Low filled conductive P(VDF-TrFE) composites: Influence of silver particles aspect ratio on percolation threshold from spheres to nanowires

Abstract

Polymer composites filled with silver nanowires enable the highest value of electrical conductivity known up to now in the case of conductive nanoparticle dispersion with a percolation threshold less than 1 vol%. Silver nanowires with high aspect ratio were elaborated by two types of synthesis: electrochemical deposition in a template and polyol synthesis. For the first time the influence of each kind of nanowires in composites was studied and compared to spherical nanoparticles as reference. The value of percolation threshold and conductivity level above the percolation threshold were measured and compared. These silver nanowires were introduced into poly(vinylidenedifluoride-trifluoroethylene) in comparison to spherical silver nanoparticles. The preparation method modified the effective aspect ratio of nanowires. The low percolation threshold and the microscopy observations confirmed the good dispersion of nanowires in composites. The lowest percolation threshold was determined in the case of the polyol synthesis nanowires (0.63 vol%) in comparison with electrochemical deposited nanowires (2.2 vol%). The level of conductivity above the percolation threshold obtained with each kind of particles is in the same range near 100 S.m −1 . The value of electrical conductivity obtained above the percolation threshold is unusual at this low content of conductive filler and is observed for the first time in a conductive polymer composite.

High-performance thermoplastic composites poly(ether ketone ketone)/silver nanowires: Morphological, mechanical and electrical properties

“…The conductivity values obtained above the percolation threshold are higher than those measured for polymer nanocomposites (~20 S ⋅m − 1 ) filled with Ag and Cu nanowires performed by solvent way and melt mixing [21,42]. However, results are in accordance with measured values obtained with almost the same type of NWs in other matrix by Lonjon et al [6,19,22,23]. The percolation threshold fitted (0.59 vol%) is very low in comparison with values measured in literature.…”

“…The percolation threshold fitted (0.59 vol%) is very low in comparison with values measured in literature. P c is largely lower than for dispersed silver particles (p c = 12 vol%) [23] and for copper particles (p c = 10 vol%) [42,43] but closer to values with good dispersion achieved [22]. The difference with metallic particles highlights the role of aspect ratio of silver nanowires.…”

“…Lonjon et al have shown the importance to introduce nanowires without oxidative layer on their surface. Conductive polymer composites realized with silver nanowires [18,22,23] provide the best compromise to prevent oxidative surface layer and exhibit higher conductivity with an acceptable weight increasing. Xia [24] and Sun [25] have described a polyol process where AgWs with high aspect ratio can be elaborated in large scale by using AgNO 3 as precursor and PVP as capping agent in ethylene glycol.…”

Synthesis, physical and magnetic properties of BaFe12O19/P(VDF-TrFE) multifunctional composites

“…The electrical conductivity of the insulating P(VDF-TrFE) copolymer is 10 À12 S/m at room temperature [20]. The a.c. conductivity of the fabricated composites has been estimated by using the expression:…”

Scalable synthesis of the mono-dispersed silver micro-dendrites and their applications in the ultralow cost printed electrically conductive adhesives

“…Considering the fact that most of the available ECAs are based on the 2-D silver microflakes and 0-D silver nanoparticles [7][8][9][10], one may think of other morphologies which may help further optimize the percolation network. During the past years, dendritic morphology of noble metals (including silver) captured the attention of materials scientists, for their attractive structures and important applications as catalysts and sensing substrates for surface enhanced Raman scattering (SERS) [11][12][13].…”