Synthesis, characterisation, and thermal conductivity of resorcinol–formaldehyde aerogel
Ki-Pung Yoo, Sun Young Kim, Dong Ho Yeo, Jae Woo Lim, Ok-Joo Lee, Kun-Hong Lee, Irina Smirnova, Wolfgang Arlt
Resorcinol – formaldehyde (RF) organic aerogels were synthesised by sol-gel processing and supercritical carbon dioxide drying over a wide range of processing conditions. The thermal conductivity was measured by a transient hot-wire method for aerogels prepared at various conditions. In general, the thermal conductivity of RF aerogels tends to decrease with decreasing density. When the density of RF aerogels is lower than 67 kg m-3, the thermal conductivity tends to increase. The RF aerogel obtained by a resorcinol/catalyst (R/C) ratio of 300 shows a lower thermal conductivity compared to other R/C ratios. With respect to low thermal conductivity, we found that the R/C ratio is one of the most important process variables. The aerogel prepared by an R/C ratio of 300 and a density of 67 kg m-3 shows a lower thermal conductivity than those obtained by other conditions.