An integrative approach for analyzing metal-polyelectrolyte interactions

An integrative approach based on the combined use of both experiments and m odelling is discussed here aimed at investigating metal-polyelectrolyte int eractions in solution. Electrochemical techniques are applied because of th eir potential to measure the actual speciation without disturbing the solut ion physico-chemical equilibrium. The experimental methodologies are comple mentary since the ranges of applicability depend on the solution compositio n itself. To complement and interpret the results of these experimental tec hniques, a physico-chemical association model, based on the so-called 'chem ical model' of counterion condensation theory, is used. The model considers that, in addition to the usual electrostatic interactions and entropic eff ects, territorial affinity and chemical bonding interactions take place bet ween the small counterions in solution and the: polyelectrolyte. A number o f particular cases of metal/polyelectrolyte systems are discussed aimed at showing that the integrative approach leads to additional information about the solution system which can not be deduced from experimental results sol ely. Future challenges with respect to the applications in the study of nat ural aquatic systems are pointed out. (C) 2000 Elsevier Science B.V. All ri ghts reserved.