1 research outputs found
One-Step Preparation of Silver Hexagonal Microsheets as Electrically Conductive Adhesive Fillers for Printed Electronics
A facile one-step solution-phase
chemical reduction method has
been developed to synthesize Ag microsheets at room temperature. The
morphology of Ag sheets is a regular hexagon more than 1 μm
in size and about 200 nm in thickness. The hexagonal Ag microsheets
possess a smoother and straighter surface compared with that of the
commercial Ag micrometer-sized flakes prepared by ball milling for
electrically conductive adhesives (ECAs). The function of the reagents
and the formation mechanism of Ag hexagonal microsheets are also investigated.
For the polyvinylpyrrolidone (PVP) and citrate facet-selective capping,
the Ag atoms freshly reduced by N<sub>2</sub>H<sub>4</sub> would orientationally
grow alone on the {111} facet of Ag seeds, with the synergistically
selective etching of irregular and small Ag particles by H<sub>2</sub>O<sub>2,</sub> to form Ag hexagonal microsheets. The hexagonal Ag
microsheet-filled epoxy adhesives, as electrically conductive materials,
can be easily printed on various substrates such as polyethylene terephthalate
(PET), epoxy, glass, and flexible papers. The hexagonal Ag microsheet
filled ECAs demonstrate lower bulk resistivity (approximately 8 ×
10<sup>–5</sup> Ω cm) than that of the traditional Ag
micrometer-sized-flake-filled ECAs with the same Ag content of 80
wt % (approximately 1.2 × 10<sup>–4</sup> Ω cm)