Electrically Conductive Nanoparticle-Enhanced Epoxy Adhesives for Localised Joule Heating-Based Curing in Composite...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Composite bonding requires efficient and localized curing methods.
• Carbon nanotubes (CNTs) offer unique electrical and thermal properties for advanced materials.

Purpose of the Study:

• To investigate CNT-enhanced epoxy adhesives for localized Joule heating-based composite bonding.
• To evaluate the impact of CNT alignment on electrical, thermal, and mechanical properties.
• To establish CNT-enhanced Joule heating as a viable curing technique.

Main Methods:

• Epoxy adhesives with varying CNT loadings (0.25-1 wt%) were prepared and characterized.
• A DC voltage method was used for CNT alignment.
• Finite element modeling and infrared thermal imaging were employed for thermal analysis.
• Lap shear tests and scanning electron microscopy (SEM) were used for mechanical evaluation and failure analysis.

Main Results:

• CNT alignment significantly reduced the percolation threshold and improved electrical conductivity.
• Aligned CNTs led to increased localized temperatures and more uniform heating.
• A peak shear strength of 10.16 MPa was achieved at 0.5 wt% CNT loading, a 9% increase over pure epoxy.
• SEM analysis revealed aligned CNT clusters and a transition in failure modes with increasing CNT loading.

Conclusions:

• CNT alignment is crucial for enhancing localized conductivity and curing efficiency in epoxy adhesives.
• CNT-enhanced Joule heating is a promising, scalable alternative for efficient composite bonding in demanding applications.
• This method offers improved mechanical performance and controlled failure mechanisms for structural composites.