(196g) Synthesis, Characterization, and Assembly of All Polyelectrolyte Diblock Copolymers from Poly (ionic liquid) and Weak Polyelectrolyte Blocks

Poly(ionic liquids) (PILs) are a special type of strong polyelectrolytes that combine the diverse functionality and unique properties of ionic liquids (ILs) with the mechanical stability, long-range ordering, and processability of polymers. In recent years, PILs have found application in a variety of fields including battery electrolytes, separations, nanomaterials, and more. In one growing field, PILs have been combined with highly incompatible neutral polymers to form block copolymers (BCPs). These systems have been used in forming polymer films and membranes with unique nanostructures such as lamellae, cylinders, spheroids, and bicontinuous structures. Depending on the structure, these morphologies can enhance the properties of PILs materials, such as ion conductivity in battery electrolytes or interfacial behavior in coatings. However, only a few studies have investigated block copolymers composed of PILs with weak polyelectrolytes, which can modulate their charge density based on degree of protonation. Such materials show conformational changes in response to environmental stimuli such as changes in pH and salt. Synthesizing and characterizing PIL-b-polyelectrolytes will aid in the development of novel all polyelectrolyte materials for applications in stimuli response, polymer battery electrolytes, and flexible electronics. In this work, (PIL-b-polyelectrolyte) BCPs are synthesized through the SARA ATRP controlled free radical polymerization technique. Specifically, poly[vinylbenzyl butyl imidazolium bis(trifluoromethanesulfonyl) imide] was polymerized utilizing a tertiary amine weak polyelectrolyte macroinitiator. The synthesized polymers were characterized for their chemical properties and molecular weight through GPC, NMR, and FITR. The solubility and solution behavior of these block copolymers were investigated with DLS. Thermal properties were characterized with DSC and TGA. A preliminary examination of the block copolymer self-assembled films on wafers was also performed with optical microscopy, SEM, and combined FTIR-AFM.