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.