Investigation of some physical properties of Rochelle salt/polymer composite for flexible electronic applications

The current work investigates the structural, optical, electrical, and mechanical properties of Rochelle salt (RS)-doped polyvinyl alcohol (PVA) composite. The RS with concentrations (0 to 50 wt%)-filled PVA were prepared via the casting method. X-ray diffraction (XRD) of PVA and RS indicates the semi-crystalline nature of PVA and the crystal nano-size of RS. Moreover, the XRD of RS-doped PVA composites confirms the interaction and miscibility between PVA and RS. The changes in molecular structure were investigated by using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and confirmed the interaction and structure change in PVA by doping RS. The optical properties of the RS-doped PVA composites are greatly dependent on the RS concentrations. The absorption edge, direct, and indirect band gap increase with doping RS compering with pure PVA. The dielectric constant, loss, real and imaginary parts of dielectric modulus, and alternating current (AC) conductivity were investigated. Decrease in dielectric constant and loss followed by constant values with frequency increase due to the interfacial polarization. Also, increased AC conductivity and dielectric moduli with frequency increase and only a single relaxation peak were found and shifted to lower frequencies by increasing RS concentrations. Moreover, mechanical measurements reveal a significant improvement in the flexibility of RS-doped-PVA composites. The modulus of elasticity decreased by 72% compared with pure PVA. Dynamic mechanical analysis also reveals a decrease in storage modulus by 76% compared with pure PVA. Also, the RS concentrations greatly affect peak height, width, and position of loss factor.