SURFACE CHEMICAL ANALYSIS OF C.I. LEUCO SULPHUR BLACK 1 DYED COTTON FABRIC AFTER-TREATED WITH PLANT-DERIVED TANNIN-BASED PROTECTIVE AGENT

In this investigation, the X-ray photoelectron spectroscopic technique has been used to examine the surface chemistry of C.I. Leuco Sulphur Black 1 dyed cotton fabric, which has been after-treated with a tannin-based commercial product, Bayprotect CL, and laundered in accordance with ISO 105 C06 and C09 washing protocols. The dyeings were evaluated for colour strength, wash fastness and colour loss. Surface chemical compositions of the dyeings were analysed to relate visual changes with surface chemical changes. Alterations in percentage atomic concentrations of carbon, nitrogen, oxygen and sulphur were compared for untreated, after-treated, unlaundered and laundered dyed samples. After-treated and laundered dyed samples exhibited higher content of surface sulphur and lower surface oxidation, as compared to the untreated counterparts. The S (2p) spectra of after-treated and laundered samples demonstrated reduced over-oxidised (S6+) species at 168 eV. There was 5% and 4% less surface oxidation for ISO 105 C06 and C09 washing systems, respectively.