The drying of silica aerogel is a process to remove most of the solvents in the gel, so that the medium filled in the spatial network structure of the gel is gas. According to the different drying conditions of silica aerogels, the drying technology is divided into supercritical drying method, atmospheric drying method, drying technology with pressure between supercritical pressure and atmospheric pressure, and freeze drying method. Supercritical drying is one of the earliest and most mature drying methods, but due to its high temperature and pressure conditions, complex equipment, high risk, and high energy consumption, the current research direction of drying technology mainly focuses on atmospheric pressure drying technology and freeze-drying technology.
     Application of silica aerogel
The silica aerogel material has gradually moved from the laboratory research and development stage to the industrial application stage, but its production cost is high and the production scale is small, resulting in its limited application scale and application fields. At present, the application of silica aerogel is mainly concentrated in the fields of thermal insulation, military and aerospace.

Although silica aerogels have good thermal insulation, sound insulation, nonlinear optical properties, filtering and catalytic properties, refractive index adjustability and other properties. However, in addition to good application in the field of thermal insulation, other performance applications of silica aerogels have not been well developed. The future development direction of silica aerogels is: low-cost, large-scale, lightweight, composite and flexible.
summarize
    Aerogel is called "magic material that changes the world", "ultimate thermal insulation material" and "super sponge". Based on the many magical characteristics of aerogels, aerogels have great application space and development prospects in the future. After nearly 80 years of research on aerogels, the production process of aerogels tends to mature. After greatly reducing the production cost, aerogel will gradually replace the traditional materials in the civil field, and the new material aerogel, which has been precipitated for a long time, is about to usher in an outbreak of application.