FT-NIR spectroscopy offers a simple tool to identify different types of textiles, with distinct spectral features observed at wavelengths >1350 nm. This approach may be useful for authentication of natural and synthetic consumer textile products.
Vibrational spectroscopy is widely used for the non-destructive characterization of materials. As light interacts with the material, molecules bend and stretch creating vibrations specific to the chemical bonds and functional groups within the material. These vibrations give rise to a unique spectral fingerprint that can be used to characterize and even identify the material analyzed.
Vibrational spectra are measured using either Raman or infrared spectroscopy techniques that differ based on the specific light interaction measured. Raman measures the inelastic scattering of monochromatic laser light while infrared spectroscopy measures the absorption of infrared wavelengths. These complementary techniques have their strengths and weaknesses, with both techniques often used together for more complete characterization of the material.
Both Raman and infrared spectroscopy techniques have been used to characterize textiles and fabrics for incoming inspection of raw materials and to assess the authenticity of products produced from these materials. In the case of colorful textiles and fabrics, infrared spectroscopy is sometimes preferred to Raman to avoid the strong Raman background spectrum that can arise from the dyes found in brightly colored textiles.
In this post, Ocean Insight describes how a compact, MEMS-based, single-photodetector NIR device, the NanoQuest spectral sensor, can be used to distinguish different types of textiles.