Fig. 4: Nanofluidic diodes with an asymmetric structure and chemistry.
From: A universal tunable nanofluidic diode via photoresponsive host–guest interactions
a Schematic illustration of the two states of the asymmetric modification: in the “T(+)-B(−)” state, Azo-NH2 was introduced on the tip side and Azo-COOH on the base side, and in the “T(−)-B(+)” state, Azo-COOH was introduced on the tip side and Azo-NH2 on the base side. b Contour plot of the pR values of the “T(+)-B(−)” state at asymmetric pH values (pHTip = 2, 3, 5, 7, 9, 11; pHBase = 2, 3, 5, 7, 9, 11). c Contour plot of the pR values of the “T(−)-B(+)” state under asymmetric pH values (pHTip = 2, 3, 5, 7, 9, 11; pHBase = 2, 3, 5, 7, 9, 11)
