Sub-nanoparticles crosslinking network organogel as the underwater adhesive

Adhesives are applied extensively in daily life, and due to performance failure of conventional polymer adhesives in underwater environments, there is an urgent demand for highly stable underwater adhesives to meet application requirements of stable adhesion in humid environments and rapid leak sealing. Herein, crosslinking network of aluminum oxo clusters sub-nanoparticles (CN ASNPs) is prepared on a large-scale through a facile stirring reaction at room-temperature and atmospheric pressure, showing good gelation properties in non-polar solvents. The organogel exhibits outstanding underwater adhesive performance, arising from synergy effect of hydration layer disruption, micro-nano mechanical interlocking, high polymerization degree and intermolecular forces. And through being modified with perfluorodecyltriethoxysilane (FDETS) and methyltrimethoxysilane (MTMS), the adhesive performance can be further improved based on enhanced hydrophobicity and cohesion. The CN ASNPs organogel adhesive is suitable for various substrates, and for steel, the underwater adhesive strength can achieve ~ 2.41 MPa. More importantly, this adhesive exhibits excellent stability, whether in tap water or saltwater, whether under changed temperature (25–90 °C) or prolonged time (~ 180 days) conditions. And this adhesive will not cause any damage to substrates or leave hard-to-remove residues after bonding. Overall, the CN ASNPs organogel adhesive has great potential for practical applications in underwater and humid environments.