Effects of three-dimensional pore structure on effective thermal conductivities of thermal insulation materials

Synchronous Radiative Cooling and Thermal Insulation in SiO2/Poly(vinyl alcohol) Composite Aerogel for Energy Savings in Building Thermal Management

“…3,6,41,42 It was found that adding acetone reduced the thermal conductivity of the PVA aerogel from 0.0492 to 0.0421 W/mK and reduced the thermal diffusion coefficient from 0.5815 to 0.5490 mm 2 /s (Figure 1f) resulting from the structural changes which increased the proportion of micro-and nanopores inside the aerogel and reduced the macro-gaps. 43 Further, the incorporation of SiO 2 particles made the thermal conductivity decreased to 0.0390 W/mK and decreased the thermal diffusion coefficient to 0.4770 mm 2 /s. It is noteworthy that the solar reflectance of the SiO 2 /PVA composite aerogel increased from 81.50% to 91.20% (Figure 1g), and the midinfrared (8−13 μm) emissivity of the SiO 2 /PVA composite aerogels increased from 96.24% to 97.85% compared to the pure PVA aerogel (Figure 1h).…”

“…High porosity and low density of aerogels with nanomicro–multistage porous structure often result in good thermal insulation and thus are widely used as thermal insulation materials , or radiative cooling materials. ,,, It was found that adding acetone reduced the thermal conductivity of the PVA aerogel from 0.0492 to 0.0421 W/mK and reduced the thermal diffusion coefficient from 0.5815 to 0.5490 mm 2 /s (Figure f) resulting from the structural changes which increased the proportion of micro- and nanopores inside the aerogel and reduced the macro-gaps . Further, the incorporation of SiO 2 particles made the thermal conductivity decreased to 0.0390 W/mK and decreased the thermal diffusion coefficient to 0.4770 mm 2 /s.…”

Evaluation of Two Chilean Native Macroalgae: “Pelillo” (Gracilaria chilensis) and “Lamilla” (Ulva sp.) for Thermal Insulation Application

“…These properties enable the prolongation of heat flow from one end to the other, leading to enhanced thermal conductivity. As a result, this leads to reduced thermal transmittance values for construction solutions [46]. This context is linked to algae native to Chile, and while certain chemical properties are consistent across all macroalgae, they can vary depending on the species, season, and location [47].…”

Scaling of inter-pore spacing of lotus-type pores

“…In the welding, the casting and the 3-D printing the pore formation is a problematic issue due to the degradation of the mechanical properties of the metals [1,2]. On the other hand, ordered cylindrical pores in metals are often used to improve the functional properties, such as impact energy absorption, air or water permeability, materials properties, thermal or electrical conductivity, bone regeneration, biocompatibility, and bioresorbability, etc in various engineering and medical and technologies [3][4][5][6][7][8]. The ice crystals incorporating the bubbles containing the ozone gas have also been developed for the food preservation and the sterilization [9].…”