Porous polymer films cast from latex–glucose dispersions

Macroporous films of glassy polymer are prepared from stable aqueous dispersions of latex with dissolved glucose, coated on a carrier substrate and dried at elevated temperature to a hybrid film, followed by water immersion to leach out the glucose and any redispersible latex. Temperature and time of drying must be tailored to facilitate local coalescence of latex particles by glucose expulsion while avoiding complete demixing of the two phases. The conditions for which mutual interpenetration of locally film-formed latex and glucose networks can be kinetically locked-in to maximize film yield and porosity are elucidated as a function of glucose/latex content. The porous films were analyzed gravimetrically and by UV–vis spectroscopy and scanning electron microscopy. They possess a disordered connected network of sub-micron pores graded in the film thickness direction, with accessibility decreasing from upper to lower surface due to upward transport of mobile glucose by capillarity and convection.