Expanded graphite–silver (EG–Ag) composites are expected to play an important role as heat dissipation materials for 

electronic components, which were synthesized via a supercritical CO2 fluid process (SCFP), enabling uniform dispersion

of silver (Ag) particles within the expanded graphite (EG) matrix. AgNO3 was dissolved in a binary solvent system 

consisting of either ethanol (EtOH) or methanol (MeOH) diluted with deionized water (DI water), adsorbed onto the EG 

surface through SCFP, and followed by thermal treatment to form the EG–Ag composites. The effects of reaction time, 

co-solvent composition, and post thermal treatment on the structural morphology and its thermal properties of EG–Ag 

composites were investigated. The SCFP showed the performance of improved Ag particle dispersion on EG surface, 

and yielded the formation of a continuous thermal conduction network on the EG-Ag composites. Optimization of the 

co-solvent composition and post thermal treatments further enhanced thermal conductivity in both the through-plane and 

in-plane directions. These results demonstrate that SCFP is a promising method for fabricating EG–Ag composites with 

high structural integrity and superior thermal dissipation properties, offering great potential for usage in thermal interface 

materials for high-power electronic and optoelectronic systems.