Electrokinetic energy conversion of power-law fluids in hydrophobic nanochannels

We demonstrate that a strategy coupling hydrophobic nanochannels with shear-thinning power-law fluids creates a synergistic framework for amplified electrokinetic energy conversion. The investigation systematically examines two critical operational configurations: hydrophobic nanochannels with fixed surface charges and hydrophobic nanochannels with mobile surface charges. The results indicate superior streaming potential and output power in both types of hydrophobic nanochannels compared to hydrophilic counterparts. This enhancement, however, does not extend to conversion efficiency in all cases: while hydrophobic channels with fixed charges achieve higher efficiency, those with mobile surface charges exhibit a reduction. Through parameter optimization, the maximum streaming potential, output electrical power, and conversion efficiency obtained in current systems are −1104 V/m, 6.7 × 10−11 W, and 16%, respectively, all attained in hydrophobic nanochannels with fixed surface charges. The output power achieved is more than twice that of the power obtained in hydrophilic nanochannels. This dual-strategy investigation provides fundamental insight into interfacial electrokinetic phenomena while offering practical pathways for advanced energy harvesting device design.