A general approach to composites containing nonmetallic fillers and liquid gallium

We report a versatile method to make liquid metal composites by vigorously mixing gallium (Ga) with non-metallic particles of graphene oxide (G-O), graphite, diamond, and silicon carbide that display either paste or putty-like behavior depending on the volume fraction. Unlike Ga, the putty-like mixtures can be kneaded and rolled on any surface without leaving residue. By changing temperature, these materials can be stiffened, softened, and, for the G-O-containing composite, even made porous. The gallium putty (GalP) containing reduced G-O (rG-O) has excellent electromagnetic interference shielding effectiveness. GalP with diamond filler has excellent thermal conductivity and heat transfer superior to a commercial liquid metal-based thermal paste. Composites can also be formed from eutectic alloys of Ga including Ga-In (EGaIn), Ga-Sn (EGaSn), and Ga-In-Sn (EGaInSn or Galinstan). The versatility of our approach allows a variety of fillers to be incorporated in liquid metals, potentially allowing filler-specific fit for purpose materials.

Automated summary

A versatile method has been reported for making liquid metal composites by mixing gallium with non-metallic particles, resulting in materials with different properties that can be stiffened, softened, and made porous by changing temperature. The gallium putty containing reduced graphene oxide exhibits excellent electromagnetic interference shielding effectiveness, while the material with diamond filler has superior thermal conductivity and heat transfer performance. Additionally, composites can be formed from eutectic alloys of gallium, allowing a variety of fillers to be incorporated in liquid metals for specific purposes.