Fine polybenzimidazole-containing particles

Fine, porous polybenzimidazole-containing particles prepared by spray-atomizing/quenching a polybenzimidazole-containing polymer solution into porous polybenzimidazole-containing particles, and fluidized bed, oppose jet milling the particles into fine, porous polybenzimidazole-containing particles. The milled particles exhibit a narrow particle size distribution centered at about a 5 mu m mean particle size, a surface area of about 35 m2/g, and an open porosity of about 1.2 cm2/gm which is at pore radius of less than about 100 nm.