表面活性剂对苯胺电聚合的影响

利用胶束在电极一有面的定向及增溶作用研究了表面活性剂对苯胺电聚合的影响，结果表明：在阴离子表面活性剂十二烷基硫酸钠（ＳＤＳ）胶束体系中，胶束介质能催化苯胺的电聚合反应，使其氧化电位负移，减少膜的降解，提高膜的稳定性，同时，也使得聚合速率增大，在０．１ｍｏｌ／Ｌ的ＳＤＳ的胶束溶液中，其聚合效率提高到不含ＳＤＳ的纯体系的２５倍，在含有１０＾－４ｍｏｌ／ＬＳＤＳ的硫酸溶液中，聚苯胺（ＰＡＮ）的成核生长为     

阳离子表面活性剂和有机酸混合水溶液的热响应特性

用稳态和动态流变学方法研究了阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和有机酸3-甲基水杨酸(3MS)的混合水溶液随浓度和温度变化的流变特性。在加热过程中混合溶液呈现三种不同类型的温度响应。其中最有趣的是,当3MS的浓度在80与100 mmol·kg^-1之间时,有浅蓝色的稀溶液出现。随着温度的升高,样品由浅蓝色溶液转化成透明的粘弹性溶液,同时聚集态从囊泡转变成长的蠕虫状胶束,且开始转化的温度随溶液中3MS浓度的增加而升高。利用流变温度扫描和电导率测定对此转变进行了验证。定性解释这个转化是因为在高温下吸附的3MS分子从囊泡上解吸被溶解到水相中。     

Influence of the hydrophobic tail of alkyl glucosides on their ability to solubilize stratum corneum lipid liposomes

The lytic interactions of a series of alkyl glucosides (alkyl chain lengths ranging from C₈ to C₁₂) with liposomes formed by a mixture of lipids modeling the stratum corneum (SC) lipid composition were investigated. The surfactant-to-lipid molar ratios (Re) and the normalized bilayer/aqueous phase partition coefficients (K) were determined by monitoring the changes in the static light-scattering (SLS) of the system during solubilization. The fact that the free surfactant concentrations were always similar to their critical micelle concentrations indicates that the liposome solubilization was mainly ruled by the formation of mixed micelles. At the two interaction levels studied (100 and 0% SLS) the nonyl glucoside showed the highest ability to saturate and to solubilize liposomes (lowest Re values), whereas the dodecyl glucoside showed the highest degree of partitioning into liposomes or affinity with these structures (highest K values). Comparison of the data for octyl glucoside with that reported for the interaction of this surfactant with phosphatidylcholine (PC) liposomes shows that whereas the SC lipid liposomes were more resistant to the action of this surfactant (higher Re values), its degree of partitioning into SC bilayers was both in the saturation and solubilization of liposomes similar to that exhibited in PC vesicles (similar K values). Received: 27 November 2000/Accepted: 19 February 2001     

表面活性剂对分散体系粘度影响的特殊性

通过液体石蜡的水基化分散对影响分散体系粘度的粒子大小、表面活性剂胶束和界面膜等因素进行了研究.结果表明,表面活性剂胶束对分散体系粘度的影响极为有限,而在分散相粒子界面上由表面活性剂分子所形成的界面膜是导致分散体系粘度产生变化的重要因素.实验数据表明,对于分散体系的稳定性,存在一个表面活性剂浓度变化的临界值,而该临界值所对应的是表面活性剂分子在粒子表面以最紧密和规整的方式形成的界面膜,该种界面膜使分散体系粘度达到最大值,从而最大限度地保证了分散体系的稳定性.     

Interactions between a skin penetration enhancer and the main components of human stratum corneum lipids

The study employed isothermal titration calorimetry (ITC) technique to investigate the interactions between a skin penetration enhancer, laurocapram, and three representatives of the human stratum corneum (SC) intercellular lipids, i.e., ceramide-3, cholesterol and behenic acid. Experiments were performed using a TAM2277 (Thermometric AB, Sweden) calorimeter. Results showed that, firstly, two laurocapram molecules were bound to one ceramide-3 molecule in propylene glycol solution. The binding was enthalpy-driven and system entropy decreased after binding. Secondly, the binding ratio between cholesterol and laurocapram molecule was one to one. It was mainly an entropy-driven process, suggesting the ordered cholesterol molecules in SC lamella were disturbed by the introduction of laurocapram. Hydrogen bonding might be the main force of the binding. The three different interaction modes showed that the chemical enhancers selectively interacted with the components of SC lipids so that the SC can still retain its barrier function.     

基于光纤折射率传感原理的表面活性剂临界胶束浓度测定方法

提出并研究了一种新颖的基于光纤折射率传感原理的表面活性剂临界胶束浓度(cmc)测定方法.应用此方法测定有代表性的阴离子表面活性剂十二烷基硫酸钠(SDS)与阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)在25℃下的cmc分别为8.05×10-3和9.11×10-4mol·L-1,与文献值比较,结果相当吻合.从而证实了本方法的准确性.进一步研究了各种条件对测量表面活性剂cmc的影响,结果表明温度和无机盐NaCl的加入对本方法测量的准确性影响小,证明了本方法对测试环境的要求不苛刻,适用性好.最后对本方法进行了重复性和稳定性测试,相对标准偏差(RSD)为0.17%,与预期符合,效果良好.     

Aggregation Number of Ionic Surfactants and its Application for Alkyltrimethyl Ammonium Bromides and Sodium Tetradecyl Sulfate by Potentiometric Technique

A potentiometric technique based on surfactant ion selective electrode has been used for various cationic and anionic surfactants. The data obtained contain m ₁ (surfactant monomer concentration); m ₂ (free counterion concentration) and α (degree of dissociation of micelle) were used for determination of aggregation number at and above cmc (critical micelle concentration). Data fitting show a relationship between aggregation number with such parameters. The correlation equation obtained shows that size of ionic micelle vary sharply after cmc. Also, the equation obtained shows size of micelle growth with increase in counterion concentration.     

胶束溶液中某些氨基酸和二肽的解离常数

用ｐＨ电位法测定了在ＳＤＳ（十二烷基磺酸钠）胶束溶液中甘氨酰丙氨酸和六种氨基酸（甘氨酸、丙氨酸、缬氨酸、亮氨酸、异亮氨酸、苯丙氨酸）的两级酸解离常数ｐＫａ１和ｐＫａ２,发现与水溶液相比,ｐＫａ值均显著增加,即ＳＤＳ胶束形成强烈抑制质子解离,结合＾１ＨＮＭＲ测定结果,讨论了ｐＫａ１和ｐＫａ２随ＳＤＳ浓度的变化规律以及与各配体自身结构的关系。     

胶束溶液中某些氨基酸和二肽的解离常数

用pH电位法测定了在SDS(十二烷基磺酸钠)胶束溶液中甘氨酰丙氨酸和六种氨基酸(甘氨酸、丙氨酸、缬氨酸、亮氨酸、异亮氨酸、苯丙氨酸)的两级酸解离常数 pKa1 和 pKa2,发现与水溶液相比 ,pKa 值均显著增加 ,即SDS胶束形成强烈抑制质子解离.结合1HNMR测定结果 ,讨论了pKa1和 pKa2 随SDS浓度的变化规律以及与各配体自身结构的关系     

表面活性剂和助表面活性剂对镍的缓蚀作用

在ＨＣｌ水溶液中,三种典型的表面活性剂（ＣＴＡＢ、ＳＤＳ和Ｔｒｉｔｏｎ Ｘ－１００）对镍均有缓蚀作用,其缓蚀效率、腐蚀活化能的大小顺序是：ＣＴＡＢ〉Ｔｒｉｔｏｎ ｘ－１００〉ＳＤＳ。助表面活性剂正丁醇可作为缓蚀调节剂,其加入可控制金属镍在ＨＣｌ水溶液中的腐蚀速率。金属镍在各介质中腐蚀速率的顺序为ＨＣｌ（ａｑ）〉知性剂＋丁醇＋ＨＣｌ（ａｑ）〉表面活性剂＋ＨＣｌ（ａｑ）〉表面活性剂＋丁醇（ａｑ）〉表面     

Supercritical fluid extraction of nylon 6: An investigation into the factors affecting the efficiency of extraction of caprolactam and its oligomers

Caprolactam and oligomers can be efficiently extracted from nylon 6 by use of supercritical fluid extraction with carbon dioxide containing 7.5 % (m/m) methanol as the extraction fluid. The application of a static extraction, using an additional amount of methanol, is necessary to obtain high extraction efficiencies.     

聚合物PVP与表面活性剂AOT相互作用的介观模拟

用耗散颗粒动力学模拟(DPD)方法研究了聚乙烯吡咯烷酮(PVP)与2-乙基己基琥珀酸酯磺酸钠(AOT)之间的相互作用.在三维模拟格子中,聚合物链均方末端距〈r²〉随着表面活性剂浓度的增加呈现一种首先减小,接着增加,然后又减小的趋势.构型和结构分析表明,AOT的加入能够引起聚合物链的二面角分布发生改变,这意味着AOT与PVP产生了相互作用.同时表面活性剂/聚合物体系的聚集形态也可以在DPD三维模拟格子中直观显现出来.     

DNA与表面活性剂的相互作用(Ⅰ)--基于相行为的宏观研究进展

综述了以相行为为基础的DNA与表面活性剂在水及有机溶剂中相互作用的研究进展及其相关研究方法.阐述了静电作用及疏水作用对相行为的影响.介绍了用光散射法及浊度法确定沉淀边界和用键合等温线及恒温滴定量热法考察DNA与表面活性剂相互作用的键合度及协同键合过程的能量变化,以及利用短链DNA与表面活性剂复合物在固体表面的吸附等温线来考察沉淀后复合物的构象变化.     

淀粉糖苷表面活性剂的吸湿保湿性能研究

以马铃薯淀粉为糖源,利用转糖苷法合成淀粉糖苷表面活性剂,用重量法测定其吸湿性和保湿性,并与甘油、山梨醇、聚乙二醇、木糖醇、烷基多苷进行比较。结果表明,在30℃,相对湿度43%和相对湿度81%环境条件下,制得的淀粉糖苷表面活性剂的保湿性优于对比试样,72h后保湿率均在70%以上;其吸湿性仅次于甘油,72h后吸湿率达到50%。     

Study on osmotic pressure of non-ionic and ionic surfactant solutions in the micellar and microemulsion regions

To investigate the osmotic pressure of non-ionic and ionic surfactant solutions in the micellar and microemulsion regions, a potential of mean force including hard-core repulsion, van der Waals attraction and electric double layer repulsion is proposed to describe the interactions between micelles and between microemulsions. Both van der Waals attraction and electric double layer repulsion are represented using Yukawa tails. The explicit analytical expression of osmotic pressure derived from the first-order mean spherical approximation is implemented by accounting for the Donnan membrane effect. The proposed theory has been applied to micelle solutions of the non-ionic surfactant, n-dodecyl hexaoxyethylene monoether, the cationic surfactant, cetylpyridinium chloride, the anionic surfactant, sodium dodecyl sulfate, and spherical oil-in-water microemulsion system. Successful comparison is made between the proposed theory and the experimental osmotic pressure data for the studied surfactant solutions. Theoretical results show that the long-range electric double layer repulsion dramatically influences the osmotic pressure of both cationic and anionic surfactant solutions in the micellar region. The regressed model parameters such as effective micelle diameter, the mean aggregation number and effective micellar charge are in good agreement with those from static light scattering studies in the literature.     

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。     

Surfactant addition effects on dispersion and microdomain orientation in SBS triblock copolymer/alumina nanoparticle composites

The aim of this study was to investigate the effects of surfactant addition on the dispersion of 1–3 wt.% alumina nanoparticles on the self-assembled morphology of poly(styrene-b-butadiene-b-styrene) (SBS) linear triblock copolymer. The neat triblock copolymer microphase separated into PS cylinders self-assembled on a hexagonal array in the PB matrix, being the orientation of domains dependent on the annealing conditions. UV–vis and AFM analyses showed an improvement on dispersion of Al₂O₃ nanoparticles into SBS matrix by adding dodecanethiol as organic surfactant, due to its miscibility with PS block. Interactions between surfactant-coated Al₂O₃ nanoparticles with PS block were demonstrated by the variation on the glass transition temperature of this block. AFM analysis showed that the incorporation of surfactant-coated Al₂O₃ nanoparticles in the SBS matrix have great influence on the orientation of microphase separated domains in SBS nanocomposites.     

SDS胶束对孔雀绿褪色反应的影响

研究了十二烷基硫酸钠（SDS）表而活性剂胶束和预胶束对孔雀绿褪色可逆反应的影响，建立了1－1型可逆反应的胶束催化模型和预胶束催化模型，获得了胶束相中正逆反应的速率常数和预胶束的平均聚集数．结果表明，SDS胶束和预胶束对正反应有禁阻作用，而对逆反应有催化作用．     

A novel copolymerizable surfactant and its application based on concentrated emulsion polymerization

A three-arm copolymerizable surfactant (surfmer) which possesses (1) a side chain terminated with a double bond and (2) a double bond in the hydrophobic moiety was synthesized. Because, one of the double bonds was located at the end of the side chain, the hydrophilicity of the surfmer was not affected in a major way by its copolymerization with the monomer. In addition, because of its three-arm structure, its self-polymerization was greatly inhibited, but not its capability for copolymerization. The surfmer was employed to prepare polystyrene particles of uniform size via the concentrated emulsion polymerization.