The surface potential of each particle system was measured using a Malvern Zetasizer Nano ZS with DTS1070 folded capillary cells. Measurements were performed on highly dilute samples equilibrated in 10 mM NaCl. Zeta potentials were calculated using the Smoluchowski approximation (Henry's function f (κa) = 1.5), with refractive indices of 1.39 for PFPMA particles and 1.59 for PS particles.