Aerogel glass is a new generation of building enclosure structure product developed based on the new aerogel material and traditional hollow glass technology. It can effectively solve the current problems of high energy consumption, low safety and poor comfort of building glass. 
A gel-filled glass is a type of gel core structure formed by filling transparent gel between the glass layers. The overall appearance is a semi-transparent frosted glass effect, appearing in shades of cyan, white or blue under sunlight. The middle layer of the insulating glass can be filled with transparent gel particles or a whole piece of transparent gel. Generally, filling with a whole piece of gel results in higher transparency, but the cost of a whole piece of transparent gel is high and it is not cost-effective for widespread use. Therefore, the current market mainly sees the use of filling with transparent particles. 
The new type of aerogel insulation glass, which is made by filling silica aerogel as a layer between two layers of glass, has a thermal conductivity as low as 0.002 W·m-1·K-1. 
Aerogel glass is mainly applied to the skylights of public buildings such as airport terminals, railway stations, libraries, art galleries, art centers, hospitals, shopping malls, etc., as well as the sunrooms of villas. 
Transparent aerogels require strict control over the processes of sol-gel and drying, as well as the pore structure of the aerogel, in order to ensure their optical properties. During the actual production process, strictly controlling these conditions will significantly increase costs. Therefore, aerogel glass is rarely used in the current domestic market and is mainly used for display or demonstration purposes. 
The desert areas abroad have a relatively higher usage rate of this technology. American companies have long launched aerogel glass. The main and auxiliary halls of the Li Zijian Art Museum project in Xiangjiang New District, Changsha, have a total area of 1,000 square meters and a height of approximately 10 meters. The dome of the hall uses light-gathering aerogel glass. This solution addresses the problems of poor indoor light environment in the shading roof in hot summer and cold winter regions, as well as high energy consumption in summer and winter. It also effectively meets the comprehensive requirements of the building for energy efficiency, safety, aesthetics, and comfort. 
The applications of aerogel glass mainly fall into three forms: aerogel-coated glass, whole-piece aerogel glass, and granular aerogel-filled glass. 
Aerogel-coated glass panel 
The preparation process of the aerogel film is divided into two types depending on the sequence of gel formation and coating. 
The first process: First, apply a sol-gel coating on the substrate, and then proceed with the subsequent gelation and drying procedures. 
The second process: After preparing the sol, first gel it, then use sol-etching ultrasonication or homogenization dispersion to disperse the gel, and finally apply a coating. 
(2) Block-shaped aerogel glass 
The manufacturing process of the block-shaped aerogel glass mainly involves placing the block-shaped aerogel between two pieces of glass, and then sealing it with a sealant. 
Compared with granular aerogels, the solar heat gain coefficient (SHGC) of the block-shaped aerogels is higher. 
For example: The solar heat gain coefficient of a 10 mm thick solid aerogel glass is 0.9, while that of a glass filled with aerogel particles is 0.5. 
(3) Particle-based aerogel filled with glass 
Directly filling the aerogel particles into the cavities of two pieces of glass results in aerogel glass. 
In terms of market application, some businesses have emerged that produce granular aerogel-filled glass. However, they are currently mainly concentrated in Europe and the United States, while there has been relatively little involvement in this area in China. 
A university in Newark, New Jersey, USA, has implemented an energy-saving renovation project using aerogel glass. The results showed that the aerogel glass system achieved four times the energy-saving effect compared to the ordinary glass system.