Nanosized n-eicosane as phase change materials: Phase behaviors and phase transition kinetics

Abstract

Through confined in nanopores, the model compound of normal eicosane (n-C20H42, C20) shows tunable melting temperature and enthalpy change, which provides a series of nanosized phase change materials with various melting points. The phase behaviors of C20 in the pores of controlled pore glasses (CPGs) and SBA-15 are estimated using differential scanning calorimetry. The melting point of C20 decreases with the decreasing pore size, following a relation by the Gibbs–Thomson equation. Maximum decreases of C20 in the pores of CPGs and SBA-15 are about 7 and 13 K, respectively, which are the melting point widows for thermal energy storage formed by the nanoconfinement. Kinetics of melting of the bulk and nanoconfined C20 reveals reduced effective activation energy in the pores. The nanosized C20 is a good example to obtain PCMs with adjustable thermal properties.

Keywords

• Confinement
• Eicosane
• Size effect
• Phase change material