(590a) Polyelectrolytes in Multivalent Ionic Media: New Physics and New Materials
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Engineering Sciences and Fundamentals
Tribute to Jacques L. Zakin: Scholar, Teacher and Mentor III (Invited Talks)
Wednesday, October 31, 2018 - 3:30pm to 3:55pm
Multi-valent interactions in systems of polyelectrolytes can exhibit dramatic, non-monotonic effects, for example, switching forces from repulsive to attractive, and back to repulsive again, in some cases. We have been studying these patterns of behavior with the surface forces apparatus (SFA) and with electrochemical methods, such as cyclic voltametry, which enables the quantitative determination of the number of multi-valent ions residing in thin layers of charged polymers. At fixed ionic strength, all cause strong shrinkage and condensation of poly(styrene sulfonate) brushes over a narrow range of ratio multi-valent to mono-valent ions. When the multi-valent ion is an oppositely charged polymer, new fluid phases can form. Charged blocks in copolymers leads to materials with new types of ordered phases. Effects of these multi-valent interactions on supermolecular and biomolecular assembly will be discussed. There are many possibilities for the creation of new materials based on electrostatic assembly involving multi-valent interactions.