Directional Water Collection in Nanopore Networks

GIMENEZ, ROCIO; BELLINO, MARTÍN GONZALO; BERLI, CLAUDIO LUIS ALBERTO

ACS Omega

American Chemical Society

Año: 2018 vol. 3 p. 16040 - 16045

2470-1343

The development of artificial nanosystems that mimic directional water-collecting ability of evolved biological surfaces is eagerly awaited. Here we report a new type of addressable water collection that is induced by coupling both vapor gradients like a road drawn and the temperature-tuned condensation in nanopores as step signals. What distinguishes the motion described here from the motions reported earlier is the fact that neither bulk liquid infiltration nor displacement of droplet are required. Instead, the motion results from a scanned water capture due to the temperature-dependent condensation command acting on the vapor pressure gradient track originated by a droplet without a bulk fluidic connection with a mesoporous film. This novel working principle demands only a small range surface temperature control, which was entirely generated by a thermoelectric cell integrated to the mesoporous substrates. The strategy opens the route to achieving precise control over wetting location (from a few to hundreds of microns) and hence over the direction of water collected by these widely employed nanomaterials. Furthermore, as water is collected from condensation into the pores, the system naturally involves purification and subsequent delivery of clean water, which provides an added value to the proposed strategy.