image: The particles on the crystalline surface are picked up by water and carried down the channel as the channel sublimes and widens. view more
Credit: Courtesy of NYUAD
Fast facts:
- The global shortage of fresh water currently affects hundreds of millions of people around the world, and it is estimated that by 2025, 1.8 billion people will experience severe water scarcity and hunger due to loss of fertile farming lands caused by droughts.
- The discovery of alternative water-harvesting technologies holds the potential to alleviate the foreseeable socioeconomic impacts of severe water scarcity.
Abu Dhabi, UAE, March 16 2023: Researchers of the Smart Materials Lab (SML) and the Center for Smart Engineering Materials (CSEM) at NYU Abu Dhabi (NYUAD) have reported a novel method of harvesting water from naturally occurring sources such as fog and dew.
In the study, Research Scientist Patrick Commins and Post-doctoral Associate Marieh B. Al-Handawi observed for the first time the process of water spontaneously condensing from its vapor to liquid form and moving across the surface of a slowly subliming organic crystal. This was found to be caused by changes in the width of small channels that appear on the surface of the crystal over time, which guide the condensed water across the crystal’s surface.
In the paper titled Autonomous and Directional Flow of Water and Transport of Particles across a Subliming Dynamic Crystal Surface published in the journal Nature Chemistry, researchers describe the process of condensation and movement of water that carries particles on the surface of crystals of hexachlorobenzene, a compound that is often used as a fungicide. Due to sublimation, the surface of this material has a rigid topography with defined parallel channels. Small solid particles such as dust or even metallic nanoparticles were observed to move autonomously along the channels. The motion of these particles was found to be caused by the condensed aerial water, which migrates through the channels due to the change in the cross-section and width of the channels over time.
Autonomous water flow has previously been achieved utilizing either surface chemical modifications or precisely fabricated microchannels, or on the surface of natural systems such as some plants or insects. The findings from this new study hold the potential to guide the creation of new technologies to utilize naturally occurring sources of water such as dew and fog, which are currently only used by some desert plants and animals for survival. The new research builds on the understanding of water collection mechanisms of such biological structures, while it presents a fundamentally different mechanism for water transportation.
“The motion of water on solid surfaces is one of the most fundamental phenomena found in nature,” said Panče Naumov, a leader of the Smart Materials Lab and Director of the Center for Smart Engineering Materials, and the corresponding author of the study. “Through millennia-long evolutionary processes, surfaces of natural organisms have been optimized for efficient transport of water for a variety of life-supporting functions. Plants have been seen to do this by moving water against gravity. Our team has discovered a new way to move water across a dynamic solid surface, a fundamentally new underlying principle of water collection. This can provide an inspiration for emerging technologies that could potentially maximize the efficiency of experimental systems used for the collection of aerial humidity.”
About NYU Abu Dhabi
NYU Abu Dhabi is the first comprehensive liberal arts and research campus in the Middle East to be operated abroad by a major American research university. NYU Abu Dhabi has integrated a highly selective program with majors in the sciences, engineering, social sciences, arts, and humanities with a world center for advanced research. Its campus enables students to succeed in an increasingly interdependent world, and to advance cooperation and progress on humanity’s shared challenges. NYU Abu Dhabi’s high-achieving students have come from some 125 countries and speak over 100 languages. Together, NYU's campuses in New York, Abu Dhabi, and Shanghai form the backbone of a unique global university, giving faculty and students opportunities to experience varied learning environments and immersion in other cultures at one or more of the numerous study-abroad sites NYU maintains on six continents.
Journal
Nature Chemistry
Article Title
Autonomous and directional flow of water and transport of particles across a subliming dynamic crystal surface