Antifouling performance of in situ synthesized chitosan-zinc oxide hydrogel film against alga M. aeruginosa

The undesirable settlement and growth of microalgae on submerged installations is a universal problem in water environment. Soft hydrogels are promising fouling-resistant materials due to the inherent surface properties. Herein, a kind of chitosan hydrogels with increasing zinc oxide (ZnO) mineral phase content were prepared by in situ sol-gel and solvent casting method, to prevent growth of algae Microcystis. aeruginosa. Incorporation with ZnO mineral phase improved mechanical property, water absorption, and stability of the obtained chitosan-zinc oxide (CS@ZnO) hydrogel films in Zn dose-dependent manner. The highest strength and growth inhibition (63.45 +/- 8.93%) were observed by CS@ZnO-1.5 hydrogel films with the concentrations of 1.5% precursor in comparison with other hydrogel films. During this process, algal cell membrane was slightly damaged (24.5 +/- 1.57%) and accompanied by significantly synthesis inhibition such as chlorophyll a (55.22 +/- 2.72%) and total soluble protein (42.97 +/- 1.66%). To sum up, synthesis inhibition of algal cell is the main mechanism of CS@ZnO hydrogel films inhibiting algal growth, which has the potential in antibiofouling application.

Automated summary

This study demonstrated the successful inhibition of Microcystis aeruginosa growth using chitosan-zinc oxide hydrogel films. The main mechanism involves synthesis inhibition of algal cells, presenting potential in antibiofouling applications.