Abstract: A PBI compound includes imidazole nitrogens at least a portion of which are substituted with a moiety containing a carbonyl group, the substituted imidazole nitrogens being bonded to carbon of the carbonyl group. At least 85% of the nitrogens may be substituted. The carbonyl-containing moiety may include RCO—, where R is alkoxy or haloalkyl. The PBI compound may exhibit a first temperature marking an onset of weight loss corresponding to reversion of the substituted PBI that is less than a second temperature marking an onset of decomposition of an otherwise identical PBI compound without the substituted moiety. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may use more than 5 equivalents in relation to the imidazole nitrogens to be substituted.

Abstract: A filter and method of forming a filter is described and which includes a porous inorganic substrate having a plurality of pores, and which permits the passage of a fluid therethrough, and a ceramic filtration media formed of particles having a particle size which permits the ceramic filtration media to be embedded in at least some of the porous inorganic substrate and positioned at and/or below the top surface of the inorganic substrate.