Chitosan Nanocomposite Coatings Containing Chemically Resistant ZnO–SnOx Core–shell Nanoparticles for Photocatalytic Antifouling

Abstract

Functional nanocomposites with biopolymers and zinc oxide (ZnO) nanoparticles is an emerging application of photocatalysis in antifouling coatings. The reduced chemical stability of ZnO in the acidic media in which chitosan is soluble affects the performance of chitosan nanocomposites in antifouling applications. In this study, a thin shell of amorphous tin dioxide (SnOx) was grown on the surface of ZnO to form ZnO–SnOx core–shell nanoparticles that improved the chemical stability of the photocatalyst nanoparticles, as examined at pH 3 and 6. The photocatalytic activity of ZnO–SnOx in the degradation of methylene blue (MB) dye under visible light showed a higher efficiency than that of ZnO nanoparticles due to the passivation of electronic defects. Chitosan-based antifouling coatings with varying percentages of ZnO or ZnO–SnOx nanoparticles, with or without the glutaraldehyde (GA) crosslinking of chitosan, were developed and studied. The incorporation of photocatalysts into the chitosan matrix enhanced the thermal stability of the coatings. Through a mesocosm study using running natural seawater, it was found that chitosan/ZnO–SnOx/GA coatings enabled better inhibition of bacterial growth compared to chitosan coatings alone. This study demonstrates the antifouling potential of chitosan nanocomposite coatings containing core–shell nanoparticles as an effective solution for the prevention of biofouling.

Ecosafety Screening of Photo-Fenton Process for the Degradation of Microplastics in Water

“…The preparation of ZnO NRs coated SnO x as follow; the glass fibers coated with ZnO NRs was placed into autoclave containing 75 ml SnCl 2 (0.l mM) at pH 5 and the autoclave was heated at 180 C for 15 min (Kumar et al, 2021). The glass fibers was then washed with water several time and air dried.…”

Chitosan-Based Antimicrobial Coating for Improving Postharvest Shelf Life of Pineapple

“…Chitosan (CS) is a soluble form of chitin, and it is commercially obtained through partial deacetylation of chitin, which is extracted from crustacean and fish processing wastes [26]. Chitosan has inherent antimicrobial and antioxidant properties [14,27], but it is essential to enhance these functionalities in chitosan-based coatings to achieve improved results leading to higher shelf life of coated fruits. Improvement of shelf life of fruits such as guava [28], green tomato [29], longan fruit [30], plum [31], and strawberry [32] by applying chitosan-based coatings, alone or incorporated with active agents, has been reported in the literature.…”

Fabrication of Paper Sheets Coatings Based on Chitosan/Bacterial Nanocellulose/ZnO with Enhanced Antibacterial and Mechanical Properties

“…Chitosan is also known as an antimicrobial agent and is recognized as a non-toxic, biodegradable polysaccharide. It is the second most abundant natural polymer, after plant cellulose [ 33 ]. Moreover, it exhibits excellent coating properties and therefore, it played a dual role in the prepared composites—the film-forming matrix in which ZnO-modified bacterial cellulose is incorporated and the antimicrobial agent.…”