Dynamic Surface Charge Distribution: Examining its effect on the electric double layer using Molecular Dynamics simulation

In the pursuit of gaining a better understanding of the mechanisms of oxide-electrolyte interfaces, this thesis presents a working model that mimics a dynamic surface charge distribution by introducing protonation and deprotonation events using MD simulation. Due to the limitations of measurement equipment that operate on an atomic scale, literature cannot provide us with exact time scales for protonation and deprotonation events. Consequently, previous research simulated the surface charge distribution of oxide surfaces as being static and assumed the effect of local protonation and deprotonation to be negligible. This work shows that varying the (de)protonation event period τ significantly influences the characteristics of the electric double layer (EDL). Continuous protonation and deprotonation changes the diffusion coefficient and subsequently alters the structure of the Stern layer, screening function, and preferential adsorption type. As a whole, dynamic surface charge distribution has a considerable impact on the characteristics of the electric double layer depending on τ and should be considered in future MD simulations

Surface Protolysis and Its Kinetics Impact the Electrical Double Layer

Surface conductivity in the electrical double layer (EDL) is known to be affected by proton hopping and diffusion at solid-liquid interfaces. Yet, the role of surface protolysis and its kinetics on the thermodynamic and transport properties of the EDL are usually ignored as physical models consider static surfaces. Here, using a novel molecular dynamics method mimicking surface protolysis, we unveil the impact of such chemical events on the system’s response. Protolysis is found to strongly affect the EDL and electrokinetic aspects with major changes in Formula Presented potential and electro-osmotic flow.Complex Fluid Processin