Understanding Thermal Insulation in Porous, Particulate Materials
| Autor: | Pia Ruckdeschel, Alexandra Philipp, Markus Retsch |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Thermal contact conductance
Materials science business.industry 02 engineering and technology Colloidal crystal 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics Thermal conduction Thermal diffusivity 01 natural sciences 0104 chemical sciences Electronic Optical and Magnetic Materials Condensed Matter::Soft Condensed Matter Biomaterials Thermal conductivity Thermal insulation Thermal Electrochemistry Composite material 0210 nano-technology business Porosity |
| Zdroj: | Advanced Functional Materials. 27:1702256 |
| ISSN: | 1616-301X |
| DOI: | 10.1002/adfm.201702256 |
| Popis: | Silica hollow nanosphere colloidal crystals feature a uniquely well-defined structure across multiple length scales. This contribution elucidates the intricate interplay between structure and atmosphere on the effective thermal diffusivity as well as the effective thermal conductivity. Using silica hollow sphere assemblies, one can independently alter the particle geometry, the density, the packing symmetry, and the interparticle bonding strength to fabricate materials with an ultralow thermal conductivity. Whereas the thermal diffusivity decreases with increasing shell thickness, the thermal conductivity behaves inversely. However, the geometry of the colloidal particles is not the only decisive parameter for thermal insulation. By a combination of reduced packing symmetry and interparticle bonding strength, the thermal conductivity is lowered by additionally 70% down to only 8 mW m−1 K−1 in vacuum. The contribution of gaseous transport, even in these tiny pores ( |
| Databáze: | OpenAIRE |
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