Highly flexible, erosion resistant and nitrogen doped hollow SiC fibrous mats for high temperature thermal insulators
Highly flexible, erosion resistant and nitrogen doped hollow SiC fibrous mats for high temperature thermal insulators
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DOI：
10.1039/c6ta09475a
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发表时间：
2017-02-14
影响因子：
11.9
通讯作者：
Kim, Hak Yong
中科院分区：
文献类型：
--
作者：
Liu, Yanan;Liu, Yang;Kim, Hak Yong
耐热耐化学性碳化硅纤维垫作为高端设备和工艺中的高温绝热材料备受关注。本文报道了一种新型的具有超低导热系数的自立式、柔韧性、耐酸碱和氮掺杂(N掺杂)中空碳化硅纤维垫。材料的制备分为三步：聚合物前驱体共轴电纺制备核壳纤维，热或电子束辐照固化工艺和热解工艺。所制得的连续纤维呈椭圆形中空结构，腔壁厚度约为1.5微米，在氮气气氛下1300℃以上热解后得到晶型。详细分析了具有织构和多孔表面的含N中空碳化硅纤维的形态、组成、固化和形成机理。这些易于制备的N掺杂中空碳化硅纤维垫具有良好的柔韧性、不可燃性、高热稳定性、耐冲蚀、重量轻(0.218 g cm(-3))和低高温导热系数(0.039 W m(-1)K-1)，有望作为高温绝热材料应用。
Thermally stable and chemical resistant silicon carbide (SiC) fibrous mats have drawn much attention as a high-temperature thermal insulator in top end equipment and technology. Herein, novel free-standing, flexible, acid/alkali-resistant and nitrogen doped (N-doped) hollow SiC fibrous mats bearing ultralow thermal conductivity are reported. The materials were fabricated via a three-step process: the preparation of core-shell fibers from polymeric precursors by co-axial electrospinning, the thermal or electron beam irradiation curing process and pyrolysis process. The as-obtained continuous fibers manifested an oval-shape hollow structure and the thickness of the cavity wall was approximately 1.5 mu m. The crystal pattern was obtained after pyrolysis over 1300 degrees C under a nitrogen atmosphere. The morphology, composition, curing and formation mechanisms of N-containing hollow SiC fibers with texture and porous surfaces were elaborately analysed. These facilely fabricated N-doped hollow SiC fibrous mats possess good flexibility, noninflammability, high thermal stability, erosion resistance, light weight (0.218 g cm(-3)) and low thermal conductivity at high temperature (0.039 W m(-1) K-1), suggesting promising application as a high temperature thermal insulator.