Preparation of tannic acid based zwitterionic polymer functionalized coating on glass surface for antibacterial and antifouling applications

Herein, a silica sol was firstly prepared and coated on the glass substrate, followed by a co-deposition of tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) to form a hydrophilic layer. Subsequently, the zwitterionic polymer PEIS (polyethylenimine-quaternized derivative) was grafted onto the glass surface via Schiff-base reaction and/or Michael addition between the amino of PEIS and phenolic hydroxyl groups of TA, resulting in the formation of zwitterionic polymer PEIS-functionalized glass substrate (Glass@Silica Sol-PEIS). The thickness and surface roughness of the as-prepared Glass@Silica Sol-PEIS coating was 0.71 μm and 60.2 nm measured by AFM, respectively. Compared with the unmodified glass substrate, the Glass@Silica Sol-PEIS effectively prevented the adhesion of over 96 % of microalgae and 80 % of bacteria on its surface. The excellent antibacterial and antifouling ability can be attributed to the bactericidal activity of quaternary amine groups in PEIS and strong surface hydration effect of zwitterionic polymer PEIS. In addition to glass substrate, the novel coatings demonstrate versatility by being applicable to various substrates such as metal, fabric and plastic, showing a promising prospects for widespread application.