Effect of headgroup dissociation on the structure of Langmuir monolayers
The authors present results of grazing incidence X-ray diffraction studies concerning the effect of pH (and thus, of headgroup dissociation) on Langmuir monolayers of fatty acids, in the absence of any divalent cations in the aqueous subphase. An increase in pH transforms the distorted-hexagonal S phase first to the partially disordered Rotator-I phase with less distortion, and then to the completely disordered Rotator-II phase with an undistorted hexagonal structure. The S-Rotator-I and Rotator-I-Rotator-II transitions are pushed to lower temperatures with increase in pH. The fact that the effects of pH increase are almost identical to the effects of increasing temperature indicates the important role of headgroup-headgroup interactions in these monolayer phases.
- Research Organization:
- Northwestern Univ., Evanston, IL (US)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG02-84ER45125
- OSTI ID:
- 20015194
- Journal Information:
- Langmuir, Vol. 16, Issue 3; Other Information: PBD: 8 Feb 2000; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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