Abstract
We consider the influence of the ion-partitioning effect, enabled by the permittivity difference at the interface, to investigate the formation of blue energy within the nanochannel having pH-sensitive polyelectrolyte layer (PEL) under a salinity gradient. By altering the pH of right reservoir (pHR) and permittivity ratio of electrolyte solution to PEL, respectively, we investigated the electric-double layer (EDL) potential field, cationic concentration field, transference number, maximum power generation, optimum power production and its density, conductance, and optimum energy conversion efficiency. It turns out that due of the decrease in screening effect caused by the reduction in cationic concentration, the EDL potential is significantly increased by the ion-partitioning effect. We found that PEL permittivity and pHR have a considerable impact on ionic selectivity of nanochannel. For strongly acidic solutions, it implies that power generation decreases at smaller PEL permittivity. Additionally, at both lower and higher pHR values, the maximum energy conversion efficiency decreases as PEL permittivity decreases. Furthermore, the higher power generation density attained at lower pHR—an analysis conducted in this work, supports the novelty of the current energy-generating nanofluidic device when compared to the previously published work.