Processing Conditions and Aging Effect on the Morphology of PZT Electrospun Nanofibers, and Dielectric Properties of the Resulting 3–3 PZT/Polymer Composite

Abstract

Lead zirconate titanate (PZT) nanofibers are obtained by electrospinning a sol–gel based solution and polyvinyl pyrrolidone (PVP) polymer, and by subsequent sintering of the electrospun precursor fibers. The average diameter of the precursor PZT/PVP green fibers has increased with the aging of the precursor solution along with an increase in the viscosity. Bead‐free uniform green PZT/PVP fibers were collected at about an ∼230 nm average fiber diameter using a 28 wt% PVP ratio solution with a viscosity of 290 mPa. Shrinkage of 40% was recorded on the fiber diameter after sintering. The X‐ray diffraction pattern of the annealed PZT fibers exhibits no preferred orientation and a perovskite phase. Preparation of 3–3 nanocomposites by the infusion of polyvinylester into the nanofiber mat facilitates successful handling of the fragile mats and enables measurements of the dielectric properties. The dielectric constant of the PZT/polyvinylester nanocomposite of about 10% fiber volume fraction was found to be fairly stable and vary from 72 to 62 within the measurement range. The dielectric loss of the composite is below 0.08 at low frequencies and reaches a stable value of 0.04 for most of the measured frequencies.

Elucidating the Piezoelectric, Ferroelectric, and Dielectric Performance of Lead-Free KNN/PVDF and Its Copolymer-Based Flexible Composite Films

“…Recently, considerable attention has been given to the charge storage applications and, therefore, a number of research works have been conducted for the development of polymer-based dielectric materials, which possess high dielectric permittivity and low dielectric loss. − In the case of polymers, the dielectric permittivity is too low , and, thus, it is a challenge to achieve high permittivity and low loss in polymers. Addition of ceramic fillers is one of the approaches taken to improve the dielectric permittivity almost 10 times than that of the pristine polymer, and this has been achieved by filler loadings up to 50 vol %. − However, such a high loading of fillers deteriorates the mechanical performance of the composites. Here, it was observed that nanocomposites fabricated with lower filler loadings resulted in higher dielectric properties.…”

Electrical and dielectric properties of foam injection-molded polypropylene/multiwalled carbon nanotube composites

“…Recently, polymer-based composites have been tried as dielectrics for charge storage applications in capacitors and organic circuit boards [1][2][3][4][5][6][7][8]. Such composites should exhibit high dielectric permittivity (ε') and low dielectric loss (tan δ) to be an effective dielectric [1][2][3][4][5].…”

“…Such composites should exhibit high dielectric permittivity (ε') and low dielectric loss (tan δ) to be an effective dielectric [1][2][3][4][5]. However, the dielectric permittivity of polymers is very low (e.g., ε' of PP < 3) and achieving a high ε' and low tan δ in a polymer system remains challenging [1][2][3][4][5][6][7][8]. One approach is to add ceramic fillers, which can increase ε' of polymer by about ten times at loadings close to 50 vol.% [6][7][8].…”

“…However, the dielectric permittivity of polymers is very low (e.g., ε' of PP < 3) and achieving a high ε' and low tan δ in a polymer system remains challenging [1][2][3][4][5][6][7][8]. One approach is to add ceramic fillers, which can increase ε' of polymer by about ten times at loadings close to 50 vol.% [6][7][8]. However, ceramic fillers at such loadings are detrimental to the composites' mechanical performance and sometimes to their electromechanical reliability [1,2].…”