Shape-stabilized composite phase change film with good reversible thermochromic properties fabricated: Via phase inversion-assisted impregnation

Abstract

In this study, the regenerated porous cellulose film (LD) was properly prepared by dissolving cellulose in a LiCl/DMAc solvent though a simple phase inversion method. LD has a porous structure, good mechanical properties and great thermal stability. In order to form a shape-stabilized reversible thermochromic phase change film (DTLD), a reversible thermochromic compound (DTBC) was added into the LD by simple vacuum impregnation. The effect of the weight ratio of 1-dodecanol/tetradecanol complex solvent (3:7, 2:8, 1.5:8.5 and 1:9) on the phase change properties was investigated. DTLD (1.5:8.5) showed the highest latent heat storage of 174.00 J g-1 with the suitable phase change temperature at 37.5 °C. The low thermal conductivity of DTLD (1.5:8.5) at 10 °C (50 °C) was 0.396 ± 0.004 W m-1 K-1 (0.408 ± 0.002 W m-1 K-1). The color of DTLD (1.5:8.5) can change reversibly between colorless and blue as temperature changes. Melting-cooling tests after 100 cycles indicated that DTLD (1.5:8.5) has a high latent heat storage capacity of 169.65 J g-1. A shape-stable reversible thermochromic phase change composite assembled from a regenerated porous cellulose membrane as a support matrix is expected to be applied to the field of thermal energy storage.