Silicon nanowire aqueous dispersions for processing into macroscopic network materials.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• High aspect ratio nanoparticles, such as nanowires, are crucial for creating network materials that bridge nano and macro scales.
• Existing methods for producing these materials often lack scalability and efficiency.

Purpose of the Study:

• To develop a scalable synthesis method for crystalline silicon nanowires (SiNWs).
• To demonstrate the processing of SiNWs into macroscopic materials like films and sheets.
• To characterize the properties of the resulting SiNW-based materials.

Main Methods:

• Utilized a floating catalyst chemical vapour deposition (FCCVD) method for gram-scale daily production of SiNWs.
• Produced SiNW dispersions in water via sonication, employing steric and electrostatic stabilization techniques.
• Processed SiNW dispersions into transparent films and freestanding sheets, analyzing their structural and mechanical properties.

Main Results:

• Achieved scalable production of crystalline SiNWs using FCCVD.
• Successfully created stable SiNW dispersions with concentrations up to 52 μg mL⁻¹.
• Fabricated freestanding SiNW sheets exhibiting paper-like characteristics, with tensile strength >10 MPa, modulus >1 GPa, and toughness of 0.5 J g⁻¹.

Conclusions:

• The FCCVD method provides a scalable route to SiNWs suitable for macroscopic material fabrication.
• SiNWs can be processed into robust, transparent films and strong, aligned sheets.
• This work facilitates the integration of nanowire materials into diverse technological applications.