Metastable and Electronically Percolating Silver Nanowire-Polymer Composites by Spray Drying.

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Silver nanowires (AgNWs) are key for 2D conductive composites in computing.
• 3D AgNW composites present unique conduction mechanisms compared to 2D networks.
• Scaling 2D AgNW networks into bulk 3D structures is a significant challenge.

Purpose of the Study:

• To develop a reproducible 3D metastable AgNW composite using spray drying.
• To characterize the electronic percolation and conductivity of the 3D composite.
• To explore the dimensional effects on conductivity in AgNW systems.

Main Methods:

• Spray drying of AgNWs with poly(vinylpyrrolidone) to create 3D composites.
• Four-point probe (4PP) measurements for electronic percolation characterization.
• Electrochemical impedance spectroscopy (EIS) to analyze pressure-dependent conductivity.

Main Results:

• The 3D composite exhibited a wide conductivity range (10^-8 to 10^2 S/cm) dependent on AgNW loading.
• EIS revealed a two-order-of-magnitude conductivity increase with applied pressure (0.3–50 MPa).
• Spray drying enabled scalable production, prioritizing throughput over nanoscale precision.

Conclusions:

• The developed 3D AgNW composite is a versatile precursor for industrial applications.
• Spray drying offers a viable, scalable method for producing bulk AgNW conductive materials.
• The study highlights dimensional effects and pressure-induced percolation in 3D AgNW systems.