first class lithopone factory

The author thanks Marco Leona, Scientist-in-Charge of the Department of Scientific Research at the Metropolitan Museum of Art for conducting fluorescence spectrometry on Wheel of Fortune and a valuable discussion of the research, as well as Silvia Centeno, Research Scientist at the Metropolitan Museum of Art, who performed Raman analysis on the watercolors and also contributed her insight. The phenomenon of the phosphorescing lithopone was originally discovered during the author's fellowship in the Sherman Fairchild Center for the Conservation of Works on Paper, funded by the Andrew W. Mellon Foundation. The author thanks all her colleagues for their ideas and support during the research of this paper, and special thanks to Rachel Mustalish for her assistance in editing this work.

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The neuromorphic nature of the resistive switching in TiO2 memristors has triggered a series of studies addressing their functional coupling with living biological systems. The common features of the electroconductive behavior of memristive and biological neural networks have been revised in terms of physical, mathematical, and stochastic models (Chua, 2013Feali and Ahmadi, 2016). The memristive electronics was shown to support important synaptic functions such as spike timing-dependent plasticity (Jo et al., 2010Pickett et al., 2013). Recently, a memristive simulation of important biological synaptic functions such as non-linear transmission characteristics, short-/long-term plasticity, and paired-pulse facilitation has been reported for hybrid organic–inorganic memristors using Ti-based maleic acid/TiO2 ultrathin films (Liu et al., 2020). In relation to this, functionalized TiO2 memristive systems may be in competition with the new generation of two-dimensional memristive materials such as WSe2 (Zhu et al., 2018), MoS2 (Li et al., 2018), MoS2/graphene (Kalita et al., 2019), and other systems (Zhang et al., 2019a) with ionic coupling, ionic modulation effects, or other synapse-mimicking functionalities. Furthermore, the biomimetic fabrication of TiO2 (Seisenbaeva et al., 2010Vijayan and Puglia, 2019Kumar et al., 2020) opens up new horizons for its versatile microstructural patterning and functionalizations.

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  • Background and overview

    Globally, 
    Iron Oxide is the second largest inorganic pigment after Titanium Dioxide and the first largest color inorganic pigment. Iron oxide pigments mainly include iron oxide red, yellow, black and brown with iron oxide as the basic material. Iron oxide yellow, also known as hydroxyl iron oxide (FeOOH), will be dehydrated and decomposed into red at about 177 ℃, so the application of ordinary iron yellow pigment in high-temperature occasions such as plastic processing and baking coatings is limited. Iron oxide yellow pigment can improve its temperature resistance through surface coating, so as to expand the application field of iron oxide yellow pigment.

    The chemical formula of iron oxide yellow (also known as hydroxyl iron) is α- Fe2O3 · H2O or α- FeOOH, with needle like structure and yellow powder, is a kind of particle size less than 0.1 μ m. Iron series pigment with good dispersibility in transparent medium has strong coloring power, high covering power, insoluble in alkali and slightly soluble in ACID. Synthetic iron oxide yellow has the characteristics of light resistance, good dispersion, non-toxic, tasteless and difficult to be absorbed by human body. It is widely used in coatings, plastics, ink and pharmaceutical industry.

    Physical and chemical properties and structure

    1. Iron oxide yellow pigment has acid and alkali resistance, resistance to general weak and dilute acids, and is very stable in alkaline solution of any concentration.

    2. Iron oxide yellow pigment has certain light resistance, heat resistance and weather resistance. Its coating color is durable and can keep the coating from being damaged in light. Iron oxide yellow pigment is stable in a certain temperature range, but beyond the limit temperature, its color begins to change, and the degree of change is more significant with the increase of temperature. Iron oxide yellow pigment is not affected by cold, heat, dry and wet weather conditions.

    3. Iron oxide yellow pigment is very stable in any ambient atmosphere (such as gases containing H 2S, Co, so 2, HCl, no, etc.). And resistant to pollution, water, oil and solvent penetration, insoluble in water, mineral oil or vegetable oil.

    4. Iron oxide yellow pigment has strong coloring power and high hiding power. With the decrease of pigment particle size, its coloring power is stronger.

    application

    Nano iron oxide yellow has the characteristics of acid resistance, alkali resistance, non toxicity and low price. It is widely used in coatings, plastics and rubber. The particle size of nano iron yellow is less than 100 nm, which makes it have some unique characteristics. When light shines on its surface, transmission and diffraction will occur, showing transparent yellow, and can strongly absorb ultraviolet rays, Therefore, it can be used as a functional pigment for the surface paint of high-grade cars, precision instruments, bicycles, motorcycles, cosmetics, food, drugs and other coloring additives.

  • The supply in North America remained adequate, as companies were seen constantly altering their production rates in response to the volatility in the demand pattern. In the final week of September, news of Chemours' forthcoming titanium dioxide factory in Georgia valued USD 86 million alleviated fears about supply strain.

  • Regulatory agencies around the world are currently working to establish guidelines for the safe use of TiO2 in consumer products and water supplies. In the meantime, consumers can take steps to minimize their exposure to TiO2 by choosing products that do not contain the pigment and using water filters that can remove nanoparticles.