Abstract
Photochromic materials are those which react reversibly to light. Photochromism is therefore distinguished from the familiar photographic processes, which, because of the chemical development of the image, are essentially irreversible. Many organic materials, and a few inorganic ones, show this phenomenon. Their general properties are described, with particular emphasis on those of a system of photochromic glasses. The behaviour of these glasses results from reaction of light with silver halide crystals deliberately formed in the glass during its manufacture. The mechanism of the photolytic reactions is postulated, and compared with the theory of the photographic process for silver halides. Reversibility of photochromism in these glasses is explained by prevention of diffusion of the products of photolysis from the original crystal site within the glass structure, and their subsequent recombination when the activating light is removed. These glasses show large ranges in all their photochromic properties resulting from ranges in composition, and in size and number of the included crystals. The behaviour of typical glasses, in both sunlight and under artificial sources, is reported in this paper, and some applications for these glasses are suggested.
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References
G. H. Brown and W. G. Shaw, Rev. Pure Appl. Chem. (Australia) 11 (1961) 2.
H. Schwab and R. C. Bertelson, Symp. Unconventional Photo. Systems (The Society of Photographic Scientists and Engineers, Washington DC, October 1964), p. 94.
Photochromism and Phototropism, US Department of Commerce, National Bureau of Standards, Clearing-House for Federal Scientific and Technical Information, Springfield, Virginia (November 1964).
M. W. Windsor, “Photochromism”, Encyclopedia of Chemistry edited by G. L. Clark (Reinhold, 1966), p. 816.
R. Radler and D. Chenot, Technical Documentary Report AL TDR 64–170 (October 1964).
A. J. Cohen and H. L. Smith, Science 137 (21 September 1962) 981; Ceram. Abs. (February 1963) 41i.
E. L. Swarts and J. P. Pressau, J. Amer. Ceram. Soc. 48 (1965) 333.
W. H. Armistead and S. D. Stookey, Science 144 (10 April 1964) 15; US Patent 3208860 (8 September 1965).
G. P. Smith, “Photochromic Silver Halide Glasses”, Paper 108, 7th Int. Cong. of Glass, Brussels, July 1965 (Gordon and Breach, 1966).
J. S. Stroud, internal report, Corning Glass Works.
F. Moser, N. R. Nail, and F. Urbach, The Phys. and Chem. of Solids 9 (1959) 217.
These electron micrographs were prepared by G. B. Carrier, Corning Glass Works.
See Moser, Nail, and Urbach, Loc. cit., for discussion of the role of copper as a sensitiser of silver halides.
C. B. King and W. A. Plummer, internal reports, Corning Glass Works.
G. K. Megla, Applied Optics 5 (6 June 1966) 945.
S. D. Stookey, internal report, Corning Glass Works.
R. J. Araujo, internal report, Corning Glass Works.
B. Justice and F. B. Leibold Jr, Information Display (November–December 1965) 23.
P. Moon, J. Franklin Inst. (USA) 23 (November 1940) 583.
H. R. Condit and F. Grim, J. Opt. Soc. (USA) 54 (July 1964) 937.
G. Smith and B. Justice, “Photochromic Glass: Light and Heat Control with Variable-Transmittance Glazing”, Amer. Soc. Mech. Engnrs., Winter Meeting (1964).
A. J. Britten, “Eye-Protective Devices”, Ordnance (November–December 1964).
J. L. Kropp, M. W. Windsor, J. M. Brake, and R. S. Moore, USAF Materials Laboratory Technical Report AFML-TR-423 (March 1966).
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Smith, G.P. Photochromic glasses: Properties and applications. J Mater Sci 2, 139–152 (1967). https://doi.org/10.1007/BF00549573
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DOI: https://doi.org/10.1007/BF00549573