For a substance that is relatively unknown to the public, it’s amazing how many everyday products TiO2 can be found in. Because of its many varied properties, our skin, cities, cars, homes, food and environment are made brighter, safer, more resilient and cleaner by TiO2. With a legacy of 100 years of safe commercial use, TiO2 is only going to become more vital as our environment faces greater challenges from a growing population.
Zinc oxide. Zinc oxide is a popular cross-linking agent for rubber and for various resins. It is essential in the formulation of solvent-borne polychloroprene adhesives. Furthermore, zinc oxide is a good UV stabilizer, has biocidal activity and has a relatively high refractive index (2.0) which makes it an efficient white pigment. Some typical properties are: density 5.6 g/cm3; particle size 0.036-3 μm; oil absorption 10–20 g/100 g; specific surface area 10–45 m2/g. Zinc oxide is produced by reaction of the metal in the vapour state with oxygen. Zinc oxide is nonporous and is quite pure. Thus, the high surface area of some grades is due to the small particle size of zinc oxide. Some grades, especially for use in the rubber industry, are surface modified by deposition of 0.2-0.4% of stearic acid, propionic acid, or light oil [47].
The Journal of the American Institute for Conservation (JAIC) is an international peer-reviewed periodical for the art conservation profession. The Journal publishes articles on treatment case studies, current issues, materials research, and technical analyses relating to the conservation and preservation of historic and cultural works. The topics encompass a broad range of specialties including architectural materials, archeological objects, books and paper, ethnographic materials, objects, paintings, photographic materials, sculpture, and wooden artifacts. Started as the Bulletin of the International Institute for Conservation-American Group (IIC-AG), in April 1961, the Journal matured into its current form in 1977. Since that time JAIC has become a repository for the core body of conservation information through its documentation of new materials, changing methods, and developing standards in the conservation profession. The four-color publication is distributed three times a year to AIC members and museum, library, and university subscribers.
The precipitation of titanium dioxide is a crucial process in the manufacturing of this important industrial material. Titanium dioxide is a white pigment that is widely used in various industries, such as paints, coatings, plastics, and cosmetics, due to its excellent opacity, brightness, and UV resistance.
The chemical is also found in common household and industrial products such as paints, coatings, adhesives, paper, plastics and rubber, printing inks, coated fabrics and textiles, as well as ceramics.
Resumen–En este artículo se discute el descubrimiento del litopón fosforescente en dibujos a la acuarela por el artista americano John La Farge, fechados de 1890 a 1905, y la historia del litopón en la industria de los pigmentos a finales del Siglo XIX y principios del Siglo XX. A pesar de tener muchas cualidades deseables para su uso en pintura para acuarela o pinturas al óleo blancas, el desarrollo del litopón como pigmento para artistas fue obstaculizado por su tendencia a oscurecerse con la luz solar. Su disponibilidad para los artistas y su adopción por ellos sigue siendo poco clara, ya que por lo general los catálogos comerciales de los coloristas no eran explícitos al describir si los pigmentos blancos contenían litopón. Además, el litopón se puede confundir con blanco de plomo durante el examen visual, y su fosforescencia de corta duración puede ser fácilmente pasada por alto por el observador desinformado. A la fecha, el litopón fosforescente ha sido documentado solamente en otra obra mas: una acuarela por Van Gogh. Además de la historia de la fabricación del litopón, el artículo detalla el mecanismo para su fosforescencia, y su identificación con la ayuda de espectroscopía de Raman, y de espectrofluorimetría.