Experimental validation of the Knudsen effect in nanocellular polymeric foams
DUMON, Michel
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
< Leer menos
Laboratoire de Chimie des Polymères Organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
Idioma
en
Article de revue
Este ítem está publicado en
Polymer. 2015, vol. 56, p. 57-67
Elsevier
Resumen en inglés
This paper is focused on demonstrating that it is possible to reduce the thermal conductivity of polymeric foams by reducing the average cell size below the micron. For this purpose, a wide set of samples with cell sizes ...Leer más >
This paper is focused on demonstrating that it is possible to reduce the thermal conductivity of polymeric foams by reducing the average cell size below the micron. For this purpose, a wide set of samples with cell sizes from 90 nm to 100 gm and relative densities from 0.12 to 0.6 has been produced and analyzed. In addition, a characterization procedure that allows identifying independently some of the heat transfer mechanisms in polymeric foams has been developed. As a result, it has been demonstrated that Knudsen effect takes place in nanocellular polymeric foams, being this effect very positive to reduce the overall heat transfer. Through the understanding of the underlying mechanisms it has possible to model the thermal conductivity behavior of these materials in the entire range of cell sizes, and overall porosities. It has been proved that the reduction of the cell size has an effect on the thermal conductivity through the solid phase, this contribution is reduced due to an increment of the tortuosity of the cellular structure and/or a confinement effect in the polymeric matrix.< Leer menos
Palabras clave en inglés
AEROGELS
POLYOLEFIN FOAMS
BLOCK-COPOLYMERS
Nanocellular foams
Knudsen effect
Thermal conductivity
PRESSURE CARBON-DIOXIDE
THERMAL-CONDUCTIVITY
CELLULAR STRUCTURE
SUPERCRITICAL CO2
HEAT-TRANSFER
METHACRYLATE
TRANSPORT
Orígen
Importado de HalCentros de investigación