A mixed solvent approach to make poly(vinylidene fluoride) nanofibers with high β-phase using solution blow spinning

The excellent mechanical and piezoelectric properties of poly(vinylidene fluoride) (PVDF) are its most valuable characteristics, and improving the piezoelectric performance of PVDF is an important subject of the study. However, several existing methodological studies have been regarded as complex and ineffective. The most efficient method to produce PVDF nanofibers with high β-phase contents is still electrospinning; however, this process does not facilitate the mass production of PVDF nanofibers and produces PVDF with a relatively low fraction of β-phase. Both these issues can be solved by solution blow spinning (SBS). This work focused on the optimum ratio of solvents to produce beadless PVDF nanofibers and highlighted the relationship between the spinning solution viscosity and the average diameter of the SBS nanofibers obtained. Using Fourier transform infrared reflection, it was evaluated that the fraction of the β-phase increased after the SBS process, which was calculated to be 85%; this value was considered as a relatively high fraction of β-phase, which was similar to that obtained by electrospinning. Consequently, a simple and convenient alternative to produce PVDF nanofibers with high β-phase contents was achieved.