Recently TWI upgraded its Fourier Transform Infra-Red microscopy facility with a Perkin-Elmer system 2000 FTIR spectrometer with an i-series FTIR microscope, and a new attenuated total reflectance objective.
This enables fast, inexpensive positive identification of non-metallic materials, thus avoiding the potential embarrassment of using the wrong material.
Samples may be solid, liquid or thin film. Sample size can be down to 10 x 10 microns, or films down to a micron thickness.
Some of the samples analysed are listed below.
- Polymers and rubber
- Organic liquids
- Corrosion products on PCBs
- Multi-layer paint coatings
- Thin films
- Clean room contaminants
- Composites and fibres
- Inorganic substances
- Adhesives
- Quantitative determination of crystallinity and molecular orientation
- Polymer degradation
- Contaminants in fuel from Formula One racing cars
- Recycled polymers
Infrared spectroscopy exploits the fact that molecules absorb specific frequencies characteristic of their molecular structure. A spectrum is recorded by passing a beam of IR light through the sample. Examination of the transmitted light reveals how much energy was absorbed at each wavelength.
Using a Fourier transformation instrument enables the measurement of all wavelengths simultaneously. A transmittance or absorbance spectrum is produced, showing at which IR wavelengths the sample absorbs.
Each material will have a characteristic fingerprint which is easily identifiable.
For further information, please contact sheila.stevens@twi.co.uk.
