Grafting Robust Thick Zwitterionic Polymer Brushes via Subsurface-Initiated Ring-Opening Metathesis Polymerization for Antimicrobial and Anti-Biofouling

Abstract

In the present work, high-thickness zwitterionic polymer brushes based on imidazolium salts were successfully grafted via a novel subsurface-initiated ringopening metathesis polymerization (subsurface-initiated ROMP) from polydimethylsiloxane (PDMS), and their antifouling performance was evaluated in detail. First, an initiator-embedded PDMS was prepared via copolymerization of PDMS prepolymer and ROMP initiator, and then zwitterionic polymer brushes were grafted via subsurfaceinitiated ROMP from surface to subsurface of the PDMS due to the implanted ROMP initiator. Results from a series of characterization methods such as infrared spectroscopy, X-ray photoelectron spectroscopy, contact angle, and atomic force microscopy proved the zwitterionic polymer brushes' successful grafting. The grafting thickness of zwitterionic polymer brushes via subsurface-initiated ROMP can reach the micron scale, and the as-prepared zwitterionic polymer based surfaces showed good lubricating properties compared to traditional surfaceinitiated ROMP, which hints that polymer brushes can be grafted not only on the surface but also on the subsurface of PDMS. The protein adhesion test and biofouling assay of zwitterionic polymer brushes were tested in the laboratory, and the results indicated that the zwitterionic polymer-functionalized PDMS can effectively resist the adhesion of bovine serum albumin and algae (Porphyridium and Dunaliella) and has good anti-bacterial activity against both Escherichia coli and Staphylococcus aureus.

A Bioinspired Hydrogel-Elastomer Hybrid Surface for Enhanced Mechanical Properties and Lubrication

“…33 These three peaks were not present on the PDMS, and they belonged to amide groups of polyacrylamide (PAAm). In Figure 1e, the XPS spectrum of the PDMS substrate 34 These peaks can also be found in the XPS spectrum of the hybrid surface but with weaker signals of the Si 2s and Si 2p transition, the atomic percentage of which declined from 25.53 to 8.62%. The signal at 399.1 eV, which was only detected in the spectrum of the hybrid surface, belonged to the N 1s transition, and its atomic percentage increased from 0.46% of the substrate to 7.76% of the hybrid surface.…”

Synthesis and Characterization of Cationic Dendrimer‐PDMS Hybrids

“…[2,[5][6][7] One approach to fabricate silicones resistant to biofilm is to make their surfaces antimicrobial. While several methods to render silicone surfaces antimicrobial exist, including through coatings, [8][9][10][11][12][13][14][15] additives, [16][17][18][19] or surface functionalization, [20][21][22][23][24] each has advantages and disadvantages. Coatings and surface functionalization place antimicrobials directly at environmental interfaces but require multistep processing during device manufacturing.…”

One-step zwitterionization and quaternization of thick PDMAEMA layer grafted through subsurface-initiated ATRP for robust antibiofouling and antibacterial coating on PDMS

“…More specifically, zwitterionic polymer brushes with strong hydration capacity and quaternary ammonium salts with bactericidal ability were sequentially grafted on polyamide membranes via ATRP technique [31]. Although ''grafting-from" approach has been recognized as a powerful technique because of its ability to obtain dense polymer brushes with narrow polydispersity, controlled architecture and well-defined thickness and composition [32], the polymerization only on surface limits the expansion of film thickness that is usually up to a few tens of nanometers [33]. Such a nano-thickness coating associated with low density and poor mechanical robustness inhibits the development of excellent and long-term antifouling and antibacterial surfaces [34].…”