Correlation of microstructure and thermal conductivity in nanoporous solids: The case of polyurea aerogels synthesized from an aliphatic tri-isocyanate and water

Polyurethane aerogels synthesis for thermal insulation – textural, thermal and mechanical properties

“…Similar evolution of the texture of organic aerogels with bulk density has already been described elsewhere [30]. In particular, analogous trend have been observed in flexible polyurethane aerogels by Leventis et al [15], who demonstrates that as an increase in bulk density is followed by a decrease in pore size towards mesoporous range and a decrease in particle size, coinciding with a rise of S BET up to a given bulk density range.…”

Correlation between the elastic modulus and heat transport along the solid phase in highly porous materials: Theoretical approaches and experimental validation using polyurea aerogels

“…The macroscopic material properties depend on the density of the samples and the processing conditions. Specific information about the reactants and synthesis procedure are given in references [27][28][29]. The first sample series consists of six samples (A-F) of different density between 0.040 and 0.530 g/cm 3 that were derived by varying the monomer concentration in the sol solution.…”

“…Details with respect to the experimental setups and sample preparation are given in [28] and [29], respectively.…”

Heat transfer in microcellular polystyrene/multi-walled carbon nanotube nanocomposite foams

“…According to Planck's law, the radiative energy of a black body is a function of wavelength (k). At the room temperature, over 90% of the radiative energy is in the wavelength range of 2.5-25 lm, which is covered by Fourier transform infrared spectroscopy (FTIR) [24]. Therefore, the transmittance of infrared (IR) through the foam is equal to the transmitted radiative energy.…”

“…Boldor's study shows that MWCNTs have an extremely high electromagnetic spectrum absorbency, which is much higher than that of graphite in the NIR region [38]. Although thermal radiation at the room temperature occurs mainly in the IR region [24], the MWCNT's strong absorption of IR radiation can be expected to reduce transmitted thermal radiation.…”