<abstract xmlns="http://www.w3.org/1999/xhtml"> The critical thickness (hcr) for foam films of n-dodecyl β-D maltoside (C12G2) and of its mixed solutions with dodecanol (C12Е0), hexaethyleneglycol dodecyl ether (C12E6) and dodecyl trimethylammonium bromide (C12TAB) of different molar ratio (50:1; 1:1;1:50) at low and high ionic strength was measured interferometrically. It was found that the hcr increases with the increase of the film radius independently of solutions composition. At low ionic strength the type of surfactant affects the critical thickness and the equilibrium state of the film. hcr for the films of mixture with C12E0 increases with the increase of the total surfactant concentration, while hcr for the films of mixture with C12TAB decreases. For the values of the critical thicknesses for films from individual surfactant solutions the following sequence hcr (C12TAB) > hcr (C12E6) > hcr (C12G2) is found. At high ionic strength the quantity of nonionic additive does not substantially affect the value of hcr, while the quantity of ionic additive influences it by two different ways (i) in 50:1 mixture C12TAB supports C12G2 in the reducing of negative charge; (ii) in 1:1 mixture C12TAB recharges the film surfaces. </abstract>

The critical thickness (hcr) for foam films of n-dodecyl β-D maltoside (C12G2) and of its mixed solutions with dodecanol (C12Е0), hexaethyleneglycol dodecyl ether (C12E6) and dodecyl trimethylammonium bromide (C12TAB) of different molar ratio (50:1; 1:1;1:50) at low and high ionic strength was measured interferometrically. It was found that the hcr increases with the increase of the film radius independently of solutions composition. At low ionic strength the type of surfactant affects the critical thickness and the equilibrium state of the film. hcr for the films of mixture with C12E0 increases with the increase of the total surfactant concentration, while hcr for the films of mixture with C12TAB decreases. For the values of the critical thicknesses for films from individual surfactant solutions the following sequence hcr (C12TAB) > hcr (C12E6) > hcr (C12G2) is found. At high ionic strength the quantity of nonionic additive does not substantially affect the value of hcr, while the quantity of ionic additive influences it by two different ways (i) in 50:1 mixture C12TAB supports C12G2 in the reducing of negative charge; (ii) in 1:1 mixture C12TAB recharges the film surfaces.

Critical thickness of foam films stabilized by nonionic, ionic surfactants and their mixtures

Faculty of Natural Sciences, Konstantin Preslavsky University of Shumen, 115 Universitetska str., 9712 Shumen, Bulgaria

Faculty of Chemistry and Pharmacy, Sofia University, 1 James Bourchier Blvd, 1164 Sofia, Bulgaria

Acta Scientifica Naturalis

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The critical thickness (hcr) for foam films of n-dodecyl β-D maltoside (C12G2) and of its mixed solutions with dodecanol (C12Е0), hexaethyleneglycol dodecyl...

Critical thickness of foam films stabilized by nonionic, ionic surfactants and their mixtures

Published Online: Mar 26, 2016

Page range: 45 - 51

Received: Oct 30, 2015

Accepted: Mar 11, 2016

DOI: https://doi.org/10.1515/asn-2016-0007

Keywords
foam films, n-dodecyl β-D maltoside (C12G2), mixed solutions of nonionic and ionic surfactants, molar ratios 50:1, 1:1;50:1, experimental critical thickness

© 2016

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Critical thickness of foam films stabilized by nonionic, ionic surfactants and their mixtures

Published Online: Mar 26, 2016

Page range: 45 - 51

Received: Oct 30, 2015

Accepted: Mar 11, 2016

DOI: https://doi.org/10.1515/asn-2016-0007

Keywordsfoam films, n-dodecyl β-D maltoside (C12G2), mixed solutions of nonionic and ionic surfactants, molar ratios 50:1, 1:1;50:1, experimental critical thickness

© 2016

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
foam films, n-dodecyl β-D maltoside (C12G2), mixed solutions of nonionic and ionic surfactants, molar ratios 50:1, 1:1;50:1, experimental critical thickness