Molecular mobility modulates the chemical and physical stability of amorphous biomaterials. This study used steady-state and time-resolved phosphorescence of erythrosin B to monitor mobility in thin films of amorphous solid sucrose as a function of temperature. The phosphorescence intensity (lifetime), emission energy, and red-edge excitation effect were all sensitive to localized molecular mobility on the microsecond timescale in the glass and to more global modes of mobility activated at the glass transition. Blue shifts in the emission spectrum with time after excitation and systematic variations in the phosphorescence lifetime with wavelength indicated that emission originates from multiple sites ranging from short lifetime species with red-shifted emission spectrum to long lifetime species with blue-shifted emission spectrum; the activation energy for nonradiative decay of the triplet state was considerably larger for the blue-emitting species in both the glass and the melt. This study illustrates that phosphorescence from erythrosin B is sensitive both to local dipolar relaxations in the glass as well as more global relaxations in the sucrose melt and provides evidence of the value of phosphorescence as a probe of dynamic site heterogeneity as well as overall molecular mobility in amorphous biomaterials.

including the URL of the record and the reason for the withdrawal request. Highlights for Preparation of alginate microgels in a simple one step process via the Leeds Jet Homogenizer by Pravinata et al. Calcium alginate microgel particles down to size 100 nm have been produced Their formation depends on rapid & highly turbulent mixing of separate alginate and Ca 2+ Oppositely charged protein present during formation acts as a dispersant & reduces particle size *Highlights (for review)

This is a repository copy of Encapsulation of water-insoluble polyphenols and β-carotene in Ca-alginate microgel particles produced by the Leeds Jet Homogenizer.