EFFECT OF ADDED SODIUM AND LITHIUM CHLORIDES ON INTERMICELLAR INTERACTIONS AND MICELLAR SIZE OF AQUEOUS DODECYL-SULFATE AGGREGATES AS DETERMINED BY SMALL-ANGLE NEUTRON-SCATTERING
EFFECT OF ADDED SODIUM AND LITHIUM CHLORIDES ON INTERMICELLAR INTERACTIONS AND MICELLAR SIZE OF AQUEOUS DODECYL-SULFATE AGGREGATES AS DETERMINED BY SMALL-ANGLE NEUTRON-SCATTERING
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DOI：
10.1021/la00084a005
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发表时间：
1988-11-01
期刊：
影响因子：
3.9
通讯作者：
JONES, RRM
中科院分区：
文献类型：
--
作者：
BERR, SS;JONES, RRM
用小角中子散射(SANS)研究了添加电解质对离子胶束尺寸和粒子间相互作用的影响。表面活性剂锂和十二烷基硫酸钠(LDS和十二烷基硫酸钠)保持在固定浓度(0.05M)，而它们各自的氯化物浓度(LiCl和氯化钠)增加。随着添加盐浓度的增加，胶束间的库仑排斥力降低到吸引力(可能是范德华力)可能占主导地位的程度。此外，添加的电解质似乎屏蔽了胶束内的头基团排斥，允许胶束以增加的聚集数的形式增长，发现钠在屏蔽电荷时比锂有效得多。当[NaC l]从0.0增加到0.6时，十二烷基硫酸钠胶束的N从54增加到928，接触电势从16下降到-221kJ/mol。当[LiCl]从0.0M增加到0.8M时，LDS的N从53增加到91，接触电势从14下降到-2.5kJ/mol。
The effect of added electrolyte on ionic micelle size and interparticle interactions has been studied by small-angle neutron scattering (SANS). The surfactants, lithium and sodium dodecyl sulfate (LDS and SDS), were kept at a fixed concentration (0.05 M), while their respective chloride concentrations (LiCl and NaCl) were increased. As the concentration of added salt was raised, intermicellar Coulombic repulsions decreased tothe point where attractive (possibly van der Waals) forces could dominate. Furthermore, the added electrolyte appeared to screen intramicellar head-group repulsions, allowing the micelles to grow in terms of an increased aggregation number, N. Sodium was found to be much more effective than lithium at screening charge. N for SDS micelles increased from 54 to 928, and the contact potential decreased from 16 to-221 kJ/mol when [NaCl] was increased from 0.0 to 0.6. N for LDS, on the other hand, went from 53 to 91, and the contact potential decreased from 14 to-2.5 kJ/mol as [LiCl] was increased from 0.0 to 0.8 M.