Similarities Between Polyelectrolyte Gels and Biopolymer Solutions

Correspondence to: F. Horkay (E-mail: [email protected]) ABSTRACT: Small angle neutron scattering (SANS) measurements and osmotic swelling pressure measurements are reported for polyelectrolyte gels and solutions under nearly physiological conditions. A synthetic polymer (sodium-polyacrylate) and three biopoly­ mers (DNA, hyaluronic acid, and polyaspartic acid) are studied. The neutron scattering response of these anionic polyelectrolytes is closely similar, indicating that at larger length scales the organization of the polymer molecules is not significantly affected by the fine details of the molecular architecture (e.g., size and chemical structure of the mono­ mer unit, type of polymer backbone). The results suggest that specific interactions between the polyelectrolyte chains and the surrounding monovalent cations are negligi­ ble. It is found that the osmotic compression modulus of these biopolymer solutions deter­ mined from the analysis of the SANS response decreases with increasing chain persist­ ence length. V2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3679–3686, 2006 C