Organic–Inorganic Double-Gel System Thermally Insulating and Hydrophobic Polyimide Aerogel

Abstract

Aerogel materials are used in various fields, but there is a shortage of aerogel materials with an excellent combination of mechanical properties, thermal stability, and easy preparation. In this study, polyimide aerogel materials with superior mechanical properties, thermal stability, and low thermal conductivity were prepared by forming a double-gel system in the liquid phase. The amino-modified gel, prepared by coating SiO2 nano-microspheres with GO through a modified sol-gel method (SiO2@GO-NH2), was subsequently homogeneously dispersed with PAA wet gel in water to form a double-gel system. The construction of a double-gel system enabled the PI aerogel to shape a unique honeycomb porous structure and a multi-layered interface of PI/SiO2/GO. The final obtained PI aerogel possessed effective thermal conductivity (0.0309 W/m·K) and a high specific modulus (46.19 m2/s2). In addition, the high thermal stability (543.80 °C in Ar atmosphere) and the ability to retain properties under heat treatment proved its durability in high thermal environments. The hydrophobicity (131.55°) proves its resistance to water from the environment. The excellent performance of this PI aerogel and its durability in thermal working environments make it possible to be applied in varied industrial and research fields, such as construction and energy, where heat and thermal insulation are required.

Direct synthesis of ultralight, elastic, high-temperature insulation N-doped TiO2 ceramic nanofibrous sponges via conjugate electrospinning

“…By adding inorganic fillers, such as silicates and clay, organic inorganic hybrid aerogels can be prepared, and the flame retardation can be increased to 400 °C, 47 or even about 600 °C. 48,49 Silicon aerogels 50,51 and carbon aerogels 52,53 were used at higher temperatures; however, structural contraction and combustion still occurred when exposed to fire above 600 °C. The prepared N-TiO 2 CNSs have not only thermal resistance and low density similar to common ceramic aerogels, but also superelasticity similar to polymer elastomers.…”

Green Preparation of Thermal-Insulative, Flame Retardant, and Hydrophobic Silica Aerogel Reinforced Poly(vinyl alcohol) Composites

“…Table compared the typical properties of the PSG composite with other PVA-based or polymer-based composites. − Results show that the PSG composites possess relatively high modulus, low thermal conductivity and good hydrophobicity, despite its relative high density. It should be noticed that the PSG composites are prepared via a purely green route, without using any toxic substances in the preparation process.…”

Effect of AH3-PCE Ultrafine Composites on the Properties of Sulfoaluminate Cement-Based Materials

“…The dispersion characteristics of inorganic ultrafine materials can be significantly enhanced through the synthesis of organic and inorganic composites. , Diverse techniques, such as coprecipitation, hydrothermal, and sol–gel methods, can be employed to synthesize ultrafine organic–inorganic composites. Among these techniques, the sol–gel approach yields materials with more refined particle sizes, heightened activity, and enhanced control over size and morphology.…”