Thermal conductivity of epoxy adhesive enhanced by hybrid graphene oxide/AlN particles

This study aims to improve the heat dispersion of electronic equipment by utilization of thermal conductive adhesive composed of epoxy matrix and filler. AlN particles with different size, graphite, graphene oxide (GO) were used alone or in a synergistic manner to prepare thermal conductive adhesives. The structure of prepared GO was characterized by XRD, FT-IR, Raman spectra and AFM. The analysis indicates that most of prepared GO is in single layer structure. The thermal conductivity and viscosity of adhesive were measured by thermal constants analyzer and rotational viscometer respectively. The results show adhesives filled with larger AIN particles possess higher thermal conductivity than that filled with smaller particles at the given filling content. GO is better than graphite as the filler to improve the thermal conductivity of the epoxy resin. When 8 wt% GO or 70 wt% 5 μm-AlN particles was added, the thermal conductivities of adhesives were about 6.42 times and 11.8 times that of pure epoxy respectively. To further improve the thermal conductivity, 50 wt% 5 μm-AlN particles and 6 wt% GO hybrid filler were proposed, and the final thermal conductivity reached up to 2.77 W/m k, that was 14.6 times of that of neat epoxy. In addition, Agari equation as a systematic theoretical modelling was cited to analyze the effect of each filler on improvement of thermal conductivity of adhesive.