EFFECT OF POLYVINYL ALCOHOL ON NITROGEN SURFACE AREA AND PORE STRUCTURE OF SOILS

Changes in the specific surface area and pore size distribution due to adsorption of polyvinyl alcohol (PVA) by aggregates of a clay soil have been determined from the desorption isotherms for N at -195[degree]C. The specific surface area was reduced. The volume of pores less than 30 A wide decreased by an amount considerably in excess of the volume of PVA adsorbed. These results are interpreted in terms of "peripheral pore occupation" by the polymer, preventing access of N molecules to pores and surfaces within domains. Adsorption data previously obtained also indicated limited penetration of domains by the polymer.