• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Polymer Science >Anisotropic polyimide aerogels fabricated by directional freezing
【24h】

Anisotropic polyimide aerogels fabricated by directional freezing

机译：通过定向冷冻制造的各向异性聚酰亚胺气凝胶

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In this study, we adapted a simple, low-cost, and environmentally friendly method to fabricate anisotropic polyimide (PI) aerogels. During directional freezing of an aqueous poly(amic acid) ammonium salt solution from the profile to the center axis of the cylindrical mold, the ice crystals preferred to grow along the radial direction of the cylindrical mold. After the ice crystals were sublimated by freeze drying, an anisotropic pore structure was formed in the aerogels. The prepared PI aerogels had lower densities (0.04-0.22 g/cm(3)) and higher porosities (84-97%) and exhibited anisotropy in both their pore structures and properties. Their compressive modulus and strength in the horizontal direction were both higher than those in the vertical direction, and they also had good compression recovery in the vertical direction. Moreover, their heat-transfer performance also exhibited anisotropy. The heat transfer in the horizontal direction of the aerogels was much faster than that in the vertical direction. (c) 2018 Wiley Periodicals, Inc.
机译：在这项研究中，我们改善了制造各向异性聚酰亚胺（PI）气凝胶的简单，低成本和环保的方法。在向圆柱形模具的曲线到中心轴的轮廓到中心轴线的曲线方向冻结水性聚（氨基酸）铵盐溶液期间，冰晶沿圆柱形模具的径向生长。通过冷冻干燥升华冰晶后，在气凝胶中形成各向异性孔结构。制备的PI气凝胶具有较低的密度（0.04-0.22g / cm（3））和更高的孔隙率（84-97％），并在其孔隙结构和性质中表现出各向异性。它们的压缩模​​量和水平方向上的强度均高于垂直方向的压缩模量，并且它们在垂直方向上也具有良好的压缩恢复。此外，它们的传热性能也表现出各向异性。气凝胶水平方向上的热传递比垂直方向的水平方向更快。 （c）2018 Wiley期刊，Inc。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号