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Title: The optimization of methods of synthesis of nickel nanoparticles with silver nanoshell as component of conductive materials

Anna Pajor-Swierzy

Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Science, Poland

Biography

Anna Pajor-Świerzy has completed her PhD from the Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences and postdoctoral studies from Casali Center for Applied Chemistry of the Hebrew University of Jerusalem. She is the assistant of professor (adiunkt) of Jerzy Haber Institute of Catalysis and Surface Chemistry PAS. The field of her research is the synthesis of metallic nanoparticles for preparation of conductive materials. She has published more than 11 papers in reputed journals.

Abstract

Conductive inks based on nickel nanoparticles (NPs) have attracted much attention as a low-cost replacement for the currently used silver and gold NPs for fabrication of printed electronic circuits and devices. The nickel NPs as a component of conductive inks should be stable against oxidation process at all stages of preparation of conductive patterns: ink formulation and storage, printing, and post-printing treatment. In the present study, spontaneous oxidation of nickel was prevented by the formation of a silver shell on their surface, which results in the formation of nickel-silver core-shell (Ni@Ag) NPs. Those NPs were formed in the two-step process: (1) the formation of a dispersion of Ni nanoparticles; and (2) the transmetalation (galvanic displacement) reaction, where the surface of the Ni NPs acted as the reducing agent of silver ions. In the optimal condition of synthesis, Ni@Ag nanoparticles with about 50 and 210 nm-diameter Ni core coated with a thin (~10-20 nm) silver shell, were obtained. Finally, the stability of the synthesized spherical shaped Ni@Ag NPs was tested and the results indicate long-term stability against aggregation and nickel oxidation. Thick films composed of Ni@Ag NPs were deposited on a glass substrate and then sintered at temperatures ranging from 250°C to 370°C. The conductivity of Ni@Ag based coatings after sintering at 350°C was high, 11% of that for a bulk nickel. The obtained results clearly indicate that prepared metallic ink based on Ni@Ag NPs possess promising properties for its application in the printing technology of circuit board.

Audience take away:

• The simple and fast methods of synthesis of air-stable Ni@Ag NPs.
• The implementation of obtained results will allow fabricating convenient and low-cost material for application in conductive features. 
• This approach is very important from an economic point of view and will make possible preparation of metallic conductive materials for large scale commercial application.