| 摘要 |
<p>A novel crystalline silica composition having uniform pore dimensions of approximately 6 Angstrom units is prepared by calcining a crystalline hydrated alkylonium silicate prepared hydrothermally from a reaction mixture containing as essential reagents, water, amorphous silica and a quaternary ammonium compound at a pH of at least 10. The crystalline silica, because of its uniform pore structure, is capable of making size-selective separations of molecular species, but neither it nor its silicate precursor exhibit ion-exchange properties. This absorbent has a very useful hydrophobic/ organophilic characteristic which permits its use in selectively adsorbing organic materials from water, either in liquid or vapor phase.</p> |
