Polyelectrolyte: Thermodynamics and Rheology.- Structure and Thermodynamics of Polyelectrolyte Complexes.- Polyelectrolyte: Science and Application.- Biological polyelectrolytes: Solutions, Gels, Intermolecular complexes and nanoparticles.- Polyelectrolyte Hydrogels: Thermodynamics.- Thermodynamic and rheological properties of polyelectrolyte systems.- Complexes formation between proteins and polyelectrolytes and their application in the downstream processes of enzyme purification.- Polyelectrolyte complexes: Bridging the ensemble average - single-molecule strategies.- Stratified Interpolyelectrolyte Complexes: Fabrication, Structure and Properties.- Monte Carlo Studies in Polyelectrolyte Solutions: Structure and Thermodynamics.-