Generating a technology platform for water harvesting from humid air using carbon nanotube-based nanocomposites

该项目涉及开发一种基于气相中大气湿度回收的水生成创新策略。它试图避免目前雾收集技术的障碍，该技术基于从雾和云，即从非常潮湿的空气中回收水微滴。实现一种低成本的方法，即使在低相对湿度（RH）下，也能够从环境空气中收集水，在干旱地区低至20%RH左右，这将对世界上许多地区产生强烈影响，特别是在目前的气候变化演变中。所提出的想法在于迫使空气中的水蒸气在具有强烈增强的表面积的超疏水表面上非均匀地成核成水滴，并使用基于疏水性和多孔介质的各种策略来提取水滴。从湿空气中产生的水对应于典型的除湿装置。然而，挑战在于产生一种表面，在该表面上，在低于环境温度的非常小的冷却温度下发生异质成核，即气体到液体的微滴产生。换句话说，除湿器需要最小的能量输入。麦吉尔大学的等离子体处理实验室证明，这种情况发生在功能化到完全无规性的碳纳米管森林中。水被证明是被捕获的，而被功能化为疏水的区域被证明能够提取水滴。这个合作项目的重点是评估三种潜在的途径设计的水收集结构，所有这三个基础上的方法开发的PPL功能化森林的碳纳米管。

This project involves the development of an innovative strategy for water generation based on the recovery ofatmospheric humidity in the gas phase. It tries to avoid the current hindrances in fog harvesting technologiesbased on the recovery of water micro droplets from fog and clouds, i.e. from very humid air. Achieving a lowcost method able to collect water from ambient air even at low relative humidity (RH), down to around 20%RHin arid regions, would strongly impact many regions of the world particularly in the present climate changeevolution. The proposed idea consists in forcing the water vapor in the air to nucleate heterogeneously intowater droplets on super-hydrophillic surfaces having strongly enhanced surface area, and extracting the waterdroplets using various strategies based on hydrophobicity and porous media. Water generation from humid aircorresponds to typical dehumidification devices. The challenge is however to generate a surface on which theheterogeneous nucleation, i.e. the gas-to-liquid micro-droplet generation, is made to occur under a very smallcooling temperature below the ambient temperature. In other words, a dehumidifier requiring a minimal energyinput. Such conditions were shown by the Plasma Processing Laboratory at McGill University to occur onforests of carbon nanotubes functionalized to full hydrophillicity. Water was shown to be captured, while zonesfunctionalized to be hydrophobic were shown to enable the extraction of water droplets. This collaborationproject focusses on evaluating three potential avenues for the design of water-collecting structures, all threebased on the approach developed by PPL for functionalized forests of carbon nanotubes.