Molecular Dynamics and Neutron Scattering Study of Glucose Solutions Confined in MCM-41
Résumé
Glucose aqueous solutions con!ned in MCM-41 cylindrical pores of diameter 3.2 nm have been studied by molecular dynamics (MD) simulations and quasielastic neutron scattering (QENS). MD simulations reveal a strong preferential interaction of glucose molecules with the silica walls, which induces signi!cant concentration gradients within the pore. The in"uence of glucose on the structural and dynamical properties of water strongly depends on the region of the pore considered. The distortion of the hydrogen bond network (HBN) and of the tetrahedral organization of interfacial water molecules induced by silica is much stronger than that induced by glucose molecules. The interfacial glucose molecules di#use about 1 order of magnitude slower than those in the core region. Di#erences in a$nities for silica of the di#erent species in con!ned hydrogen-bonded mixtures induce signi!cant structural and dynamical heterogeneities not present in bulk solutions.