Thermally conductive polymeric composites incorporating 3D MWCNT/PEDOT:PSS scaffolds

Although several types of stabilizers have been investigated recently to disperse carbon nanotubes (CNTs), the most common of them are thermal insulators that increase the thermal resistance and hinder the heat conduction across the CNT junctions. In this study, we dispersed multi-wall carbon nanotubes (MWCNTs) using the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a functional surfactant. Upon sonication, PEDOT:PSS covered the surfaces of the MWCNTs, thereby preventing their π-stacking and increasing their dispersion. Moreover, PEDOT:PSS acted as a thermally conductive bridge that connected the MWCNTs and decreased their thermal resistance. We employed a freeze-drying method to prepare MWCNT/PEDOT:PSS composites with hierarchical microstructures. After introducing polydimethylsiloxane (PDMS) into the MWCNT/PEDOT:PSS foam, the thermal conductivity of the MWCNT/PEDOT:PSS and PDMS composite reached 1.16 W/mK—over 550% higher than that of pure PDMS. These results suggest that such PDMS composites might be useful as thermal interface materials for thermal management in electronic and photonic applications.