Synthesis of polypyrrole silver graphene ternary nanocomposite and its thermal diffusivity study by thermal lens method

Efficient thermal management materials with tunable thermal diffusivity are increasingly required for advanced electronic, photonic, and energy applications. However, simultaneously achieving both thermal conductivity enhancement and thermal insulation within a single material system remains a significant challenge. In this work, we have synthesized polypyrrole silver graphene (PPy/Ag/Gr) ternary nanocomposites with varying concentrations of graphene by a simple one-pot chemical synthesis method.The photoluminescence spectrum of all the samples of PPy/Ag/Gr showed a quenching in the intensity due to the presence of graphene. Raman spectrum analysis confirmed good coordination of silver and graphene in the ternary composite. Morphological study was done using field emission scanning electron microscopy (FESEM). The thermal diffusivity of the binary composites polypyrrole silver (PPy/Ag) and polypyrrole graphene (PPy/Gr) as well as the ternary composites with varying concentrations of graphene were done using the highly sensitive thermal lens method using two laser sources, one as a pump source and the other as a probe beam. The results of the study show that the thermal diffusivity (D) of PPy/Ag/Gr with 0.2 wt.% of graphene is slightly greater than the binary composites and can be used as a coolant. Another exciting result of this study is that at higher concentrations of graphene the D values of the ternary composites decrease below the D value of the base fluid used. This interesting property of the samples can be exploited by using them as thermal insulators • First time report of thermal diffusivities of polypyrrole silver graphene composites. • Ppy/Ag/Gr(0.2 wt%) has the maximum thermal diffusivity (D). • Ppy/Ag/Gr(0.2 wt%) can be used as a coolant. • Higher concentration of graphene decreases the D value. • These samples can be used for thermal insulation.