“Egyptian blue”

Venus Pigments intends to produce the ancient material “Egyptian blue” as a response to the new challenges in the inorganic blue pigments industry. In addition to creating new circular economies, for example from rice production waste and eggshells, its goal is to launch a pilot plant that can do without scarce and dangerous raw materials such as cobalt. Egyptian blue is not just a blue pigment, but it also has other interesting high-value market opportunities due to its extraordinary properties as a luminescent marker, its high stability and resistance, its antibacterial and antialgal properties, and its non-toxicity and non-hazardous nature for humans and the environment.

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Venus Pigments intende produrre l’antico materiale “blu egizio” come risposta alle nuove sfide del settore dei pigmenti blu inorganici. Oltra a dare vita a nuove economie circolari a partire ad esempio da scarti di produzione del riso e gusci di uova, il suo obiettivo è quello di avviare un impianto pilota in grado di fare a meno di materie prime carenti e pericolose come il cobalto. Il blu egizio non è solo un pigmento blu ma ha altri interessanti sbocchi di mercato ad alto valore aggiunto in virtù delle sue straordinarie proprietà di marker luminescente, per le sue doti di elevatissima stabilità e resistenza, per la sue proprietà antibatteriche e antialga e per la non tossicità e non pericolosità per l’uomo e l’ambiente.

Egyptian blue, Chinese blue, and related two-dimensional silicates: from antiquity to future technologies.

Part A: general properties and historical uses

Citation: Nicola, Marco, Gobetto, Roberto and Masic, Admir. 2023. “Egyptian blue, Chinese blue, and related two-dimensional silicates: from antiquity to future technologies. Part A: general properties and historical uses.” As Published: https://doi.org/10.1007/s12210-023-01153-5 Publisher: Springer International Publishing Persistent URL: https://hdl.handle.net/1721.1/150498 Version: Final published version: final published article, as it appeared in a journal, conference proceedings, or other formally published context Terms of use: Creative Commons Attribution

Abstract

The ancient Egyptian blue pigment was developed over 5000 years ago and was used extensively for around four millennia until its use mysteriously declined dramatically during the Early Middle Ages. It recently attracted a lot of attention along with some related materials, leading to a fast-growing number of applications in felds, such as sensors, solar concentrators, energy-saving, and medicine. The new surge in interest began in 1996 with the discovery of their intense NIR photoluminescence that surprisingly can be triggered even by visible light. In 2013, the possibility of exfoliating them and producing NIR luminescent nanosheets was established, expanding the family of 2D nanomaterials. More recently, the discovery of their high antibacterial efects and biocompatibility, and very promising optical, electric and magnetic properties, has further boosted their applications. The characteristics of Egyptian blue are due to its main component: the very stable crystalline compound CaCuSi4O10. This tetragonal sheet silicate is the synthetic analogous of the rare cuprorivaite mineral. In Part A of this review, we summarize the historical uses and main properties (i.e., composition, structure, color, stability, luminescence, and biological activity) of cuprorivaite and related 2D silicates, i.e., BaCuSi4O10 (the main constituent of the ancient pigment Chinese Blue), BaCuSi2O6 (the main constituent of the ancient pigment Chinese Purple), SrCuSi4O10 (synthetic analogous of wesselsite) and BaFeSi4O10 (synthetic analogous of gillespite). The Part B of the review will focus on the modern rediscovery of these materials, their modern synthesis and exfoliation, and the innovative applications based on their properties. Keywords Egyptian blue · Han blue · Han purple · Cuprorivaite · Wesselsite · Gillespite · Luminescence