Synthesis of high active-site density nanofibrous MnO2-base materials withenhanced permeabilities

An aqueous solution reaction method is described for preparing nanofibrous MnO2-base materials. A critical step in the synthesis is an extended period of refluxing of the reactive constituents, which enables the gradual trans formation of an initial nanoparticle agglomerated mass into a random-weave nanofibrous structure. Partial transformation of the material realizes a no vel bimodal morphology, which combines a high density of chemically active sites with an enhanced fluid permeability rate. Nigh resolution TEM observa tions reveal that the nanoscale fibers are b-axis oriented single crystals, which contain lattice defects in the form of dislocation dipoles, molecula r pores, and nanoscale holes. (C) 1998 Acta Metallurgica Inc.