Sphere to rod transitions in homologous alkylpyridinium salts: A Stauff-Klevens-type equation for the second critical micelle concentration

Explaining the growth behavior of surfactant micelles

“…It is seen that both surfactants display a conspicuous abrupt increase in aggregation numbers when going from a region of weakly growing micelles to a region of strongly growing micelles. This particular behavior appears to be typical for a large number of micellar systems and the concentration above which micelles begin to grow more strongly in size has traditionally been denoted the second cmc [14][15][16]19,20]. The micelles reach a highest measured aggregation number equal to N = 390 (12, 6-Br).…”

“…In accordance, both surfactants were observed to grow weakly at low surfactant concentrations followed by a much stronger growth behavior beyond a certain surfactant concentration. Such a more or less abrupt increase in the extent of growth has been observed for several surfactant systems and the surfactant concentration where the aggregation numbers start to grow rapidly is often referred to as the second cmc [14][15][16][17][18][19][20][21].…”

Micellar properties of surface active ionic liquids: A comparison of 1-hexadecyl-3-methylimidazolium chloride with structurally related cationic surfactants

“…Although the micellar properties of C 16 PyCl have been studied by several authors [9][10][11][12][13][14][15][16][17][18][19][20][21], none has covered the temperature range employed in the present study (15-75°C). More importantly, however, there are problems associated with the calculation of the degree of counter-ion dissociation, a mic ; the enthalpy of micellization, DH mic , or both, vide infra and The concentration of water in the interfacial regions has been calculated by employing an anionic solvatochromic indicator, 1-methylquinolinium-8-olate-5-sulfonate, QBS, Chart 2; the values were found to be 42.2 ± 2 and 38.5 ± 2 mol L À1 , depending on the binary solvent mixture that is used as a reference for interfacial water.…”

Aphrons Obtained From Different Nonionic Surfactants: Properties and Filtration Loss Evaluation

“…The ionic surfactants contribute to stability due to electrostatic interactions and surface forces, once charge repulsion between the ionic groups retards bubbles coalescence. Nonionic surfactants stabilize aphrons by a steric effect [12][13].…”

“…This mass transfer induced by a surface tension gradient is known as Marangoni effect [2]. The viscous water phase also entraps gas molecules in the core [13]. Different types of viscosifier have been used, such as the partially hydrolyzed polyacrylamide (PHPA) [14], bentonite [27], styrene-ethylene copolymers [28], some polysaccharides like starch and potassium alginate, but guar gum and xanthan gum are the mostly used ones [15,17].…”