Simultaneous Measurements of Thermal Conductivity and Diffusivity of Hen Egg-White Lysozyme Crystals Using a Transient Short Hot Wire Method and Magneto-Archimedes Effect

Abstract

By using simultaneously the magnetic levitation technique and the transient short hot wire method, thermal conductivity and diffusivity of hen egg-white lysozyme (HEWL) crystals were measured for the first time. In order to attach the HEWL crystals onto the wire, crystal growth was carried out at the air-liquid interface of the solution by the magneto-Archimedes effect. Gadolinium chloride (a paramagnetic subject) was used as a precipitant agent of crystallization. The thermal conductivity and diffusivity of the HEWL crystals at the applied magnetic field (H) of μ₀H = 4.0 T and the temperature of 17.2 °C were determined to be 0.410 W/(m·K) and 3.77 × 10^-8 m²/s 14 h later from the start of the crystal growth, and 0.438 W/(m·K) and 5.18 × 10^-8 m²/s 20 h later, respectively. In this measurement, the concentrations of HEWL and GdCl₃ were 6.53 wt% and 0.362 mol/kg, respectively, and the pH was 3.30.