Templated nanoporous membranes based on hierarchically self-assembled materials

The preparation of nanoporous materials from columnar hexagonal liquid crystalline networks has been accomplished by the crosslinking of a H-bonded supramolecular system, formed by a central tricarboxylic molecule (template) and three promesogenic units with a pyridine based donor/acceptor synthon and vinyl groups. Such supramolecular systems exhibit a columnar hexagonal mesophase, whose order is fixed by the photoinitiated polymerization reaction of the vinyl groups and 2,2'-(ethylenedioxy)diethanedithiol (EDDT), used as a crosslinker. Further removal of the stacked molecules used as templates leads to nanoporous materials (membranes) with the hexagonal columnar order provided by the mesophase. These membranes have demonstrated the ability to selectively adsorb certain acid dyes, depending on their size and acid strength. Moreover, the possibility of preparing organic-inorganic composite materials has been explored. Silver nanoparticles (AgNPs) with a controlled size have been grown in the cavities of the materials by means of chemical reduction of silver ions.