-N-甲基吡咯烷衍生物,详细研究了其在电喷雾条件下的质谱行为。由结果可知,该类化合物在电喷雾电离过程中易得到电子而负离子化;当衍生物结构中有相对易质子化基团或有活泼氢时,则可获得质子化和去质子的正负离子谱图;衍生物在负离子模式下容易失去吡咯环产生富勒烯负离子,且在合适能量碰撞下易发生衍生化基团内部的逆环加成反应,通过失去1个中性小分子物质CH2‖N—CH3,产生新的一取代亚甲基富勒烯衍生物。基于电喷雾电离源技术联合离子阱分析器建立的质谱分析方法,不但能提供准确的分子量信息,还能通过获得高分辨同位素谱峰和丰富的二级碎片离子峰,进一步确认化合物的分子结构,是一种先进、快速的富勒烯吡咯烷衍生物定性分析方法。     

N-甲基-2-(4''-N-乙基咔唑基)-[60]富勒烯吡咯烷及其衍生物的合成, 电荷分离态特征

通过1,3-偶极环加成方法在微波照射下合成了N-甲基-2-(4'-N-乙基咔唑基)-富勒烯吡咯烷(C₆₀-Cz)和N-甲基-2- (4'-N,N-二苯基氨基)-富勒烯吡咯烷(C₆₀-TPA), 用质谱, ¹H NMR, IR等对其结构进行了表征. 用激光光解时间分辨瞬态谱研究了N-甲基-2-(4'-N-乙基咔唑基)-富勒烯吡咯烷的分子内电荷转移过程, 在近红外区观测到了长寿命电荷分离态C₆₀^•--C_Z^•+的存在, 其寿命为0.28 μs. 运用Gaussian 98量子化学程序包, 利用密度泛函的方法对N-甲基-2-(4'-N,N-二苯基氨基)-富勒烯吡咯烷几何构型进行了优化, 并在优化基础上用ZINDO方法计算了化合物C₆₀-TPA的电子光谱, 计算结果表明, 光谱吸收峰在440 nm, 与实验值433 nm基本一致.     

N-辛酰吡咯烷萃取苯酚水溶液

辛酰氯与吡咯烷反应合成了新型萃取剂N－酰吡咯烷（OPOD）,并考察了以煤油为稀释剂,OPOD萃取苯酚的性能,研究了萃取剂浓度、苯酚浓度、酸度和温度对苯酚萃取的影响以及反萃的可行性,由斜率法确定了萃合物的组成,计算了萃取反应的平衡常数以及有关的势力学函数,同时根据红外光谱和核磁共振谱讨论了萃取过程及萃合物的结构,实验结果表明,OPOD对苯酚具有良好的萃取性能。     

离子色谱法检测盐酸头孢吡肟中的N-甲基吡咯烷

建立了一种盐酸头孢吡肟中的N-甲基吡咯烷的离子色谱分析方法.采用阳离子交换柱IonPac CS12A作分析柱,甲烷磺酸-乙腈为淋洗液,外加水电抑制模式,电导检测,在10 min内即可完成分析.线性良好(r2=0.9985),样品的RSD在5%以下(n=6),回收率在89.5%～108.4%之间.方法可在盐酸头孢吡肟产品的检验中发挥作用.     

蒙脱士负载钯催化芳基溴化物脱溴性能研究

芳基溴化物催化脱溴 ,无论在有机合成 ,还是消除芳基溴化物对环境的污染方面均具有重要意义 .催化脱卤已有许多研究报道 [1] .常用的负载催化剂为 Pd/C[2 ] ,这种催化剂催化活性较高 ,但对不同卤素的选择性较差 ,贵金属钯损失较大 .用功能化的蒙脱土负载钯催化剂 [3 ]催化芳基溴化物的脱溴 ,有较好的脱溴性能 ,但脱溴时间较长 ,且催化剂制备困难 .我们用胺为吸附质 ,将钯负载在廉价的蒙脱土上制成蒙脱土负载钯催化剂 ,并将其用于催化有机卤化物脱卤 .结果表明 ,该负载钯催化剂对芳基溴化物脱溴具有显著的催化活性和选择性 ,且催化剂易于制…     

N-甲基-N-(2-甲基丙烯酰氧乙基)-对-甲苯胺对甲基丙烯酸甲酯聚合的影响

<正> 我们曾报道可聚合的芳叔胺N-甲基-N-(2-甲基丙烯酰氧乙基)苯胺(MEMA)与有机过氧化物如过氧化二苯甲酰(BPO)、过氧化二月桂酰(LPO)组成氧化还原引发体系用于甲基丙烯酸甲酯的聚合。虽然文献报道了N-甲基-N-(2-甲基丙烯酰氧乙基)-对-甲苯胺(MEMT)的合成,但没有研究它对甲基丙烯酸甲酯自由基聚合的影响。本文研究了MEMT对BPO或LPO引发MMA聚合的影响,从聚合动力学研究表明BPO/MEMT组成氧化还原引发体系。其引发机理与BPO/MEMA很相似。     

Systematic Study of Quaternary Ammonium Cations for Bromine Sequestering Application in High Energy Density Electrolytes for Hydrogen Bromine Redox Flow Batteries

Bromine complexing agents (BCAs) are used to reduce the vapor pressure of bromine in the aqueous electrolytes of bromine flow batteries. BCAs bind hazardous, volatile bromine by forming a second, heavy liquid fused salt. The properties of BCAs in a strongly acidic bromine electrolyte are largely unexplored. A total of 38 different quaternary ammonium halides are investigated ex situ regarding their properties and applicability in bromine electrolytes as BCAs. The focus is on the development of safe and performant HBr/Br₂/H₂O electrolytes with a theoretical capacity of 180 Ah L⁻¹ for hydrogen bromine redox flow batteries (H₂/Br₂-RFB). Stable liquid fused salts, moderate bromine complexation, large conductivities and large redox potentials in the aqueous phase of the electrolytes are investigated in order to determine the most applicable BCA for this kind of electrolyte. A detailed study on the properties of BCA cations in these parameters is provided for the first time, as well as for electrolyte mixtures at different states of charge of the electrolyte. 1-ethylpyridin-1-ium bromide [C2Py]Br is selected from 38 BCAs based on its properties as a BCA that should be focused on for application in electrolytes for H₂/Br₂-RFB in the future.     

Simultaneous determination of bromide and iodide ions by capillary isotachophoresis using quaternary ammonium salts

Bromide and iodide ions were determined simultaneously by capillary isotachophoresis using an aqueous electrolyte system; the separation principle was based on the ion-pairing equilibria between tetradecyldimethylbenzylammonium ion and these anions in the leading electrolyte. The interaction between iodide ion and tetradecyldimethylbenzylammonium ion was stronger than that for bromide ion. Thus complete separation of bromide and iodide ions could be obtained by using a leading electrolyte containing 1.5 mM tetradecyldimethylbenzylammonium ion. The pH of the leading electrolyte was adjusted to 5.0. The relative standard deviations of the zone length for bromide and iodide ions were 1.1 and 1.2%, respectively, when mixture of 3.0 mM of these ions was analysed. A 150-μl volume could be injected for the simultaneous determination of low concentrations of bromide and iodide ions.     

Cross-linking copolymers of acrylates’ gel electrolytes with high conductivity for lithium-ion batteries

The cross-linking gel copolymer electrolytes containing alkyl acrylates, triethylene glycol dimethacrylate, and liquid electrolyte were prepared by in situ thermal polymerization. The gel polymer electrolytes containing 15 wt% polymer content and 85 wt% liquid electrolyte content with sufficient mechanical strength showed the high ionic conductivity around 5?×?10^?3 Scm^?1 at room temperature. The gel electrolytes containing different polymer matrices were prepared, and their physical observation and conductivity were discussed carefully. The cross-linking copolymer gel electrolytes of alkyl acrylates with other monomers were designed and synthesized. The results showed that copolymerization can improve the mechanical properties and ionic conductivities of the gel electrolytes. The polymer matrices of gels had excellent thermal stability and electrochemical stability. The scanning electron microscope analysis showed the gel electrolyte was the homogeneous structure, and the cross-linking polymer host was the porous three-dimensional network structure, which demonstrated the high conductivity of the gel electrolytes. The gel polymer Li-ion battery was prepared by this in situ thermal polymerization. The cell exhibited high charge-discharge efficiency at 0.1 C. The results of LiFePO4-PEA-Li cell and graphite-PEA-Li cell showed that gel polymer electrolytes have good compatibility with the battery electrodes materials.     

Bromination of alkylbenzenes in 1-butyl-3-methylimidazolium bromide and its dibromide complex

Alkylbenzenes were subjected to bromination with molecular bromine using 1-butyl-3-methylimidazolium bromide as solvent. A complex of 1-butyl-3-methylimidazolium bromide with bromine was synthesized. It ensured bromination of alkylbenzenes with no bromine and solvent. The results of bromination in binary solvents and ionic liquids, 1-butyl-3-methylimidazolium bromide and tribromide were compared. The bromination of ethylbenzene with 1-butyl-3-methylimidazolium tribromide was accompanied by formation of a considerable amount of α-bromoethylbenzene, which is not typical of electrophilic aromatic substitution process.     

Boron Clusters as Highly Stable Magnesium‐Battery Electrolytes

Boron clusters are proposed as a new concept for the design of magnesium‐battery electrolytes that are magnesium‐battery‐compatible, highly stable, and noncorrosive. A novel carborane‐based electrolyte incorporating an unprecedented magnesium‐centered complex anion is reported and shown to perform well as a magnesium‐battery electrolyte. This finding opens a new approach towards the design of electrolytes whose likelihood of meeting the challenging design targets for magnesium‐battery electrolytes is very high.     

Hydrogen production in the radiolysis of bromide solutions

The radiolysis of water without a protecting agent is found to form a low steady-state concentration of molecular hydrogen. The addition of bromide anion leads to a linear response for molecular hydrogen production with doses up to 300 kGy. Bromide concentrations are found to remain constant over this dose range due to recycling of the oxidized species containing the bromine atom by hydrated electrons, H atoms or HO₂ (O₂⁻). This process appears to occur many times with little change in total bromide anion concentration. Efficient electron scavengers are found to have no effect on bromide anion concentration except possibly at extremely high concentrations. Nitrous oxide saturated solutions show a significant depletion of bromide anion concentration with a concurrent formation of BrO₃⁻ and a suppressed yield of molecular hydrogen.     

锂离子电池电解液除酸除水添加剂的研究进展

商用锂离子电池电解液在应用过程中存在电解质锂盐六氟磷酸锂（LiPF₆）易在痕量水环境中发生水解反应，进而导致锂离子电池体系的综合电化学性能受损。因此，亟需控制电解液本体中痕量水的引入以及减小锂盐与痕量水反应产物对电池体系影响的措施。本文主要综述了含有不同官能团的添加剂在除去电解液中痕量水和酸时所具有的特性，并重点分析介绍了其除酸除水的作用机理。 最后，对除酸、除水型添加剂未来的研究方向和应用前景进行了展望。     

电解质对锂离子电池正极材料界面特性的影响

研究L iPF6、L iC lO4和L iBF43种电解质对L iCoO2材料界面特性的影响.结果表明:化成后的L iCoO2表面存在固态电解质膜(SEI膜);在不同成分的电解液中,L iCoO2表面SEI膜的形成电位、形貌特征以及材料的可逆容量、平均放电电压和电化学反应阻抗不同.     

On-line speciation of bromine and bromide using sequential injection analysis with spectrophotometric detection

An on-line procedure for the simultaneous determination of bromine and total bromine (bromine+bromide oxidised to bromine) is proposed, which lead to the determination of bromide by subtraction. Phenol red was used as chromogenic reagent for bromine and total bromine after bromide was oxidised to bromine by Chloramine T. The linear range found is 1-10 mg L(-1) with a detection limit of 0.6 mg L(-1) for bromine, and a linear range of 0.8-15 mg L(-1) with a detection limit of 0.4 mg L(-1) for total bromine. The calculated RSD for bromine is less than 0.8% and for total bromine less than 0.7%. The system is fully computerised and able to run 30 samples per hour with an automated rinsing step that eliminates sample carry-over. The results for both bromine and bromide from the proposed sequential injection analysis (SIA) system compare favourably with standard manual methods and statistical evaluation proves no significant difference between the results of the proposed SIA system and the standard method at the 95% confidence level. The presence of other halides was found not to interfere.     

Polymer battery R&D in the U.S.

Polymer electrolytes that have been developed for battery applications fall into two general classes, neat or “pure” polymer and plasticized or gel in which the polymer is combined with a conducting organic electrolyte. The polyethylene oxide (PEO) and its modifications are typical of the “pure” polymer electrolytes. They have poor conductivity at room temperatures, but at elevated temperatures, their conductivity is of the order of 10⁻³ to 10⁻⁴ S/cm. The PEO electrolytes have found application in the high temperature (>60°C) lithium metal anode battery systems. The high temperature necessary for good operation makes them unsuitable for use in small consumer appliances. The polymer electrolyte battery development activities have resulted in several high performance battery systems now just entering the market. Not all of the developments have resulted in commercial cell production. The commercialization activities of high performance lithium‐ion (Li‐Ion) batteries have been based on two general plastic polymer systems: poly‐vinylidene difluoride‐hexafluoropropylene copolymer (PVdF‐HFP) and polyacrylates. The polymer cells are expected to have advantages in manufacturing, flexibility, thin cell formats and lightweight packaging. Important parameters in PVdF gel electrolyte performance include the electrolyte type (combination of organic carbonates), temperature, and HFP copolymer content. Li‐Ion coin cells fabricated with a polyolefin separator with either liquid electrolyte or with the PVdF gel polymer electrolyte have equivalent performance.