Fabrication of high strength and thermal insulation porous ceramics via adjusting the fiberglass contents

Abstract

Fiberglass porous ceramics were successfully prepared via a foam‐gelcasting process with fiberglass and glass particles. The effects of fiber content on the rheology of foaming slurries and the structure and mechanical properties of as‐prepared porous ceramics were investigated. The results showed that as the ratio of fiberglass to glass particles increased, the thixotropy of slurries decreased, which affected the foamability of slurries. When the ratio of fiberglass to particle was 75:25, the slurries exhibited excellent flowability and outstanding foamability, which was beneficial to optimize the structure of pores and improve the properties of the porous ceramics. The porosity, compressive strength, and thermal conductivity of porous ceramics with a content of 75 wt.% fiberglass treated at 750°C were 78.3%, 2.15 MPa, and .11 W/(m·K) (room temperature), respectively. Therefore, the prepared porous ceramics with a ratio of fiberglass to particle 75:25 were regarded as an ideal candidate for thermal insulation materials.

Low‐cost porous thermal insulation materials with tunable pore structures derived from fly ash by foam‐gelcasting

“… 24 When the excess dispersant was added to the slurries, flocculation occurred in the slurries. Because the dispersants could improve the particle dispersion in a suspension, while excess amounts of dispersant would increase the viscosity of the foaming slurries, then the dispersant molecules entangled in the particles and hindered the movement, then the distance between the fly ash floating beads was too short to hold the excess dispersant molecules, resulting in the generation of a network structure in the slurries caused by the free dispersant molecules, which effectively hinder the movement between particles 20,25–27 . The movement of floating beads in the slurries was inhibited, which has a negative influence on the foaming process.…”