Air stable copper-silver core-shell submicron particles: Synthesis and conductive ink formulation.

Citation:

Pajor-Swierzy A, Farraj Y, Kamyshny A, Magdassi S. Air stable copper-silver core-shell submicron particles: Synthesis and conductive ink formulation. Colloids Surf., AColloids and Surfaces, A: Physicochemical and Engineering Aspects. 2016 :Ahead of Print.

Date Published:

2016///

Abstract:

We report on the synthesis of copper-silver core-shell (Cu@Ag) particles with about 1 μm-diam. Cu core coated with a thin (∼20 nm) silver shell, for application in printed electronics as low cost conductive ink. The process is based on using the environmentally friendly sodium formaldehyde sulfoxylate dehydrate as a reducing agent for copper ions and two types of polymeric stabilizers (nonionic PVP and anionic PAA). The formation of core-shell particles is followed by transmetallation reaction on the surface of the Cu particles, where copper atoms function as the reducer for silver ions. Characterization of the submicron particles by SEM, EDS and XRD confirm the core-shell structure. The resulting Cu@Ag particles enable overcoming a major challenge in copper ink, their rapid oxidn. in air. It was found that ink formulations based on propylene glycol as the liq. vehicle and contg. a silicone based wetting agent possesses the optimal characteristics (wetting, sintering) for printing on a glass substrate. To obtain conductive metallic structures, thermal sintering of metallic patterns was used. The Cu@Ag coating are stable to oxidn. for at least 6 mo at room temp., and also during sintering process which is carried out at temps. up to 250 °C. The cond. of Cu@Ag coatings after sintering at 250 °C was high, 16% of that for bulk copper. [on SciFinder(R)]

Notes:

CAPLUS AN 2016:1406488(Journal)