Mussel inspired coatings based on tannic acid and polyamines

Abstract

Mussels attach to solid surfaces in the sea through their adhesive (foot) proteins which are rich in 3,4-dihydroxy-l-phenylalanine (DOPA). The catechol unit in DOPA, which oxidizes to quinones is extremely reactive to both amines and thiols by Schiff base or Michael addition reactions, was found to be responsible for the adhesion capability of mussels [1]. In the past few years, researchers have been trying to mimic mussel foot proteins to fabricate multifunctional polydopamine based coatings [2]. Inspired by the mussel foot proteins, we prepared coatings using tannic acid (TA) and various polyamines (PA) instead of DOPA. TA, which is a polyphenol, is highly reactive towards amine or thiol groups. In this study, thin TA/PEA films and coatings on glass slides were produced. Effect of PA structure and TA/PA ratio on the properties of the coatings were investigated. Depending on the TA/PA composition it was possible to get extremely rigid to highly elastomeric materials. Films obtained were characterized by ATR-IR spectroscopy, DSC, SEM, AFM, tensile tests and advancing and receding water contact angle measurements