Charge Delocalization Modulates Zwitterionic Surface Hydration and Antifouling Performance*

Polymeric zwitterions exhibit exceptional fouling resistance through formation of a strongly hydrated surface of immobilized water molecules. While extensively tested for application-specific performance, the characteristics of this hydration layer and the role of molecular design on broad fouling resistance remain unclear. This work identifies charge delocalization as a key parameter affecting the hydration structure and dynamics around polymeric zwitterions. Sum frequency generation vibrational spectroscopy reveals that diffuse zwitterions form more hydrated surfaces with improved marine fouling resistance. Meanwhile, Overhauser dynamic nuclear polarization (ODNP) relaxometry shows that charge screening accelerates surface water dynamics, with more dense zwitterions approaching bulk water dynamics.