Hydrothermal synthesis of a novel expanded vermiculite/xonotlite composite for thermal insulation

• Published in: Construction & building materials Vol. 367; p. 130254
• Main Authors: Wang, Xiaoben, Feng, Jinpeng, Hwang, Jiann-Yang, Dai, Tianya, Liu, Shuhan, Wu, Zhenjiang, Mo, Wei, Su, Xiujuan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 27.02.2023
• Subjects: Composite material; Intercalation; Thermal conductivity; Vermiculite; Thermal conductivity; Intercalation; Composite material; Vermiculite
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2022.130254

[Display omitted] •A novel expanded vermiculite/xonotlite insulation composite was prepared via the hydrothermal method.•Vermiculite thermal expansion and nano xonotlite fiber synthesis were comprehensively studied.•The effect of intercalation on thermal insulating performance was systematically investigated. Natural disasters caused by global warming are threatening the survival of mankind. Reducing carbon emissions is an effective way to prevent global warming. In recent years, the construction industry is playing a dominant role in global energy consumption. Aimed to solve the problem of high energy consumption in the construction industry, a novel expanded vermiculite/xonotlite thermal insulation composite was successfully prepared via the hydrothermal method. The microstructure and thermal performance of the composite were systematically analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), laser flash analysis (LFA), and infrared thermal imaging. The test results indicated that xonotlite fibers could be inserted well into the interlayers of expanded vermiculite. And the intercalation of xonotlite greatly improved the thermal insulation performance of expanded vermiculite at high temperature. The thermal conductivity of this composite decreased with intercalation rate increasing. The composite with intercalation rate of 51.43 % had the lowest thermal conductivity of 0.2116 W/mK at 800 °C which was 55.36 % lower than the expanded vermiculite sample. Meanwhile, this composite had good thermal stability and high temperature resistance. In addition, the thermal expansion of vermiculite and the synthesis of nano-xonotlite fibers were comprehensively studied and discussed. This study will provide a new perspective and ideas for developing vermiculite-based thermal insulating materials.