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 TiO 2 and α-Fe 2O 3 and colloidal Fe(C 2O 4)·2H 2O metal salt are achieved with comb-polyelectrolyte surfactants and/or mildly polar resins. TiO 2 dispersions are spun and solidified “on the fly” by UV radiation into continuous ceramic/polymer nanocomposite fibers with dimensions below 10 μm. Fe(C 2O 4)·2H 2O dispersions provide a UV curable alternative to α-Fe 2O 3 dispersions which can only be thermally cured. The Fe(C 2O 4)·2H 2O nanocomposites transform to α-Fe 2O 3 below 550 °C. Novel cellular Al 2O 3, TiO 2 and α-Fe 2O 3 articles with porosity >80% and precise replication of the pore-forming agents have also been produced from such dispersions. Al 2O 3 nanocomposite microspheres are produced by emulsification of the dispersions in an appropriate medium and UV curing.