Thermal Evolution of Silicon and Fluorine Species in Fluorosilane-Modified Carbon Aerogel Composites
- 1Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China
- 2Hunan Provincial Key Laboratory of High-Speed Aerodynamic Metamaterials, Changsha 410073, China
Abstract
Carbon aerogels are widely used for thermal protection in extreme high-temperature environments under inert atmospheres because of their excellent thermal insulation. However, their high specific surface area and open-pore structure promote moisture uptake, necessitating hydrophobic or low-surface-energy functionalization for practical use. Existing studies have primarily focused on room-temperature wettability after modification, while the high-temperature decomposition of functional layers, elemental evolution, and volatile release remain insufficiently understood. Herein, vapor-phase fluorosilane (FAS)-modified carbon aerogel composites were investigated by combining solid-state chemical characterization with evolved-gas analysis to clarify the thermal evolution of the functional layer under inert high-temperature conditions. FAS modification produced a superhydrophobic surface with an initial water contact angle of approximately 163°. During heating, the FAS-derived functional layer entered a rapid-decomposition stage at approximately 372 °C, followed by the principal fluorinated-volatilization stage near 443 °C. Perfluoroalkyl-chain cleavage progressively removed fluorine from the material through the release of CxFy-containing volatile species, accompanied by the disappearance of C–F, CF2, and CF3 structures. In contrast, part of the silicon-containing fraction was retained and evolved into a Si–C-related residual structure. Although high-temperature exposure eliminated FAS-derived hydrophobicity, the nanoparticle-assembled nanoporous carbon framework remained intact without obvious structural collapse. These findings establish a selective thermal-failure pathway in which fluorinated chains preferentially decompose and volatilize, whereas silicon-containing species are partially retained and reconstructed on the carbon framework, clarifying the failure mechanism of surface-modified carbon aerogel nanomaterials in extreme thermal environments.
Related
- Investigation on the Degradation Mechanisms and Mechanical Property Evolution of 3D-SiO2-Fiber-Reinforced Polyimide Composites After Thermal Aging
- Topochemical Fluorination of the Ruddlesden−Popper In/Sb-Mixed Oxide Ba2In0.5Sb0.5O4; Staged Anion Insertion and Structural Evolution toward the Fluorine-Rich Oxyfluoride Ba2In0.5Sb0.5O2F4
- The Thermal Conductivity of Polymer-Derived Amorphous Si-O-C Compounds and Nano-Composites
- Enhanced thermal conductivity of polyurethane composites via microstructural design of 3D interconnected boron nitride networks
- Bio-based chitosan aerogel composites with multifunctional combination of thermal insulation, sound absorption, flame retardancy, and superhydrophobicity
BibTeX
@article{long2026thermal,
title = {{Thermal Evolution of Silicon and Fluorine Species in Fluorosilane-Modified Carbon Aerogel Composites}},
author = {Yiren Long and Junzong Feng and Yonggang Jiang and Yijie Hu and Jian Feng},
journal = {Nanomaterials (Basel, Switzerland)},
year = {2026},
month = oct,
doi = {10.3390/nano16191250},
url = {https://europepmc.org/article/PMC/PMC13667006},
note = {CC BY},
}
RIS
TY - JOUR
TI - Thermal Evolution of Silicon and Fluorine Species in Fluorosilane-Modified Carbon Aerogel Composites
AU - Yiren Long
AU - Junzong Feng
AU - Yonggang Jiang
AU - Yijie Hu
AU - Jian Feng
PY - 2026
DA - 2026/10/01
JO - Nanomaterials (Basel, Switzerland)
DO - 10.3390/nano16191250
UR - https://europepmc.org/article/PMC/PMC13667006
AB - Carbon aerogels are widely used for thermal protection in extreme high-temperature environments under inert atmospheres because of their excellent thermal insulation. However, their high specific surface area and open-pore structure promote moisture uptake, necessitating hydrophobic or low-surface-energy functionalization for practical use. Existing studies have primarily focused on room-temperature wettability after modification, while the high-temperature decomposition of functional layers, elemental evolution, and volatile release remain insufficiently understood. Herein, vapor-phase fluorosilane (FAS)-modified carbon aerogel composites were investigated by combining solid-state chemical characterization with evolved-gas analysis to clarify the thermal evolution of the functional layer under inert high-temperature conditions. FAS modification produced a superhydrophobic surface with an initial water contact angle of approximately 163°. During heating, the FAS-derived functional layer entered a rapid-decomposition stage at approximately 372 °C, followed by the principal fluorinated-volatilization stage near 443 °C. Perfluoroalkyl-chain cleavage progressively removed fluorine from the material through the release of CxFy-containing volatile species, accompanied by the disappearance of C–F, CF2, and CF3 structures. In contrast, part of the silicon-containing fraction was retained and evolved into a Si–C-related residual structure. Although high-temperature exposure eliminated FAS-derived hydrophobicity, the nanoparticle-assembled nanoporous carbon framework remained intact without obvious structural collapse. These findings establish a selective thermal-failure pathway in which fluorinated chains preferentially decompose and volatilize, whereas silicon-containing species are partially retained and reconstructed on the carbon framework, clarifying the failure mechanism of surface-modified carbon aerogel nanomaterials in extreme thermal environments.
SN - 2079-4991
ER -