Development of Strong and Tough Silicone Hydrogels Enabled by Polymerization‐Induced Microphase Separation and Multiscaled Electrostatic Interactions and Their Application as Water‐Shrinkable Sleeves

Abstract Silicone hydrogels (SiHys) have attracted significant attention due to their potential applications, including biomedical devices and soft robotics. However, their widespread use is severely constrained by the inadequate mechanical performance and low silicone content. To address this challenge, this work develops a SiHys with high strength, toughness, and silicon content through polymerization‐induced microphase separation and multiscaled electrostatic interactions. A “Salt‐Forming” reaction between hydrophobic amino‐modified polydimethylsiloxane (APSi) and acrylic acid (AA) is leveraged, which converts APSi into a hydrophilic polymer. Upon polymerization induced by ultraviolet light, the polyacrylic acid (PAA) chains will interact with APSi, effectively reducing its hydrophilicity and inducing in situ microphase separation. This microphase separation, in conjunction with a hierarchical network of strong and weak electrostatic interactions between APSi and PAA, significantly enhances the mechanical properties of the hydrogels. By tuning the molecular structure of APSi and feed concentrations delicately, precise control over the hydrogel's aggregation structure is achieved, yielding impressive mechanical properties, including adjustable tensile strength (0.39–16.2 MPa), elongation at break (559.71–1680.86%), Young's modulus (0.16–11.76 MPa), and toughness (3.88–49.59 MJ m ^{− 3} ). Notably, leveraging the water diffusion‐driven shape memory effect, SiHys can function as “Water‐shrinkable sleeves,” enabling the secure gripping of heavy objects underwater.