Double Bubble Electrospinning: Patents and Nanoscale Interface

Background: Bipolymeric nanofibers have gained significant attention in various fields due to their enhanced functionality, improved mechanical properties, and controlled release capabilities. However, the fabrication of these composite fibers with a well-defined polymer-polymer interface remains a challenging task. Methods: The double bubble electrospinning setup was developed and simulated using Maxwell 3D to analyze the electric field. PVP and PVA polymers were electrospun simultaneously to create bipolymer nanofibers with an interface. The resulting nanofibers were compared with nanofibers made from pure PVA, PVP, and a PVA/PVP blend. The characterization of the nanofibers was performed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Results: The SEM images showed the formation of PVA/PVP interfacial nanofibers aligned side by side, with a diameter of a few thousand nanometers on each side. By increasing the voltage from 20 kV to 40 kV during electrospinning, the diameter of the nanofibers on the PVA and PVP sides was successfully reduced by 60.8% and 66.3%, respectively. FTIR analysis confirmed the presence of both PVA and PVP in the bipolymeric interfacial nanofibers. TGA analysis demonstrated a weight retention of 14.28% compared to PVA, PVP, and the PVA/PVP blend even after degradation at 500°C. The Maxwell simulation of double bubble electrospinning revealed a stronger and more uniform electric field pattern at 40 kV compared to 20 kV. Conclusion: The study has demonstrated the potential of double bubble electrospinning for the fabrication of bipolymer nanofibers with an interface, opening new avenues for the development of functional nanofibers.