MSE Masters Thesis Final Presentation: Jianyu Wu

MSE Master’s Final Thesis Presentation: Jianyu Wu

TITLE: A Modular Block Copolymer Platform for Studying Nanostructured Ion-Conducting Membranes

ADVISOR: Joerg Werner (ME, MSE, Chemistry)

COMMITTEE: Srikanth Gopalan (ME, MSE)

ABSTRACT: Nanostructured ion-conducting membranes with independently tunable chemistry and morphology remain a central challenge in advanced energy materials. Here, we report a modular block copolymer platform based on crosslinked poly(isoprene)-block-poly(styrene)-block-poly(glycidyl methacrylate) (xISG) triblock terpolymers. Membranes are fabricated via evaporation-induced self-assembly and selectively crosslinked, followed by post-synthetic sulfonation and secondary amine-mediated crosslinking. This strategy enables control over ion exchange capacity while preserving long-range ordered gyroid morphologies, as confirmed by small-angle X-ray scattering. Systematic studies reveal that sulfonation enhances water uptake and ionic functionality, whereas secondary crosslinking effectively suppresses swelling and stabilizes the nanostructure. By overcoming the intrinsic coupling between chemical composition and morphology in conventional systems, this platform establishes a versatile design framework for high-performance ion exchange membranes, with implications for fuel cells, electrochemical energy storage, and separations technologies.