Contact-Biocide TiO 2 Surfaces by Surface-Initiated Atom Transfer Radical Polymerization with Chemically Stable Phosphonate Initiators

• Published in: Langmuir 2023-08, Vol.39 (31), p.11063-11072
• Main Authors: Zorn, Eilika, Knaack, J Iven H, Burmeister, Nils, Scharnagl, Nico, Rohnke, Marcus, Wicha, Sebastian G, Maison, Wolfgang
• Format: Article
• Language: English
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.3c01366

Surface-initiated atom transfer radical polymerization (SI-ATRP) is a powerful tool for grafting functional polymers from metal surfaces. It depends on the immobilization of suitable initiators on the surface before radical polymerization. Herein, we report a set of bifunctional initiators bearing a phosphonic acid group for surface binding and a bromoisobutyramide moiety for SI-ATRP. We have analyzed the impact of the connecting alkyl spacers on the grafting process of (vinylbenzyl)trimethylammonium chloride (VBTAC) from titanium as a base material. The thickness of the grafted polymer increased with the spacer length of the initiator. We obtained chemically stable polycationic surfaces with high charge densities of ∼10 N /cm leading to efficient contact activity of modified titanium coupons against . Notably, SI-ATRP grafting was efficient with VBTAC as a styrene-derived ammonium compound. Thus, the reported protocol avoids post-grafting quaternization with toxic alkylating reagents.