Design and Performance Comparison of Polymer-Derived Ceramic Ambigels and Aerogels

Traditional methods for producing ceramic aerogels often rely on complex and costly supercritical drying processes. These approaches limit widespread adoption due to high costs and technical barriers. While ambient drying techniques have been explored, their effectiveness in preserving critical material properties remains unclear. Previous studies have demonstrated that supercritical drying can yield aerogels with low thermal conductivity and high porosity. However, no prior work had resolved whether ambient drying could match these outcomes without significant property loss. This gap motivated researchers to investigate alternative drying methods for preceramic materials. The need for cost-effective and scalable production techniques has driven recent interest in ambient drying approaches. Understanding the relationship between drying method and material performance is essential for advancing ceramic aerogel applications. This study addresses that need by comparing two drying methods for polymer-derived SiOC aerogels.

The study aimed to evaluate the feasibility of replacing supercritical CO2 drying with ambient pressure drying in the production of SiOC aerogels. Researchers sought to determine if ambient drying could maintain key structural and functional properties. The specific problem addressed was the high cost and complexity of supercritical drying processes. By comparing two drying methods, the study aimed to identify whether ambient drying could offer a viable alternative. The motivation stemmed from the need for scalable and affordable ceramic aerogel production. Researchers focused on assessing microstructural features like density, porosity, and thermal conductivity. The goal was to determine if these properties remain consistent across different drying techniques. This approach aimed to provide insights into cost-effective manufacturing for ceramic aerogels.

The study used a commercial siloxane resin as the starting material for aerogel synthesis. Two drying methods were applied: ambient pressure drying and CO2 supercritical drying. The resulting materials were designated as ambigels and aerogels. Both samples underwent ceramic conversion processes to produce SiOC structures. Microstructural analysis included measurements of density, porosity, pore size, and specific surface area. Thermal conductivity was measured at room temperature and at 500°C. Oil sorption and water cleaning capabilities were tested to assess functional performance. The comparison focused on whether drying method affected final material properties.

Ambient pressure drying produced ambi/aerogels with microstructural features similar to supercritically dried samples. Both materials showed comparable density, porosity, and pore size distributions. Specific surface area values were nearly identical between the two drying methods. Thermal conductivity measurements revealed low values of 0.046 W·m⁻¹·K⁻¹ at room temperature. At 500°C, thermal conductivity increased to 0.073 W·m⁻¹·K⁻¹ for supercritically dried aerogels. Oil sorption tests indicated strong performance in both materials for environmental applications. Water cleaning capabilities were also demonstrated by both drying methods. These findings suggest that ambient drying does not significantly degrade key material properties.

The study found that ambient pressure drying can replace supercritical CO2 drying without significant property degradation. Both drying methods produced SiOC aerogels with similar microstructural and functional characteristics. The results suggest that ambient drying is a viable alternative for ceramic aerogel production. This approach could reduce manufacturing costs and simplify production processes. The authors propose that this finding has implications for scaling up aerogel production. The study supports the use of ambient drying for maintaining thermal and sorption properties. No essential differences in material performance were observed between the two methods. The findings align with the goal of developing cost-effective ceramic aerogel fabrication techniques.