High-Strength Thermally\nActivated Shape-Adaptive Plugging\nHydrogels with Plastic Semicrystalline Metallosupramolecular Polymer\nNetworks

Plugging materials are employed to repair holes or cracks\nin pipes,\nvessels, other equipment, or even formations. Traditional packing\ntape or sealant could seal only small cracks and leaks. Epoxy resins\nand polyurethane foams are appropriate for sealing relatively large\napertures. However, their application is limited by a long curing\ntime or low mechanical performance. Herein, we report thermally activated\nshape-adaptive plugging materials based on shape-memory hydrogels\nwith high strength and deformation capacity. Owing to the stiff hydrophobic\ncrystalline side segments in the hydrogel network, the shape-memory\nhydrogel showed high mechanical performances with a compressive strength\nof 17.57 MPa and toughness of 2760 kJ m<sup>–3</sup>. Upon\nimmersion in Fe<sup>3+</sup> solution, the integration of these two\northogonal supramolecular interactions bestows the hydrogel with high-strength\nmechanical properties and a distinctive dual-programmed shape-memory\nperformance. Importantly, the excellent shape-memory properties can\nallow the hydrogel to exhibit a distinctive shape-adaptive plugging\nbehavior. When activated, the flaky intelligent hydrogel expands into\na granular shape, allowing them to adaptively match fracture apertures\nin the leakage zone within a range of 2 to 4 mm, which result in high\nplugging efficiency and high plugging strength. Therefore, this intelligent,\nadaptive plugging based on high-strength shape-memory hydrogels could\nbe a prominent candidate for a generation of plugging materials that\ncan be applied in the oil field, waste gas or oil pipeline repairs,\nand various other plugging scenarios.