Interfacial Coordination Interaction Enables Soft Elastomer Composites High Thermal Conductivity and High Toughness

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Soft elastomers are crucial for soft electronics and robotics due to their large deformation capabilities.
• Existing elastomers face challenges with poor toughness and thermal conductivity, often sacrificing softness when fillers are added.
• Achieving a balance of thermal conductivity, toughness, and softness in elastomers remains a significant materials science challenge.

Purpose of the Study:

• To develop a strategy for creating soft elastomer composites with simultaneously high thermal conductivity and toughness.
• To investigate the role of interfacial coordination interactions in enhancing elastomer properties.
• To demonstrate the potential applications of these advanced elastomer composites.

Main Methods:

• Utilized poly(lipoic acid) elastomer and silver-coated aluminum filler.
• Formed silver-sulfur coordination cross-links at the elastomer-filler interface.
• Employed time domain thermoreflectance to measure interfacial thermal resistance and thermal conductivity.
• Characterized mechanical properties including Young's modulus, stretchability, and toughness.

Main Results:

• Achieved elastomer composites with high stretchability (450%), high thermal conductivity (2.35 W m^-1 K^-1), low modulus (321 kPa), and high toughness (3496 J m^-2).
• Demonstrated that silver-sulfur coordination interaction effectively lowers interfacial thermal resistance, enhancing thermal conductivity.
• Observed that interfacial coordination cross-links contribute to superior softness and toughness compared to traditional covalent cross-links.

Conclusions:

• Interfacial coordination interaction is a viable strategy for developing high-performance soft elastomer composites.
• The developed elastomers exhibit a unique combination of thermal conductivity, toughness, and softness.
• These materials show promise for thermal management in chip and soft electronic device applications.