Lakhasly

1.In event of melt electrospinning and subsequent comparison of the spun fibers with the macroscopic molded films, the differences in the conditions of their production are not so obvious and related to heat dissipation more likely, that is, by cooling specification of fibers and films.As it can show in Figure 1A,B the averaged diameters of the fibers coincide well with the newly obtained results on the diameter dimensions which are equal to 10 um and 12.2 um respectively obtained by SEM and AFM techniques.[16] The variance in structure-morphology characteristics of polymer fibers obtained via classical solvent electrospinning and corresponding films obtained via solution casting could be explained by the discrepancy in the formation conditions and primarily by the difference of solvent evaporation conditions.Almost at the same SEM magnification the surface of the molded films with the analogues PHB/PLA proportion looks lightly structured with uneven Pt-shading density that corresponds to the alternation of petty bulges and notches.For instance, in the work[17] it was stated that for the nanofibers under electrospinning conditions the time of desorption should take several millisecond, while solvent evaporation from the films with analogous content is gradually performed for essentially longer time, namely dozens of hours and even more.Additionally, the surface of filaments is quite perfect and has not visible cracks and pores.

1. Surface Morphological Patterns
   The surface morphology of a single filament which is typical for
   PLA/PHB/DPD blend nanofibers (9/1 þ 1% DPD) and the
   surface pattern of the PHB/PLA/DPD blend film are shown in
   Figure 1 (A and C, respectively) for the comparison. Additionally,
   the AFM image of the same single fiber is presented in
   Figure 1B. Both micrographs (A,C) obtained by different
   techniques indicate that the melt-electrospun nanofibers with
   the PHB/PLA blend ratio 1:9 have a uniform structure without
   any features of cylindrical form deformation. Additionally, the
   surface of filaments is quite perfect and has not visible cracks
   and pores. Almost at the same SEM magnification the surface of
   the molded films with the analogues PHB/PLA proportion looks
   lightly structured with uneven Pt-shading density that corresponds to the alternation of petty bulges and notches.
   In our previous paper[9] it was reported, that the PHB loading
   to PLA matrix decreases the mean fiber diameter from
   20.0 2.5 μm at the 9:1 ratio to 18.8 2.5 μm at the 7:3 ratio
   and finally to 10.6 2.5 μm at the PLA/PHB ratio equals to 6:4.
   The drug embedding in the polymer system decreases the mean
   fiber diameter up to 10.7 2.5 μm for 7:3 þ1% DPD system and
   simultaneously leads to narrower diameter distribution. As it
   can show in Figure 1A,B the averaged diameters of the fibers
   coincide well with the newly obtained results on the diameter
   dimensions which are equal to 10 μm and 12.2 μm respectively
   obtained by SEM and AFM techniques.[16]
   The variance in structure-morphology characteristics of
   polymer fibers obtained via classical solvent electrospinning
   and corresponding films obtained via solution casting could be
   explained by the discrepancy in the formation conditions and
   primarily by the difference of solvent evaporation conditions. In
   framework of diffusion model, the rate of solvent desorption
   from an ultrathin cylindrical filament with diameter about
   100 nm (107 m) and from the surface of a plane macroscopic
   film with the thickness equals to about 100 μm (104 m) should
   differ by as much as six order. For instance, in the work[17] it was
   stated that for the nanofibers under electrospinning conditions
   the time of desorption should take several millisecond, while
   solvent evaporation from the films with analogous content is
   gradually performed for essentially longer time, namely dozens
   of hours and even more.
   In event of melt electrospinning and subsequent comparison
   of the spun fibers with the macroscopic molded films, the
   differences in the conditions of their production are not so
   obvious and related to heat dissipation more likely, that is, by
   cooling specification of fibers and films. It is quite difficult to
   describe the differences in temperature gradients for the
   formation of fibers and films from a melt and such description