Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

This project involves the development of an innovative strategy for water generation based on the recovery ofx000D
atmospheric humidity in the gas phase. It tries to avoid the current hindrances in fog harvesting technologiesx000D
based on the recovery of water micro droplets from fog and clouds, i.e. from very humid air. Achieving a lowx000D
cost method able to collect water from ambient air even at low relative humidity (RH), down to around 20%RHx000D
in arid regions, would strongly impact many regions of the world particularly in the present climate changex000D
evolution. The proposed idea consists in forcing the water vapor in the air to nucleate heterogeneously intox000D
water droplets on super-hydrophillic surfaces having strongly enhanced surface area, and extracting the waterx000D
droplets using various strategies based on hydrophobicity and porous media. Water generation from humid airx000D
corresponds to typical dehumidification devices. The challenge is however to generate a surface on which thex000D
heterogeneous nucleation, i.e. the gas-to-liquid micro-droplet generation, is made to occur under a very smallx000D
cooling temperature below the ambient temperature. In other words, a dehumidifier requiring a minimal energyx000D
input. Such conditions were shown by the Plasma Processing Laboratory at McGill University to occur onx000D
forests of carbon nanotubes functionalized to full hydrophillicity. Water was shown to be captured, while zonesx000D
functionalized to be hydrophobic were shown to enable the extraction of water droplets. This collaborationx000D
project focusses on evaluating three potential avenues for the design of water-collecting structures, all threex000D
based on the approach developed by PPL for functionalized forests of carbon nanotubes.