油漆鉴别

Identification of different paints is in high demand in the art conservation and forensic communities. In general paint is composed of several chemical compounds: pigments, binder, and additives. Pigments give color and opacity to paints. The most common pigments are inorganic such as titanium dioxide, calcium carbonate, iron oxides, and zinc oxide. Zinc phosphate can also be added to inhibit corrosion. Polymers such as acrylates or epoxides are used as a paint binder. A commonly used technique for paint identification involves the comparison of infrared spectra of an unknown paint against a spectral library. Inorganic pigments have characteristics bands in the Far IR (FIR) range below 400 cm-1 (~12THz) while polymer binders have distinctive spectral features in the Mid-IR spectral range (4000-400 cm-1). Measuring both ranges allows accurate paint identification. As a result a spectrometer that is capable of acquiring data both in the MIR and FIR ranges can be used as an excellent tool for this application.