Morphology and surface area of cellular structured resorcinol/formaldehydemicrospheres: Effect of ageing conditions

Cellular structured resorcinol/formaldehyde (R/F) microspheres were synthes ized via the sol-emulsion-gel reaction and followed by supercritical drying with CO2. The materials were characterized by thermogravimetry, Fr-IR spec troscopy, nitrogen physisorption technique and scanning electron microscopy . Variation of ageing conditions leaded to different micro and macro-struct ure, 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 st ructured R/F microspheres. As the ageing temperature increased, the bulk de nsity increased and the surface area decreased. The pore morphology depende d on the ageing temperature and it was evidenced by nitrogen physisorption experiments.