Reference

Stabilized photochromic materials

Stabilized photochromic materials. Uhlmann, Donald R.; Snitzer, Elias; Hovey, Richard J.; Chu, Nori Y. C.; Fournier, Joseph T., Jr. (American Optical Corp., USA). U.S. US 4046586 6 Sep 1977, 7 pp. (English). (United States of America). CODEN: USXXAM. CLASS: IC: C08L001-10. NCL: 106194000. APPLICATION: US 74-498506 19 Aug 1974. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Fabrication and Uses) Ag halide photochromic crystals (30-10,000 .ANG.) are sealed with an inorg. coating material and incorporated into plastic eyeglass lenses esp. useful as sunglasses. Thus, a AgBr [7785-23-1] sol was stabilized by treating with poly(vinylpyrrolidinone) [9003-39-8] in EtOH and the particles were treated with titanyl sulfate [13825-74-6], dried, and incorporated (0.7 g) into allyl diglycol carbonate prepolymer [25656-90-0] contg. 5 g iso-Pr2O2. The mixt. was formed into plastic lenses in the usual way. The lenses were colorless and turned a gray shade in bright sunlight; they returned to their normal colorless condition in 20-30 min when brought indoors.

Direct observation of hydrogen entrapment

Direct observation of hydrogen entrapment. Aucouturier, M.; Lapasset, G.; Asaoka, T. (Lab. Metall. Phys., Univ. Paris-Sud, Orsay, Fr.). Metallography, 11(1), 5-21 (English) 1978. CODEN: MEIJAP. ISSN: 0026-0800. DOCUMENT TYPE: Journal CA Section: 55 (Ferrous Metals and Alloys) Entrapment of H in Fe alloys was obsd. directly in the 1000-kV electron microscope by electron micro-autoradiog., without conventional replication. Entrapment was examd. after tritium charging of maraging steel [67622-28-0] having a coarse martensitic structure, and of the Fe-0.15%Ti alloy (contg. 50 ppm C) heat treated to modify the ppt. structure. Thinned foils were cathode-charged with H and tritium, polished, and coated with a monolayer of Ilford L-4 [7785-23-1] gel emulsions. After 10-day autoradiog. exposure in Ar at -30°, the foil samples were photog. developed, and obsd. in an electron microscope with 3000 ? point-source resoln. The new technique of electron micro-autoradiog. was extended to H for the 1st time. Preliminary results are given for the steel and Fe-Ti alloy samples, confirming the findings from examn. with conventional replica techniques. High-pressure H entrapment is possible in the Fe-Ti alloy, confirming the model of A. S. Tetelman (1973).