This work explores the effect of glycerol, a low molecular weight polyol, on the molecular packing, thermodynamic state and water sorption of low water content gelatin films. For this purpose, bovine gelatin films with different glycerol contents (0-10% wt.) were equilibrated at a range of relative humidities (RH=11-44%, T=298K). Our PALS measurements show that over the concentration range studied, glycerol acts as a packing enhancer (causing a non-linear decrease in the average molecular hole size), whilst reducing the glass transition temperature of the gelatin films. Glycerol also alters the water sorption behaviour of the glassy gelatin films, (whereby reducing the amount of water absorbed at well defined relative humidities), highlighting the importance of molecular packing for the sorption of water vapour in the glassy state.
|Journal||Journal of Physics: Conference Series|
|State||Published - 2013|
|Event||16th International Conference on Positron Annihilation, ICPA 2012 - Bristol, United Kingdom|
Duration: 19 Aug 2012 → 24 Aug 2012