Surface Area Determination of Soils by Adsorption of Ethylene Glycol Vapor

Abstract

Abstract Surface area was determined from ethylene glycol (EG) retained by vapor‐wetted soils and clays in equilibrium with EG‐bentonite or ‐resin buffers. The method compared favorably with previously proposed equilibrium and nonequilibrium methods. Only small excesses of EG are adsorbed by vapor‐wetted samples. This reduces equilibration time, extends buffer life, and eliminates hysteresis on the drying curve at the monolayer point. The determination is independent of sample size; moderate temperature fluctuations; or moisture present in EG, buffer, or sample. Use of redistilled EG is not necessary. The monolayer end point can be determined using a series of EG‐bentonite buffers independently of other methods. Buffers containing more than a monolayer of EG can be used if suitable corrections are made.