Nacre inspired tailoring of mechanically strong hydrophobic coatings through Layer-by-Layer assembly

Nacre has been an extensively studied biomaterial exhibiting remarkable and myriad strength, stiffness, and toughness. Inspired by its mechanical property, bricks and mortar structure of seashell nacre was replicated by alternatively embedding building blocks into hybrid films using. Layer-by-Layer (LbL) deposition technique. The prepared artificial nacre-like hybrid films show enhanced mechanical property and solvent resistance. Synthesis of desired oligomeric siloxane was evident via FTIR and VPO, while FTIR, ellipsometer, XPS and SEM analysis indicated a successful deposition of multilayered thin films comprising polyethyleneimine (PEI), montmorillonite (MMT) and oligomeric siloxane. A strong electrostatic and hydrogen bonding enabled the nanostructured film to reach reduced modulus of ~65 GPa which is higher than previously prepared PEI-Clay coatings. The films exhibit high hardness (H), reduced modulus (Er) with a smooth surface, henceforth durable. When combined with hydrophobicity and chemical resistance of multilayered thin films, these mechanical properties indicate their promising feature for several potential applications as protective coatings in heavy mechanics, transportation, surface-sensitive substrates and adsorption of hydrophobic agents from water.