TY - GEN
T1 - Bound and free water in surfactant micelles and lipid vesicles
AU - Picquart, Michel
AU - Valdez, Donato
AU - Vázquez, Humberto
AU - Urbach, Wladimir
AU - Waks, Marcel
PY - 2005/4/21
Y1 - 2005/4/21
N2 - Inverse micelles of surfactant AOT at low water contents are studied. From RMN measurements the molar fraction of bound water was obtained. Ultrasonic measurements, which depend on the compressibility, permit to determine the internal radius (water radius) of the micelles. With both results, the size of the bound water layer in this system was found around 0.3 nm. Correlated changes in the FT-IR absorption spectra give us information about the interaction between water and the polar head of AOT. Multilamellar vesicles, at different concentrations, of phospholipid DPPC, studied by DSC and FT-IR present a sub-zero transition near -40°C. This transition is attributed to the interstitial water, i.e. the water confined between two DPPC bilayers. These results emphasize the peculiar properties of the bound water in such systems.
AB - Inverse micelles of surfactant AOT at low water contents are studied. From RMN measurements the molar fraction of bound water was obtained. Ultrasonic measurements, which depend on the compressibility, permit to determine the internal radius (water radius) of the micelles. With both results, the size of the bound water layer in this system was found around 0.3 nm. Correlated changes in the FT-IR absorption spectra give us information about the interaction between water and the polar head of AOT. Multilamellar vesicles, at different concentrations, of phospholipid DPPC, studied by DSC and FT-IR present a sub-zero transition near -40°C. This transition is attributed to the interstitial water, i.e. the water confined between two DPPC bilayers. These results emphasize the peculiar properties of the bound water in such systems.
UR - http://www.scopus.com/inward/record.url?scp=33748555935&partnerID=8YFLogxK
U2 - 10.1063/1.1928163
DO - 10.1063/1.1928163
M3 - Contribución a la conferencia
AN - SCOPUS:33748555935
SN - 0735402442
SN - 9780735402447
T3 - AIP Conference Proceedings
SP - 103
EP - 110
BT - MATERIALS SCIENCE AND APPLIED PHYSICS
T2 - 2nd Mexican Meeting on Mathematical and Experimental Physics
Y2 - 6 September 2004 through 10 September 2004
ER -