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

Abstract

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 dm 3 /m 3 . 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.

Nanochitin: Chemistry, Structure, Assembly, and Applications

“…Moreover, the respective cryogel was reusable, exhibiting a high methylene blue adsorption capacity (505 mg g –1 even after five successive adsorption–desorption cycles). A recent report indicates the use of ChNF cryogels decorated with silica toward superhydrophobic adsorbents for underwater collection of methane . The underlying mechanism of such an action of the ChNF cryogel relates to the formation of a silver mirrorlike film, making possible the entrance of methane gas through the pores.…”

“…A recent report indicates the use of ChNF cryogels decorated with silica toward superhydrophobic adsorbents for underwater collection of methane. 657 The underlying mechanism of such an action of the ChNF cryogel relates to the formation of a silver mirrorlike film, making possible the entrance of methane gas through the pores. No such film was formed with pure ChNF, which resulted in aggregation of methane bubbles underneath the hydrophilic surface.…”

Superhydrophobic Modification of Biomass Cuttlebone Applied to Oil Spill Remediation

“…The absorption peak at 3453 cm −1 in the spectrum of the polydopamine-modified cuttlebone could be assigned to the superimposed stretching vibration of the N-H bonds and O-H bonds. In the spectrum of the superhydrophobic cuttlebone, the adsorption peaks at 1248 cm −1 and 776 cm −1 could be ascribed to the stretching vibrations of the C-F bonds and Si-O-Si bonds, and the peak at 470 cm −1 could be ascribed to the stretching vibrations of the Si-O bond in SiO 2 [29]. These results indicate that the surface modification using polydopamine and fluorinated silica is successful.…”

“…With high porosity (~93%) and excellent mechanical properties, cuttlebone has great potential for fabrication of new materials [18,20]. Compared to cellulose aerogel [22][23][24][25][26][27][28] and chitin aerogel [16,29], and chitin/cellulose aerogel [30], the high porosity, ultra-low density, high permeability, and high robustness of cuttlebone make it a great candidate for high-performance adsorption materials [31][32][33].…”

Elastic Agarose Nanowire Aerogels for Oil–Water Separation and Thermal Insulation

“…To create novel environmentally friendly aerogels with high-performance oil–water selectivity, some hydrophobic natural polymer aerogel materials have also been prepared. − Among the numerous oil absorbents, natural polymer aerogel materials have received considerable attention owing to their natural abundance, biodegradability, renewability, and environmental friendliness . Furthermore, natural polymer aerogels derived from animals or plants, such as cellulose, ,− chitosan, chitin, pectin, starch, and all kinds of polysaccharides, − have a variety of structures and functional groups, which make it easy to chemically and physically modify them . For instance, Yu et al, prepared superhydrophobic cellulose/poly (vinyl alcohol) (PVA) aerogels through chemical crosslinking, freeze drying, and silanization, which exhibited durable superhydrophobicity and remarkable separation performances.…”