Characterization of Natural Dyes and Traditional Korean Silk Fabric by Surface Analytical Techniques

Abstract

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS) are well established surface techniques that provide both elemental and organic information from several monolayers of a sample surface, while also allowing depth profiling or image mapping to be carried out. The static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric and biological materials. In this work, TOF-SIMS, XPS and Fourier Transform Infrared (FTIR) measurements were used to characterize commercial natural dyes and traditional silk fabric dyed with plant extracts dyes avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. Silk textiles dyed with plant extracts were then analyzed for chemical and functional group identification of their dye components and mordants. TOF-SIMS spectra for the dyed silk fabric showed element ions from metallic mordants, specific fragment ions and molecular ions from plant-extracted dyes. The results of TOF-SIMS, XPS and FTIR are very useful as a reference database for comparison with data about traditional Korean silk fabric and to provide an understanding of traditional dyeing materials. Therefore, this study shows that surface techniques are useful for micro-destructive analysis of plant-extracted dyes and Korean dyed silk fabric.

Keywords: FTIR; TOF-SIMS; XPS; mordants; natural dyes; surface techniques; traditional silk fabric.

Figure 1

Fourier transform infrared spectra of five commercial dyes and the dyed silk fabric between 600 and 1800 cm⁻¹: (a) curcumin; (b) indigo; (c) brazilin; (d) shikonin; and (e) quercetin.

Figure 2

Fourier transform infrared spectra of undyed silk textile with commercial indigo and silk textile dyed with indigo plant extract. The characteristic peaks allow easy identification. The spectra are vertically shifted for sake of clarity.

Figure 3

Survey XPS spectra of (a) undyed silk and sappanwood-dyed silk textiles; (b) without mordant and with various mordants: (c) KAl(SO₄)₂; (d) FeSO₄; (e) SnCl₄; and (f) CuSO₄.

Figure 4

Results of the curve fitting analysis of C1s spectrum measured for silk textiles dyed with plant extracts. (a) Turmeric; (b) Indigo; (c) Sappanwood; (d) Gromwell; (e) Quercetin.

Figure 4

Results of the curve fitting analysis of C1s spectrum measured for silk textiles dyed with plant extracts. (a) Turmeric; (b) Indigo; (c) Sappanwood; (d) Gromwell; (e) Quercetin.

Figure 5

Positive ion TOF-SIMS spectra of commercial natural dyes on the silicon substrate. (a) curcumin; (b) indigo; (c) brazilin; (d) shikonin; (e) quercetin.

Figure 6

Positive ion TOF-SIMS spectra of silk fabric (a) undyed and dyed with commercial natural dyes: (b) curcumin; (c) indigo; (d) brazilin; (e) shikonin; (f) quercetin.

Figure 6

Positive ion TOF-SIMS spectra of silk fabric (a) undyed and dyed with commercial natural dyes: (b) curcumin; (c) indigo; (d) brazilin; (e) shikonin; (f) quercetin.

Figure 7

Positive ion TOF-SIMS spectra of sappanwood-dyed silk textiles (a) without mordant and with various mordants: (b) KAl(SO₄)₂; (c) FeSO₄; (d) SnCl₄; and (e) CuSO₄.

Figure 8

Positive ion TOF-SIMS spectrum of silk textile dyed with indigo plant extract and Zn powder.

Figure 9

Positive TOF-SIMS images of sappanwood on silk textile: Na(m/z 23), Sn(m/z 120), brazilin(m/z 286) and total ion.