The synthesis, full characterisation and utilisation of template-free silica sodalite, a novel polymorph of silica

Empty glass: Subjecting ethylene glycol silica sodalite to heat (680 °C) under a nitrogen atmosphere (i) successfully removes the templating agent to give cubic silica sodalite, which, upon consequent heating under an oxygen atmosphere (ii), transforms into a rhombohedral form of the empty sodalite, in effect a novel polymorph of silica.