Effect of Na+ MMT-ionic liquid synergy on electroactive, mechanical, dielectric and energy storage properties of transparent PVDF-based nanocomposites

摘要

Transparent dielectric composites with high electroactive, low dielectric loss and high energy density are highly desirable due to the potential applications in electronic and electric industry. In this work, simultaneously achieving excellent electroactive, high dielectric and energy storage performance in a transparent dielectric composite is proposed by compounding nano-montmorillonite (Na+ MMT) and ionic liquid (IL) with poly (vinylidene fluoride) (PVDF) through one-step melt blending technique. The microstructure, crystal forms, transparency, mechanical, dielectric and energy storage performances of PVDF/MMT/IL nanocomposites were systematically investigated. The existence of IL and shearing force contributes to the effective exfoliation of MMT in the PVDF matrix. Based on the synergy of Na+ MMT and IL, the PVDF/IL/MMT composites not only exhibited almost 100% polar phase PVDF but also the optical transmittance was significantly enhanced. The improved dielectric constant and reduced dielectric loss were successfully achieved in the PVDF/IL/MMT nanocomposites due to the inhibition of ion migration by exfoliated silicate layers. Moreover, the PVDF/IL/MMT nanocomposite exhibited improved energy storage performance compared with the nanocomposites containing IL or Na+ MMT independently. Therefore, the PVDF/IL/MMT nanocomposite with high electroactive, excellent transparency, high dielectric and energy storage performance shows potential applications in microelectronic device.