Bio-inspired eco-friendly wheat gluten based underwater adhesives with instant, robust and harsh environment adhesion properties.

Underwater adhesives are essential in industry, biomedical field, as well as our daily life. Herein, inspired by the natural plant protein, an eco-friendly, cost-effective and renewable bio-resources gliadin/TA adhesive was developed by a facile and effective strategy. The prepared gliadin/TA adhesive displayed exceptional substrate universality, rapid self-healing ability, instant and long-term underwater adhesion, strong affinity and good environmental adaptability. In the dry environment, the glued woods with a lab-shear bond can lift a weight of 11.62 kg object with a bond area was 2.15 cm2. In the water, the gliadin/TA adhesives can successfully lift 1 kg stainless steel and maintained effective adhesion for up to 50 days without detachment. Meanwhile, the gliadin/TA adhesives exhibited excellent environmental adaptability, including 1 M NaCl, extreme acidic (pH = 2), alkaline (pH = 14) and high-temperature (48 °C) aqueous solutions. Additionally, the potential applications of gliadin/TA adhesives have been proved by repairing porcine skin and bones, bonding wood particles together rapidly to withstand water-flushing, plugging leaky containers and broken pig intestine. This work presents a distinctive and facile strategy for designing and developing the eco-friendly, cost-effective and renewable bio-resources underwater adhesives.