Abstract
The effect of a self-pulsing non-equilibrium plasma discharge on piezoelectric PVDF nanofiber membrane was investigated. The plasma discharge was generated in air with a DC power source, with a discharge current of 0.012 mA, a nominal interelectrode separation of 1 mm, and discharge voltage of ~970 V. In a continuous fabrication process, the electrospinning method was used to generate thin nanofiber membrane with a flow rate of 0.7–1 mL h−1 and 25–27 kV voltage to obtain the nanofiber with high sensitivity and a higher degree of alignment and uniformity over a larger area. Plasma treatment was applied on both single layer and multi-layer (three layers) nanomembranes. In addition, simultaneously, the nanofiber membranes were heat-treated at a glass transition temperature (80–120 °C) and then underwent plasma treatment. Fourier-transform infrared (FTIR) spectroscopy showed that the area under the curve at 840 and 1272 cm−1 (β phase) increased due to the application of plasma and differential scanning calorimeter (DSC) indicated an increase in the degree of crystallinity. Finally, PVDF sensors were fabricated from the nanofibers and their piezoelectric properties were characterized. The results suggested that compared to the pristine samples the piezoelectric properties in the plasma and plasma-heat-treated sensors were enhanced by 70% and 85% respectively.
Highlights
Polyvinylidene fluoride (PVDF) is a widely studied polymer that exists in non-linear, piezo, and pyroelectric forms with potential applications in a variety of sensors and actuators
It should be noted that the traditional plasma treatment methods of polymers utilize glow discharges that have low discharge current, high electric field, and are highly non-equilibrium
The results suggest that a transient high electric field, together with charged species interaction in plasma, can lead to an increasing ordering of the β phase
Summary
Polyvinylidene fluoride (PVDF) is a widely studied polymer that exists in non-linear, piezo-, and pyroelectric forms with potential applications in a variety of sensors and actuators. Due to its low cost, resistance to chemicals, oxidation, and UV radiation, as well as its favorable mechanical properties, PVDF is used in pressure sensors, bimorph actuators, microphones, gas flow, and humidity sensors, as well as electro-mechanical and ultrasonic sensors. Low pressure or vacuum plasmas were applied in treating polymer surfaces [17,18], and results reported show an increase in surface energy, adhesive bond strength, and wettability [19]. It should be noted that the traditional plasma treatment methods of polymers utilize glow discharges that have low discharge current, high electric field, and are highly non-equilibrium. To evaluate the piezoelectric responses from the proposed plasma-treated PVDF nanofibers, a unique characterization setup was developed. First the plasma-treated fibers were used to fabricate sensors embedding the fibers between two copper electrode thin films, and the piezoelectric coefficients of the fabricated sensors were measured and determined using the newly developed impact test setup
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
