Lightweight quasi-layered elastic fibrous porous ceramics with high compressive stress and low thermal conductivity

Abstract

• An elastic fibrous porous ceramic (EFPCs) was successfully prepared using a simple filter press process. • The inter-layer gaps created by the quasi-layered structure and the well bonding between the layers are the keys to the elastic properties. • Compared with other elastic porous ceramics or fibrous aerogel, the as-prepared EFPCs have higher compressive stress, which endows it better shape-maintaining ability. • EFPCs have temperature-invariant elastic properties and low thermal conductivities. Fibrous porous ceramics are attractive for use as thermal insulation materials. However, the intrinsic brittleness of rigid materials has remained challenging and severely restricts their applications. Here, we demonstrated a facile method for fabricating elastic fibrous porous ceramics (EFPCs) with high compressive strength and low thermal conductivity through ordinary press filtration and subsequent heat treatment. The quasi-layered structure and the well-bonded bridging fibers between layers are the key points for the elasticity of EFPCs. The advanced EFPCs exhibited low density (∼0.126 g cm −3 ), high compressive stress (∼0.356 MPa), and low thermal conductivity (∼0.026 W m −1 K −1 ). Compared with rigid porous fibrous materials, the EFPCs had deformability and excellent shape recovery. In contrast to flexible materials, the EFPCs possessed high compressive stress, thus endowing them with good resistance to deformation. The emergence of this fascinating material may provide new insights for candidate materials in thermal insulation and other fields. In this paper, we demonstrated a facile method for fabricating elastic fibrous porous ceramics (EFPCs) with high compressive stress and low thermal conductivity by using silica fibers through ordinary press filtration method. The inter-layer gaps created by the quasi-layered structure and the well bonding between the layers are the keys to the elastic properties. Compared with traditional ceramics, the EFPCs possessed high compression ability up to 20% strain with ultimate stress as high as 0.356 MPa and high compression fatigue resistance of 200 cycles at 15% strain. The compressive test in the alcohol lamp flame and liquid nitrogen proved that the samples exhibited excellent temperature-invariant mechanical properties. The ideal combination of these properties may make EFPCs a strong competitor for thermal insulation and other applications in many areas