A convenient swelling-permeation strategy for constructing high-performance fiber reinforced composite hydrogel

Ligaments are a unique wet biological tissue with ultrahigh tensile strength, modulus, and flexural flexibility. Developing artificial materials with similar properties is important but challenging. Herein, we present a novel swelling-permeation strategy for preparing high-performance fiber reinforced composite hydrogels capable of mimicking the ligaments. Through pre-swelling the meta-aramid fibers in good solvents to vastly boost their porosity, large amounts of pre-gel solution can permeate into the pores of fibers during the soaking process. After the polymerization of pre-gel solutions inside and around fibers, the interpenetrating networks form directly between the hydrogel matrix and meta-aramid fibers. The mechanical interlock and abundant hydrogen bond of interpenetrating networks enable the generation of strong interfacial binding between hydrogels and fibers. In consequence, the as-prepared composite hydrogel has high tear resistance (405.30 kJ/m2), tensile strength (125 MPa), and modulus (218 MPa), superior to previously reported composite hydrogels. Meanwhile, the resulting composite hydrogels have outstanding flexibility and good biocompatibility, thereby exhibiting great potential as artificial ligaments. The preparation method proposed in this paper is simple, controllable, and scalable, which opens up the possibility of large-scale production of artificial ligaments.