Conductometric study of antidepressant drug-cationic surfactant mixed micelles in aqueous solution

Conductivity measurements have been carried out on aqueous solutions of two antidepressant drugs (nortriptyline hydrochloride and clomipramine hydrochloride) with four cationic surfactants (monomeric: cetyltrimethylammonium bromide, tetradecylammonium bromide; dimeric: 1,5-pentanediyl-alpha-omega-bis(hexadecyldimethylammonium bromide), 1,4-butanediyl-alpha,omega-bis(hexadecyldimethylammonium bromide) as well as with sodium chloride. Counterions from NaCl adsorb to the charged headgroup of the drug molecules and reduce the repulsion, hence cmc decreases. cmc values decreased with the addition of surfactants indicating mixed micelle formation. Experimental mole fraction of surfactants in micelle (X1) and their ideal values (X1 id) also support this explanation. Interaction parameter, beta, and excess free energy of micellization are negative suggesting synergism in mixed state. Activity coefficients are less than unity which means non-ideal mixing.     

脂肪醇对环氧乙烷环氧丙烷嵌段共聚物破乳效果的影响 Ⅱ.O/W型乳状液的破坏

环氧乙烷(EO)环氧丙烷(PO)的共聚物有较好的破乳效果,是目前较理想的破乳剂,已在油田得到应用。这类表面活性剂的特点是只要适当调节EO和PO的比例,就既可用作W/O型乳状液的破乳剂,也可用作O/W型乳状液的破乳剂,但关于后者的研究很少。前已报导加入脂肪醇可显著提高这类表面活性剂对W/O型乳状液的破乳效果。本文继续研究脂肪醇对这类表面活性剂破坏O/W型乳状液的影响。     

Efficient Dimeric Esterification of Alcohols with NBS in Water Using L-Proline as Catalyst

The L-proline-catalyzed oxidation of aliphatic primary alcohols with N-bromosuccimide (NBS) in water at room temperature to afford the corresponding dimeric esters in good to excellent yields was described. This pathway of dimeric esterification was proved to be very simple and environmentally friendly.     

吖啶作为检测试剂脂肪醇和脂肪酸的间接光度高效液相色谱研究

以吖啶作为新型检测试剂,研究C_4～C_(12)脂肪醇、C_6～C_(16)脂肪酸的间接光度高效液相色谱,探讨影响色谱保留和产生间接光度响应的因素,从分离检测机理解释两类化合物色谱行为和检测响应的差别,提出新的分离测定脂肪醇和脂肪酸的间接光度高效液相色谱系统。     

Vapor pressure of selected aliphatic alcohols by ebulliometry. Part 2

Vapor pressures of six pentanols, 2-methyl-1-butanol (CAS Registry Number 137-32-6), 2-methyl-2-butanol (CAS Registry Number 75-85-4), 3-methyl-1-butanol (CAS Registry Number 123-51-3), 3-methyl-2-butanol (CAS Registry Number 598-75-4), 2-pentanol (CAS Registry Number 6032-29-7) and 3-pentanol (CAS Registry Number 584-02-1), were measured by the precision ebulliometry over an approximate pressure range from 9 to 99 kPa. The absolute uncertainties in pressure and temperature are estimated to be less than or equal to 7 Pa and 0.02 K, respectively. The results are represented by the Antoine equation and compared with available literature data.     

Vapor pressure of selected aliphatic alcohols by ebulliometry. Part 1

Vapor pressures for liquid 2,2-dimethyl-1-propanol (CAS Registry Number 75-84-3), 1-hexanol (CAS Registry Number 111-27-3), 1-heptanol (CAS Registry Number 111-70-6), 1-octanol (CAS Registry Number 111-87-5) and 1-tetradecanol (CAS Registry Number 112-72-1) were measured by the precision comparative ebulliometry over an approximate pressure range from 8 to 100 kPa. The relative uncertainty in pressure is estimated to be less than or equal to 0.05% of the measured value and the absolute uncertainty in temperature is estimated at less than or equal to 0.01 K on ITS-90. The results are represented by the Antoine equation and compared with available literature data. A new transformation of vapor pressure data, which facilitates the detection of systematic errors, is presented.     

Spectrophotometric Study of Interaction of Comenic Acid with Cetylpyridinium Chloride

The interaction of comenic acid with cetylpyridinium chloride in aqueous solutions was studied by spectrophotometry. Compositions of ionic associates formed depending on cetylpyridinum chloride concentration were found, and logarithms of equilibrium constants of corresponding association reactions were determined.     

Bubble temperature measurements on the binary mixtures formed by chlorobenzene with methanol,ethanol, n-propanol and sec-butanol at 94.6 kPa

Bubble temperatures at 94.6?kPa, over the entire composition range have been measured for the binary mixtures formed by chlorobenzene with methanol, ethanol, n-propanol and sec-butanol using a Swietoslawski type ebulliometer. The liquid phase composition versus temperature data are found to be well represented by the Wilson model.     

高效毛细管电泳电导检测器的研制

研制了一种毛细管电泳电导检测器。采用激光烧蚀毛细管涂层、HF腐蚀和阴离子交换膜封堵制作在柱导电接口连接电泳毛细管和电导池,高压电场被有效隔离,以铂丝为工作电极实现柱后电导检测,在内径为50μm毛细管上分离检测了几种氨酸和金属离子,结果表明该系统性能优良。     

DDACLB膜的电学性质研究（I）-电导率

沉积在聚脂基片上的表面软化剂DDAC多分子层,在不同的湿度条件下,其横向导电特性标志该表面活性剂在纤维表面处理过程中驱除静电能力的大小。由原子力显微镜（AFM）图像表明,DDAC的2、4、8多分子层薄膜上的结晶颗粒随层数的增加而增大,因此采用电导率描述其导电性质并借助薄膜电阻加以解释。对复合分子层的电导率的非线性变化除借用了半导体物理学中的渗透理论（PercolationTheory）加以解释外,还建立了线束重叠（Patch-Overlapping）模型以讨论电流渗透中的饱和现象。得出了提高相对湿度对可使流经多分子层的电流强度增加的结论同时又对膜厚、湿度对电流强度的贡献及其相互制约的关系提出了理论解释。     

Kinetics and mechanism of oxidation of aliphatic alcohols by tetrabutylammonium tribromide

Oxidation of nine primary aliphatic alcohols by tetrabutylammonium tribromide (TBATB) in aqueous acetic acid leads to the formation of the corresponding aldehydes. The reaction is first order with respect to TBATB. Michaelis-Menten type kinetics is observed with respect to alcohols. The reaction failed to induce the polymerization of acrylonitrile. Tetrabutylammonium chloride has no effect on the reaction rate. The proposed reactive oxidizing species is the tribromide ion. The oxidation of [1,1-²H₂]ethanol exhibits a substantial kinetic isotope effect. The effect of solvent composition indicates that the rate increases with increase in the polarity of the solvent. The reaction is susceptible to both polar and steric effects of substituents. A mechanism involving transfer of a hydride ion in the rate-determining step has been proposed.     

Effects of Metal Ions on the Micellization of Ionic Surfactants

The effect of metal ions (Cu(II), Zn(II), Co(II), Ni(II), La(III), Fe(III)) on the critical micelle concentration (CMC) of ionic surfactants (sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (CTAB)) were investigated at 25±0.1°C, μ = 0.1 M (KNO₃), using conductivity method in this paper. A series of general empirical expressions about the relationship between the CMC values for SDS and CTAB and the concentrations of metal ions have been derived. The results showed that the CMC values for both SDS and CTAB decreased with increasing the concentrations of metal ions. This can be interpreted by the counterion effect and the entropy driving effect.     

表面活性剂胶束化物理化学性质研究

通过电导法考查温度和盐浓度对十二烷基硫酸钠(SDS)临界胶束浓度(CMC)的影响,研究表面活性剂形成胶束过程的物理化学性质。根据拟相分离模型求得胶束化热力学函数,并讨论体系电导活化能随温度和SDS浓度变化关系。结果表明:SDS的CMC随温度升高而增加,随氯化钠浓度增大而减小。在热力学上SDS在水溶液中形成胶束是一个自发、放热、熵增的过程;在动力学上,SDS溶液电导率与温度关系符合Arrhenius公式,通过电导活化能信息可揭示离子型表面活性剂形成胶束的机理特征。     

Conductometric studies of DyCl3 in dilute aqueous solution

The limiting conductivity of Dy³⁺(aq) has been determined for the first time by linear extrapolation of conductivity measured in dilute aqueous solutions of (DyCl₃+HCl) at 25°C as ^o(Dy³⁺, aq) = (62.9±0.7) S-cm²-eq^-1. A second set of conductivity measurements in dilute aqueous solutions of DyCl₃ has given evidence of very slight hydrolysis of the cation, with a first hydrolysis constant of 6 x 10^–8 mol-dm^–3 (pK=7.2±0.5) calculated by applying the Onsager-Kim law of electrolyte mixtures.     

十六烷基三甲基氯化铵在β-环糊精水溶液中的胶束化行为

通过测定十六烷基三甲基氯化铵（CTAC）+H_2O和CTAC+β-环糊精（β-CD） +H_2O体系在298.15K时的电导和密度，计算了一系列重要的热力学参数，如临界胶 束浓度、胶束离解主工、CTAC分子碳链从β-环糊精水溶液到胶束的转移自由能、 CTAC的标准偏摩尔体积以及CTAC和β-CD形成的包络物的计量比和包络常数等，结 果表明，β-CD对CTAC的胶束化有较显蓍的影响，由于CTAC的疏水碳链被β-CD空腔 包络，CTAC的热力学活度降低，削弱了其胶束的生成，但是，β-CD及其包络物基 本上不参与CTAC胶束的生成，而且一旦胶束形成，包络物对CTAC的胶束性质也没有 明显的影响，在简单模型的基础上不参与CTAC胶束的生成，而且一旦胶束形成，包 络对CTAC的胶束性质也没有明显的影响，在简单模型的基础上，计算了CTAC分子碳 链进入β-CD疏水空腔的CH_2基团的数目，从另一方面证明β-CD与CTAC分子形成了 包络物，当β-CD的浓度较高时，包络物的计量比为2∶1。     

芳胺氮芥衍生物的合成与生理活性研究

以芳香氮芥N,N-二(2-氯乙基)-1,4-苯二胺为药效基团,4位取代的苯胺和α-萘胺为载体,通过尿素的连接方式,合成了5个芳胺类氮芥衍生物,所有化合物的结构经元素分析、1HNMR、13CNMR和MS测试确证。对K562(白血病细胞),B16(黑色素瘤)和CHO(中国仓鼠卵巢癌细胞)三种细胞模型进行了体外抗肿瘤活性测试,结果表明部分化合物的活性较N,N-二(2-氯乙基)-1,4-苯二胺有明显提高,其中化合物5e在一定的浓度范围内与商品药物美法仑相当。     

Phase equilibria in the binary mixtures formed by ethylbenzene with some aliphatic alcohols at 95.8 kPa

Phase equilibria are determined over the entire composition range, through measurements on the bubble points of the binary mixtures of ethylbenzene with methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and tert-butanol. A Swietoslawski-type ebulliometer is used for the measurements. The liquid phase composition versus temperature measurements, found to be well represented by the Wilson model, are used to establish the phase equilibria.