Fourier Transform Infrared Spectroscopy (FTIR) is a powerful analytical technique used to obtain the infrared spectrum of absorption or emission of a solid, liquid, or gas sample. The key principle behind FTIR is that different chemical bonds in a molecule absorb characteristic frequencies of infrared radiation, depending on the types of bonds and the functional groups present in the sample.
How FTIR Works:
- IR Radiation Exposure: The sample is exposed to infrared radiation, which passes through or reflects off the sample.
- Absorption of IR Radiation: The sample absorbs specific wavelengths of infrared light, causing vibrational transitions in the chemical bonds of the molecules.
- Interferogram: FTIR uses a technique called Fourier Transform to convert the raw data (called an interferogram) from a time domain into a frequency domain spectrum. This process allows the measurement of the absorbance at different frequencies.
- Spectrum Generation: The result is an infrared absorption spectrum, which can be analyzed to determine the chemical composition, molecular structure, and functional groups present in the sample.
Key Features of FTIR:
- High Sensitivity: It can detect very low concentrations of molecules in a sample.
- Non-destructive: In most cases, FTIR analysis is non-destructive to the sample.
- Versatility: It can analyze solids, liquids, and gases.
- Speed: FTIR spectra can be obtained rapidly, often within a few seconds to minutes.
Applications:
- Chemical analysis: Identifying functional groups, chemical bonds, and molecular structures.
- Materials science: Analyzing polymers, composites, and coatings.
