Silica–Resorcinol–Melamine–Formaldehyde Composite Aerogels as High-Performance Thermal Insulators
Romain Civioc, Wim J. Malfait, Marco Lattuada, Matthias M. Koebel, Sandra Galmarini
Abstract
. The possible reasons behind this interesting insulation performance and the mechanisms leading to the underlying gel structure are discussed in depth. A focus is made on the different gelation modes happening between the RMF and silica phases, from a coating of silica surfaces with RMF species to discontinuous RMF particles within a silica backbone and a continuous RMF backbone with isolated silica particles. The implications in terms of mechanical properties and thermal conductivity are elaborated upon. The initial ratio of silica-RMF species in this ethanol-based synthesis affects the micro- and macrostructure of the composites, resulting in materials with drastically different pore structures and thus an interesting array of possibilities for a new class of silica-organic composite aerogels, based on a sol-gel process.