Effect of nanosilica on characteristics of carbonizates of phenol-formaldehyde resin – Fe(acac)3

A series of carbon–iron–silica (CIS) composites (carbonizates) were prepared by carbonization of phenol-formaldehyde resin – Fe(III) acetylacetonate mixtures with addition of different amount of nanosilica A380 and compared with a composite prepared without silica (CFe composite). The characteristics of the composites differ because two type iron silicates were formed at a surface of silica nanoparticles and affected structure of carbon–iron phases. The textural characteristics of the CIS composites show a decrease in meso- and macroporosity and an increase in nanoporosity because new nanoparticles are formed in voids between silica nanoparticles. The CFe particles, including graphite-like structures, metallic iron nanoparticles and Fe3C, are larger than the CIS particles, which also include iron silicates, amorphous and crystalline silica. The presence of metallic α-Fe nanoparticles can provide the magnetic properties of the composites.