Fluorinated Graphene Thermally Conductive Hydrogel with a Solid-Liquid Interpenetrating Heat Conduction Network

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Flexible electronic devices require materials with excellent mechanical flexibility.
• Low thermal conductivity of conventional hydrogels limits their application in high-power integrated flexible electronics.

Purpose of the Study:

• To develop highly thermally conductive composite hydrogels for advanced flexible electronics.
• To create a hydrogel with a double cross-linked network and enhanced properties.

Main Methods:

• Composite hydrogels were constructed using aromatic polyamide nanofibers (ANF) and fluorinated graphene (FG) reinforced poly(vinyl alcohol) (PVA).
• Cross-linking was achieved through tannic acid (TA) solution immersion, forming a solid-liquid interpenetrating thermal conductivity network.
• Characterization of mechanical properties, friction coefficient, and thermal conductivity.

Main Results:

• The PVA-ANF-FG3^T-11.1% composite hydrogel demonstrated improved mechanical properties (tensile modulus: 0.89 MPa, tensile strength: 1.23 MPa, energy of rupture: 3.45 MJ cm^-3) due to multihydrogen bonding.
• A low friction coefficient of 0.178 was achieved, suitable for high-friction applications.
• High thermal conductivity of 1.42 W m^-1 K^-1 was observed, attributed to the synergistic solid-liquid network.

Conclusions:

• The developed composite hydrogels exhibit superior mechanical and thermal properties compared to conventional materials.
• The synergistic thermal conductivity network enhances heat dissipation capabilities.
• These hydrogels show significant potential for applications in flexible wearable electronics and thermal interface materials (cooling paste).