shows the morphology of the PLA/Sr1.97MgSi2O7:0.01Eu2+,
0.02Dy3+ composite fibers obtained in our work. Fig. 3a (SEM)
shows that the composite fibers are randomly oriented and have
uniform fiber shape. The complicated process of electrospinning
is influenced by many factors, such as strength of electric field,
the concentration of polymer, the mixing rate of the nanoparticles,
temperature and the humidity of ambient. Therefore, the morphologies
and microstructure of electrospun fibers are not perfectly
identical after process. As is shown in Fig. 3b (SEM), the morphological
surface of the composite fiber is smooth. Because the fibers
slightly shrink following the evaporation of the liquid phase, the
nanoparticles which are close to the surface of fiber are uniformly
exposed. TEM image (Fig. 3c) shows that Sr2MgSi2O7:Eu2+, Dy3+
nanoparticles (size: from 50 nm to 300 nm) were cladded into
the fibers (diameter: 1.5 lm). Different shapes of the nanoparticles
are randomly distributed in the fibers