NON-IONIC-CATIONIC MICELLAR PROPERTIES OF DIMETHYLDODECYLAMINE OXIDE
NON-IONIC-CATIONIC MICELLAR PROPERTIES OF DIMETHYLDODECYLAMINE OXIDE
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DOI：
10.1021/j100808a025
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发表时间：
1962-01-01
影响因子：
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通讯作者：
HERRMANN, KW
中科院分区：
文献类型：
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作者：
HERRMANN, KW
胶束性质的表面活性剂显示在水溶液中的非离子和阳离子的字符，取决于pH值，使用光散射法测定。的临界胶束浓度，胶束分子量和相互作用系数的中性和带正电的表面活性剂物种在水中和0.2 M NaCl中所示的差异被注意到和讨论。虽然胶束的结果是一致的，每个单独的物种，阳离子和非离子改性的性质的直接比较显示出一些不一致的胶束形成时，考虑到目前的概念。此外，胶束性质的变化已被确定为非离子表面活性剂（二甲基烷基胺氧化物）链长的函数和作为C12同系物的温度的函数。这些结果被用来计算胶束形成的热力学量。在解释离子表面活性剂溶液的光散射数据方面的许多争议是由于胶束所携带的电荷。自从德拜首次指出，胶束的信息可以通过应用光散射方法获得洗涤剂溶液，2在文献中报道的大多数工作都涉及阴离子和阳离子洗涤剂体系的胶束性质。[3]人们曾试图通过使用非离子表面活性剂分子来避免电相互作用;然而，这些物质是具有大极性头的聚合物缩合物，虽然是分馏的，但可能由链长分布组成。4-6如果要进一步发展胶束溶液理论，就必须研究表征良好的非离子表面活性剂。本文研究了一种纯物质的胶束分子量和临界胶束浓度，它可以以非离子和阳离子两种形式存在，这取决于溶液的pH值。这两种形式是：二甲基十二烷基胺氧化物（DDAO），C12 H26 N（CH 8）2· 0和二甲基-十二烷基-N-羟基氯化铵（DDHAC），[C12 H26 N（CH 3）2 OH] Cl。它们之间的关系是
The micellar properties of a surfactant showing both non-ionic and cationic character in aqueous solution, depending on pH, were determined using light scattering methods. Differences in the critical micelle concentrations, micelle molecular weights and interaction coefficients shown by the neutraland positively charged surfactant species in water and in 0.2 M NaCl are noted and discussed. Although the micellar results are consistent for each individual species, a direct comparison of the properties of the cationic and non-ionic modifications shows some inconsistencies when current concepts of micelle formation are considered. In addition, changes in micellar properties have been determined as a function of non-ionic sur-factant (dimethylalkylamine oxide) chain length and as a function of temperature for the C12 homolog. These results were used tocalculate thermodynamic quantities for micelle formation.Much of the controversy over the interpretation of light scattering data obtained on solutions of ionic surface active agents is due to the electrical charge carried by the micelles. Since Debye first showed that micellar information can be obtained by applying light scatteringmethods to detergent solutions, 2 most of the work reported in the literature has dealt with the micellar properties of anionic and cationic detergent systems. 3 Attempts have been made toavoid electrical interactions by using non-ionic surfactant molecules; however, these substances have been polymeric condensates with large polar heads which, although fractionated, may consist of a distribution of chain lengths. 4-6 It is desirable that well characterized, non-ionic sur-factants be investigated if the theory of micellar solutions is to be developed further. The present work deals with the micellar molec-ular weights and critical micelle concentrations of a pure species which can exist in bothnon-ionic and cationic form depending upon the pH of the solu-tion. These two forms are: dimethyldodecylamine oxide (DDAO), Ci2H26N (CH8) 2-»· 0 and dimethyl-dodecyl-N-hydroxyammonium chloride (DDHAC),[C12H26N (CH3) 2OH] Cl. They are related by the equilibrium