Electroless silver plating on modified fly ash particle surface

In the graph, the scanning electron microscopy image shows the micro morphology and structure of the electroless Ag plating fly ash particles. The energy dispersive spectroscopy result shows the elements distribution of particles. The X-ray photoelectron spectroscopy results conclude the electroless plating mechanisms. Ag film adheres on the FA particles surface which are pretreated through Alkali cleaning and coupling agents strongly by N-Ag coordination bond. The Ag-plated FA powders have good electrical conductivity. [Display omitted] •The light electric micro powders are prepared by electroless Ag plating on the fly ash particles.•The fly ash particles are pretreated through alkali cleaning and coupling agents.•Ag film adheres on the fly ash particles strongly by N-Ag coordination bonds.•The Ag-plated fly ash particles have good electrical conductivity. Ag-plated fly ash (FA) powders were prepared through modified electroless plating, which could be utilized for manufacturing conductive polymers for Electromagnetic interference (EMI) shielding applications. In order to improve the FA surface activity, alkali cleaning and coupling modification were employed. Extensive characterizations of Ag-plated FA particles were carried out by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) techniques. The mechanism of electroless Ag plating was mainly studied by using XPS. The XPS results showed that the diammonia functional group from the coupling agent adsorbed silver ions to form the N-Ag coordination bond and produce pure Ag film. In addition, electrical conductivity and electromagnetic properties were studied by Four-probe resistance tester and vector network analyzer, respectively. The results indicated that uniform and compact Ag films were formed on FA particle surface strongly after alkali cleaning and coupling modification. The electrical conductivity of the as-prepared 0.6-FA-S-Ag particles with a coated thickness of 200 nm was about 8.2 × 10−5 Ω·cm. The electromagnetic parameters and calculated reflection loss indicate that Ag-plated FA powders have no magnetic conductivity and the main contribution of electromagnetic loss comes from dielectric loss.