Zinc oxide-integrated hydroxyethyl cellulose/lignin aerogel-epoxy/ erythritol composite for multifunctional thermal insulation

초록

Efficient thermal management is essential for improving the thermal reliability of advanced thermal management systems. Although conventional aerogels provide passive thermal insulation, they lack active energy storage capability and often suffer from structural instability or leakage when combined with phase change materials (PCMs). In this study, we developed a multifunctional zinc oxide (ZnO)-integrated hydroxyethyl cellulose (HEC)/lignin (LGN) aerogel-BAET composite (ZHLA-BAET) that integrates thermal insulation, latent heat storage, leakage resistance, and flame-retardant performance through a simplified fabrication process. Here, BAET refers to a phase-change epoxy phase consisting of erythritol (ET) physically incorporated within a bisphenol A epoxy resin (BA)/D-230 cured matrix. The fabrication strategy involved the in situ incorporation of ZnO nanoparticles during hydrogel formation from HEC and LGN to establish a reinforced ZnO-containing HEC/ LGN aerogel (ZHLA). The BAET phase was subsequently introduced into the porous ZHLA scaffold through vacuum-assisted impregnation and thermal curing, enabling effective integration of the phase-change component while preserving ZHLA. The resulting ZHLA-BAET composite maintained its three-dimensional microporous architecture and exhibited a low thermal conductivity of 0.1029 W & sdot;m- 1 & sdot;K- 1 together with a latent heat of 148.79 J & sdot;g- 1. The composite also showed improved leakage resistance and thermal cycling reliability, retaining 97.4% of its initial latent heat after 50 repeated heating/cooling cycles. In addition, ZHLA-BAET exhibited enhanced flame-retardant behavior, as evidenced by reduced heat release and smoke production, a UL-94 V0 rating, and a limiting oxygen index (LOI) value of 28.7%. Overall, the ZHLA-BAET composite provides a promising material platform for advanced multifunctional thermal management by combining simplified fabrication with low thermal conductivity, latent heat storage, leakage resistance, structural reliability, and improved fire safety.

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