POLYMERIC MEMBRANES FROM COLLOIDAL CRYSTAL TEMPLATES WITH TUNABLE MORPHOLOGY

N. CASIS, M. M. FIDALGO DE CORTALEZZI, S. RAVAINE, AND D. A. ESTENOZ

Montreal, Canadá

Congreso; 8th World Congress of Chemical Engineering; 2009

Congress of Chemical Engineering

Polymeric porous membranes were fabricated from silica particle templates. This fabrication process allows a high control of pore size and morphology. Silica particles with a narrow size distribution were synthesized in the laboratory. The templates were obtained by vertical deposition of the particles on a glass substrate and by the Langmuir-Blodgett technique to create templates of different particle sizes. Polystyrene (PS) and diethyleneglycol dimethacrylate (DEGDMA)-urethane dimethacrylate (UDMA) copolymers were used as membrane materials. The procedure involved the infiltration of monomers in the templates filing the voids spaces among the colloidal particles by capillarity, and UV polymerization. The silica particles were then, etched away in a solution of hydrofluoric acid, leaving behind a 3D porous membrane consisting of a highly ordered architecture of interconnected spherical pores. Both particles and porous films were characterized by scanning electron microscopy (SEM). The pre-specified pore morphology of these membranes makes them of special interest in water treatment process, where sharp molecular weight cut offs are required for contaminant removal. In addition to their uses in filtration, separation, and tissue engineering, the porous membranes described in this work should also find applications in fabricating sensors materials due to their three-dimensional periodic structures and high specific surface areas.