Influence of thermal annealing on structural properties of silica aerogel super insulation material
- PDF / 985,800 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 25 Downloads / 219 Views
Influence of thermal annealing on structural properties of silica aerogel super insulation material Ákos Lakatos1 · István Csarnovics2 Received: 29 September 2019 / Accepted: 8 November 2019 © The Author(s) 2019
Abstract Nowadays, aerogel materials are some of the lightest thermal insulation materials available on the construction market; they are produced by the mixing of polymers with solvents since they create a gel. Insulated fibrous-enhanced forms are the most frequently used ones. The type, which is used for thermal insulation, is usually produced by mixing the glass fiber net with the liquid–solid solution. The present paper talks about the structural modifications caused by heat treatment of the aerogel-reinforced with fiberglass. The aerogel probes were subjected to thermal annealing, and once they got isothermal heat treatments for weeks at 70 °C, moreover, untreated samples were subjected to stepwise thermal treatments between 100 and 250 °C for 1 day. Both the heat treatments were executed in dryer equipment under atmospheric air. Changes both in the structure and in chemical bonds of the untreated and annealed samples were followed. Raman spectra have been obtained for the samples. The structural changes have an influence on the studied material as well as in thermal properties. The structural and thermal properties were put under investigation after executing heat treatments on them. Jumps in the thermal conductivity could be connected with some structural changes. Due to the annealing intensity of the peaks connected with Si–O, crystalline SiO is increased, while CH, CH2, CH3, –OH and others are decreased. Keywords Glass fiber-reinforced aerogel · Thermal insulation · Thermal aging · Raman spectroscopy
Introduction A possibility to moderate the applied energy of buildings and to reduce the emission of both C O2 and other greenhouse gases is to apply building or pipe insulations. Nowadays, the use of advanced insulation materials is truly widespread. The development of advanced or the so-called super insulation materials points to reach energy, since money savings, and it is an important focus point in the building sector [1–4]. Aerogels, pyrogels and cryogels are a special class of materials having nanostructure with very low density and very high porosity, having tuneable physicochemical behavior. Silica aerogels are open cell, mesoporous materials and * Ákos Lakatos [email protected] 1
Department of Building Services and Building Engineering, Faculty of Engineering, University of Debrecen, Debrecen, Ótemető Str. 2‑4, 4028, Hungary
Department of Experimental Physics, Faculty of Science and Technology, University of Debrecen, Debrecen, Tér 18/a, 4032, Hungary
2
have reasonable thermal conductivity (λ ≈ 0.017 W/mK) [5]. They have very good properties like low dielectric constant, low density, low speed of sound as well as high porosity. Besides the vacuum insulation panels, aerogel materials are said to be the most promising thermal insulations. It was presented in several articl
Data Loading...
