FT-IR study of the interlamellar water confined in glycolipid nanotube walls.
The local hydrogen-bonding environment of water confined in glycolipid nanotubes (LNTs) was investigated by Fourier transform infrared (FT-IR) spectroscopy. Using X-ray diffraction (XRD), we estimated the thickness of an interlamellar water layer, which was confined between the bilayer membranes constructing the walls of the LNTs, to be 1.3 +/- 0.3 nm. FT-IR spectroscopic measurement of the confined water showed an obvious reduction in IR absorption in both the low-energy (around 3000 cm(-1)) and high-energy regions (around 3600 cm(-1)) of the OH stretching band as compared to bulk water. The reduction around 3000 cm(-1) indicated a decrease in the relative proportion of the water molecules with a long-range network structure due to a geometrical restriction. This agrees with the results obtained for other multilamellar systems. On the other hand, the remarkable reduction around 3600 cm(-1), which was not observed in the other systems, indicated the absence of weakly hydrogen-bonded water aggregates due to the effect of sugar headgroups.
Guo
Yanli
Y
Department of Advanced Materials Science, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
Yui
Hiroharu
H
Minamikawa
Hiroyuki
H
Masuda
Mitsutoshi
M
Kamiya
Shoko
S
Sawada
j Tsuguo
jT
Ito
Kohzo
K
Shimizu
Toshimi
T