title: Carbon aerogel composites prepared by ambient drying and using oxidized polyacrylonitrile fibers as reinforcements.
abstract: Carbon fiber-reinforced carbon aerogel composites (C/CAs) for thermal insulators were prepared by copyrolysis of resorcinol-formaldehyde (RF) aerogels reinforced by oxidized polyacrylonitrile (PAN) fiber felts. The RF aerogel composites were obtained by impregnating PAN fiber felts with RF sols, then aging, ethanol exchanging, and drying at ambient pressure. Upon carbonization, the PAN fibers shrink with the RF aerogels, thus reducing the difference of shrinkage rates between the fiber reinforcements and the aerogel matrices, and resulting in C/CAs without any obvious cracks. The three point bend strength of the C/CAs is 7.1 ± 1.7 MPa, and the thermal conductivity is 0.328 W m(-1) K(-1) at 300 °C in air. These composites can be used as high-temperature thermal insulators (in inert atmospheres or vacuum) or supports for phase change materials in thermal protection system.
authors: Key Lab of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, 109 De Ya Rd, Changsha, Hunan, 410073, China.
authors: Junzong
authors: J
authors: Feng
authors: Changrui
authors: C
authors: Zhang
authors: Jian
authors: J
authors: Feng
authors: Yonggang
authors: Y
authors: Jiang
authors: Nan
authors: N
authors: Zhao