University of Sydney Researchers Report First Measurements of Moisture Transport in 10 nm Nanochannels

Building on their earlier work, Professor David McKenzie and Wenwen Lei reported the first known measurements of moisture flows in 10nm diameter capillaries using AAO substrates from InRedox. Using an elegantly simple ‘mass loss’ experimental setup, a water / glycerol mixture in a vial was used to adjust the partial pressure and 50 µm thick AAO membranes with varying pore diameters (10, 20, 40, 120 nm) allowed diffusion out of the vial over time. A careful set of measurements show that actual flow rates fall about one order of magnitude less than Washburn flow would predict. The authors examine competing theories and calculations to account for surface roughness of the pores.

“Nanoscale Capillary Flows in Alumina: Testing the Limits of Classical Theory”, Wenwen Lei and David R. McKenzie, J. Phys. Chem. Lett., 2016, 7, pp 2647–2652