Piezoelectric and Dielectric Properties of Electrospun Polyvinylidene Fluoride (PVDF) Blended with Cellulose Nanocrystals (CNCs)

PVDF is a semicrystalline polymer made up of repeating units of ─CH₂CF₂─ monomer and has five crystalline phases, which are α, β, γ, δ, and ε-phases. However, piezoelectricity of PVDF is dependent on the β-phase crystalline. Thus, to increase the formation of the β-phase, CNCs with various weights (1%–5%) are incorporated into PVDF by using the electrospinning method. The influence of CNCs on electrospun PVDF/CNCs is investigated by using analytical methods such as FESEM, FTIR, XRD, universal testing machine (UTM), electrochemical impedance spectroscopy (EIS), and piezoelectric d₃₃ meter. After incorporating CNCs into electrospun PVDF, two peaks of α-phase diminished in FTIR absorption and the addition also enhanced mechanical and dielectric properties of the membrane. The piezoelectric constant, dielectric properties, and β-phase content also increased with higher CNCs addition. PVDF with 4% CNCs has the highest β-phase content up to 91.74% with the maximum piezoelectric constant, d₃₃ of 45.0 pCN⁻¹ and dielectric constant of 5.4.