Aerogels are excellent thermal insulators and have other exceptional physical properties. However, by themselves, aerogel materials are generally quite fragile and lack the required strength for various end use applications. To this end, there have been various attempts to strengthen aerogels, particularly by adding fibers to them when they are made, such as by the well known sol-gel processing, or infiltrating stronger porous structures with the aerogel precursor composition. The combination of these materials can provide a composite material that has overall improved properties relative to either the aerogel material or porous carbon structure material by itself. Further, these composite materials may be useful in a variety of applications such as thermal protection systems for spacecraft, etc., or as furnace insulation or fire protective barriers, as well as for thermal and sound insulation, and in electronic components such as supercapacitors.
Such is the case of a composite of an organic aerogel and a carbon foam material, reticulated vitreous carbon (RVC). The aerogel provides exceptional optical, thermal, acoustic, and electrical properties, whereas the RVC provides strength to the composite. Furthermore, the aerogel and the RVC can both be very lightweight. To this end, it is possible to make a composite of the aerogel with the RVC by infiltrating the aerogel precursor composition into the already processed RVC foam. However, conventional aerogel infiltration processes require large, capital-intensive processing equipment. Additionally, subsequent processing of the aerogel is known to cause shrinking and cracking of the aerogel, which can reduce the properties of the resulting composite.
Thus, described herein are methods for producing organic aerogel and RVC composites by a more readily scalable and cost effective process. The process can reduce the total processing time required to manufacture the composite and further reduces or eliminates the conventional shrinking and cracking of the composite.