Tuning Interparticle Interactions in Graphene Oxide Dispersions for Enhanced Shear-Induced Alignment

The macroscopic behavior of colloidal materials is governed by interactions between their microscopic building blocks. In anisotropic colloidal systems, subtle variations in interparticle forces can lead to dramatic changes in phase behavior, flow response, and alignment under shear. Here, we systematically investigate how ionic strength controls the structural state, rheology, and alignment dynamics of aqueous graphene oxide (GO) dispersions, and how these effects translate into the performance of wet-spun fibers. By varying the NaCl concentration, we tune the GO system across three regimes: a jammed repulsive glass state at low salt, an aggregation-dominated state at high salt, and a relaxed soft glassy state that allows for structural rearrangement. In this intermediate regime (∼1-5 mM NaCl), the dispersions exhibit the lowest yield stress and the fastest domain reorientation under sh…