Silica-pillared micas

Prodn. of a silica-pillared mica comprises: (a) contacting a fluoromica having layers with an organosilicon precursor or organosilicon oligomer for a time and at a temp. sufficient to allow it to intercalate between the fluoromica layers; (b) calcining for a time and at a temp. sufficient to decompose the intercalated material into a silica pillar and form an intermediate pillared mica prod.; (c) washing; and (d) recalcining for a time and at a temp. sufficient to form a silica pillared mica. The calcination temp. of (b) is 200 - 600 deg. C.. The recalcination temp. of (d) is 400 - 800 deg. C.. The organosilicon precursor or oligomer contains a positively charged gp. and its pH is adjusted to above 5. The organosilicon oligomers are oligosilsesquioxanes of formula (XSiO1.5); n = even number of at least 4; X = organyl, (m)ethyl, propyl, butyl, hexyl, heptyl, vinyl, allyl, benzyl, 2-methylbenzyl, 4-methylbenzyl, nitrobenzyl, triethylammonium, aminopropyl and/or 2-pyridoethyl; pref. including homosilsesquioxanes of formula (XSiO1.5)n(OSiX2)m; m, n = integers.