Fig. 1.

Model system for dissipative self-assembly of pH-responsive particles. (A) The model system is composed of equal numbers of a-type and b-type particles: a-type particles model pH-responsive negatively charged colloids with pK_a = 5 (e.g., carboxylate-coated colloids), which have a −z₀ charge at pH 7 and zero charge at pH 3; b-type particles model pH-responsive positively charged colloids with pK_a = 5 (e.g., pyridine-coated colloids), which have a +z₀ charge at pH 3 and zero charge at pH 7. (B) Charge of the colloids as a function of pH (determined with Eq. 1).