Adsorption of a polyelectrolyte chain to a charged surface

摘要

The criteria for the adsorption of a polyelectrolyte chain in a salt solution on a uniformly charged planar membrane are derived using mean field arguments. Explicit formulas are obtained to describe the adsorption characteristics for varying surface charge density, charge on the polymer, Debye screening length kgr;minus;1, chain lengthL, and temperatureT. The adsorption can be tuned using any one of these parameters. WhenTis the tuning variable, for example, the chain is adsorbed atTTc, whereTcis proportional to kgr;minus;3Lminus;1and kgr;minus;11/5Lminus;1/5in the weak and strong Coulombic screening limits, respectively. The thickness of the adsorbed layer is derived to vary linearly with kgr;minus;1thinsp;ln(Tc/T) forTTc.