Discrepancies over the onset of surfactant monomer aggregation interpreted by fluorescence, conductivity and surface tension methods

Química Nova

Maria De Fátima Carvalho Costa¹  Sandro José Froehner¹  Ângelo Adolfo Ruzza¹  Sônia De Fátima Santos¹  Dino Zanette¹ 

[1] ,Universidade Federal de Santa Catarina Departamento de Química Florianópolis SC

关键词: 1-butanol/sodium dodecylsulfate mixtures;    critical aggregation concentration;    polymer-surfactant interactions;    ketal hydrolyses;   

DOI  :  10.1590/S0100-40421998000300007

来源: SciELO

【 摘 要 】

Molecular probe techniques have made important contributions to the determination of microstructure of surfactant assemblies such as size, stability, micropolarity and conformation. Conductivity and surface tension were used to determine the critical aggregation concentration (cac) of polymer-surfactant complexes and the critical micellar concentration (cmc) of aqueous micellar aggregates. The results are compared with those of fluorescent techniques. Several surfactant systems were examined, 1-butanol-sodium dodecylsulfate (SDS) mixtures, solutions containing poly(ethylene oxide)-SDS, poly(vinylpyrrolidone)-SDS and poly(acrylic acid)-alkyltrimethylammonium bromide complexes. We found differences between the cac and cmc values obtained by conductivity or surface tension and those obtained by techniques which use hydrophobic probe.

【 授权许可】

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