Single-particle dynamics of water molecules confined in a lecithin-based gel

Citation
F. Aliotta et al., Single-particle dynamics of water molecules confined in a lecithin-based gel, PHYS REV E, 60(6), 1999, pp. 7131-7136
Citations number
18
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW E
ISSN journal
1063651X → ACNP
Volume
60
Issue
6
Year of publication
1999
Part
B
Pages
7131 - 7136
Database
ISI
SICI code
1063-651X(199912)60:6<7131:SDOWMC>2.0.ZU;2-8
Abstract
We present experimental measurements, obtained by a quasielastic neutron sc attering experiment, of the self-diffusion coefficient of water confined in the dense structure of lecithin-based gels. The inelastic neutron scatteri ng (INS) technique was also used to monitor the dynamic state of water mole cules involved in the gel structure. It is shown that, at least in highly c oncentrated systems, the diffusional properties of water can be related wit h the growth process of wormlike aggregates. However, an interpretation of our data consistent with a number of experimental results in the literature and with INS indications requires the adoption of a model in which the gel structure is better described in terms of percolating aggregates rather th an the usually described polymerlike entangled (not interconnected) network . In such a way, we are pointing out the existence of an interpretative con troversy calling for further investigation to be disentangled. The source o f the inconsistencies is found in the commonly accepted basic assumption of the existence of a simple scaling law, relating the average micellar lengt h to the concentration. [S1063-651X(99)04312-3].