The hydrogen bonding in the Raman O-H stretching band of propylene glycol in nanometre confined space. Surface interactions and finite-size effects

Valentina Venuti (1) , Vincenza Crupi (2) , Francesca Longo (2) , Domenico Majolino (2) , Placido Migliardo (2)

1 Physics Department
2 Physics Department

The O-H stretching vibration of Propylene Glycol (PG) has been investigated by Raman spectroscopy in the -15°C ÷ +60°C temperature range, in the bulk state and confined to the ~ 26 Å pores of a controlled porous glass. By modifying (from hydrophilic to hydrophobic) the nature of the substrate we separated the surface-like and the finite-size contributions to the high-frequency vibrational dynamics of this glass-forming system. The spectra have been fitted by four Gaussian peaks associated with PG molecules exhibiting different H-binding states (i.e. non H-bonded, chain-end, and doubly bonded). The T-dependencies of the peak wavenumbers and relative areas of the resolved components furnished a quantitative description of the role played by polymer-surface interactions and topological effects on the connectivity distribution of confined PG molecules.

Mots clés: Physical Sciences

Valentina Venuti, Vincenza Crupi, Francesca Longo, Domenico Majolino, Placido Migliardo. The hydrogen bonding in the Raman O-H stretching band of propylene glycol in nanometre confined space. Surface interactions and finite-size effects. Philosophical Magazine, 2007, 87 (3-5), pp.705-714. ⟨10.1080/14786430600880744⟩. ⟨hal-00513734⟩