Negative thermal expansion and negative compressibility in heterogeneous lyophobic systems
Abstract: Thermal expansion and compressibility are among the basic characteristics of material/system. In most cases, materials expand when heated and shrink when cooled. Similarly, majority of materials shrink when compressed and expand when decompressed. The opposite effects –negative thermal expansion and negative compressibility – are extremely rare, while being attractive for wide range of applications, such as sensing, actuation, zero-expansion materials and many more. In this presentation, we demonstrate how system consisting of a porous material and a non-wetting liquid permits achieving negative thermal expansion and negative compressibility orders of magnitude larger compared to the state-of-the-art. Severa l strategies are discussed, which include exploiting flexibility of nanoporous materials, temperature dependent interfacial properties and CO2-assisted drying of nanopores.
Date: 8th 14.30-15.30
Room: Sala didattica palatina E