Functional ceramic and nanocomposite fibers, cellular articles and microspheres via radiation curable colloidal dispersions

We present here new cellular ceramics, fibers and microspheres produced by novel and general microshaping techniques employing colloidal dispersions in solvent free radiation curable monomer mixtures. High loading, low viscosity dispersions of functional nanoparticles such as TiO2 and α-Fe2O3 and colloidal Fe(C2O4)·2H2O metal salt are achieved with comb-polyelectrolyte surfactants and/or mildly polar resins. TiO2 dispersions are spun and solidified “on the fly” by UV radiation into continuous ceramic/polymer nanocomposite fibers with dimensions below 10 μm. Fe(C2O4)·2H2O dispersions provide a UV curable alternative to α-Fe2O3 dispersions which can only be thermally cured. The Fe(C2O4)·2H2O nanocomposites transform to α-Fe2O3 below 550 °C. Novel cellular Al2O3, TiO2 and α-Fe2O3 articles with porosity >80% and precise replication of the pore-forming agents have also been produced from such dispersions. Al2O3 nanocomposite microspheres are produced by emulsification of the dispersions in an appropriate medium and UV curing.