Through-Plane and In-Plane Thermal Diffusivity Determination of Graphene Nanoplatelets by Photothermal Beam Deflection Spectrometry

Abstract

In this work, in-plane and through-plane thermal diffusivities and conductivities of a freestanding sheet of graphene nanoplatelets are determined using photothermal beam deflection spectrometry. Two experimental methods were employed in order to observe the effect of load pressures on the thermal diffusivity and conductivity of the materials. The in-plane thermal diffusivity was determined by the use of a slope method supported by a new theoretical model, whereas the through-plane thermal diffusivity was determined by a frequency scan method in which the obtained data were processed with a specifically developed least-squares data processing algorithm. On the basis of the determined values, the in-plane and through-plane thermal conductivities and their dependences on the values of thermal diffusivity were found. The results show a significant difference in the character of thermal parameter dependence between the two methods. In the case of the in-plane configuration of the experimental setup, the thermal conductivity decreases with the increase in thermal diffusivity, whereas with the through-plane variant, the thermal conductivity increases with an increase in thermal diffusivity for the whole range of the loading pressure used. This behavior is due to the dependence of heat propagation on changes introduced in the graphene nano-platelets structure by compression.

Tailoring the Thermal Diffusivity of Polyvinylidene Fluoride via Carbon Source Integration: A Photothermal Beam Deflection Study

“…These techniques include photothermal microscopy for high-resolution imaging of temperature variations, photothermal spectroscopy for assessing optical absorption and thermal properties, photothermal radiometry for measuring infrared emission and thermal parameters, photothermal deflection spectroscopy for monitoring deflections induced by thermal expansion, photothermal optical coherence tomography for subsurface thermal imaging, and photothermal therapy for targeted medical treatments [12,14,19]. These techniques play a vital role in materials science, biology, medicine, and environmental monitoring, providing valuable insights into thermal properties, imaging, spectroscopy, and therapeutic applications [13,17,20,21]. Among these PT techniques, the present work employed the photothermal beam deflection technique (BDS) to investigate the TD of the samples.…”

Cationic Pollutant Removal from Aqueous Solution Using Reduced Graphene Oxide

“…Although there are several methods for synthesizing graphene and its derivatives (e.g., liquid exfoliation [ 43 , 44 ], zeolite-assisted exfoliation [ 45 ], hydrothermal exfoliation [ 46 ], and microwave-assisted exfoliation [ 47 , 48 , 49 , 50 , 51 , 52 , 53 ]), the present study focuses on the eco-friendly oxidation-reduction protocol [ 33 ] to transform as-made GO into rGO.…”

The Effect of Curing Temperature and Thickness of Polybutyl Methacrylate Siloxane Coatings on the Corrosion Protection of Structural Steel S355

“…The material's opened and closed porosity are found by using a method of leastsquares fitting procedure of the theoretical dependencies described in the literature [49] to the experimental data.…”