A density functional theory study on the underwater adhesion of catechol onto a graphite surface

• Published in: Physical chemistry chemical physics : PCCP Vol. 23; no. 2; pp. 131 - 137
• Main Authors: Chitumalla, Ramesh Kumar, Kim, Kiduk, Gao, Xingfa, Jang, Joonkyung
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 21.01.2021
• Subjects: Adhesion; Bonding strength; Catechol; Charge transfer; Density functional theory; Graphite; Hydrogen bonds; Hydrophilicity; Hydrophobic surfaces; Hydrophobicity; Silicon dioxide; Underwater; Water chemistry; Water resistance
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d0cp05623e

Mussel foot proteins (MFPs) strongly adhere to both hydrophilic and hydrophobic surfaces under wet conditions. This water-resistant adhesion of MFP is ascribed to catechol (1,2-dihydroxybenzene) which is highly contained in the MFP. Currently, little is known about the molecular details of the underwater adhesion of catechol onto a nonpolar hydrophobic surface. By using the density functional theory, we investigate the adhesion of catechol onto a wet graphite surface. We unveil the molecular geometry and energy in the course of the wet adhesion of catechol. Catechol adheres through π-π stacking with the underlying graphite. The surrounding water molecules further strengthen the adhesion by forming hydrogen bonds with catechol. In addition, a significant charge transfer has been observed from wet graphite to the catechol. Consequently, catechol adheres onto the present hydrophobic surface as strongly as onto a hydrophilic silica surface. By employing periodic-DFT simulations, we unveil that the wet adhesion of mussels onto a hydrophobic graphite surface is significantly strong and is comparable with that on a hydrophilic silica surface.