Biomimetic Multifunctional Nanochannels Based on the Asymmetric Wettability of Heterogeneous Nanowire Membranes

A charged heterogeneous nanowire membrane with asymmetric wettability serves as a biomimetic passive channel when the bilayer is hydrophilic; It also functions as pH valve based on the hydrophobic CaWO4 layer (contact angle of 145.3˚±0.3˚) and hydrophilic MnO2 layer. Moreover, a reversible ionic rectification is realized in the above-mentioned semi-hydrophobic and hydrophilic state with strong acid environment or in the complete hydrophobic stage with a moderate discrepancy (CA of CaWO4 and MnO2 layer are 141.3˚±0.3˚ and 157.6˚±2.0˚, respectively) in near neuter condition.