A family of cationic polyelectrolytes possessing defined chain lengths, narrow chain length distributions, uniform charge d., but substituents of different hydrophilicity at the quaternary ammonium group served as model compds. for adsorption studies. These studies quant. revealed that polymer characteristics and electrostatic parameters affect the adsorption behavior on oppositely charged porous column materials. The presence of electrostatic exclusion, in addn. to size exclusion, was proved comparing mol., electrostatic and geometrical parameters. The dominance of electrostatic effects could be concluded evaluating the relation between mol. and electrostatic dimensions. The results provide a contribution how to est. the threshold for electrostatic exclusion from pores as a function of dimensions and exptl. conditions. [on SciFinder (R)]