A semitransparent and tough wood-based adhesive gels with excellent adhesion both in air and underwater for emergency pipeline repair

Abstract

The instant biomass-based adhesive gels have demonstrated promising potentials in various applications, including wound dressing, sensors, and underwater repair engineering. However, existing biomass-based gels usually have relatively poor mechanical and adhesion properties, and even lose their adhesion in wet conditions or underwater due to their inherent hydrophilicity, which remains a considerable challenge for its further application. Herein, we developed a semitransparent wood-based gel patch that can achieve instant and robust adhesion to various substrates both in air and underwater. In briefly, natural wood with porous channels was employed as the skeleton to enhance the mechanical strength of gels. Polymerizable ionic liquid (PIL) and acrylic acid (AA) were selected as the polymeric monomer and filled into the wood channels to synthesize gels by in-situ polymerization in the absence of chemical cross-linker agents. Abundant noncovalent bonds gave gels with superior adhesion to various substrates such as plastic, metal, polytetrafluoroethylene (PTFE), glass and wood. Additionally, the presence of C-F bond endowed the gels with low surface energy which could repel water molecules from the interface between gels and substrates, resulting in the outstanding underwater adhesion. The resultant wood-based gels displayed high tensile stress (6.10–9.34 MPa), which was 3.56–5.46 times higher than that of pure gels without the incorporation of wood. The maximum adhesion strength of gels could reach approximately 350 kPa in air and 345 kPa underwater. This work showed a promising application in emergency repair engineering of broken pipeline both in air and underwater.