Underwater antiadhesion hydrogel coatings with spontaneous segment orientation

• Published in: Chemical engineering science 2025-01, Vol.301, p.120700, Article 120700
• Main Authors: Xu, Xiubin, Liu, Jianwei, Weng, Jiahao, Wen, Wu, Yu, Danfeng, Wen, Jinxiong, Wu, Xu
• Format: Article
• Language: English
• Subjects: Anti-oil adhesion; Hydrogel coating; Substrate bonding; Underwater superoleophobicity
• ISSN: 0009-2509
• DOI: 10.1016/j.ces.2024.120700

•A spontaneous segment orientation strategy is proposed for achieving hydrogel coatings with underwater substrate adhesion and antifouling properties.•The coating process could be performed by brushing, dipping, or spraying without any pretreatment of the substrates.•The synergy between the mussel-inspired catechol group and the hydrophilic PEG segment realized the antiadhesion coating surface with substrate adhesion in water.•The critical point is that the long hydrophilic PEG segment can stretch to the coating surface, binding more water molecules and masking the hydrophobic benzene in dopamine. Achieving strong underwater bonding between hydrogels and diverse substrates to endow the surfaces with antifouling properties in a facile and universal approach is critically challenging. The existing methods rely on complex chemical pretreatment of substrates, which limits their practical application. To address this issue, a facile spontaneous segment orientation strategy is proposed by presenting a polyurethane hydrogel coating inspired by mussels in a large scale-up to diverse substrates through brushing, rolling, or spraying without the need for chemical pretreatment. The bonding-functional groups could be selectively enriched on the surface of substrates owing to the hydrogen bonding, coordination bonding, and π–π stacking, in addition to the hydrophobic interaction. At the same time, the hydrophilic segments are inclined to migrate to the coating surface and form hydration layer with water molecules, endowing the substrate with underwater superoleophobicity. Hence, this strategy has the potential to become a pioneering universal strategy for achieving versatile hydrogel coatings with strong underwater substrate adhesion and excellent antifouling properties, particularly in surface/interface science and engineering.