Speaker
Description
Poly(vinylidene fluoride) (PVDF) is one of the most attractive electroactive polymers due to its piezoelectric, pyroelectric, and ferroelectric properties, which are strongly dependent on the content of the polar β crystalline phase. The development of a high β phase content is highly sensitive to processing conditions and post processing treatments.
The spin coating method is one of the promising routes for obtaining thin films with a high content of β phase.
In this study, the influence of molar mass, solution concentration, and spin-coating speed on the β phase content of PVDF thin films was systematically investigated. Three PVDF samples with low, medium, and high molar mass (with different concentrations in DMF/Ac.) were used in this research. Thin films were deposited onto indium tin oxide (ITO) coated glass substrates by spin coating at rotational speeds between 1000 and 5000 rpm. The crystalline phase composition was analyzed by Fourier Transform Infrared Spectroscopy (FTIR). The experimental design enabled evaluation of the individual and combined effects of molar mass, solution concentration, and spin-coating speed on β crystal phase development. Variations in solution viscosity and chain entanglement associated with molar mass, together with differences in centrifugal stretching and solvent evaporation rates during spin coating, were found to influence the crystallization behavior of PVDF.
The results provide valuable insights into the optimization of processing conditions for enhancing β phase formation in PVDF thin films. The findings contribute to the development of high performance PVDF based piezoelectric and ferroelectric devices, fabricated through scalable solution processing techniques.