The soft template-assisted foaming technique's impact on biopitch-based porous carbon foam features

Abstract

Thermoplastic features, high carbon content, low ash level, and abundant phenolic chemical content of biopitch have made it a suitable precursor for carbonaceous materials. The present study aimed to investigate the utilization of a previously untested soft template-assisted foaming technique in the fabrication of biopitch-based carbon foam that provided brightness to the research in the literature. The hornbeam sawdust pitch-based carbon foams were formed by incorporating the non-ionic surfactant P123 into the synthesis solution. The research focused on understanding the effects of the foaming technique (conventional or template-assisted), template ratio, and chemical activation on the foam's physical, chemical, and mechanical properties via several analytical and characterization test methods. Raman spectroscopy, scanning and transmission electron microscopy analyses were performed to characterize the pore structures and carbon hybridization types, deducing highly aligned graphitic-like structures. Moreover, the mechanical strength of carbon foam was also enhanced via soft-template addition before foaming and diminished after chemical activation. The highest mechanical strength of 9.79 MPa with suitable thermal conductivity of 0.044 W/m.K and the lowest porosity of 71.41 % were attained when the template amount was 1 wt%. Surface areas of activated carbon foams ranged from 92.3 to 1121.2 m2/g. Accordingly, the adjustable pore structures of the developed materials allowed them to be considered promising adsorbents according to the need to remove pollutants of different sizes. The results obtained from the study will provide valuable insights into the effectiveness of the soft template-assisted foaming technique in high-quality and hierarchically arranged graphitic carbon foam production and its potential applications in thermal insulation.