Utilization of Longan Leaf Extract for Dyeing and UV Protection of Silk Fabric Using Pre-Mordanting Method

Abstract

Natural dye extracted from the longan leaves was applied to a silk fabric by an exhaustion dyeing process. The dyeing was conducted with and without metallic salt mordants using pre-mordanting. It was observed that with an increase in the dye concentration, the ultraviolet (UV) protection factor (UPF) values ranged between good and very good for the silk fabric. In addition, a darker color, such as that provided by a CuSO4 and FeSO4 mordant, gave better protection because of higher UV absorption. The results confirmed that natural dyes from longan leaf extract with metal mordants have potential applications in fabric dyeing and in producing UV-protective silk fabrics.

Dyeing Silk Fabric with Natural Dye from Longan Leaves Using Simultaneous Mordanting Method

“…The resulting solution was clear with a linear dependence on the concentration-absorbance relation at an absorption peak (λ max ) of 250 nm. The initial concentration of 2.1 g/L was calculated from a calibration curve based on absorbance at λ max 250 nm [7][8].…”

“…We have already investigated pre-mordanting and dyeing of silk fabric with aqueous longan leaves extract and also examined the dyeing and UV-protection properties. [7][8] In this paper dyeing of silk fabric with dye solution from longan leaves extract using simultaneous mordanting process and alteration of colour values and fastness properties examined and reported.…”

Dyeing of Silk Fabric with Natural Colorant from <i>Dimocarpus longan</i> Leaves

“…The dilution of the longan leaves extract showed a clear solution with a linear dependence on the concentration-absorbance relation at an absorption peak (λ max ) of 250 nm. The concentration of 2.1 g/L was calculated from a standard curve of concentrations of the longan leaves extract dye solution versus absorbance at the wavelength mentioned [3][4].…”