Thermal conductivities of MgO–Al2O3 hollow fibers formed by biomimetic synthesis. Issue 17 (1st December 2019)

• Record Type: Journal Article
• Authors: Dai, Changhao; Li, Yicong; Liao, Zhengwei; Kong, Jian; Wang, Tianchi
• Is Part Of: Ceramics international. Volume 45:Issue 17(2019)Part B
• Page Start: 23826
• Page End: 23829
• Publication Date: 2019-12-01
• Subjects: Thermal conductivity -- MgO–Al2O3 -- Biomimetics -- Hollow fibers; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.08.038
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: MgO–Al2 O3 hollow fibers were effectively prepared by bionics using cogon as a low-cost natural template. Through orthogonal experimental design, the preparation parameters were optimized as follows: Al2 O3 : MgO ratio of 0.60, mass ratio of 25% solute in the mixture, drying temperature of 80 °C, and sintering temperature of 1100 °C. Overall, with inner pore sizes ranging from 5 μm to 10 μm, the MgO–Al2 O3 hollow fibers are a novel low-cost lightweight refractory material. Their stack density is approximately 0.120 g cm −3 and thermal conductivity is 0.2050 W m −1 K −1 at 1273 K. In addition, the porosity and average pore area of the hollow fibers are 80.9% and 0.96 m 2 g −1, respectively. Here, the effects of pore size, average pore area, and phase composition on the thermal conductivity of the MgO–Al2 O3 hollow fibers are discussed synthetically. Graphical abstract: By applying a biomimetic synthesis method, MgO–Al2 O3 hollow fibers were prepared from the hollow-structured cogon plant. The preparation parameters were optimized by orthogonal experiment design. Accordingly, the thermal conductivity, stack density, and average pore area of the optimal hollow fibers are 0.2050 W m −1 K −1 at 1273 K, ~0.120 g cm −3, and 0.96 m 2 g −1, respectively.Image 1 Highlights: A biomimetic method to fabricate hollow MgO–Al2 O3 fibers using a cogon-template. Orthogonal experimental design (OED) is used to optimize the synthesis of the fibers. OED demonstrates the relative importance of compositional and processing parameters.