With the continuous progress of science and technology, the methods of preparing aerogels are also constantly improving and perfecting. Recently, a new method for preparing aerogels, namely the lyophilizer-ultrasonic-assisted preparation method, has attracted widespread attention. The advantage of this method is that it can be carried out at lower temperatures and at the same time it can be more homogeneous.
1. Dense aerogel.
The specific steps of the lyophilizer-ultrasonic-assisted preparation method are as follows:
First, the solution or suspension of the aerogel to be prepared is poured into a lyophilizer for freezing. During the freezing process, the formation and growth of ice crystals can be controlled by adjusting the temperature and time of the freezer.
Second, when the freezing is complete, the sample is removed from the lyophilizer and placed in an ultrasonic cleaner for sonication. The vibration of the ultrasonic waves can promote the separation and shedding of ice crystals, while also making the pores inside the sample more homogeneous.
Finally, the ultrasonicated samples are vacuum-dried. In a vacuum, the ice crystals inside the sample will gradually sublimate, eventually leaving behind an aerogel with a loose and porous structure.
The advantage of this method is that the freeze process can be carried out at a lower temperature by means of a lyophilizer, which avoids the decomposition and deterioration of the sample at high temperatures. At the same time, the vibration of the ultrasonic wave can promote the separation and shedding of ice crystals, making the pores inside the sample more uniform. In addition, vacuum drying can effectively remove water and other volatile components from the inside of the sample, making the prepared aerogel have higher purity and quality.
In addition to its excellent preparation effect, the lyophilizer-ultrasonic-assisted preparation method also has a wide range of application prospects. For example, the method can be applied to the preparation of various types of aerogels, such as silicon aerogels, carbon aerogels, polymer aerogels, etc. At the same time, this method can also be used to prepare other types of porous materials and nanostructured materials. Therefore, the research and development of this method is of great significance and application value.
In conclusion, the lyophilizer-ultrasonic-assisted preparation method is a new method for the preparation of aerogels, which has excellent preparation effects and a wide range of application prospects. With the in-depth research and improvement of this method, it is believed that it will play a more important role in the field of materials science in the future.