Direct 3D print polyimide aerogels for synergy management of thermal insulation, gas permeability and light absorption

Abstract

To improve the accessibility of polyimide aerogels (PAs) in diverse application scenarios, the major objective is to create PAs in dimension/geometry on demand. However, their ability to deliver excellent performance and expanded applications remains challenging. Herein, the three-dimensional (3D) printing of Pas, which simultaneously addresses the above concerns, is proposed using a combination of a one-step chemical-imidization sol–gel strategy and direct ink writing. The resultant 3D-printed PAs exhibit many desirable properties, such as high specific surface area (561.7 m² g⁻¹), low density (66.1 ± 1.4 kg m⁻³), low thermal conductivity (39.89 ± 0.16 mW m⁻¹ K⁻¹), low shrinkage (<7%), exceptional thermal stability (up to 450 °C) and good mechanical properties. They also possess excellent heat/cold preservation, heat/cold/moisture insulation, air/light permeability, and ammonia/moisture adsorption. All of these are highly desirable for addressing severe environmental concerns. Moreover, the application scalability of 3D-printed PAs is confirmed by the successful incorporation of carbon nanotubes, and the subsequent expanded functionality and application potential. The flexibility of inks/materials and the manipulability of the structures and functions, demonstrates great prospect for synergy management of thermal insulation, gas permeability and light absorption, thus expanding the application of PAs.