RT info:eu-repo/semantics/article T1 Reaching a near zero radiative heat transfer by the inclusion of modified multiwalled-carbon nanotubes (MWCNTs) in polyurethane-polyisocyanurate aerogels A1 Merillas Valero, Beatriz A1 Gómez Álvarez Arenas, Tomás Enrique A1 Villafañe González, Fernando A1 Rodríguez Pérez, Miguel Ángel K1 Thermodynamics K1 Aislamiento térmico K1 Carbon nanotubes K1 Radiative contribution K1 Polyurethane aerogels K1 Nanotubos de carbono K1 Contribución radiativa K1 Aerogeles de poliuretano K1 3312 Tecnología de Materiales AB This article studies the effect of adding different contents of surface-modified multiwalled carbon nanotubes (CNTs) on the structure and final properties of polyisocyanurate-polyurethane aerogels. The produced samples were characterized in terms of density, porosity, shrinkage, textural properties, mechanical behavior, ultrasonic behavior, and thermal conductivity. Low-weight aerogels were obtained with densities between 89 and 95 kg/m3. The inclusion of homogeneously dispersed carbon nanotubes protected the aerogel structure during supercritical drying decreasing the final shrinkage of these samples and, therefore, increasing their porosity. The porous structure of the aerogels containing CNTs was modified, and slightly larger pores were formed. The structural modifications contribute to decrease the stiffness of the samples while improving their resilience and elasticity. Finally, a significant enhancement on the insulating performance of the aerogels has been found when CNTs were added reaching values as low as 12 mW/mK. These fillers were proved to act as infrared opacifiers by absorbing and scattering the infrared radiation, a relevant contribution in these lightweight materials. In fact, the radiation contribution was strongly reduced when the content of CNTs reached 3 wt%, being this contribution near zero. Thus, this content was considered as the optimum for the final properties-balance in these aerogels. PB Elsevier SN 2468-5194 YR 2023 FD 2023 LK https://uvadoc.uva.es/handle/10324/62998 UL https://uvadoc.uva.es/handle/10324/62998 LA eng NO Materials Today Chemistry, 2023, vol.34, 101789 NO Producción Científica DS UVaDOC RD 22-nov-2024