The effect of colloids on nanofluidic power generation

Abstract

We discussed the influences of colloidal particles on ion transport in nanofluidic power generation system, which is an unavoidable issue for actual membrane-based power generation systems. By introducing negatively charged colloidal particles (∼100 nm) with different concentrations, power generation by reverse electrodialysis in a porous anodic alumina membrane was analyzed. The power was enhanced in a colloid concentration of (2.6–4.2)×10-5g/ml. The maximum power was acquired when the colloid (∼3.05×10-5g/ml) was on the same side as the salt solution (1 M KCl). Modifying the surface of the porous anodic alumina membrane by using an ultra-thin metal layer (10 nm of platinum) achieved almost the same maximum power, but the colloid concentration range of the power enhancement broadened. The electrokinetic interplay between colloidal particles and nanofluidics is complex. The appearance of colloidal particles in water bodies does not always result in a reduction in power generation, and their effects can be effectively regulated by engineering parameters.