Gouy-Chapman-Stern Double Layer (2D)

The 3D version renders the Stern layer and the diffuse ion cloud as a scene you orbit around; this 2D companion strips that away and puts the actual numbers on screen instead. It solves the Gouy-Chapman-Stern model self-consistently — the compact Stern layer as a parallel-plate capacitor in series with the full nonlinear Grahame relation for the diffuse layer — by bisecting for the potential at the Stern/diffuse boundary on every slider move, rather than assuming a fixed split the way a purely illustrative exponential-decay approximation would. Two live charts track the result: a potential-decay curve φ(x) from the electrode surface out through the shaded Stern region and into the diffuse tail, and a paired cation/anion density profile showing the Boltzmann-weighted counter-ion pile-up and co-ion depletion near a charged surface. A side panel exposes electrolyte valence, bulk concentration, electrode surface potential and Stern-layer thickness, with six live readouts (Debye length, Stern potential, surface charge density, and all three capacitances) so the effect of each parameter on real electrochemical quantities is immediate rather than inferred from a rotating mesh.