Carbon foam composites based on expanded graphite for electrochemical application

Abstract

Polymer composites containing modified graphite structures as fillers have been successfully processed exhibiting attractive features for different applications. Carbon foams derived from polymer precursor is brittle and the addition of some reinforcement to produce them is of great interest not only to improve their mechanical properties, but also to use them for multifunctional purposes. Considering the advantages provided by different modified graphite structures added to polymer composites, including low price, ease of dispersion, good thermal stability, electrical conductivity, and mechanical properties, expanded graphite (EG) was chosen as filler for the carbon foams processing to produce reticulated vitreous carbon (RVC) composites. Poly(furfuryl alcohol) was used as the carbon matrix precursor and different amounts of EG were dispersed in the resin to impregnate the polyurethane foam template. The RVC_EG composites were analyzed by scanning electron microscopy, Raman spectroscopy, X-ray diffraction, compression test, and cyclic voltammetry. EG presence on RVC_EG composites showed synergic effects contributing to their crystallinity, compressive strength, and charge transfer reactions improvement as well as their specific electrochemical surface area increase. Therefore, the effectiveness of the resulting carbon composite was mainly attributed to the good interaction between EG and carbon matrix.