In Nature, minerals such as Hackmanite are well known for displaying photochromism by irradiation with UV light. In some cases those minerals also exhibit photoluminescence and therefore they are a very nice example of the ways that Nature finds to achieve such photochemical properties. Those materials are indeed a source of inspiration for the development of new pigments on an inorganic framework. Potentially inorganic photochromic or photoluminescent pigments are resistant to oxidative photodegradation and therefore have a much large durability when compared with organic pigments. However such inorganic pigments are still not available, with the exceptions of photochromic glass (using AgCl colloids), quantum dots and photoluminescent rare earth pigments. Within the SACS project and in collaboration with VICARTE, new synthetic routes are being explored.

Photoluminescent functionalized glasses and zeolites.

With VICARTE, innovative ideas using multicomponent glass enabled the development of new photoluminescent and photochromic glass avoiding the use of expensive rare earths minerals. These new materials are non-toxic and do not fade their performance. The other strategy with the SACS project is the development of functionalized zeolites and nanozeolites with chalcogen (sulfur, selenium, and tellurium) clusters confined in the zeolite cages inspired by the Nature example of Hackmanite. By careful control of the synthesis conditions new photoluminescent pigments with fluorescence quantum yields up to 50% were developed. In parallel inorganic photochromic pigments were made, with color transitions from white to pink by irradiation with UV light. All these pigments may have applications in lightning devices, interactive surfaces, augmented reality (with www.yvision.com), molecular sensors or fluorescence imaging.

Development of chromogenic materials.

Flavylium-based compounds

Development of functional ionic liquids

Conservation and restauration of Portuguese cultural heritage

Solar energy conversion