"ATR衰减全反射光谱原理简介及PPT教学"

Attenuated Total Reflection Infrared (ATR-FTIR) spectroscopy is a powerful technique used for the analysis of both solids and liquids. This technique measures the changes in an infrared beam when it comes into contact with a sample through total internal reflection. ATR-FTIR is widely used for surface analysis of materials, as it provides valuable information about the chemical composition and structure of the sample. The principle behind ATR-FTIR spectroscopy is based on the fact that when infrared light is directed into a crystal, it undergoes multiple internal reflections before exiting the crystal. As the infrared beam interacts with the sample placed on the crystal surface, some of the light is absorbed by the sample, while the rest is reflected back into the crystal. The absorbed light generates vibrational modes in the sample molecules, which are then detected by the instrument. One of the key advantages of ATR-FTIR spectroscopy is that it requires minimal sample preparation, making it a fast and convenient technique for analyzing a wide range of materials. In addition, ATR-FTIR can provide both qualitative and quantitative information about the sample, making it a versatile tool for chemical analysis. In a typical ATR-FTIR experiment, the infrared beam is directed into the crystal, where it undergoes total internal reflection. The sample is then placed on the crystal surface, allowing it to interact with the infrared beam. The changes in the infrared spectrum caused by the sample are then measured and analyzed to determine the chemical composition and structure of the sample. Overall, ATR-FTIR spectroscopy is a valuable technique for surface analysis of solids and liquids, offering fast and convenient analysis with minimal sample preparation. Its ability to provide both qualitative and quantitative information makes it a versatile tool for a wide range of applications in chemistry, materials science, and other fields.