JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yuhan Ren,Biao Zhang,Zhaoxin Zhong,Jian Ye,Jiawei Zhang,Zhiyong Fang,Feng Ye
In this study, monolithic Al 2 O 3 –SiO 2 aerogels with excellent thermal stability and high specific surface area were synthesized using boehmite nanorods (L=20–30 nm, D=3–5 nm). The high specific surface area of aerogels was maintained after calcination at 800 °C (663.54 m 2 /g), 1000 °C (486.91 m 2 /g), and 1100 °C (230.76 m 2 /g). The anti-sintering mechanism of the Al 2 O 3 -SiO 2 aerogels was discussed. Thanks to the composite of Al 2 O 3 -SiO 2 aerogel and mullite fibers, the disadvantages of brittleness and low strength of aerogel are overcome. The thermal conductivity of the composite is extremely low at 0.034 W/(m·K)-0.089 W/(m·K) (25 °C-1000 °C). Five muffle cycle back-temperature tests at 1000 °C and a butane blowtorch back-temperature test at 1350 °C also proved that the composites have excellent thermal insulation properties. Composites with excellent thermal insulation properties combined with lightweight, thinness, machinability, and good dielectric properties meet the need for high-temperature thermal insulating-wave transmitting integrated materials for hypersonic missile radomes.
研究领域:
材料科学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2023
·Vol. 30
·期 5
·1753-1761
·
IF 2.6
Zhao Wenpu,Ji Yuecheng,Pang Yifan,Li Xiaolei,Ji Huiming
Al 2 O 3 -SiO 2 aerogel (ASA) was prepared by convenient ambient pressure drying using inexpensive AlCl 3 ·H 2 O as precursor, and silicon was deposited during the aging of aluminum gel. To explore the influence of Chloride ion on the property of ASA, ion exchange technology was used to remove the Chloride ion in the aluminum sol. ASA exhibits a low thermal conductivity of 0.029 W m −1 K −1 at room temperature, and the specific surface area of Cl-free ASA after heat-treated at 1200 °C is 95.2 m 2 /g, which is higher than that of the chlorine-containing aerogel (11.4 m 2 /g), showing enhanced thermal stability of ASA. Analysis of XRD and XPS indicate that the removal of chloride ions makes it more difficult for ASA to establish Al–O–Si groups during the aging process, so the γ-Al 2 O 3 and cristobalite phase do not transform to mullite phase at 1200 °C. Due to the better thermal stability of ASA, it has great potential for high-temperature applications in the fields of insulation, thermal protection materials, and building external wall thermal insulation.
研究领域:
材料科学
·
纳米技术
·
热工工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·
IF 6.2
Hao Zhang,Zhen Teng,Yiwang Bao,Man Jiang,Qingguo Feng,Chunfeng Hu
Oxide ceramic aerogels, one of the most important aerogels, hold significant application promise in thermal insulation and protection. However, their low strength, long preparation cycle, and supercritical drying dependence hinder their widespread use. In this study, we proposed a hybrid interpenetrating network strategy and prepared a hybrid Al 2 O 3 -SiO 2 aerogel (PAS) via ambient pressure drying. The structures, mechanical properties, thermal insulation performance, and mechanisms of PAS were systematically investigated. PAS exhibited remarkably low drying linear shrinkage (6.08%), substantially compressive strength (8.05 MPa), and impressive strain capacity (45%). Furthermore, PAS demonstrated exceptional thermal insulation (0.039 W/m·K at 25°C) and high-temperature structural stability. Mechanistic studies revealed that the hybrid interpenetrating network significantly reinforced the Al 2 O 3 -SiO 2 network, and inhibited the phase transition of Al 2 O 3 -SiO 2 in high-temperature. This study provides a reproducible approach for the rapid preparation of high-strength, low-thermal conductivity oxide ceramic aerogels and demonstrates its promising application potential in thermal protection.
研究领域:
材料科学
·
陶瓷材料
·
热工工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2018
·
IF 2.488
Huijun Yu,Yiting Jiang,Yufa Lu,Xiaolei Li,Hangyuan Zhao,Yuecheng Ji,Mingjing Wang
A low-cost and high-performance quartz fiber/Al 2 O 3 -SiO 2 aerogel (QF/ASA) composite insulation material has been successfully prepared by vacuum filtration molding and sol-gel impregnation following surface-modified ambient pressure drying (APD). The macroporous in the quartz fiber perform are filled by Al 2 O 3 -SiO 2 aerogels with a large amount of mesoporous. The morphology, microstructure, thermal conductivity and thermal stability of the QF/ASA composite were investigated. Compared to the fiber/aerogel materials dried by supercritical drying, the composite exhibits similar low density (0.36 g·cm −3 ), high specific surface area (580.5 m 2 ·g −1 ), low thermal conductivity (0.049 W·m −1 ·K −1 ) at room temperature. The compressive strength of the composite up to 0.85 MPa which is approximately triple as much as that of fiber perform. After being heated at 600 to 1100 °C, the specific surface area of composite aerogel decrease from 578.0 to 113.6 m 2 ·g −1 and the linear shrinkage is almost zero. The XRD patterns show that mullite (3Al 2 O 3 ·2SiO 2 ) appeared in the Al 2 O 3 -SiO 2 aerogel after heat-treatment at 1100 °C, which is consistent with the molar ratio of silica and alumina of 2:3.
研究领域:
材料科学
·
化学工程
·
热绝缘
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）