Research ArticleAPPLIED PHYSICS

Pigment darkening as case study of In-Air Plasma-Induced Luminescence

See allHide authors and affiliations

Science Advances  07 Jun 2019:
Vol. 5, no. 6, eaar6228
DOI: 10.1126/sciadv.aar6228
  • Fig. 1 Optical absorbance.

    (A) Absorbance spectra for Naples yellow taken at regular intervals of 30 min. (B) Total absorbance a in the entire visible range, obtained as integral of a(λ), evaluated between 400 and 800 nm. (C) Variation of the total absorbance with respect to the nonaged layers as function of aging time.

  • Fig. 2 In-Air-PIL spectra for the different pigments.

    In-Air-PIL spectra between 580 and 760 nm for all the analyzed elements (as indicated on top of each panel) before aging (black line) and after light irradiation (red line). The insets show the Gaussian analysis on the spectra for identifying the band position and its width. The PIL band positions are listed in the table at the bottom right.

  • Fig. 3 PIXE results for the different pigments.

    PIXE results for Naples yellow, chrome yellow, and orpiment (as indicated below the panels); the left panels display the major elements, whereas the right panels display the minor elements. Note that our PIXE diagnostics used a detector only able to detect elements with an atomic mass heavier than Na. The error bars in the concentration measurements performed by the PIXE facility are indicated in red.

  • Fig. 4 XRD pattern and XRF spectrum.

    (A) XRD patterns of Naples yellow before (black line) and after (red line) aging, as a representative example for all pictorial layers. The letter P indicates the crystalline lines of the pigments, and C indicates those of the canvas. (B) XRF spectrum of the white canvas.

  • Fig. 5 Experimental setup.

    Sketch of the experimental setup for the In-Air-PIL.

  • Table 1 Summary of changes in the total absorbance as function of aging time.

    PigmentsIncrease in absorbance when at saturation value (%)Aging time for saturation (min)
    Naples yellow55%150
    Cadmium yellow40%150
    Litharge25%150
    Chromium yellow15%20
    Orpiment8%20
  • Table 2 Summary of the EDX results for major constituents (in %).

    Naples yellowCadmium yellowLithargeChrome yellowOrpiment
    O7Pb2Sb2CdSPbOPbCrO4As2S3
    BeforeAfterBeforeAfterBeforeAfterBeforeAfterBeforeAfter
    PbO262.7063.19SO337.0437.38PbO220.8822.20PbO280.9678.81As2O350.7851.16
    Sb2O333.5833.16CdO45.2344.68CO279.1277.80Cr2O319.0421.19SO349.2248.84
    ZnO3.723.65BaO7.237.25
    ZnO10.5010.69

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/5/6/eaar6228/DC1

    EDX spectra

    SEM Images

    XRD results

    Fig. S1. Summary of EDX spectra for all pigments.

    Fig. S2. Summary of SEM image for all pigments.

    Fig. S3. Summary of XRD spectra for different pigments.

    Table S1. Summary of XRD results for Naples yellow.

    Table S2. Summary of XRD results for the cadmium yellow.

    Table S3. Summary of XRD results for the litharge.

    Table S4. Summary of XRD results for the chrome yellow.

    Table S5. Summary of XRD results for the orpiment.

  • Supplementary Materials

    This PDF file includes:

    • EDX spectra
    • SEM Images
    • XRD results
    • Fig. S1. Summary of EDX spectra for all pigments.
    • Fig. S2. Summary of SEM image for all pigments.
    • Fig. S3. Summary of XRD spectra for different pigments.
    • Table S1. Summary of XRD results for Naples yellow.
    • Table S2. Summary of XRD results for the cadmium yellow.
    • Table S3. Summary of XRD results for the litharge.
    • Table S4. Summary of XRD results for the chrome yellow.
    • Table S5. Summary of XRD results for the orpiment.

    Download PDF

    Files in this Data Supplement:

Stay Connected to Science Advances

Navigate This Article