High-Strength Anisotropic Fluorescent Hydrogel Based on Solvent Exchange for Patterning

Abstract

Aggregation-induced emission (AIE)-active fluorescent hydrogel materials have found extensive applications in soft robotics, wearable electronics, information encryption, and biomedicine. Nevertheless, it continues to be difficult to create hydrogels that are both highly luminescent and possess strong mechanical capabilities. This study introduces a combined approach of prestretching and solvent exchange to create anisotropic luminous hydrogels made of poly(methacrylic acid-methacrylamide). This method restricts the intrachain rotation of AIE molecules and adjusts the orientation of the polymer network. The increased luminescence and mechanical qualities are determined to be caused by the clustering of AIE molecules, the creation of the associated hydrophobic phase and the asymmetrical polymer network. The fluorescent hydrogels exhibit exceptional mechanical characteristics, including a high fracture stress of 5.97 MPa, an outstanding elastic modulus of 93.97 MPa, and a fracture toughness of 7.21 MJ/m³. Furthermore, the AIE fluorescent hydrogels demonstrate outstanding water retention, antiswelling capabilities, and a writing function for solvent-regulated fluorescent information. This work presents a highly efficient technique for creating anisotropic hydrogels with changeable luminescence properties, which have the potential to be used in several applications, including information encryption, flexible sensors, and soft robots.