Fabrication of Photothermally Responsive Nanocomposite Hydrogel through 3D Printing

The responsive hydrogels have received great attention in many fields. However, the molding method and response mode of such hydrogels are criticized when it comes to real applications. In this work, a novel class of poly(N-isopropyl acrylamide)/graphene oxide (PNIPAm/GO) nanocomposite hydrogel through self-assembly three-dimensional (3D) printing via ultraviolet light polymerization. The precursor is ordinarily constituted by NIPAm monomer, crosslinker, and water mixed with a photoinitiator, besides the introduction of nanoclay adjusts the shear thinning properties to an optimal level, which is important for the 3D printing precision. Then, the graphite oxide as infrared light absorber endows the hydrogel fast photothermal excited responsivity instead of conventional temperature response. The shrinkage and swelling of the composite hydrogel can be controlled by turning the near-infrared light on or off. Meanwhile, the reversible behavior of as-prepared hydrogel is easily regulated by altering the content of GO and illumination time of near-infrared light. Additionally, a round tube is obtained based on the as-prepared hydrogel, which can be driven to get a pencil, indicating their potential applications in actuator and other functional program.