Browsing by Author "Zhang, Dou"

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    Low-temperature thermally modified fir-derived biomorphic C–SiC composites prepared by sol-gel infiltration
    (Elsevier, 2023-02-10) Li, Guo-Qing; Yu, Min; Luo, Hang; Huang, Ze-Ya; Fu, Ren-Li; Gucci, Francesco; Saunders, Theo; Zhu, Kong-Jun; Zhang, Dou
    In order to solve the problems (i.e. low infiltration efficiency, cracks, interface separation and poor mechanical properties) in the process of wood-derived C–SiC composites, the thermal modification of fir at low temperatures (300 °C ∼ 350 °C) combined with sol-gel infiltration was used to successfully produce biomorphic ceramics. The prepared materials were comprehensively characterized and exhibited improved interfacial bonding between C and SiC and mechanical properties. The weight gain per unit volume (0.123 g/cm3) of SiO2 gel in the fir thermally modified at 300 °C is 167.4%, higher than that (0.046 g/cm3) of the unmodified fir. A well-bonded interface was formed between the SiO2 gel and the pore wall of the fir thermally modified at 300 °C. With the increase of modification temperature from 300 °C to 350 °C, the distance between SiO2 gel and the pore wall increases, and a gap (1–3 μm) is observed between SiO2 gel and the pore wall of the fir carbonized at 600 °C. The C–SiC composites sintered at 1400 °C exhibited the highest compressive strength and bending strength of 40.8 ± 5.8 MPa and 11.7 ± 2.1 MPa, respectively, owing to the well-bonded interface between C of fir thermally modified at 300 °C and SiC. However, the composites sintered at 1600 °C for 120 min exhibited the lowest compressive strength and bending strength of 28.1 ± 13.4 MPa and 5.7 ± 1.6 MPa, respectively, which are 31.1% and 51.3% lower than those sintered at 1400 °C for 120 min, respectively. This might result from the porous structure formed by the excessive consumption of fir-derived carbon during the reaction between C and SiO2 at 1600 °C for 120 min. Therefore, thermal modification in the preparation of biomorphic C–SiC composites can promote slurry infiltration and the formation of a well-bonded interface between C and SiC, thus improving the mechanical properties of the composites.
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    Review of bioinspired composites for thermal energy storage: preparation, microstructures and properties
    (MDPI, 2025-01-15) Yu, Min; Wang, Mengyuan; Xu, Changhao; Zhong, Wei; Wu, Haoqi; Lei, Peng; Huang, Zeya; Fu, Renli; Gucci, Francesco; Zhang, Dou
    Bioinspired composites for thermal energy storage have gained much attention all over the world. Bioinspired structures have several advantages as the skeleton for preparing thermal energy storage materials, including preventing leakage and improving thermal conductivity. Phase change materials (PCMs) play an important role in the development of energy storage materials because of their stable chemical/thermal properties and high latent heat storage capacity. However, their applications have been compromised, owing to low thermal conductivity and leakage. The plant-derived scaffolds (i.e., wood-derived SiC/Carbon) in the composites can not only provide higher thermal conductivity but also prevent leakage. In this paper, we review recent progress in the preparation, microstructures, properties and applications of bioinspired composites for thermal energy storage. Two methods are generally used for producing bioinspired composites, including the direct introduction of biomass-derived templates and the imitation of biological structures templates. Some of the key technologies for introducing PCMs into templates involves melting, vacuum impregnation, physical mixing, etc. Continuous and orderly channels inside the skeleton can improve the overall thermal conductivity, and the thermal conductivity of composites with biomass-derived, porous, silicon carbide skeleton can reach as high as 116 W/m*K. In addition, the tightly aligned microporous structure can cover the PCM well, resulting in good leakage resistance after up to 2500 hot and cold cycles. Currently, bioinspired composites for thermal energy storage hold the greatest promise for large-scale applications in the fields of building energy conservation and solar energy conversion/storage. This review provides guidance on the preparation methods, performance improvements and applications for the future research strategies of bioinspired composites for thermal energy storage.