photochromism
(fəʊtəʊˈkrəʊmɪz(ə)m)
[f. asphotochromy (c) + -ism.]
The phenomenon whereby certain substances undergo a reversible change of colour or shade when illuminated with light of appropriate wavelength.
| 1951 Physics Abstr. A. LIV. 204/2 (heading) Photochromism in the bianthrone series. 1953 [see photochromic a.]. 1960 New Scientist 2 June 1424/1 This new kind of reversible colour change in organic compounds was first described by me [sc. Yehuda Hirshberg] in 1950, and I called it ‘photochromism’. Ibid. 1425/3 Another recent development in photochromism is the discovery that many compounds which undergo reversible colour changes by exposure to ultraviolet light show the same effect when subjected to high-energy electrons or to any ionizing radiation. 1972 Nature 31 Mar. 245/2 Photochromism is an effect associated with compounds which reversibly change their absorption spectra on illumination with light. |