Mesoporous metals with chiral nematic ordering
Christopher Walters, University of British Columbia, Vancouver, CanadaKeegan Adair, University of British Columbia, Vancouver, CanadaGeorg Meseck, University of British Columbia, Vancouver, CanadaHamad Wadood, FPInnovations, Vancouver, CanadaMark MacLachlan, University of British Columbia, Vancouver, Canada
In this study, we demonstrate a novel vacuum-assisted loading technique used for developing chiral nematic mesoporous metal nanocomposites. Using a soft templating strategy, chiral nematic mesoporous silica is obtained from cellulose nanocrystals. We then load the pores of this mesoporous silica template with various aqueous metal solutions through vacuum infiltration. Significant metal loading is achieved after a single loading into the mesoporous silica template. Calcination of the films yield metal oxide nanocrystals which adopt the chiral ordering of the template and maintain high surface area and porosity. Scanning electron microscopy and nitrogen sorption confirm that the template was not destroyed during crystallite growth, and that growth was contained within the pores. Furthermore, the silica template was etched to reveal free-standing metal films on a centimeter-scale with different nanostructured networks. These materials have a host of applications including catalysis and sensing.