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1.
采用溶胶-凝胶水热法制备了锐钛矿型纳米晶TiO 2薄膜电极,在乙二醇碳酸酯(EC)/1,2-丙二醇碳酸酯(PC)电解液体系中,研究了I 2和KI含量对电极光电性能的影响,发现随着电解液中I 2含量的增加,电池的短路光电流呈现先增加后减小的趋势,但光电流增加和减少的幅度并不大,同时体系的暗电流不断增加,光电压不断下降;随着电解液中KI含量的增加,电池的短路光电流也不断增加,当KI的含量大于0.2 mol/L时,电池的短路光电流的增加的趋势减缓.并对电解液中I 2和KI含量对电池光电性能影响的原因进行了初步的探讨. 相似文献
2.
在乙腈体系中,以不同的乙酸盐作催化剂,研究了CO2与二醇合成环状碳酸酯的反应.乙腈在反应过程中不仅是溶剂,而且还起到了脱水剂的作用,促进了反应的进行.以1,2-丙二醇为反应物对催化剂进行筛选,发现无水乙酸锌具有最高的催化活性.在无水乙酸锌上考察了二氧化碳和不同二醇的反应,结果表明,五元环碳酸酯的产率明显高于六元环碳酸酯,其中碳酸丙烯酯的产率最高.以1,2-丙二醇为反应基质,无水乙酸锌为催化剂,确定了最佳反应条件,1,2-丙二醇100 mmol,乙睛10 mL,催化剂2.5 mmol,反应压力10 MPa,温度170 ℃,反应12 h.在此条件下,碳酸丙烯酯的产率达到了24.2%,1,2-丙二醇的转化率为38.9%. 相似文献
3.
对2~6个环的多环芳烃的氢提取反应类进行了系统研究, 提取氢原子的不饱和自由基包括丙炔基自由基(C 3H 3)、 烯丙基自由基(C 3H 5)、 丁二烯基自由基(nC 4H 5, iC 4H 5)、 环戊二烯基自由基(C 5H 5)以及苯基自由基(C 6H 5). 采用M06-2X/cc-pVTZ方法得到了多环芳烃的电子结构信息, 利用过渡态理论并结合Eckart隧道校正, 计算了所有反应在500~2500 K范围内的反应速率常数.考察了多环芳烃的大小、 结构对反应速率常数的影响, 对比了不同氢提取自由基及不同氢提取反应类型的速率常数. 结果表明, 多环芳烃的大小对反应速率常数影响不大, 但是多环芳烃的环结构对反应速率常数影响较大. 将不同的氢提取反应类简化为发生在五元环上的C 5类和发生在六元环上的C 6类两类, 结果表明, C 6类的反应活性高于C 5类. 研究了nC 4H 5, iC 4H 5以及C 6H 5自由基与多环芳烃的氢提取反应, 它们的氢提取反应活性大小顺序为C 6H 5>nC 4H 5>iC 4H 5. 通过对每类典型反应的速率常数取平均值, 总结出相应类型的速率规则, 可用于构建多环芳烃和碳烟机理. 相似文献
4.
通过六氟丙烯三聚体(全氟壬烯)氧基苯磺酸钠(C 9F 17OC 6H 4SO 3Na, OBS)与阳离子碳氢表面活性剂C nNR[C nH 2n+1N(CH 3) 3Br, C nNM, n=8, 10和C nH 2n+1N(CH 2CH 3) 3Br, C nNE, n=8, 10, 12]复配, 研究了OBS与C nNR的摩尔比、 C nNR疏水链长及C nNR亲水基团大小对此类阴、 阳离子碳氟-碳氢表面活性剂混合体系的临界胶束浓度(cmc)、 最低表面张力(γ cmc)、 总饱和吸附量(Γ tm)及极限分子面积(A min)的影响. 结果表明, 通过与C nNR复配, OBS的cmc和γ cmc均大幅下降, 达到了全面增效的结果. 不同摩尔比的OBS-C 8NE混合体系中, 摩尔比为1:1时表面活性最好, cmc和γ cmc均最小; 偏离等摩尔比时, OBS过量时混合体系的cmc小于C 8NE过量时混合体系的cmc, 但γ cmc相差不大. 与单体系相比, OBS-C 8NE混合体系的Γ tm明显增大、 A min明显变小. OBS与不同疏水链长的C nNE复配时, cmc的变化规律为C 8NE>C 10NE>C 12NE, 表明C nNE疏水链长的增加能降低混合体系的cmc. 通过比较C nNM和C nNE(n=8, 10)的表面活性发现, 改变混合体系中C nNR的亲水基团大小对混合体系的表面活性无明显影响. 相似文献
5.
用INDO系列方法对C 602-与CH 3反应的中间体C 60(CH 3) -进行理论研究,得到具有Cs对称性的构型。结果表明,CH 3加成到C 15上,将使与其相邻的双键碳(C 30)的电荷密度和自旋密度达极大值,故加成反应部位在C 30处;另外,C 15的对位C 12(或C 27)也较其它部位易于反应,且有两个反应场所,因而产物C 60(CH 3) 2可能为六元环上的1,2-加成和1,4-加成两种异构体的混合物。同时对两种加成产物的结构和电子光谱进行了理论研究,指认其电子跃迁,并讨论了其光谱红移的原因。 相似文献
6.
摘要绿色表面活性剂烷基糖苷C 12G 1.46具有混合糖苷组成, 将其分别与十二烷基三氧乙烯磺酸钠C 12E 3S、 十二烷基三甲基氯化铵C 12TAC、 三硅氧烷非离子表面活性剂BE-6、 聚醚类表面活性剂 TMN-6复配, 在25 ℃下测定它们在0.1 mol/L NaCl溶液中的表面活性, 通过其混合表面层和混合胶束的分子交换能(ε, ε m)的计算得出如下结论: (1) C 12G 1.46的活性高于C 12G 1和C 12G 2, 即烷基混合糖苷的活性高于相同烷基的纯糖苷的结论得到了进一步证实. 利用MM2分子力场计算的能量数据可合理地解释这种混合产品活性提高的原因. (2) 在该烷基混合糖苷的二元体系溶液中, 对其表面吸附和胶束化两个过程的顺序问题进行探讨, 一种情况是先建立表面吸附, 再形成胶束(C 12G 1.46/BE-6 和 C 12G 1.46/TMN-6 体系); 另一种情况是表面吸附和胶束化同时进行(C 12G 1.46/C 12TAC和C 12G 1.46/C 12E 3S体系). 相似文献
7.
在质谱仪离子源化学电离条件下.C 60分别与1,2-二氯乙烷、1,1,2-三氯乙烷、1,1,1-三氯乙烷及1,1,2,2-四氯乙烷的主要碎片离子反应,生成多种C 60的加合离子.显示了气相中C 60的化学活泼性. 相似文献
8.
详细研究了54种常见的C 5~C 7烃类组分在S型、KCl型和M型3种类型Al 2O 3毛细管色谱柱上的分离和定性,结果显示大部分C 5~C 7烃类组分在3种类型Al 2O 3毛细管色谱柱上的分离效果良好,但也存在一些组分分离不完全或共流出的现象,3种类型Al 2O 3毛细管色谱柱上的分离效果也存在一定的差异。共测定了15个C 5烃类组分,25个C 6烃类组分及14个C 7烃类组分在这3种类型Al 2O 3毛细管色谱柱上的线性程序升温保留指数,为C 5~C 7烃类组分在Al 2O 3毛细管色谱柱上的定性提供了依据。同时定量分析了某石化企业的裂解气样品中C 5~C 7烃类组分的含量。本研究拓展了Al 2O 3毛细管色谱柱的应用范围,可以为石化企业轻烃的分析提供参考。 相似文献
9.
C 60富勒烯与2-(哌啶-硫代荒酸酯)-1,3-丁二烯通过Diels-Alder环加成反应得到C 60富勒烯-哌啶硫代荒酸酯稠合体,运用现代波谱技术等确定了产物结构;用半经验方法PM3和AM1计算预测环加成反应性和C 60富勒烯-哌啶硫代荒酸酯稠合体的性能.激光光解时间分辨技术初步探究了单加成的C 60富勒烯-哌啶硫代荒酸酯稠合体(C 60-PX)三线态特征以及与四-(2-噻吩基)-四硫富瓦烯(TT-TTF)分子间的光诱导电子转移反应. 相似文献
10.
用表面张力法研究了阳离子gemini表面活性剂乙基-1, 2-双(十二烷基二甲基溴化铵)(简写为12-2-12)和非离子表面活性剂十二烷基聚氧乙烯醚(C 12E n,其中 n = 4, 10, 23)混合体系在气液界面上的吸附行为;用扩张流变技术研究了吸附膜的扩张粘弹行为,实验数据用Lucassen-van den Tempel (LVT)模型进行拟合并根据模型得到了极限弹性值.最后研究了混合体系的泡沫行为,用泡沫塌陷到初始高度一半所对应的时间( t1/2)来表征泡沫的稳定性.结果表明,所有的非离子表面活性剂C 12E n均与12-2-12产生了吸引作用.在12-2-12浓度相同的情况下,混合吸附层中吸附分子的最小分子占据面积的顺序为12-2-12/C 12E 23 > 12-2-12/C 12E 10 > 12-2-12/C 12E 4,而极限弹性的顺序为 ε0, fit(12-2-12/C 12E 4) > ε0, fit(12-2-12/C 12E 10) > ε0, fit(12-2-12/C 12E 23).与单组分12-2-12形成的吸附膜相比,只有12-2-12/C 12E 4形成更加紧密的结构.具有较小亲水头基的非离子表面活性剂C 12E 4的加入,可增强12-2-12吸附膜的弹性,进而增强了对应体系泡沫的稳定性. 相似文献
11.
The effect of adding tri(oxyethylene) dodecyl ether (C 12EO 3) on the phase and rheological behavior of sucrose hexadecanoate and CTAB aqueous solutions in the presence of added salt (NaBr) was investigated. Viscoelastic solutions are formed in CTAB and C 16SE systems upon addition of lipophilic nonionic surfactant C 12EO 3. The zero-shear viscosity shows a maximum at a certain mixing fraction of C 12EO 3, except in the case of the aqueous CTAB/C 12EO 3 system in the absence of salt. The rheological properties are strongly affected by the addition of salt to the CTAB systems but they remain unaltered in the case of C 16SE systems. In ionic systems, the mixing fraction of C 12EO 3 for the maximum viscosity depends on salt concentration. 相似文献
12.
Thermodynamic properties of binary systems of C 60 with 1,2- and 1,3-dibromobenzenes have been studied by means of differential scanning calorimetry (DSC). Solid solvates with the compositions C 603(1,2-C 6H 4Br 2); C 602(1,3-C 6H 4Br 2) and C 600.6(1,3-C 6H 4Br 2) have been found. The solvates have been characterised by their enthalpies and temperatures of incongruent melting transition and in part by X-ray powder data. It has been shown that positional isomers 1,2- and 1,3- of the substituted benzenes formed two series of “typical” phase diagrams. Solubility behaviour of C 60 in positional isomers has been discussed. 相似文献
13.
绕轴旋转180°能与自身重合的C_2对称型手性化合物在手性催化和手性分离领域有重要应用。以L-脯氨酸苯基酰胺衍生物为手性源,合成了一类新型的C_2对称型手性固定相,并进行了手性色谱拆分评价。与单侧链取代的刷型固定相进行对比,C_2对称型手性固定相对所评价的31种酸性、中性和碱性分析物表现出更好的手性选择性。考察了固定相末端苯环上的取代基团对手性拆分的影响,综合来看,苯环上无取代基的C_2对称型手性固定相的分离性能最优。对某些手性对映体,C_2对称型手性固定相的分离因子随温度的增高而呈现异常增大的现象,表明了其有别于单侧链取代的固定相的分离机理。该类新型手性固定相的提出对进一步丰富刷型手性固定相的种类和拓展其应用具有重要意义。 相似文献
14.
A high-performance liquid chromatographic method without prederivatization was investigated for the direct determination of 4-nitrobenzoyl chloride and 4-nitrobenzoic acid. The separation was carried out on C 3, C 8 and C 18 alkyl-bonded silica columns with cyclohexane-tetrahydrofuran as the eluent. The retention behaviour observed was obviously caused by the silanophilic interaction between the solute and stationary phase. Optimum separation of 4-nitrobenzoyl chloride and 4-nitrobenzoic acid was obtained on the C 3 column and the calibration graph showed a significant linear relationship. The method was found to be quantitative, reproducible and rapid. 相似文献
15.
通过比保留体积对数值与绝对温度倒数的直线关系,水和甲醇标准曲线的正截距、氘交换以及吸附系数和溶解系数的测定,证明至少对我们的聚合物固定相来说。表面吸附对保留值是决定性的因素。 相似文献
16.
The lyotropic mesophases in binary systems of surfactants in water: n-alkylbenzenesulphonates (C 8-C 12), two chain C 12-surfactants, and dodecyl-benzenesulphonic acid, were investigated. The micellar properties were examined by conductometry and viscosimetry. The phase diagrams were determined using crossed polarizers, 2H NMR spectroscopy and polarization microscopy. Besides lamellar and inverse cubic phases, new nematic lyotropic phases have been found, presenting precursors for the lamellar phases, and exhibiting very fast alignment in a magnetic field. 相似文献
17.
A structural study of odd-numbered n-alkane (C n) binary mixtures (C 21 : C 23) was carried out on powder samples using a Guinier-de Wolff camera with increasing concentration of n-C 23 at 293 K. Despite the reports in the literature, these molecular alloys do not form an orthorhombic continuous homogeneous solid solution to C21 from C23 at “low temperature”. Instead, as already observed in two even-numbered Cn systems, X-ray diffraction results show the existence of seven solid solutions as the molar concentration of C23 increases: four terminal solid solutions, denoted β0(C21)β0(C23), isostructural with the “low temperature” phase of pure C21 and C23 (Pbcm), β′0(C21) and β′0(C23), identical to the phase β′0 which appears in pure C23 above the δ transition, and three orthorhombic intermediate solid solutions, designated β″1, β′1 and β″2. On the basis of powder X-ray photographs, the phases β″1 and β″2 (C21 : C23) are indistinguishable, and they are isostructural with the intermediate solid solution β″ of the even-numbered Cn binary systems (C22 : C24) and (C24 : C26). The phase β′1(C21 : C23) is also isostructural with the two indistinguishable intermediate solid solutions β′1 and β′2 of the molecular alloys (C22 : C24) and (24 : C26). From this study and our other laboratory results, the sequences of appearance of the solid solutions and the structural identities between these phases are established at “low temperature” for all the binary molecular alloys of consecutive Cn (odd-odd, even-even or odd-even: 19 < n < 27) when increasing the solute concentration. 相似文献
18.
A molecular thermodynamic model developed previously for fluids of chain-like molecules has been extended to correlate the pVT behavior of ionic liquids and the solubilities of gases such as CO 2, C 3H 6, C 3H 8, C 4H 10 in various ionic liquids. The relative deviation between the calculated molar volume and experimental data is less than 0.2%. It is shown that this equation of state can be used to correlate the solubility of CO 2 in ionic liquids with only one temperature-independent adjustable interaction parameter, and the accuracy of the correlation can be further improved using two temperature-independent adjustable parameters. The water content of ionic liquids has a large influence on the calculated results. For systems with water content lower than 0.1%, the average relative deviations of bubble point pressure are 3.14 and 4.90% using two parameters and one parameter, respectively. For systems containing C 3H 6, C 3H 8 and C 4H 10 two temperature dependent adjustable parameters are needed to obtain a good fit, and the corresponding deviation of the gas solubility is less than 2%, except for C 3H 8. 相似文献
19.
Several symmetrical dimers comprised of salicylaldimine-moieties connected through ester linkages to the termini of odd-parity alkanediols have been synthesized and investigated for their thermal behaviour. In order to understand the structure-property relations, the lengths of the central alkylene spacers (C 3 and C 5) as well as those of the terminal alkoxy chains (C 6 to C 22) have been varied. The dimers with a C 3-alkylene spacer are non-liquid crystalline, while some of the compounds having a C 5-alkylene spacer exhibit liquid crystalline properties. The dimer, with a C 5-alkylene spacer and C 6-alkoxy tails, shows an intercalated smectic C (SmC c) phase, whereas the C 8, C 10, C 11, and C 12 homologues are non-mesomorphic. The higher homologues of this series with C 16, C 18, C 20 and C 22 alkoxy tails show a mesophase that has the signatures of a two-dimensional banana (B 1) phase. This mesophase is enantiotropic in the C 16 and C 18 homologues while it is monotropic in the other homologues. In these dimers, the spacer length has a remarkable influence on the thermal behaviour. 相似文献
20.
Surfactants appear in multiphase fluid systems in which the interface and the adjacent bulk phase have been removed from equilibrium. Here, a new method is described for the measurement of rate constants of desorption of surface-active materials from fluid/fluid interfaces and the extent to which adsorption is reversible: the coaxial capillary pendant drop experimental technique. Kinetic constants are determined by desorption experiments in pendant drops in which the interface adjacent to a surfactant solution is removed from equilibrium by replacing the subphase of the drop with pure water. Further, we demonstrate that although the rate of subphase exchange is comparatively slow with respect to the desorption timescale, it is possible to resolve desorption processes which occur under local equilibrium with the adjacent bulk phase from those that are determined in part by sorption kinetics. Experiments which measure the desorption kinetic coefficient, , using a homologous series of n-alkyl (C8, C10, C12, C14) dimethyl phosphine oxides are presented. 相似文献
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