POLYELECTROLYTE CHAIN DIMENSIONS

The parameters that enter excluded volume theory, namely the persisten ce length and the excluded volume between segments, depend in a qualit atively obvious way on the polyelectrolyte charge and the solution ion ic strength. However, a quantitative understanding is quite difficult to achieve for realistic models of flexible chains. Therefore a simula tion of these parameters was performed for small sections of polyelect rolyte chains and the results were incorporated into excluded volume t heory. The theory was suitably modified to take into account the fact that a segment is a finite rather than an infinitesimal fraction of th e whole chain, as is usually assumed. Excellent agreement was found be tween the predicted expansions of whole chain dimensions and simulatio n results.