US EPA

2625472 

Journal Article 

Microstructure of Woolen Fiber Dyed by PbCrO4 Yellow Dyeing Technique Imported into Japan in the Last Edo Period 

Sugioka, N; Kitada, M 

2010 

Yes 

Journal of the Japan Institute of Metals/Nippon Kinzoku Gakkaishi
ISSN: 0021-4876
EISSN: 1880-6880 

74 

11 

751-757 

WOS:000285898600008 

The microstructure of woolen fiber dyed by the PbCrO4 yellow dyeing technique imported into Japan in the last Edo period has been investigated. The woolen fiber is dyed using lead acetate and potassium chromate. The color is measured with a spectrophotometer. The microstructures are observed using a scanning electron microscope and transmission electron microscope. The crystal structure is determined with an X-ray diffractometer. The composition is analyzed using an energy dispersive X-ray spectrometer. A thin film is fabricated by the focused ion beam method to observe the nanostructures. The cross section is flattened by ion milling to reduce the damage to the surface. The absorption edge at 558 nm (2.2 eV) is observed in the reflectance spectrum for lead chromate woolen threads. The edge agrees with that of PbCrO4. The dyestuff compounds, monoclinic and orthorhombic PbCrO4, are detected by X-ray diffraction analysis. The crystal compound PbCrO4 precipitates on the woolen fiber surface; and the length and width of the crystals are 0.2 similar to 1.2 pm and 0.05 similar to 0.4 nm, respectively. Chromium, lead and sulfur are detected from the inside of the fiber, referential precipitation is observed in the fiber, and most of the precipitates align along a specific place in the fiber. The precipitate distribution shows a correlation between the precipitation phenomenon and the woolen fiber structure, and also reveals the microstructures in the woolen fiber. Although the precipitate on the fiber surface is crystalline, nanometer-size precipitates in the fiber are amorphous. 

woolen fiber; dyestuff; chrome yellow; lead chromate; microstructure; amorphous