Construction of a Soft Antifouling PAA/PSBMA Hydrogel Coating with High Toughness and Low Swelling through the Dynamic Coordination Bonding Provided by Al(OH)₃ Nanoparticles

Abstract

Marine biofouling, resulting from the adhesion of marine organisms to ship surfaces, has long been a significant issue in the maritime industry. In this paper, we focused on utilizing soft and hydrophilic hydrogels as a potential approach for antifouling (AF) coatings. Acrylic acid (AA) with a polyelectrolyte effect and N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine (SBMA) with an antipolyelectrolyte effect were selected as monomers. By adjusting the monomer ratio, we were able to create hydrogel coatings that exhibited low swelling ratio in both fresh water and seawater. The Al(OH) 3 nanoparticle, as a physical cross-linker, provided better mechanical properties (higher tensile strength and larger elongation at break) than the chemical crosslinker through the dynamic coordination bonds and plentiful hydrogen bonds. Additionally, we incorporated trehalose into the hydrogel, enabling the repair of the hydrogel network through covalent-like hydrogen bonding. The zwitterion compound SBMA endowed the hydrogel with excellent AF performance. It was found that the highest SBMA content did not lead to the best antibacterial performance, as bacterial adhesion quantity was also influenced by the charge of the hydrogel. The hydrogel with appropriate SBMA content being close to electrical neutrality exhibits the strongest zwitterionic property of PSBMA chains, resulting in the best antibacterial adhesion performance. Furthermore, the pronounced hydrophilicity of SBMA enhanced the lubrication of the hydrogel surface, thereby reducing the friction resistance when applied to the hull surface during ship navigation.

A flexible wearable sensor based on anti-swelling conductive hydrogels for underwater motion posture visualization assisted by deep learning

“…1d, the characteristic peak of PAA at 2987 cm −1 corresponds to the –O–H stretching vibration, 29 while the peak at 1726 cm −1 originated from the CO bending deformation in –COOH. 30 In the FT-IR spectra of PAB and PABC hydrogels, the stretching vibration frequencies at these positions shifted towards lower wavenumbers, suggesting that the formation and strengthening of numerous hydrogen bonds were within the polymer network. Notably, the spectrogram of PAB exhibited characteristic peaks at 1146 cm −1 and 1031 cm −1 indicative of symmetric and asymmetric stretching vibrations of SO, confirming the presence of sulfonate groups.…”

Fabrication of Poly(ionic liquid) Hydrogels Incorporating Liquid Metal Microgels for Enhanced Synergistic Antifouling Applications

“…The effectiveness of hydrophilic surfaces in resisting fouling is attributed to the formation of a dense hydration layer, similar to the surface of some animals and plants . The presence of the hydration layer has a good shielding effect, impeding the adhesion of protein molecules, bacteria, algae, and other microorganisms to the surface. , …”

Developments and Challenges of Hydrogel Coatings for Long-Term Marine Antifouling Applications

“…Synergistic work between the bacterial killing of CeO 2 nanorods and antiadhesion of the polyzwitterionic hydrogel leads to its significantly improved marine-antifouling performance. Very recently, Hu et al [47] employed Al(OH) 3 nanoparticle as a physical cross-linker to construct a soft antifouling polyacrylic acid (PAA)/PSBMA hydrogel coating with high toughness and low swelling through dynamic coordination bonding and plentiful hydrogen bonds.…”