A nanostructural investigation of the effect of glycerol on the molecular packing, thermodynamic state and water sorption behaviour of glassy gelatin films

16th International Conference on Positron Annihilation

Díaz-Calderón, P.^1 ; Roussenova, M.^2 ; Enrione, J.^3 ; Alam, M.A.^2

Department of Food Science and Technology, Universidad de Santiago de Chile, Av. Ecuador 3343, Estación Central, Santiago, Chile^1

H. H. Wills Physics Laboratory, Tyndall Avenue, Bristol, BS8 1TL, United Kingdom^2

Facultad de Medicina, Escuela Administración de Servicios, Universidad de Los Andes, San Carlos de Apoquindo 2200, Las Condes, Santiago, Chile^3

关键词: Average molecular;    Concentration ranges;    Low molecular weight;    Low water-content;    Molecular packings;    Nanostructural;    Thermodynamic state;    Water sorption;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/443/1/012056/pdf
DOI  :  10.1088/1742-6596/443/1/012056

来源: IOP

【 摘 要 】

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.