Meng Taotao, Zhu Long, Stone Dylan, Armstrong Jason N, Ren Shenqiang
Department of Materials Science and Engineering, University of Maryland, College Park, MD, 20742, USA.
Department of Mechanical and Aerospace Engineering, University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA.
Small. 2025 Jul;21(30):e2503511. doi: 10.1002/smll.202503511. Epub 2025 May 28.
Cellulosic materials offer sustainable advantages for building energy conservation. However, their development has been hindered by reduced thermal performance, often caused by structural collapse during the transition from solution to solid. Inspired by natural goose down, a bio-based, lightweight insulation foam derived from agricultural waste straw is presented. Through in situ synthesis, bio-silica fibers with branched structures capable of supporting hollow silica microspheres are fabricated. After steam-mediated processing, the resulting foam exhibit low density (95 mg cm ), high porosity (95.5%), low thermal conductivity (0.03 ± 0.003 W mK), and a cyclic compressive strength of 90 kPa at 50% strain. Owing to the synergistic microstructure formed by branched bio-fibers and hollow silica spheres, the bio-silica foam exhibit outstanding thermal insulation performance relative to other bio-based foams prepared by ambient drying. A passivated insulation panel is further developed by incorporating this material as the core component, achieving a thermal conductivity of 0.0275 W mk and flexural strength of 6.85 MPa. The panel demonstrated durability with stable thermal performance throughout a 60-day outdoor test. Moreover, the bio-silica foam shows a carbon footprint of 7.50 kgCO₂ kg at 70.2 wt.% silica, highlighting its promise as a sustainable insulation solution for green buildings.
纤维素材料为建筑节能提供了可持续的优势。然而，其发展受到热性能下降的阻碍，这通常是由从溶液到固体的转变过程中的结构坍塌引起的。受天然鹅绒的启发，提出了一种由农业废秸秆衍生的生物基轻质隔热泡沫。通过原位合成，制备出具有能够支撑空心二氧化硅微球的分支结构的生物二氧化硅纤维。经过蒸汽介导的加工后，所得泡沫表现出低密度（95毫克/立方厘米）、高孔隙率（95.5%）、低导热率（0.03±0.003瓦/米·开尔文）以及在50%应变下90千帕的循环抗压强度。由于分支生物纤维和空心二氧化硅球形成的协同微观结构，与通过常压干燥制备的其他生物基泡沫相比，生物二氧化硅泡沫表现出优异的隔热性能。通过将这种材料作为核心组件进一步开发出一种钝化隔热板，其导热率为0.0275瓦/米·开尔文，抗弯强度为6.85兆帕。在为期60天的户外测试中，该板材表现出耐久性且热性能稳定。此外，在二氧化硅含量为70.2重量%时，生物二氧化硅泡沫的碳足迹为7.50千克二氧化碳/千克，凸显了其作为绿色建筑可持续隔热解决方案的前景。
