Tailoring of density in carbon foams

Abstract

Cell-size of the sacrificial polymeric scaffolding and concentration of the impregnating phenolic resin are taken as two variables for tailoring density in the carbon foam. Effects of cell-size and resin-concentration on density of carbon foam are studied under three categories: (i) individual effect of varying cell-size with fixed resin-concentration, (ii) individual effect of varying resin-concentration with fixed cell-size, and (iii) synergistic effect of varying cell-size and resin-concentration. For a fixed resin-concentration and particularly for lower concentration of 10%, density marks a small incremental effect with the reduction in cell-size. It increases from 0.041 to 0.055 g/cc for a cell-size of 30 PPI (pores per inch) and 80 PPI respectively. For a fixed cell-size and particularly for lower cell-size of 80 PPI, density shows a large incremental effect with increase in resin-concentration. Density increases from 0.055 to 0.210 g/cc for a resin-concentration of 10% and 90% respectively. Under the combined effect of decreasing cell-size and increasing resin-concentration, density records a massive increase of 412.2% from initial combination of 30 PPI cell-size and 10% resin-concentration to last combination of 80 PPI cell-size and 90% resin-concentration.