POLYVINYL-ALCOHOL CLAY COMPLEXES FORMED BY DIRECT SYNTHESIS

Synthetic hectorite clay minerals were hydrothermally crystallized wit h direct incorporation of a series of five water-soluble polyvinyl alc ohols (PVA) of molecular weights from 9000-146,000, The molecular weig ht of PVA had little effect on the success of hydrothermal hectorite s ynthesis, d-spacing or the amount of polymer incorporated. The basal s pacings range from 19.5 Angstrom to 20.8 Angstrom and the amount of po lymer incorporated ranges from 20 wt.% to 23 wt.%. incorporation of PV A within the clay interlayers, along with Li(I) ions to compensate the lattice charge, is indicated. Thermal gravimetric analysis and small angle neutron scattering were used to further examine the polymer-clay systems. Small PVA-clay crystallites that are coated with excess PVA are indicated. Removal of the polymer does not alter the extended synt hetic clay network, and the nitrogen BET surface area increases from < 5 m(2)/g to >200 m(2)/g.