Natural and Sustainable Superhydrophobic Nanochitin Aerogels for Collecting Methane Bubbles from Underwater

This study uses a seafood byproduct, shrimp shells, as the starting material, to prepare superhydrophobic nanochitin aerogels for underwater methane bubble collection. The morphology, internal structure, and physical and chemical properties of the superhydrophobic nanochitin aerogels were analyzed. The result shows that the SNCAs show excellent hydrophobicity with a static water contact angle of 151°. Methane bubble collection and transmission were demonstrated with a static methane bubble collection apparatus with a piece of superhydrophobic nanochitin aerogel as a methane absorbent. The influence of the nanochitin concentration and the immersion depth on the methane absorption capacity was studied. When the immersion depth increases from 3.3 to 30 cm, the methane absorption capacity reaches 122.4 dm3/m3. Moreover, a continuous methane bubble collection apparatus was assembled and demonstrated. The mechanism of the methane collection process was also investigated. The preparation approach of the superhydrophobic nanochitin aerogel and its application in reducing the methane leaks from water bodies are of great significance to slow the rate of global warming.