Synthesis of composite insulation materials—expanded perlite filled with silica aerogel

Abstract

The aim of this paper is to synthesis a new type of insulation material (EPA), which fill the aerogels into the expanded perlite (EP). EP is a kind of lightweight filler, its application is constrained by the character of absorbing water easily. The silicic acid is inhaled into the expanded perlite at −0.1 MPa, aging 24 h, it becomes aerogel after solvent exchanging/surface modifying and drying. The pores of EP are filled with aerogel which affects thermal conductivity of expanded perlite little and makes it hydrophobic. EPA has a wider use than EP for its hydrophobic character. A new recipe to synthesize aerogel, filled into EP, with the thermal conductivity of 0.034 W/m K in ambient pressure drying is found in this experiment. The time and reagents dosage for synthesizing EPA are less than large block of aerogel, while the thermal conductivity is close to it. The scanning electron microscopy is used to analyze EPA’s micro structure. The thermal conductivity tester is used for testing the thermal conductivity of silica aerogel, expanded perlite and EPA.