Open AccessInfluence of Aging Factors on the Properties of Aerogels with Different Degrees of Granulation
Author(s) -
Agnieszka Greszta,
Sylwia Krzemińska,
Małgorzata Okrasa
Publication year - 2019
Publication title -
fibres and textiles in eastern europe
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 39
eISSN - 2300-7354
pISSN - 1230-3666
DOI - 10.5604/01.3001.0013.1386
Subject(s) - aerogel , materials science , composite material , thermal conductivity , relative humidity , moisture , humidity , specific surface area , thermal resistance , context (archaeology) , absorption (acoustics) , water content , thermal , chemistry , thermodynamics , paleontology , biochemistry , physics , geotechnical engineering , biology , engineering , catalysis
Aerogels are distinguished by their low density and thermal conductivity, which predisposes them for application in materials against extremely low or high temperature. Aerogel resistance to aging factors such as moisture, high temperature and thermal radiation was studied. Aerogel resistance to moisture absorption was studied by the weight method, at a relative humidity of 65% and 95%. For aerogels exposed to heat (at 260 °C) and thermal radiation (heat flux density 20 kW/m2), structural and textural characteristics (specific surface area, pore volume, pore size distribution) were determined. It was found that in an environment characterised by 95% humidity, the moisture weight absorbed was similar for all aerogels and amounted to less than 1%, corresponding to low moisture absorption capacity. The most significant changes in specific surface area were recorded for aerogels in powder form, where the value of this parameter after exposure to high temperature increased by 13% compared to the reference sample. An increase in the specific surface area can effect a reduction in thermal conductivity; thus this change is positive in character in the context of application to clothing designed against thermal factors.