Factors influencing activated carbon-polymeric composite membrane structure and performance

Hybrid carbon-polymeric composite membranes were synthesized by an immersion-precipitation method using polysulfone as polymer precusor and activated carbon dissolved in dimethyl formamide as casting solution. Surface analysis by scanning electron microscopy (SEM) allowed studying the morphology of membranes as a function of synthesis conditions (carbon loading and particle size). Membrane porosity distribution and mean pore size were obtained numerically using IFME(R) program. Effect of casting conditions over carbon was also investigated by SEM. Hybrid membrane performances were characterized in terms of water and oligomeric flux in a continuous operation mode. Selective rejection of dextranes of high molecular weight was obtained. Results showed that permeability for composite membranes is influenced basically by loading and activated carbon particle size, giving rise to materials with a better performance than non-hybrid ones for this application. (C) 2003 Elsevier Ltd. All rights reserved.