image: The MNF-TNW aerogel is constructed by in-situ growth of TiO2 nanowires on mullite nanofiber surfaces, forming a hierarchical porous structure with enhanced reflectivity and scattering efficiency. The surface reflectivity increases from 94.68% to 97.25% at 1080 nm, while the laser energy absorption decreases by 48.3%. The composite aerogel exhibits excellent thermal insulation performance, as demonstrated by the flower protection test under flame exposure. Under high-energy laser ablation (300 W·cm⁻2, spot size: Φ10 mm), the MNF-TNW aerogel withstands 30 s of continuous irradiation and repeated impacts without macroscopic damage, whereas the pristine MNF aerogel fails within 3 s. The sacrificial sublimation of TiO2 nanowires further absorbs deposited heat, extending the effective protection time.
Credit: Journal of Advanced Ceramics, Tsinghua University Press
High-energy laser weapons and intense heat fluxes pose a growing threat to lightweight thermal protection systems used in aerospace and defense applications. Ceramic fiber aerogels offer exceptional low density and thermal insulation, but their highly porous architecture allows deep laser penetration, rapid heat accumulation, and catastrophic failure. For instance, conventional mullite nanofiber (MNF) aerogels are perforated within just 3 seconds under a 300 W/cm2 continuous-wave laser.
To overcome this vulnerability, a team of materials scientists has developed a robust hierarchical composite by growing TiO2 nanowires directly onto the surface of mullite nanofiber aerogels (MNF-TNW). The in-situ hydrothermal growth process first deposits TiO2 seed crystals, followed by solvothermal reaction at 190 °C to form a dense, interlocking nanowire network. This multiscale design refines the aerogel’s mesopores from 16.75 nm to 3.52 nm and increases compressive strength by 70% compared to unmodified MNF aerogels.
“The key innovation is that the TiO2 nanowires act as both optical scatterers and thermal barriers,” said Chen Ma, the corresponding author of the study. “They greatly enhance reflectivity and scattering efficiency, cutting off the primary energy input path of the laser. At the same time, the nanowire network suppresses solid and radiative heat conduction, especially at high temperatures.”
Optical measurements show that the MNF-TNW aerogel achieves a surface reflectivity of 97.25%, up from 94.68% for the pristine MNF aerogel. This represents a 48.3% reduction in laser energy absorption. Numerical simulations based on Mie scattering theory confirm a substantially higher scattering cross-section at the 1080 nm laser wavelength.
The improvement in high-temperature insulation is equally striking. At 1000 °C, the thermal conductivity of the MNF-TNW aerogel is only 0.0596 W·m-1·K-1, which is 30.8% lower than that of the unmodified aerogel. In a butane torch test, the back-side temperature of the composite aerogel stays 51.3 °C cooler than that of the conventional material, demonstrating exceptional heat shielding.
Laser ablation tests confirm the superior resistance of the hierarchical aerogel. Under 300 W/cm2 irradiation, the pristine MNF aerogel fails within 3 seconds, exhibiting complete perforation and melted fiber structures. In contrast, the MNF-TNW aerogel remains intact after 30 seconds of continuous irradiation. Even more impressively, it withstands two consecutive 30-second laser exposures at the same spot, and only fails after a third cycle of 3 seconds. At a higher power density of 500 W/cm2 for 30 seconds, the composite aerogel shows no macroscopic damage and retains its structural integrity.
The protection mechanism involves three synergistic effects: high reflectivity/scattering that minimizes energy deposition; pore refinement and phonon scattering that reduce heat conduction; and sacrificial phase change of the TiO2 nanowires (melting, vaporization, and sublimation) that absorbs intense laser heat. X-ray photoelectron spectroscopy reveals a significant loss of Ti after ablation, confirming the energy-dissipating role of the nanowires.
“This in-situ growth strategy transforms a fragile, laser-sensitive aerogel into a resilient thermal shield capable of withstanding extreme laser fluxes,” added Chen Ma. “The material not only resists 500 W/cm2 irradiation but also survives repeated impacts, which is unprecedented for ceramic fiber aerogels.”
This work establishes a scalable design paradigm for next-generation ceramic aerogels. The team anticipates that the lightweight, robust MNF-TNW aerogels will serve as highly effective insulating interlayers in multilayer composite structures for aerospace vehicles, specialized equipment, and other platforms facing extreme thermal and laser threats.
The team published their work in Journal of Advanced Ceramics on June 25, 2026.
Other contributors include Wanxin Zhi, Jian Liu, Guohua Chen, and Baojie Zhang from the School of Materials Science and Engineering at Huaqiao University, and Zhuang Ma and Lihong Gao from Beijing Institute of Technology, China.
About Author
Chen Ma, Associate Professor at the College of Materials Science and Engineering, Huaqiao University, recipient of the Fujian Province Outstanding Youth Science Fund, and Chair of the Department of Materials Science and Engineering. He received his Ph.D. from Beijing Institute of Technology in 2020, during which he was jointly trained at Case Western Reserve University in the United States. He has long been engaged in research on high-temperature and high-energy thermal protection coatings. As the principal investigator, he has presided over 10 research projects, including the Joint Fund of the Ministry of Education for Equipment Pre-Research, the National Natural Science Foundation of China Youth Fund, and the XX Pre-Research Application Innovation Project. He has published more than 30 academic papers as the first/corresponding author in journals such as J. Adv. Ceram., Nano Res., Chem. Eng. J., Carbon, and Compos. Part B. He has been granted more than 10 national invention patents. He has received honors including Outstanding Young Editorial Board Member of the Journal of Ceramics and the Nomination Award for Excellent Doctoral Dissertation of the Chinese Society for Composite Materials.
Funding
This work was supported by National Natural Science Foundation of China (52302064), the Natural Science Foundation of Fujian Province (2025J09041), and the Fundamental Research Funds for the Central Universities (ZQN-1204).
About Journal of Advanced Ceramics
Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/34, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 Cite Score is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508
Journal
Journal of Advanced Ceramics
Article Title
In situ construction of hierarchical TiO2 nanowire/mullite fiber composite aerogels with enhanced ablation resistance
Article Publication Date
25-Jun-2026