Low Fouling Polysulfobetaines with Variable Hydrophobic Content

• Published in: Macromolecular rapid communications. 2022-06, Vol.43 (12), p.e2100589-n/a
• Main Authors: Schardt, Lisa, Martínez Guajardo, Alejandro, Koc, Julian, Clarke, Jessica L., Finlay, John A., Clare, Anthony S., Gardner, Harrison, Swain, Geoffrey W., Hunsucker, Kelli, Laschewsky, André, Rosenhahn, Axel
• Format: Article
• Language: English
• Subjects: Algae; amphiphilic; Aquatic plants; Biofouling; Coatings; Copolymers; Fibrinogen; Field tests; fouling release; Hydrogels; Hydrophilicity; Hydrophobicity; Lysozyme; marine biofouling; Marine environment; Navicula perminuta; Polymer coatings; Polymers; polyzwitterion; Ulva linza; Zwitterions
• ISSN: 1022-1336; 1521-3927
• DOI: 10.1002/marc.202100589

Amphiphilic polymer coatings combining hydrophilic elements, in particular zwitterionic groups, and hydrophobic elements comprise a promising strategy to decrease biofouling. However, the influence of the content of the hydrophobic component in zwitterionic coatings on the interfacial molecular reorganization dynamics and the anti‐fouling performance is not well understood. Therefore, coatings of amphiphilic copolymers of sulfobetaine methacrylate 3‐[N‐2'‐(methacryloyloxy)ethyl‐N,N‐dimethyl]‐ammonio propane‐1‐sulfonate (SPE) are prepared which contain increasing amounts of hydrophobic n‐butyl methacrylate (BMA). Their fouling resistance is compared to that of their homopolymers PSPE and PBMA. The photo‐crosslinked coatings form hydrogel films with a hydrophilic surface. Fouling by the proteins fibrinogen and lysozyme as well as by the diatom Navicula perminuta and the green algae Ulva linza is assessed in laboratory assays. While biofouling is strongly reduced by all zwitterionic coatings, the best fouling resistance is obtained for the amphiphilic copolymers. Also in preliminary field tests, the anti‐fouling performance of the amphiphilic copolymer films is superior to that of both homopolymers. When the coatings are exposed to a marine environment, the reduced susceptibility to silt incorporation, in particular compared to the most hydrophilic polyzwitterion PSPE, likely contributes to the improved fouling resistance. Amphiphilic polymer coatings containing zwitterionic sulfobetaine side chains and varying amounts of hydrophobic n‐butyl methacrylate are synthesized. The photo‐crosslinked coatings form hydrogel films which diminish non‐specific adsorption of proteins and biofouling by organisms drastically. In field tests, the anti‐fouling performance of amphiphilic copolymers is superior to both homopolymers partially due to reduced silt incorporation.