why tio2 is white

Lithopone or sulphide of zinc white has been in general use for twenty years or more in many industries where a white pigment of considerable body or hiding power is required that is not subject to change like lead carbonate and has not the brittle character of zinc oxide, besides being sold at a lower figure than either of these. Nevertheless it is still comparatively new to the general painting trade. Because of our tariff protection its manufacture in this country has made great progress. Yet in spite of this and the duty imposed on it, the imports are still in excess of the quantity manufactured here. A short history of its origin will no doubt prove of interest to our readers.

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Titanium dioxide (TiO2) is commonly applied to enhance the white colour and brightness of food products. TiO2 is also used as white pigment in other products such as toothpaste. A small fraction of the pigment is known to be present as nanoparticles (NPs). Recent studies with TiO2 NPs indicate that these particles can have toxic effects. In this paper, we aimed to estimate the oral intake of TiO2 and its NPs from food, food supplements and toothpaste in the Dutch population aged 2 to over 70 years by combining data on food consumption and supplement intake with concentrations of Ti and TiO2 NPs in food products and supplements. For children aged 2-6 years, additional intake via ingestion of toothpaste was estimated. The mean long-term intake to TiO2 ranges from 0.06 mg/kg bw/day in elderly (70+), 0.17 mg/kg bw/day for 7-69-year-old people, to 0.67 mg/kg bw/day in children (2-6 year old). The estimated mean intake of TiO2 NPs ranges from 0.19 μg/kg bw/day in elderly, 0.55 μg/kg bw/day for 7-69-year-old people, to 2.16 μg/kg bw/day in young children. Ninety-fifth percentile (P95) values are 0.74, 1.61 and 4.16 μg/kg bw/day, respectively. The products contributing most to the TiO2 intake are toothpaste (in young children only), candy, coffee creamer, fine bakery wares and sauces. In a separate publication, the results are used to evaluate whether the presence of TiO2 NPs in these products can pose a human health risk.

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{随机栏目} 2025-08-15 04:47 2562