Crystal polymorphism and enhanced dielectric performance of composite nanofibers of poly(vinylidene fluoride) with silver nanoparticles

Abstract

Composite nanofibers of poly(vinylidene fluoride) (PVF 2 ) with silver nanoparticles are fabricated by electrospinning. According to the X-ray diffraction patterns and Fourier transform IR (FTIR) spectra, the content of piezoelectric b-polymorph of PVF 2 is enhanced in the composite fibers of PVF 2 and silver as compared with the pristine PVF 2 raw materials and electrospun nanofibers. The differential scanning calorimeter (DSC) measurement indicates that the composite of PVF 2 and silver has higher melting point and crystallization temperature than that of pristine PVF 2 nanofibers. Moreover, the existence of silver nanoparticles greatly enhances the dielectric constant of PVF 2 nanofibers and keeps a low dielectric loss simultaneously, which mainly relates to the internal fibrous structure of the composite.

Physico-Mechanical, Dielectric, and Piezoelectric Properties of PVDF Electrospun Mats Containing Silver Nanoparticles

“…Electrons -rich AgNPs interact with fluorine atoms in the PVDF forcing its chains to be in the β-conformation, thus increasing the β-phase content. Such interactions were confirmed by using X-ray photoelectron spectroscopy (XPS) [12], and UV and FTIR spectroscopy [18].…”

“…The work reported in this paper is aimed at complementing work done by three other groups [12,17,18] in addition to investigating the piezoelectric response of the PVDF/AgNPs electrospun mats. The first group [17] used 5 nm prepared AgNPs to enhance the antifouling properties of PVDF membranes and reported that the produced nanocomposite fibers became smoother and finer with addition of silver.…”

“…An example is graphene oxide (GO), which increases the β-phase content via interaction of the polymer chain with the oxygen-rich groups on the surfaces of the GO layers [9,10], or cellulose, where the polymer interacts with the -OH groups [2,11]. In addition, electron clouds on the surfaces of the metal nanoparticles could interact with polymer chains resulting in enhancement of the β-phase content [12]. Finally, ferroelectric materials such as barium titanate were used to enhance the β-phase content as the ceramic nanoparticles act as nucleating agent for the crystallization of the PVDF matrix [13].…”

“…The first group [17] used 5 nm prepared AgNPs to enhance the antifouling properties of PVDF membranes and reported that the produced nanocomposite fibers became smoother and finer with addition of silver. The second group [12] investigated the polymorphism and dielectric properties of PVDF/AgNPs electrospun mats. They first prepared PVDF fibers with silver nitrate salts, and then kept it in daylight for a week to convert the silver nitrate to AgNPs in the range of 20-50 nm.…”

The fabrication and surface functionalization of porous metal frameworks – a review

“…The fibres' diameter, morphology and length may be varied by changing parameters such as the solution viscosity, the molecular weight of the dissolved polymer and the voltage difference between extrusion system and the reception support [112][113][114] . The incorporation of metal NPs into a polymer/solvent mixture was also performed 129 and after subsequent carbonization/annealing, led to the formation of metal/carbon rich nano-fibres 130 . However, issues related to the stability and interconnectivity of the metal NPs were raised and metal salt solution electro-spinning was shown to lead to the spinning of fibres with more controlled morphology and properties, Figure 5.…”