Synthesis of Highly Conductive, Uniformly Silver-Coated Carbon Nanofibers by Electroless Deposition

Abstract

Noble-metal-coated carbon-based nanoparticles, when used as electrically conductive fillers, have the potential to provide excellent conductivity without the high weight and cost normally associated with metals such as silver and gold. To this effect, many attempts were made to deposit uniform metallic layers on core nanoparticles with an emphasis on silver for its high conductivity. The results so far were disheartening with the metal morphology being better described as a decoration than a coating with small effects on the electrical conductivity of the bulk particles. We tackled in this work the specific problem of electroless deposition of silver on carbon nanofibers (CNFs) with the investigation of every step of the process. We performed X-ray photoelectron spectroscopy (XPS), transmission and scanning electron microscopy (TEM, SEM), zeta potential, and electrical conductivity measurements to identify a repeatable, reliable set of parameters allowing for a uniform and fully connected silver deposition on the surface of the CNFs. The bulk particles' specific electrical conductivity (conductivity per unit mass) undergoes a more than 10-fold increase during the deposition, reaching 2500 S·cm/g, which indicates that the added metal mass participates efficiently to the conduction network. The particles keep their high aspect ratio through the process, which enables a percolated conduction network at very low volume loadings in a composite. No byproducts are produced during the reaction so the particles do not have to be sorted or purified and can be used as produced after the short ∼15 min reaction time. The particles might be an interesting replacement to conventional fillers in isotropic conductive adhesives, as a conductive network is obtained at a much lower loading. They might also serve as electrically conductive fillers in composites where a high conductivity is needed, such as lightning strike protection systems, or as high surface area silver electrodes.

Effects of Graphene Nanoplatelet Size and Surface Area on the AC Electrical Conductivity and Dielectric Constant of Epoxy Nanocomposites

“…The use of epoxy polymers as a matrix has garnered significant attention in the fabrication of advanced polymer composites. The insulating nature of epoxy composites results in inferior resistance to damage and poor electrical discharge properties when subjected to electrical loads [59]. Examples of these events may include lightning strike damage on fiber-reinforced epoxy composites structures, inducing delamination damage, that further degrades the mechanical properties [60,61,62].…”

Antimicrobial activity of silver-coated hollow poly(methylmethacrylate) microspheres for water decontamination

“…To achieve this objective, AgNPs need to be immobilized to control their contact and release kinetics (of either ionic or particulate form) so that they can be applied in a cost-effective manner [30]. Hence, AgNPs have been either adsorbed on or embedded in various organic or inorganic substrates which include filter materials made of silica, zeolite, natural macroporous materials, carbon materials, fiberglass and polymers or paper of different types [36][37][38][39][40][41]. For instance, nanoparticles of silver were embedded in materials like, montmorillonites [23], polysulfone [42] cellulose acetate [37], fiberglass [43], polyurethane foams [44], ceramic filters [45][46][47][48] and activated carbon [49] to enhance their applicability, especially for water purification system.…”

“…Numerous studies have been performed on the usage of silver nanoparticles embedded polymer composites for water disinfection [23,27,38]. However, for many polymeric materials, polymer degradation is very common which causes leaching of monomer and if the polymer contains potentially harmful units like bisphenol-A, the material becomes harmful for health.…”

Wash-stable, oxidation resistant conductive cotton electrodes for wearable electronics

“…ELD of silver (Ag) on synthetic textiles has been widely reported because it offers high electronic conductivity and can be used for antibacterial and electromagnetic shielding applications. [10][11][12][13][14] However, cotton, a natural textile that is one of the most widely produced textiles for clothing, cannot be readily coated with Ag using ELD because of its extreme surface roughness/ disorder and varying surface energy. Uniformly coating cotton with silver necessitates the use of multistep surface pretreatments, such as chemical etching, coating with adhesive polymers or impregnation with nucleation directors, to encourage metal nano-or microparticle binding on the cotton surface.…”