this invention relates to a process for the preparation of silicious polymeric materials and their use in the separation of fluids in the gaseous phase , wherein the materials are obtained through three basic procedures : polymerization of monomeric substances in the presence of high purity submicroscopic silica particles in which the polymerization of the monomers can be followed by a deactivation reaction with silylating agent ; addition of high purity submicroscopic silica particles to monomeric substances , and coupling regents , which will react with surface hydroxyl groups on the silica and a polymer or monomers which are forming a polymer in the reaction medium ; through dispersion of the high purity submicroscopic particles in plymeric organic substances . the materials obtained in this invention are solid , usually white , highly porous , of relatively high surface area , thermally stable and have good mechanical strength , and when used as a packing material in a gas chromatographic column provide excellent results with respect to permeability , efficiency , and selectivity .