Nanoscale Thermal Conductivity of Kapton-derived Carbonaceous Materials

* Corresponding authors: kirill.kondratenko@iemn.fr; stephane.lenfant@iemn.fr _________________________________________________________________________ Abstract This study explores the potentialities of Scanning Thermal Microscopy (SThM) technique as a tool for measuring thermal transporting properties of carbon-derived materials issued from thermal conversion of organic polymers, such as the most commonly known polyimide (PI), Kapton®. For quantitative measurements, the Null Point SThM (NPSThM) technique is used in order to avoid unwanted effects as the parasitic heat flows through the air and the probe cantilever. Kapton® HN films were pyrolysed in an inert atmosphere at temperatures up to 1200°C to produce carbon-based residues with varying degree of conversion to free sp2 disordered carbon. The thermal conductivity of carbon materials ranges from 0.2 to 2 Wm-1K-1 depending on the temperature of the carbonization process (varied between 500°C and 1200°C). In order to validate the applicability of NPSThM approach to these materials, the results were compared to those obtained with the three more traditional techniques, namely photo-thermal radiometry, flash laser analysis and micro-Raman thermometry. It was found that NP SThM data are in excellent agreement with previous work using more traditional techniques. We used the NP-SThM technique to differentiate structural heterogeneities or imperfections at the surface of the pyrolysed Kapton on the basis of measured local thermal conductivity.