The Microstructure of Di-alkyl Chain Cationic/Nonionic Surfactant Mixtures: Observation of Coexisting Lamellar and Micellar Phases and Depletion Induced Phase Separation
- 1 September 2005
- journal article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 109 (38), 18107-18116
- https://doi.org/10.1021/jp0500788
Abstract
The evolution of the microstructure and composition occurring in the aqueous solutions of di-alkyl chain cationic/nonionic surfactant mixtures has been studied in detail using small angle neutron scattering, SANS. For all the systems studied we observe an evolution from a predominantly lamellar phase, for solutions rich in di-alkyl chain cationic surfactant, to mixed cationic/nonionic micelles, for solutions rich in the nonionic surfactant. At intermediate solution compositions there is a region of coexistence of lamellar and micellar phases, where the relative amounts change with solution composition. A number of different di-alkyl chain cationic surfactants, DHDAB, 2HT, DHTAC, DHTA methyl sulfate, and DISDA methyl sulfate, and nonionic surfactants, C12E12 and C12E23, are investigated. For these systems the differences in phase behavior is discussed, and for the mixture DHDAB/C12E12 a direct comparison with theoretical predictions of phase behavior is made. It is shown that the phase separation that can occur in these mixed systems is induced by a depletion force arising from the micellar component, and that the size and volume fraction of the micelles are critical factors.Keywords
This publication has 26 references indexed in Scilit:
- Effects of Shear on the Lamellar Phase of a Dialkyl Cationic SurfactantLangmuir, 2001
- Interaction of membrane proteins and lipids with solubilizing detergentsBiochimica et Biophysica Acta (BBA) - Biomembranes, 2000
- Mixed micelles and other structures in the solubilization of bilayer lipid membranes by surfactantsBiochimica et Biophysica Acta (BBA) - Biomembranes, 2000
- Phase boundaries in mixtures of membrane-forming amphiphiles and micelle-forming amphiphilesBiochimica et Biophysica Acta (BBA) - Biomembranes, 2000
- Phase and aggregation behaviour of double-chain cationic surfactants from the class of N -alkyl- N -alkyl?- N , N -dimethylammonium bromide surfactantsColloid and Polymer Science, 1999
- Theory of lamellar–lamellar phase transitions in pure and mixed surfactant solutionsThe Journal of Chemical Physics, 1999
- Micellar Shape and Long-Range-Ordering Transitions in Ternary Surfactant SolutionsThe Journal of Physical Chemistry B, 1997
- Behavior and Applications of Surfactant MixturesPublished by American Chemical Society (ACS) ,1986
- Counterion specificity as the determinant of surfactant aggregationThe Journal of Physical Chemistry, 1986
- Phase behaviour of polyoxyethylene surfactants with water. Mesophase structures and partial miscibility (cloud points)Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1983