Morphology and Surface Area of Cellular Structured Resorcinol/Formaldehyde Microspheres: Effect of Ageing Conditions

Cellular structured resorcinol/formaldehyde (R/F) microspheres were synthesized via the sol-emulsion-gel reaction and followed by supercritical drying with CO₂. The materials were characterized by thermogravimetry, FT-IR spectroscopy, nitrogen physisorption technique and scanning electron microscopy. Variation of ageing conditions leaded to different micro and macro-structure, which affected bulk density, pore size distribution, specific surface area, and morphology of cellular structured R/F microspheres. The resultant R/F microspheres have average pore sizes in the range of less than 100 nm. Increasing the ageing time leaded to decreased surface area of cellular structured R/F microspheres. As the ageing temperature increased, the bulk density increased and the surface area decreased. The pore morphology depended on the ageing temperature and it was evidenced by nitrogen physisorption experiments.