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Stability of stearic acid monolayers on Artificial Sea Water
- Source :
-
Colloids & Surfaces A: Physicochemical & Engineering Aspects . Aug2012, Vol. 407, p38-48. 11p. - Publication Year :
- 2012
-
Abstract
- Abstract: We studied the formation and stability of stearic acid (SA) based films on aqueous sub-phases via Langmuir trough and imaging ellipsometry experiments. The aqueous phase was based on Artificial Sea Water (ASW), a multicomponent salt solution with a total molarity of 0.53. The composition of this solution was varied via dilution (1, 10 and 100 times) and adjustment of the pH (3, 7, 10). Also water sub-phases without the ASW salts were studied. Pressure–area isotherms of the SA monolayers show an enhanced stability of the film against fracture when the pH and/or the salt concentration of the sub-phase are increased. Isobars of SA measured below the pressure needed for film fracture, indicate distinct mechanisms for loss of material: (1) at low pH and salt concentration, three dimensional (3D) structures are formed at the air/water interface via nucleation and growth and (2) at high pH and salt concentration, diffusion-controlled dissolution of molecules in the sub-phase occurs. The formation of multilayer structures was corroborated with ellipsometry images of the films after Langmuir–Blodgett transfer. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 09277757
- Volume :
- 407
- Database :
- Academic Search Index
- Journal :
- Colloids & Surfaces A: Physicochemical & Engineering Aspects
- Publication Type :
- Academic Journal
- Accession number :
- 77338161
- Full Text :
- https://doi.org/10.1016/j.colsurfa.2012.04.055