A volumetric media having an upstream end and a downstream end. The volumetric media includes one or more spacers and a packing material around the spacers. The packing material includes a foam. The packing material may include fine fibers disposed on at least a portion of the foam.

A method for the purification of a bisphenol A dianhydride composition includes contacting the bisphenol A dianhydride composition with a halogenated solvent to form a solution, and one or more of filtering the solution to remove ionic species; washing the solution with aqueous media to remove ionic species; crystallizing bisphenol A dianhydride from the solution to remove ionic species; and contacting the solution with an adsorbent to remove ionic species. A purified bisphenol A dianhydride composition is also described. The bisphenol A dianhydride composition can be used in the preparation of a poly(etherimide), and poly (etherimides) made from the bisphenol A dianhydride composition can be useful for forming a variety of articles.

An air filter medium including a porous fluorine resin membrane, the air filter medium further including a glass filter medium layer, wherein the glass filter medium layer and the porous fluorine resin membrane are placed in this order from upstream to downstream of the air filter medium configured to allow airflow to pass through the air filter medium. The porous fluorine resin membrane includes a plurality of nodes and a plurality of fibrils, and in an area distribution of the nodes, when an area of the node corresponding to a cumulative relative frequency of 95% from a smaller area is defined as S95, the porous fluorine resin membrane satisfies 2.0 m.sup.2S958.0 m.sup.2.