Advanced Opacified Fiber-Reinforced Silica-Based Aerogel Composites for Superinsulation of Exhaust Tubing Systems in Semi-Stationary Motors

Materials (Basel). 2020 Jun 12;13(12):2677. doi: 10.3390/ma13122677.

Abstract

Within this study, monolithic three-dimensional silica aerogel (SA) composite parts with super insulating properties are presented. A generic part based on fiber-reinforced (FR) silica aerogel for thermal insulation of the exhaust tubing system-to keep the exhaust gases as hot as possible to improve the efficiency of the catalyst system-was produced via a sol-gel-based molding process in combination with a supercritical drying using scCO2. A thermal conductivity of 16 mW m-1 K-1 was measured via a heat flow meter technique. In this manuscript, we present a full cycle of the material compound design, starting with fundamental material evaluation including aerogel optimization, opacifier influence, and casting process. The obtained generic part in shape of a half-shell for pipe insulation is characterized under real conditions.

Keywords: boehmite particles; fiber reinforcement; generic part; high temperature; manufacturing; opacifiers; silica aerogel; super insulation.