Molecular dynamics of confined glucose solutions.
Silica gels containing solutions of glucose in heavy water at different concentrations have been prepared by a sol-gel method. Dynamical studies with quasielastic neutron scattering, compared with previous results on bulk solutions, show that the dynamics of the glucose molecules are not appreciably affected by the confinement, even though the gels behave macroscopically as solid materials. Small-angle neutron-scattering spectra on the same systems, fitted with a fractal model, yield a correlation length that decreases from 20 to 2.5 nm with increasing glucose concentration, suggesting a clustering of glucose molecules in concentrated solutions that is consistent with the dynamical measurements. These two sets of results imply that 20 nm is an upper limit for the scale at which the dynamics of glucose molecules in solution are affected by confinement.
Lelong
Gérald
G
Centre de Recherche sur la Matière Divisée, 45071 Orléans Cedex 2, France. lelong@cnrs-orleans.fr
Price
David L
DL
Douy
André
A
Kline
Steve
S
Brady
John W
JW
Saboungi
Marie-Louise
ML
D005782:Gels / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D008968:Molecular Conformation; D036103:Nanotechnology; D009502:Neutrons; D044367:Phase Transition; D012542:Scattering, Radiation; D012822:Silicon Dioxide / Q000737:chemistry; D012996:Solutions / Q000737:chemistry
D005782:Gels; D012996:Solutions; D012822:Silicon Dioxide; D005947:Glucose