This EArly-concept Grant for Exploratory Research (EAGER) grant provides funding to study the feasibility of a manufacturing process to synthesize and embed a metallic nanowire network into phase change materials to enhance thermal performance of phase-change energy storage systems. In general, the low thermal conductivity of phase change materials is still a critical limiting factor that needs to be addressed to achieve large scale and robust energy storage systems to maximize the efficiency of renewable energy sources. The hypothesis is that the metal nanowire network will facilitate the pass for heat flow and yield significant enhancement in thermal conductivity of phase change material. The processing steps will consist of manipulating magnetic nanowires under an applied magnetic field followed by a thermal soldering process. First, multi-segmented magnetic nanowires with a magnetic core (Nickel or Cobalt) and two soldering heads will be fabricated using a template based electrodeposition method. Second, the magnetic nanowires will be assembled under a static magnetic field to form nanowire columns in the direction of the applied field. Finally, the entire phase change material will be heated to a temperature above the melting point of the solders to permanently bond nanowires into a network. The structural morphology of the nanowire network will be characterized by scanning electron microscopy. The bonded network will be subjected to melting/solidification cycles to determine the stability and mechanical integrity of the nanostructure. The heat transport capability of the nanowire network will be evaluated through electric conductance measurements. The relationships between network structure and processing parameters such as magnetic field strength, nanowire loading, heating and soldering temperatures, and material thermophysical properties will be investigated through a combined experimental and analytical approach.
If successful, the present research will enable a new kind of phase change material, which will impact the renewable energy storage industry and a number of diverse applications such as compact heat exchangers, electronic cooling, and smart textiles for thermal protection. The outcome of this research will contribute to a fundamental understanding of phase change and thermal transport processes in nanostructured composite materials. In addition, the understanding of the interactions of nanowires and formation of structural networks under a magnetic field will contribute to the nanomanufacturing of composite materials that could potentially be used in industries such as medical, automobile, food processing and semiconductor packaging.
