2.2. Fabrication of PHB nanofibers by electrospinning
PHB granules were dissolved in a 7:3 mixture of 2,2,2-trifluoroethanol
and chloroform to 10% (w/v). The polymeric solution was transferred
into a syringe and delivered to the needle at a flow rate of 0.5 mL/h. A
constant voltage of 10 kV was applied to induce fiber formation. For
preparation of nanofibers in two-dimensional (2D) sheet form,
electrospun fibers were collected on aluminum foil connected to the
ground. Three-dimensional (3D) nanofibrous sponges were prepared by
collecting nanofibers in a coagulation bath filled with a 6:4 mixture of
t-butanol and water. Prepared PHB nanofibers were dried in vacuum for 24
h, and stored in a desiccator prior to use.