Surface Functionalized Silver Nanoparticles for Ultrahigh Conductive Polymer Composites

Abstract

Silver nanoparticles were surface functionalized with diacids and then incorporated into the polymer matrix with silver flakes as conductive fillers. By using appropriate diacids, the resistivity of the silver flakes and nanoparticles (molar ratio of silver flakes to nanoparticles is equal to 6:4) incorporated polymer composites was dramatically reduced to as low as 5 × 10 -6 Ω‚cm. Morphology studies showed that the decreased resistivity resulted from the sintering of silver nanoparticles. The contact resistance of the polymer composites under 85 °C and 85% relative humidity was significantly stable with respect to aging time as a result of the further sintering of silver nanoparticles.

A Review of Conductive Metal Nanomaterials as Conductive, Transparent, and Flexible Coatings, Thin Films, and Conductive Fillers: Different Deposition Methods and Applications

“…Results showed that using an appropriate amount of diacids led to sintering of Ag NPs that resulted in reducing the resistivity of the composite to as low as 5 × 10 −6 Ω cm, which was considered stable [30]. Researchers showed that the diameter of Ag NWs does not affect their electrical properties [20], In cases of Ag NPs and NWs, solution-based methods are more popular with researchers, so a method for preparing a suitable solution (ink) composed of Ag NWs or Ag NPs with highly stable dispersion is needed.…”

“…Although Ag has many advantages, some obstacles remain. Ag NW thin film on bare substrate is very rough, and the thin film can be removed easily by friction; two solutions are using it as filler [20,[30][31][32] or burying Ag NW under the surface of a polymer matrix [18]. Ag NW or Ag NP thin films can be easily oxidized in air and need either a protective layer to prevent oxidation or strong acid treatment to remove the oxidized layer.…”

Contact Resistance and Metallurgical Connections Between Silver Coated Polymer Particles in Isotropic Conductive Adhesives

“…[13][14][15] However, the grain sizes observed in the SEM images were much larger than the particle sizes for which sintering at such low temperatures have been observed (below 20 nm), and thus the lowered sintering temperature of nanoparticles is not by itself a fully satisfactory explanation for the structural changes observed in the ICA samples in this study. Still, it should be noted that the grain sizes observed in the SEM images were those of already cured samples, and so the initial grain size of the silver coatings before curing may have been smaller.…”

A Low-Loss Substrate-Independent Approach for 60-GHz Transceiver Front-End Integration Using Micromachining Technologies

“…16 shows the integrated transceiver front-end before the lid is attached. The lid is manually bonded to the pillar-array sidewalls using high-conductivity nanoparticle silver epoxy [20]. No alignment is needed for this step.…”