Modulation of Interfacial Thermal Transport between Fumed Silica Nanoparticles by Surface Chemical Functionalization for Advanced Thermal Insulation

Since solid-state heat transport in a highly porous nanocomposite strongly depends on the thermal boundary conductance (TBC) between constituent nanomaterials, further suppression of TBC is important for improving performance insulators. Here, targeting fabricated by stamping fumed silica nanoparticles, we perform wide variety surface functionalization nanoparticles silane coupling method and investigate impact conductivity (Km). The Km approximately 20 9 mW/m/K under atmospheric vacuum condition at material density 0.2 g/cm3 without functionalization, respectively, experimental results indicate that can be modulated depending chemical structure molecules. modification with linear alkyl chain optimal length significantly suppresses 30%, enhanced to 50% infrared opacifier. magnitude was found sensitively depend terminal chain. also related number reactive silanol groups structure, where fluorocarbon gives largest suppression. hydrophobization merits insulation through significant TBC, presumably reducing water molecules otherwise would serve as conduction channels interface. On other hand, when long, counteracted phonon transmission grows length. This supported analytical model present simulation results, leading predict better insulation.