Self-organization and properties of dilute aqueous solutions of cetyltrimethylammonium bromide in a range of physiologically important temperatures

• Published in: Russian chemical bulletin 2015-03, Vol.64 (3), p.579-589
• Main Authors: Ryzhkina, I. S., Kiseleva, Yu. V., Mishina, O. A., Murtazina, L. I., Litvinov, A. I., Kadirov, M. K., Konovalov, A. I.
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Full Articles; Inorganic Chemistry; Organic Chemistry
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-015-0903-9

A combination of physicochemical methods (dynamic light scattering, nanoparticle tracking analysis, conductometry, tensiometry, and ESR spectroscopy) revealed that dilute solutions (1•10 –3 , 1.0•10 –4 , 1.0•10 –7 , and 1.0•10 –9 mol L –1 ) of surfactant (cetyltrimethylammonium bromide) in a temperature range of 25—45 °C are self-organized dispersed systems. As the temperature increases, the systems undergo rearrangements specific for each studied concentration, which is reflected as nonmonotonic temperature dependences of the parameters of domains (1•10 –3 and 1.0•10 –4 mol L –1 ) and nanoassociates (1.0•10 –7 and 1.0•10 –9 mol L –1 ) and also as interrelated dependences of the conductivity of solutions with extremes at 30, 37, and 40 °C. The ESR experiments show a nonmonotonic decrease in the rotational diffusion correlation time (τ cor ) of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) in the temperature dependences of τ cor with the temperature increase from 25 to 45 °C and the appearance of two to three plateaus, one of which (in a range of 36—40 °C) is observed in the temperature dependences for all studied concentrations.