The helical nanofilament (HNF) liquid crystal phase is a member of an unusual class of thermotropic phases with lamellar structures dominated by a tendency towards developing negative Gaussian curvature of the layers. Members of this family are sometimes termed “dark conglomerates,” due to their behavior in polarized light microscopy. These include a fluid phases - the high temperature dark conglomerate phase, which is a kind of sponge phase, and the low temperature dark conglomerate phase, also seemingly a sponge phase with structural details currently under investigation. The HNF phase, also a “dark conglomerate,” seems to be unique in the family, since slow conformational dynamics indicate a quasi-crystalline structure within layers, but no long range positional correlations across layers. We have been exploring possible applications of the HNF phase, which is highly porous, as a host for the formation of alignable composites for photovoltaics and other organic semiconductor applications. Recent results regarding the structure of these composites, including data suggesting a remarkably elegant nanostructure for HNF-chiral nematic composites, will be discussed.
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