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our mood is preserved 6 times more It has more water than any river on earth. Dew drops on the grass and water droplets on cold juice bottles are evidence of this natural water reservoir. Despite being everywhere 2000000000 People on Earth still do not have access to clean drinking water.
Some of this freshwater can be extracted from the air using a technique called air water harvesting (AWH). However, there are various challenges that prevent large-scale deployment of AWH. To make his AWH system effective and continuous, the scientist must make sure he does two things. First, water absorption from air is completely reversible, so water can be recovered and used.
The second is efficient waste heat management. When the AWH system captures water from the air, heat is released through condensation of the water. If this excess heat is not handled carefully, it can compromise the entire process. However, it now seems to be closer to a solution. Inspired by the structure of plant leaves, a Chinese research team created a core-shell structured cellulose nanofiber-based aerogel (called Core-Shell@CNF for short) that promises to overcome these challenges. .
It not only runs on sunlight, but also generates electricity.
create fresh water from thin air
Core-Shell@CNF has a hydrophilic (attracts water molecules) core and a hydrophobic (easily repels water) shell. The former consists of LiCl particles that act as adsorbents, with good ability to absorb water. The latter contains carbon black particles and has a water-resistant polydimethylsiloxane (PDMS) coating. This layered design is inspired by plant leaves, “well-designed where the leaf cuticle protects the internal mesophyll tissue from dehydration and oxidation, and the stomata allow the free transport of gaseous water molecules.” It shows a well-structured core-shell structure.”Research author Notes.
The AWH process begins by allowing the airgel to absorb moisture overnight. When air, along with water vapor, passes through the material, its large pores allow water molecules to reach her LiCl particles inside, where they are absorbed. As more water enters, the hydrated salt turns into a liquid film and then a salt solution. Meanwhile, the outer hydrophobic shell prevents liquid water from leaking out. This combination helps Core-Shell@CNF keep collecting water.
During the day, carbon black particles absorb sunlight and heat up rapidly. As a result, the temperature inside the airgel rises and water vapor begins to be released from the salt solution, reforming the original salt. Carbon can quickly absorb sunlight and convert it into heat energy, so airgel can release water quickly. The porous structure of carbon also helps transfer heat and water molecules, making the desorption process more effective.
The researchers tested the limits of AWH materials and performed multiple absorption-desorption cycles to achieve maximum efficiency. This has led to some improvements in material design. For example, the final airgel structure has fewer pores and ten times thicker outer walls than the original airgel. Thanks to these changes, [pressure]CB-PDMS@CNF could prevent water penetration and exhibit good hydrophobicity and mechanical strength,” the researchers noted.
A strong hydrophobic shell is also good at keeping airgel clean, as it separates dust particles and contaminants that accompany water molecules. When the researchers tested the airgel in his 24-hour outdoor environment, it was able to collect less than 1 gram of fresh water per kilogram of material. The researchers hoped to increase efficiency, but the water itself was ready to drink. “The results of inductively coupled plasma-mass spectrometry (ICP-MS) testing showed that the collected water met the drinking water requirements of the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA).” they added.
