Catechol grafted silica particles for enhanced adhesion to metal by coordinate bond A Physicochemical and engineering aspects

Catechol-functionalized materials have been widely studied due to improved adhesion and metal-catechol coordination properties. In this study, silica particles, which are the base material in a multitude of applications, were modified with catechol groups based on a surface grafting reaction via amine- and carboxylic acid-functionalized silica particles. The chemical compositions of the modified particles were analyzed using Fourier transform infrared (FT-IR) and thermal gravimetric analysis (TGA). The surface properties of each particle were investigated using zeta potential, contact angle, and Brunauer–Emmett–Teller (BET) analysis. A series of characterizations verified successful modification with individual catecholic monomers of dopamine onto the silica surface. On the basis of the bioinspired surface modification, catechol-functionalized silica particles (SiO2CA) exhibited outstanding adhesion properties with metals. The SiO2CA showed enhanced Fe³⁺-capturing capacity that was five times that of bare silica particles. Furthermore, SiO2CA exhibits outstanding adhesion on the TiO2-coated layer. The improved adhesion properties of SiO2CA were due to high affinity and strong binding as a result of the metal-catechol coordination.