Facile preparation of transparent poly (γ‐glutamic acid) modified poly (vinyl alcohol) hydrogels with high tensile strength and toughness

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.

Antifreezing/Antiswelling Hydrogels: Synthesis Strategies and Applications as Flexible Motion Sensors

Hydrogels are excellent materials for fabricating flexible electronic devices, such as flexible sensors. However, obtaining hydrogels with superior swelling capacity and good hydrophilicity suitable for use under extreme environments, such as cold and underwater conditions, is still challenging due to the occurrence of freezing and excessive swelling. Alternatively, hydrogels with antifreezing and antiswelling capacities exhibit minimal changes in their physical and chemical properties under extreme conditions with retained original performance, such as mechanical properties, conductivity, and adhesiveness, making them suitable for various applications. Accordingly, various multifunctional antifreezing/antiswelling hydrogels meeting practical application requirements have been developed thanks to the advancement of hydrogel technology. Examples include flexible sensors for monitoring various motion signals, such as changes during sports events. However, comprehensive reviews describing these hydrogels in terms of synthesis and application in sensors are still lacking. Herein, the design and synthetic strategies of antifreezing/antiswelling hydrogels reported in recent years are comprehensively analyzed along with their mechanisms and applications in flexible motion sensors. This review aims to provide a comprehensive understanding of the research of antifreezing/antiswelling hydrogels and offer valuable insights for researchers engaged in the development of advanced materials suitable for practical applications.