微量热法研究非离子型表面活性剂微乳液

用微量热法研究了由正十六烷／正己醇／水／烷基聚氧乙烯醚组成的微乳液中水的状态，对微乳液中水的模式对热效应的影响进行了解释。在微乳液具有异常流变性的水油比范围内，测定了体系在负触变性状态恢复期间的热效应。     

用石英晶体微天平研究表面活性剂在银固态表面上的动态吸附

吸附是表面活性剂的一个重要特征.迄今用于原位监测表面活性剂在固体表面上吸附重量变化的方法尚不多见.近年来压电石英晶体作为一种高灵敏的质量传感器(石英晶体微天平)已被用于大气和溶液中多种微量成分的监测.用石英晶体微天平研究I~-、Br~-和表面活性剂在金电极上的吸附行为亦有报道.本文研究了十六烷基三甲基溴化铵(CTAB)、十二烷基磺酸钠(SDSO)、十二烷基硫酸钠(SDS)在银固态表面上的吸附平衡动力学特性及其吸附机制.     

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%。     

C12-m-C12型阳离子Gemini表面活性剂在煤沥青表面的润湿性

利用座滴法和电泳法研究了阳离子Gemini表面活性剂C₁₂-m-C₁₂·2Br^-(m=4、6、8、10)在煤沥青表面的润湿性质及吸附机理。结果表明, 表面张力均随表面活性剂浓度的增大而减小, 超过临界胶束浓度(CMC)后趋于平稳, 接触角θ和铺展系数S的变化趋势与表面张力类似; 在所研究浓度范围内,C₁₂-10-C₁₂型表面活性剂的γ_lg~cosθ曲线符合Zisman理论, 且侵湿功(W_i)与表面张力也呈线性关系; 煤沥青表面的Zeta电位随表面活性剂浓度的增加从负电变为正电,最后趋于平稳, 且零电位对应的浓度比CMC至少低一个数量级; C₁₂-8-C₁₂型Gemini表面活性剂能显著改变煤沥青表面的润湿性. 由Gemini表面活性剂在煤沥青表面润湿结果及Zeta电位可以看出, C₁₂-m-C₁₂型Gemini表面活性剂在煤沥青表面的润湿是静电作用和范德华吸附共同作用的结果; 润湿过程可分为三个阶段。     

含氟表面活性剂溶液的动态表面张力研究

本文研究了阳离子氟表面活性剂CF₃CF₂CF₂O(CF(CF₃)CF₂O)₂CF(CF₃)CONH(CH₂)₃N⁺(C₂H₅)₂CH₃I^-(简写FC-4 )的动态表面性质，利用Krüss K12和MBP动态表面张力仪分别测定了该体系的平衡表面张力和动态表面张力。由平衡表面张力测定结果得到了临界胶束浓度和表面吸附量。利用渐进的Ward and Tordai方程对动态数据进行了分析。结果表明：在吸附的最初阶段符合扩散控制模型，而在吸附的后期，证明了吸附势垒的存在，表明在吸附后期属于混合动力学模型。计算得出25 ℃时，该体系势垒约在25到35 kJ/mol. 由于氟表面活性剂分子间作用力小，表面压是导致吸附势垒的主要原因。     

氧杂氟表面活性剂及其与同电性碳氢表面活性剂混合溶液的表面吸附和胶团形成

研究了四种氧杂氟表面活性剂及其与同电性直链碳氢表面活性剂混合体系的表面活性;考察了混合体系中的表面吸附和胶团形成现象.在吸附层中分子间有明显的互疏作用,在溶液中倾向于各自形成胶团.还讨论了反离子结合度不同对理想混合胶团的组成及cmc的计算的影响,提出了一般的计算式.实验测得这些氧杂氟表面活性剂有较低的胶团反离子结合度.     

膨胀石墨对非离子表面活性剂的吸附研究

以膨胀石墨为吸附剂,研究它对非离子表面活性剂的吸附情况。主要探讨了非离子表面活性剂的浓度、吸附时间、吸附温度、膨胀石墨粒度及不同浓度的NaCl溶液对吸附行为的影响,结果表明,在适宜条件下,膨胀石墨对壬基酚聚氧乙烯醚非离子表面活性剂的吸附速率较快;最大吸附量约为259．50μg／g,在非离子表面活性剂处理方面显示出良好的吸附性能。     

新型表面活性剂研究进展--Bola型表面活性剂与Gemini型表面活性剂

对两类新型表面活性剂--Bola型表面活性剂和Gemini型表面活性剂,从结构特点、研究历史、水中的溶解性与Krafft点、表面活性与表面吸附、临界胶团浓度、水中的聚集体类型与转化、研究前景等方面进行综述.     

高效毛细管电泳电导检测对阴离子表面活性剂分离测定的研究

以Ca2 +为分离介质 ,甲酰胺为添加剂 ,通过对缓冲体系、缓冲液浓度、酸度、Ca2 +浓度、甲酰胺浓度、电泳电压和进样时间的优化选择 ,用毛细管电泳 -电导检测法分离了十二烷基硫酸钠(K12)和十二烷基苯磺酸钠(LAS) ;在10mmol/LTris -11mmol/LCit(pH4.5)运行缓冲液中 ,上述两组分在16min内完全分离 ;K12和LAS的线性范围分别为5.0×10-6～8.0×10-3 mol/L和5.0×10-6 ～5.0×10-3 mol/L ;检出限(S/N=3)分别为2.5×10-6 和3.0×10-6 mol/L,应用于合成洗衣粉样和合成水样中K12 和LAS测定 ,结果令人满意。     

光照对含氟表面活性剂表面性质的影响

以对三氟甲基苯胺为起始原料,制备了一种部分氟化的表面活性剂CF-S,测定其紫外吸收光谱,研究其光异构化。测定CF-S溶液的表面张力,计算相应的物化参数,并与不含氟的表面活性剂CH-S的性能进行比较,结果发现,CF-S的表面活性明显强于CH-S的表面活性。在紫外光激发后,CF-S的cmc和γ_(cmc)增大,Г_(max)减小,A_(min)变大。CF-S对石英的润湿性能测试显示,含氟的表面活性剂能提高石英表面的疏水性。紫外光的照射使CF-S在石英表面的接触角降低,CF-S润湿性能增强。测定了石英在CF-S溶液中的动电位,加入CF-S后,石英表面的动电位增加。在紫外光照射后,石英的动电位降低,部分CF-S从石英表面脱附。     

An FTIR study of the adsorption of surfactants on silica

The absorption of cetyltrimethyl ammonium bromide onto silica was studied by FTIR as an example of the interaction of cationic surfactants with surfaces of medium polarity. It was found that the free silanol groups of the silica interacted strongly with the surfactant and that the methylene group adsorption bands varied with coverage in both frequency and width. These results could be interpreted in terms of chemisorption of a first layer of surfactant followed by physisorption of subsequent layers, or in terms of the inhomogeneity of the silica surface.     

Properties of complexes and particles of gelatin with ionic surfactants

 The properties of soluble gelatinionic surfactant complexes and insoluble particles were evaluated. It was found that colloidal particles of gelatin A – cationic surfactant (dodecyltrimethyl-ammonium bromide, DTAB, and cetyltrimethylammonium bromide, CTAB) were formed. Binding isotherms showed that these particles are obtained above the CMC of each surfactant, while cooperative binding takes place. Surface tension measurements conducted for both gelatin/DTAB and gelatin/anionic surfactant, SDS (sodium dodecyl sulfate) showed a break in the curve describing surface tension vs number of bound surfactant molecules, (ν) at concentrations below the CMC of each surfactant alone. This break, which is attributed to CMC 1, is observed at the same number of bound surfactant mol ecules ν∼2 for both gelatin/surfactant couples. Contact angle measurements showed that the maximal hydro-phobicity of the gelatin-surfactant particles is obtained at the same concentration range in which the precipitation occurs. It was also found that the hydrophobicity of gelatin-SDS particles, is higher than that of the gelatin-cationic surfactants, due to a different composition of the resulting particles. The zeta potential of the particles indicated charge neutralization and even charge reversal for gelatin-CTAB at high surfactant concentration. Received: 4 April 1997 Accepted: 15 December 1997     

利用吉布斯吸附等温式探索求解电解质溶液活度的新方法

以吉布斯吸附等温式积分式为基础,数学推证表面势的表达式,并应用表面势的数学表达式探求了一种测算电解质溶液活度系数的新方法.选取KIM计算电解质溶液溶质的活度系数公式为新方法的活度系数经验关系式的具体表达形式,利用实验直接测得的不同浓度下的表面张力数据,采用最优化拟合的方法,求算出活度系数经验关系式中的待定系数,从而可以求得不同浓度下的电解质溶液中的溶质的活度系数和活度.计算结果与KIM文献值对比,活度系数曲线在不同的坐标尺度下有很好的一致性,这使得通过测定电解质溶液表面张力测算其活度成为可能.     

Rheological properties of the aqueous solution for fluorocarbon‐containing hydrophobically modified sodium polyacrylic acid with various surfactants

The interaction of fluorocarbon‐ containing hydrophobically modified sodium polyacrylic acid (FMPAANa) (0.5 wt%) with various surfactants (anionic, nonionic and cationic) has been investigated by rheological measurements. Different rheological behaviors are displayed for ionic surfactants and nonionic surfactants. Fluorinated surfactants have stronger affinity with polyelectrolyte hydrophobes comparing with hydrogenated surfactants. The hydrophobic association of FMPAANa with a cationic surfactant (CTAB) and a fluorinated nonionic surfactant (FC171) is much stronger than with a nonionic surfactant (NP7. 5) and an anionic surfactant (FC143). Further investigation of the effects of temperature on solution properties shows that the dissociation energy E_m is correlated to the strength of the aggregated junctions.     

KBPh4由水到系列水-醇混合溶剂的迁移自由能

由于四苯硼盐在分析化学、生物学、电化学等各领域中的广泛用途及其大阴离子在研究与计算单个离子迁移热力学函数中所具有的特殊作用,人们对四苯硼盐的溶液热力学性质进行了广泛研究,特别是对四苯硼钠和可作为参考电解质的四苯硼盐进行了深入细致的研究 [1, 2],得到了一些重要的的结论,为溶液理论的研究提供了有力的实验基础 .但是文献中对难溶碱金属四苯硼盐由单一到不同混合溶剂中的迁移热力学性质的系统研究较少 .在前文 [3]对 KBPh4由水到水-异丙醇和由甲醇到甲醇-异丙醇混合溶剂的迁移自由能进行研究的基础上,我们系统地对 KB…     

Determination of surfactants and levoglucosan from selected vegetation by spectroscopic colorimetric method

Vegetation is one of the natural sources which contribute to the amount of surface active agent into the environment. It is believed that surfactants can be derived from various kinds of sources such as biomass burning or soil and these excessive level of surfactants emitted into the atmosphere can influence both cloud formation and climate. The objective of this study was to determine the concentration of both anionic and cationic surfactants as well as levoglucosan from vegetation and soot and at different weather conditions around the tin mine lakes environment. The samples were prepared by cutting several parts of tropical plant species, namely Cinnamomum Iners, Gliricidia Sepium and Hopea Odorata, which were mainly leaves and stems. After that, samples were allowed to dry in an oven at a temperature of 40°C for 2 h. The concentrations of levoglucosan and surfactant such as methylene blue active substance (MBAS) and disulphine blue active substance (DBAS) were analysed through the colorimetric method. The results showed that higher concentrations for both anionic and cationic surfactants were found in C. Iners leaves which give the concentrations of 86.92 ± 38.99 and 22.33 ± 10.59 µg/g. It was noted that the concentrations of anionic and cationic surfactants in this research were correlated to each other, indicating the possibility of similar sources that affect both levels of surfactants in the vegetation. In addition, the highest level of levoglucosan was dominated by the leaves from G. Sepium species with the concentration of 25.62 ± 12.65 mg/g, respectively. A positive significant correlation (r = 0.8447, 0.8355 and p = 0.0001 < 0.05) between anionic surfactants and levoglucosan was also discovered in this study.     

Membrane electrodes sensitive to doubly charged surfactants. Application to a cationic gemini surfactant

The response of a membrane electrode is not always identical to that of a redox electrode. Indeed, in the case of membrane electrode the response is not due to a redox equilibrium but to a cross-membrane potential. So, the membrane electrode's response depends mainly on the carrier system and the nature of the membrane. The properties of the membrane can favour several reactions giving rise to different ionic species diffusing in the membrane. The expression of the cross-membrane potential thus depends on the number and quantities of these ionic species. To illustrate this, we established the equations for the case of a two-charge cation detected by a univalent charged carrier. We show that the Nernstian response is not applicable to membrane electrodes. This approach allowed us to interpret results obtained with a cationic gemini surfactant-selective electrode prepared in the laboratory. To prove the well working of this electrode, we determined the critical micelle concentration in water and several NaBr solutions (0.004, 0.006, 0.01 and 0.02 M) from which the counterion binding has been determined.     

Thermodynamics of copper ion resolvation in water-isopropanol mixtures by the method of volta potential differences

From results of measuring the compensating voltages of an volta circuit by the Kenrick method at 298.15 K, real and chemical thermodynamic characteristics of copper ion resolvation in water-isopropanol mixtures are determined, as well as the surface potential at the nonaqueous-solvent/gas-phase boundary.     

Optimization of layered double hydroxide stability and adsorption capacity for anionic surfactants

Low cost adsorption technology offers high potential to clean up laundry rinsing water. From an earlier selection of adsorbents (Schouten et al. 2007), layered double hydroxide (LDH) proved to be an interesting material for the removal of anionic surfactant, linear alkyl benzene sulfonate (LAS) which is the main contaminant in rinsing water. The main research question was to identify the effect of process parameters of the LDH synthesis on the stability of the LDH structure and the adsorption capacity of LAS. LDH was synthesized with the co-precipitation method of Reichle (1986); a solution of M²⁺(NO₃)₂ and M³⁺(NO₃)₃ and a second solution of NaOH and Na₂CO₃ were pumped in a beaker and mixed. The precipitate that was formed was allowed to age and was subsequently washed, dried and calcined. The process parameters that were investigated are the concentration of the initial solutions, M²⁺/M³⁺ ratio and type of cations. The crystallinity can be improved by decreasing the concentration of the initial solutions; this also decreases the leaching of M³⁺ from the brucite-like structure into the water. The highest adsorption capacity is obtained for Mg²⁺/Al³⁺ with a ratio 1 and 2 because of the higher charge density compared to ratio 3. Storing the LDH samples in water resulted in a reduction of adsorption capacity and a decrease in surface area and pore volume. Therefore, LDH is not applicable in a small device for long term use in aqueous surroundings. The adsorption capacity can be maintained during storage in a dry N₂ atmosphere.     

Adsorption characteristics of surfactants and phenol on modified zeolites from their aqueous solutions

Adsorption characteristics of anion-, cation- and nonion-type surfactants and phenol from their aqueous solution on Na-Y zeolites modified by SiCl₄ treatment and NA-ZSM-5 zeolites with several Si/Al ratios were measured. Surfactants used were sodium dodecylbenzenesulfonte (DBS), laurylpyridinium chloride (LPC), polyoxyethylenenonylphenylether (POENPE) and phenol.Adsorption of surfactants was enhanced by SiCl₄ treatment of Na-Y, which indicates an important role of the hydrophilic-hydrophobic character in the adsorption.Adsorption isotherms were in general of Langmuir type and adsorbed amount depended on the Al/(Si+Al) or Si/Al ratio of zeolite frameworks. In case of DBS adsorption of Na-ZSM-5 series, adsorption occurred only on the outer surface due to steric hindrance. LPC adsorption abilities were observed on even hydrophilic zeolites and were ascribed to ion exchange effect. In case of phenol adsorption on hydrophobic Na-Y, the adsorption isotherm was of Type V according to BDDT classification.