THE ROLE OF POROSITY IN POLYETHYLENIMINE ADSORPTION ONTO CELLULOSIC FIBERS

The total adsorption of a given polyethylenimine on pulp fibers, the porosity of which was altered by different drying conditions, was determined and compared with the available internal surface of the fibers. Since polymer adsorption takes place in an aqueous environment, the pore volume and the internal surface of pores as a function of their size were determined from a first benzene desorption isotherm, measured on fibers in which water was replaced by benzene to preserve their swollen structure. The total adsorption of a given polyethylenimine was found to be in a direct relation to the internal surface available in pores larger than a certain size, regardless of the total porosity. Consequently, it is concluded that the adsorption capacity is determined by the accessible surface. Copyright © 1990 John Wiley & Sons, Inc.