Harnessing an Invasive Seaweed: Mechanical Reinforcement of Simonkolleite Coatings Using Brown Algae as a Sustainable Filler

Simonkolleite (Zn5(OH)8Cl2·H2O), a layered double hydroxide, is used as a fast dry coating that can be applied onto different surfaces. Due to its rapid crystallization, some problems remain during its application, e.g., crack formation, low hardness, and limited compressive strength. To solve these challenges, we propose the harnessing of brown algae, a natural plague of the Caribbean, as a filler for Simonkolleite coatings. The influence of the addition of brown algae on the structural and morphological properties of the coatings was studied, with particular emphasis on their potential for improved durability and functional performance. The addition of the algae to the coatings favored microstructural compaction, resulting in a denser and mechanically more stable coating that exhibited higher hardness and compressive strength. Also, the presence of chlorophyll in the algae could promote light utilization for other emerging applications.