ADSORPTION, SPREADING PRESSURE, AND LONDON FORCE INTERACTIONS OF HYDROCARBONS ON CELLULOSE AND WOOD FIBER SURFACES

Adsorption isotherms of some hydrocarbons on cotton cellulose paper and on thermomechanical pulp fibers are determined by a gas chromatographic technique. The isotherms are well described by the BET equation, and monolayer coverages are readily determined despite the absence of sharp knees in the isotherms. The molecular areas for the adsorbates on the two adsorbents are estimated by comparison with nitrogen adsorption data. The surface pressures, calculated from the isotherms, are analyzed in terms of Fowkes' theory. The London dispersion force contributions to the surface free energies of crystalline cellulose and of lignified wood fiber are believed to be 48 and 37 mN m-1, respectively. © 1979.