Influence of DMSO Non-Toxic Solvent on the Mechanical and Chemical Properties of a PVDF Thin Film

Abstract

Piezoelectric materials such as PVDF and its copolymers have been widely studied in different areas and with promising applications, such as haptic feedback actuators or deformation sensors for aided-mobility scenarios. To develop PVDF-based solutions, different protocols are reported in the literature; however, a toxic and harmful solvent is commonly used (dymethilformamide (DMF)). In the present study, a non-toxic solvent (dymethilsulfoxide (DMSO)) is used to dissolve PVDF powder, while a specific ionic liquid (IL), [PMIM][TFSI], is used to enhance piezoelectric properties. A PVDF/IL thin film is characterized. The physical material characterization is based on optical analysis (to ensure the sample’s homogeneity) and on mechanical linear behaviour (Young’s modulus of 144 MPa and yield stress of 9 MPa). Meanwhile, a chemical analysis focuses on the phase modifications introduced by the addition of IL (β phase increase to 80% and a degree of crystallinity, χ, of 30%). All the results obtained are in good agreement with the literature, which indicates that the proposed experimental protocol is suitable for producing PVDF-based thin films for biomedical applications.