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yexuqing木虫之王 (文学泰斗)
太阳系系主任
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Dome-celled aerogels with ultrahigh-temperature superelasticity over 2273 K
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Dome-celled aerogels with ultrahigh-temperature superelasticity over 2273 K 2273K以上超高温超弹性圆顶晶胞气凝胶 ▲ 作者：KAI PANG, YUXING XIA, XIAOTING LIU, WENHAO TONG, XIAOTONG LI, CHENYANG LI, ET AL. ▲链接： https://www.science.org/doi/10.1126/science.adw5777 ▲摘要： 气凝胶以其高孔隙率和极低密度而闻名，可由一系列材料制成，但在极端热机械条件下的应用受限于结构不稳定性。 研究组报道了194种圆顶晶胞超轻气凝胶，通过二维通道限域化学策略实现了从4.2K至2273K极宽温度范围内的优异弹性。这种气凝胶在99%应变下2万次循环后仍表现出超弹性，在2273K高温下100次循环后表现出抗热震性。 这种高熵碳化物气凝胶在1273 K和2273 K下的导热系数分别为53.4 mW·m?1·K?1和171.1 mW·m?1·K?1。温度不变弹性和化学多样性的结合使得这种气凝胶在从隔热工业到深空探索等极端热机械应用中极具前景。 ▲ Abstract： Aerogels are known for their high porosity and very low density and can be made from a range of materials, but are limited by structural instability under extreme thermomechanical conditions. We report on 194 types of dome-celled ultralight aerogels that maintain superior elasticity spanning from 4.2 kelvin (K) to 2273 K, realized by a two-dimensional channel–confined chemistry method. Such aerogels exhibit superelasticity under 99% strain for 20,000 cycles and thermal shock resistance at 2273 K over 100 cycles. The high-entropy carbide aerogel achieves a thermal conductivity of 53.4 mW·m?1·K?1 at 1273 K and 171.1 mW·m?1·K?1 at 2273 K. The combination of temperature-invariant elasticity and chemical diversity makes such aerogels highly promising for extreme thermomechanics, from heat-insulated industries to deep space exploration. |
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