Uses of 3D photothermal deflection technique for the investigation of nickel-graphene foam sheets

The aim of this work is to investigate the influence of pores density on the thermal properties of Nickel-graphene foam sheets. The study demonstrates a detailed theoretical and experimental treatment of the three-dimensional photothermal deflection (PTD) technique, under laser excitation of nickel foam of various porosity density coated graphene thin film of 200 nm thickness. Green's function and integral transformations are used in the theoretical treatment. The effect of certain parameters on the sensitivity of the PTD technique with respect to the variation in the specimens' pore density was studied via using analytical and numerical developments. The thermal properties showed that the thermal conductivity and thermal diffusivity were 4.12 W m⁻¹. K ⁻¹ and 0.147 cm². s⁻¹. The numerical results show that decreasing the modulation frequency of the laser causes a decrease in the sensitivity of the thermal signal. Photothermal deflection techniques have shown a good efficiency in determining the thermal properties of porous materials.