Nonirradiated and irradiated glucose containing samples were then lyophilized and observed with SEM. The nonirradiated
sample’s surface is very smooth and nonporous
(Figure 4(a)) while the irradiated sample’s surface appeared
to be fibrillar and pockmarked (Figure 4(d)). Cross sectional
images result in further visual differences. The irradiated
sample appears to have a more stratified appearance, where
increased density is observed at the surface interface which
is directly exposed to ultraviolet irradiation (Figures 4(b)
and 4(c)). The nonirradiated sample appears more homogenous
with fewer surface features (Figure 4(a)). As previously
mentioned, the surface penetration of the UV is limited
to micron-scale depths. Cross-linking density may decrease
with depth due to UV extinction.