Neoteric heterogeneous discarded sericultural mulberry branch-derived self-regulation thermal management functional composite phase change materials

With the booming global economy and population growth, the demand for energy has increased dramatically. It is urgent to increase the proportion of renewable energy such as solar energy and biomass energy in the energy structure and, reduce fossil energy consumption. Phase change material stores heat through phase change process, redistributing the use of energy and improving the utilization efficiency. In this paper, natural sericulture mulberry branch (NSMB, Morus alba L.) based composite phase change material (CuO/PW/DHSMB) was prepared by selectively removing partial components with chlorite-hydrolysis treatment and vacuum assisted impregnating paraffin wax (PW) after mixing with cupric oxide (CuO). Above mentioned NSMB is solid waste from sericultural industry, which possesses whole structural characteristic of trunk composed of bark, xylem, and pith. An in-depth anatomical analysis of the anisotropic porous structure of NSMB conducted through microscopy reveals the structural feature is closely linked to its physiological function, which facilitates the self-regulated thermal management of NSMB and establishes a foundation for its heat storage potential. NSMB has effective self-regulating thermal management and porous structures, which ensuring favorable shape stability. The addition of CuO enhanced thermal conductivity, and CuO/PW/DHSMB exhibited stable latent heat after 50 cycles of alternating hot and cold. The low-cost and readily available support material was used to prepare a composite phase change material with high thermal conductivity, leakage-free, and good thermal insulation properties, which provided ideal path for the thermal energy storage applications. [Display omitted] •Sericulture cyclical pruning generates the mulberry branch was more cost-effective and extensive than ripewood.•Pretreated mulberry branch of three-layer structure has uneven heat transfer and shape stability characteristics.•The heterogeneous mulberry branch-derived composite phase change material possesses self-regulation thermal management function.