Mechanical and thermal conductive properties of fiber‐reinforced silica‐alumina aerogels

Abstract

We report the formation of Al2O3‐SiO2 fiber‐reinforced Al2O3‐SiO2 aerogels with the content of fibers in the range from 40 wt% to 55 wt% by sol‐gel reaction, followed by supercritical drying. The structure and physical properties of fiber‐reinforced Al2O3‐SiO2 aerogels are studied. We find that the fiber‐reinforced Al2O3‐SiO2 aerogels can be resistant to the temperature of 1200°C. The integration of fibers significantly improves the mechanical properties of Al2O3‐SiO2 aerogels. We find that the bending strength of fiber‐reinforced Al2O3‐SiO2 aerogels increases 0.431 MPa to 0.755 MPa and the elastic modulus increases from 0.679 MPa to 1.153 MPa, when the content of fibers increases from 40 wt% to 50 wt%. The thermal conductivity of the fiber‐reinforced Al2O3‐SiO2 aerogels is in the range from 0.0403 W/mK to 0.0545 W/mK, depending on the content of fibers.

Versatile Thermal‐Solidifying Direct‐Write Assembly towards Heat‐Resistant 3D‐Printed Ceramic Aerogels for Thermal Insulation

“…These thermal conductivity values ( Figure f) of 3D‐printed ceramic aerogels are comparable to those of conventional SiO 2 aerogels (10‐25 mW m –1 K –1 ), [ 42–44 ] organic‐inorganic hybrid SiO 2 aerogels (12‐44 mW m –1 K –1 ), [ 44–46 ] TiO 2 −SiO 2 aerogels (26 mW m –1 K –1 ), [ 47 ] SiO 2 aerogel composites (18–28 mW m –1 K –1 ), [ 43,48 ] and Al 2 O 3 −SiO 2 aerogel composites (27–50 mW m –1 K –1 ). [ 49,50 ]…”

“…These thermal conductivity values (Figure 8f) of 3D-printed ceramic aerogels are comparable to those of conventional SiO 2 aerogels (10-25 mW m -1 K -1 ), [42][43][44] organicinorganic hybrid SiO 2 aerogels (12-44 mW m -1 K -1 ), [44][45][46] TiO 2 −SiO 2 aerogels (26 mW m -1 K -1 ), [47] SiO 2 aerogel composites (18-28 mW m -1 K -1 ), [43,48] and Al 2 O 3 −SiO 2 aerogel composites (27-50 mW m -1 K -1 ). [49,50] Figure 8c-e show the thermal conductivities of 3D-printed ceramic aerogels versus densities after different temperatures of heat treatment. The thermal conductivities of 3D-printed ceramic aerogels can be tailored by varying the densities.…”

Silica aerogels: from materials research to industrial applications

“…Moreover, silica aerogel has good high and low-temperature resistance, an open microstructure, high-performance stability below 300–800 ° C (depending on type), and some can even withstand higher temperatures. For example, the SiCO [89] and Al 2 O 3 -SiO 2 [90] aerogels can resist 1100 ° C and 1200 ° C, respectively. Due to the excellent thermal insulation properties, silica aerogels have great application potential in the aerospace, oil and gas, buildings, cryogenic equipment, apparel, appliances, and other fields.…”

Ultrahigh Power Density LuAG:Ce Green Converters For High‐Luminance Laser‐Driven Solid State Lighting

“…At present, LuAG:Ce‐PiG has made great progress, but more efforts are still needed to apply it to various illumination displays to achieve higher luminous efficiency at higher power density. [ 35–37 ]…”