Classification of Aerogels
There are various methods for classifying aerogels . According to the appearance of aerogels, they can be divided into monoliths, powders, and membranes. According to different microstructures, they can be classified into microporous (<2 nm) aerogels, mesoporous (2–50 nm) aerogels, and mixed porous aerogels. The most commonly used method for classifying aerogels is to distinguish them by their components, as shown in the following figure: Aerogels can be divided into two categories: single-component aerogels and aerogel composites. Single-component aerogels are divided into inorganic aerogels (silica-based and non-silica) and organic aerogels (resin-based and cellulose-based). Aerogel composites include multi-component aerogels, gradient aerogels, and micro/nano aerogel composites. Classification 1 Inorganic aerogel Inorganic aerogels are a class of porous materials with unique physical and chemical properties that have attracted much attention due to their extremely low densit...