Role of MWCNTs Loading in Designing Self-Sensing and Self-Heating Structural Elements

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Growing industrial interest in self-sensing and self-heating materials, particularly in aerospace and automotive sectors.
• Need for advanced materials capable of damage diagnosis and controlled thermal management.

Purpose of the Study:

• To develop and characterize nanocomposites with carbon nanotubes (CNTs) exhibiting self-sensing and self-heating properties.
• To evaluate the electrical and thermal performance of these nanocomposites for potential applications.

Main Methods:

• Electrical characterization to determine percolation threshold and AC conductivity (100 Hz to 1 MHz).
• Self-sensing analysis to assess damage detection capabilities via resistance changes.
• Thermal stability testing up to 300 °C.
• Scanning Electron Microscopy (SEM) for filler dispersion analysis.
• Electro-thermal investigation of resistance-temperature behavior.

Main Results:

• An electrical percolation threshold of approximately 0.5% CNTs by weight was identified.
• Nanocomposites showed purely resistive behavior beyond 0.5% CNTs.
• A gauge factor of 4.1 was achieved for self-sensing capabilities.
• Materials demonstrated solid thermal stability up to 300 °C with good heat distribution isotropy.
• Electro-thermal analysis revealed both Positive Temperature Coefficient (PTC) and Negative Temperature Coefficient (NTC) behaviors, with NTC predominating near the glass transition temperature.

Conclusions:

• The developed CNT nanocomposites possess significant self-sensing and self-heating properties.
• The materials are suitable for high-temperature heating applications and micro-damage detection.
• The findings support the use of these nanocomposites in demanding industrial fields like aerospace and automotive engineering.