SDS/正戊醇/水体系的液晶研究

在 2 5℃测定了十二烷基硫酸钠 (SDS) /正戊醇 /水三元体系的相平衡 ,确定了液晶区域的边界范围。在液晶区域内选取一系列样品点 ,用差示扫描量热法 (DSC)和2 HNMR与液晶照片对照 ,研究了该体系的液晶结构特点。结果表明 :在恒定温度下 ,该体系存在着两个液晶区域 ,并且随含水量的增加 ,液晶结构发生变化。当组成固定时 ,体系的液晶相结构随温度升高也发生变化     

丙烯酸酯与甲基丙烯酸酯的共聚及性能研究

采用悬浮聚合法，以丙烯酸－２－乙基－己酯与甲基丙烯酸十二酯为单体，合成了共聚型高吸油性树脂。研究了共聚单体的配比、交联剂用量、引发剂用量诸因素对高吸油性树脂的性能影响。制得的树脂可以吸其自身质量的１１．８倍的煤油、１４．７倍的苯、６．５倍的泵油。     

合成十二烷基葡萄糖苷的工艺条件

采用对甲苯磺酸为催化剂 ,以D 葡萄糖和正十二醇为原料直接合成十二烷基糖苷 ,研究了工艺条件对反应速率、产物收率与色泽的影响。结果表明 ,催化剂用量对产物色泽无影响 ,适宜的工艺条件为 :正十二醇 /D 葡萄糖 (摩尔比 ) =4∶1,反应温度 110～ 12 0℃ ,反应时间 4h ,反应压力 4kPa ,搅拌速率大于 840r/min ,对甲苯磺酸 /D 葡萄糖 (摩尔比 ) =1.5 %,MgO为较好的中和剂。产物为乳白色 ,十二烷基糖苷总收率大于89%。     

Solubilization of unilamellar liposomes by betaine-type zwitterionic/anionic surfactant systems

The mechanisms governing the solubilizing interactions between zwitterionic/anionic mixed surfactant systems at different molar fractions of the zwitterionic surfactant (X_zwitter) and neutral or electrically charged unilamellar liposomes were investigated. The mixed systems were formed by N-dodecyl-N,N-dimethylbetaine and sodium dodecyl sulfate in the presence of piperazine-1,4-bis-(2-ethanesulfonic acid) buffer at pH 7.20. Unilamellar liposomes formed by egg phosphatidylcholine, in some cases together with stearylamine or phosphatidic acid, were used. Solubilization was detected as a decrease in static light-scattering of liposomes. Two parameters were regarded as corresponding to the effective surfactant/lipid molar ratios (Re) at which the surfactant system (i) saturated the liposomes, Re_sat, and (ii) led to a total solubilization of liposomes, Re_sol. From these parameters the bilayer/aqueous medium surfactant partition coefficients for the saturation (K_sat) and complete bilayer solubilization (K_sol) were determined. When X_zwitter was 0.40, The Re and K parameters showed a maximum, whereas the critical micellar concentration (CMC) of these systems exhibited a minimum, regardless of the electrical charge of bilayers. Given that the ability of the surfactant systems to saturate or solubilize liposomes is inversely related to the Re_sat and Re_sol parameters, these capacities appear to be directly correlated with the CMC of the mixed systems. The similarity of both K_sat and K_sol (particularly for X_zwitter=0.2–0.8) suggests that a similar partition equilibrium governs both the saturation and the complete solubilization of bilayers, the free surfactant concentration (S_a,S_b), remaining almost constant with similar values to the CMC for each mixed system studied.     

碘与淀粉的相互作用及在Vc分析中的应用

本文探讨了碘与淀粉的相互作用以及碘－淀粉显色体系的稳定性。结果表明：在碘量一定时，体系的吸光度随淀粉用量的增大而增大，最后趋向稳定；在淀粉量一定时，体系的吸光度随碘用量的增大而增大，最后亦趋向稳定。碘－淀粉显色体系很不稳定，吸光度随时间呈比较明显的下降趋势，但加入复合表面活性剂可以使显色体系的稳定性大大提高。在上述结果的基础上，我们建立了测定Ｖｃ的新方法，此法具有简单、快捷、试剂易得、灵敏度高以及对浑浊试液不必分离即可直接测定等优点。该法的灵敏度为０．２５μｇ／ｍｌ，对１μｇ／ｍｌ的Ｖｃ试液进行平行测定，１０次平行测定结果的相对标准偏差为８．８６％，加标回收率为９０．５％－９３．６％，用于番石榴汁饮料中Ｖｃ的测定，结果满意。     

液相化学还原法制备不同形貌的多晶纳米镍

采用液相化学还原法,在1,2-丙二醇体系中,分别使用吐温-80（Tween-80）、聚乙二醇-6000（PEG-6000）和十二烷基硫酸钠（SDS）与聚乙二醇-6000（PEG-6000）的混合物作为修饰剂,利用1,2-丙二醇还原相同母体醋酸镍,制备形貌分别为海绵体、纤维状、雪花状的多晶纳米镍;在水体系中,使用SDS为修饰剂,利用水合肼还原相同母体醋酸镍,制备球形多晶纳米镍。通过X射线衍射（XRD）、透射电子显微镜（TEM）、选区电子衍射（SAED）对纳米镍进行表征。利用傅立叶红外（FTIR）分析初步解释不同形貌纳米镍的形成机理。     

Cationic surfactant-selective potentiometric sensors based on neutral ion-pair carrier complexes

Poly(vinyl chloride) (PVC) membrane electrodes to determine monomer concentrations of tetradecyltrimethylammonium ion (TTA⁺) and hexadecylpyridinium ion (HPy⁺) based on neutral ion-pair carrier complexes of tetradecyltrimethylammonium dodecyl sulfate (TTA⁺-DS⁻) and hexadecylpyridinium dodecyl sulfate (HPy⁺-DS⁻), respectively, are reported here. The electrodes exhibit a Nernstian slope of 59 mV per decade for TTA⁺ and a sub-Nernstian slope of 34.5 mV per decade for HPy⁺ ions. The TTA⁺ ion-selective electrode (ISE) and the HPy⁺-ISE can determine the monomer units down to concentrations as low as 4.0×10⁻⁴M and 1.66×10⁻⁵ M, respectively. The effect of various additives, such as the anionic polyelectrolyte sodium dextran sulfate and macrocyclic β-cyclodextrin, on the surface activity exhibited by the cationic surfactants TTA⁺-DS⁻ and HPy⁺-DS⁻, in the presence of background concentrations of NaCl was also examined with surfactant-selective sensors. The Gibbs free energy of micelle formation (ΔG _m ) of both surfactants in the presence of various additives was calculated and found to be less favorable with respect to an increase in the amount of additives due to less availability of cationic surfactant monomer units. The ion-pair complexes TTA⁺-DS⁻ and HPy⁺-DS⁻ were found to behave as selective carrier compounds in PVC membranes in determining the concentration of monomer units of both TTA⁺ and HPy⁺, respectively. The proposed sensors worked well at a fairly acidic pH of 1–6.5 with response time of 60 s. The sensors responded well to the surfactant ions even in the presence of additives at lower concentration. The lifetime of the sensors is 3 mon.     

过渡金属的液晶基元配合物纳米胶束的自组装

以异烟酸和溴代十二烷为原料合成液晶基元异烟酸十二烷基酯,在水和无水乙醇混合反应体系中,室温下分别与Pd(Ⅱ)、Cu(Ⅱ)和Ni(Ⅱ)过渡金属按4∶1的摩尔比混合反应,通过自组装形成配合物。透射电镜形态观测表明,配合物之间借助超分子力和配体的液晶性协同作用构建成25～40nm左右的棒状形态的纳米胶束。并利用红外光谱,紫外可见吸收光谱,荧光光谱等手段对其结构和性质进行了表征。     

The partition coefficients of ethylene between hydrate and vapor for methane + ethylene + water and methane + ethylene + SDS + water systems

The hydrate formation of CH₄+C₂H₄ mixture was studied experimentally in two different cases, with and without the presence of sodium dodecyl sulfate (SDS) in water. The results manifested that the presence of SDS could not only accelerate the hydrate formation process, but also increase the partition coefficient of ethylene between hydrate and vapor drastically. The partition coefficients of ethylene between hydrate and vapor for methane + ethylene + water with the presence of 500 ppm SDS in water were then systematically measured. The experimental temperature ranged from 273.15 to 278.15 K, the pressure ranged from 2.5 to 5.5 MPa, the initial gas-liquid volume ratio ranged from 95 to 240 standard volumes of gas per volume of liquid, and the mole percentage of ethylene in feed gas mixture ranged from 5.28% to 79.36%. The results demonstrated that ethylene could be enriched in hydrate phase and partition coefficients were increased with the presence of SDS in water. This conclusion is of industrial significance; it implies that it is feasible to recover ethylene from gas mixture, e.g., various kinds of refinery gases or cracking gases in ethylene plant, by forming hydrate.     

SDBS的表面张力对天然气水合物生成的影响

利用德国KRUSS公司生产的界面张力仪K11中的板法测定十二烷基苯磺酸钠在不同温度(5,10,20,30,35℃)和不同浓度下(100,400,800,1200,1600,2000 mg/L)的表面张力,确定有利于天然气水合物合成的最佳浓度为1 200 mg/L,这在工业应用中有着重要的参考价值,同时分析了表面活性剂加速天然气水合物生成的机理。