Weak polyelectrolytes in brines: effects of chemical specific interactions, topology, concentration and salt valency on conformations and pKa(eff).

Properties of weak polyeletrolytes depend on their specific chemical environment, with details such as the pH, the concentration and valency of the background salt or counterions, and their topology markedly modifying the chemical behavior of their ionizing groups. As an additional characteristic that may impact on the latter properties, also chemically specific interactions (e.g. charged hydrogen bonds, c-Hb) can play an important role.  Our investigations evidenced a strong impact of pH on polymer conformations and pKa(eff) compared to chains without c-Hb’s impacting on single species properties (local charge density, gyration radius, etc).