Listening to ancient colours
New technique may help restorers identify decades-old
pigments
A team of 捆绑SM社区 chemists have discovered that a technique known as
photoacoustic infrared spectroscopy could be used to identify the
composition of pigments used in art work that is decades or even
centuries old. Pigments give artist鈥檚 materials colour, and they
emit sounds when light is shone on them.
鈥淭he chemical composition of pigments is important to know, because
it enables museums and restorers to know how the paints will react
to sunlight and temperature changes,鈥 explained Dr. Ian Butler,
lead researcher and professor at 捆绑SM社区鈥檚 Department of Chemistry.
Without a full understanding of the chemicals involved in artworks,
preservation attempts can sometimes lead to more damage than would
occur by just simply leaving the works untreated.
Photoacoustic infrared spectroscopy is based on Alexander Graham
Bell鈥檚 1880 discovery that showed solids could emit sounds when
exposed to sunlight, infrared radiation or ultraviolet radiation.
Advances in mathematics and computers have enabled chemists to
apply the phenomenon to various materials, but the Butler鈥檚 team is
the first to use it to analyze typical聽 inorganic pigments
that most artists use.
The researchers have classified 12 historically prominent pigments
by the infrared spectra they exhibit 鈥 i.e., the range of noises
they produce 鈥 and they hope the technique will be used to
establish a pigment database. 鈥淥nce such a database has been
established, the technique may become routine in the arsenal of art
forensic laboratories,鈥 Butler said. The next steps will be to
identify partners interested in developing standard practices that
would enable this technique to be used with artwork.
The research received funding from the National Science and
Engineering Research Council of Canada and was published in the
journal Spectrochimica Acta Part A: Molecular and Biomolecular
Spectroscopy.