Elastic Network of Droplets for Underwater Adhesives.

Functionality in biological materials arises from complex hierarchical structures formed through self-assembly processes. Here, we report a kinetically trapped self-assembly of an elastic network of liquid droplets and its utility for tough and fast-acting underwater adhesives. This complex structure was made from a one-pot mixture of scalable small-molecule precursors. Liquid-liquid phase separation accompanied by silanol hydrolysis, condensation, and zwitterionic self-association yields a viscoelastic solid with interconnected liquid droplets. These hierarchical microstructures increase toughness and enable underwater adhesion for a range of substrates, offering a platform for robust adhesives for rapid underwater repair or emergency wound care.