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The use of natural dyes as textile dyes is increasingly in demand since public awareness of the dangers of synthetic dyes has been increasing. Natural dyes produce a weak color intensity and require repeated dyeing to produce the desired color. This paper studied the effect of chitosan and catechin on the intensity and protection of fabrics in natural dyes from Peristrophe bivalvis expressed by parameters of UV protection factor (UPF) and color difference values (ΔE). The effects were observed between chitosan treatment and a combination of chitosan and catechin treatment of dyed cotton fabric in various concentrations. Cotton fabric treatment was applied before and after the dyeing process, and a combination of both. As a result, as the concentration of chitosan and catechin increased, the color intensity increased, as evidenced by the increase in the ΔE value. The best UPF value was obtained by combining chitosan and catechin on cotton fabric with the concentration of chitosan and catechin, respectively, 15 g/L and 0.5 g/L in the treatment before and after dyeing in a UPF value of 7.22 and a color difference (ΔE) of 36.09. The best lightfastness was obtained by a combination treatment of chitosan and catechin, with the results increased to 3-4 (good). [ABSTRACT FROM AUTHOR]

Indonesia has high potential for biodiversity of flora as a natural dye. Noja leaf (Peristrophe bivalvis) has potential as a red natural dye. The major component of the extract of its leaf is phenoxazine. The influence of mordant type, mordant concentration, and dyeing process temperature on the performance of the dyeing process was studied. The dyeing performances of the dyeing process were appreciated by measuring the colour strength parameter (K/S). Optimization of the dyeing process was done with Response Surface Methodology (RSM). Colour fastness to sunlight, washing, and rubbing was performed. Dyeing with noja leaf extract was done on a water bath with variation of mordant type used was alum (potassium aluminium sulphate), ferrous sulphate and calcium oxide with variation concentration 5%, 10%, and 15 % of the weight of the fabric at temperature variations of 50, 60 and 70oC. The optimum condition of fabric dyed with noja leaf extract is achieved at 61oC using ferrous sulphate as mordant with 10.96% concentration yielding colour strength value (K/S) of 0.597. The results of the sunlight, washing, and rubbing fastness test indicate that the natural dye from the leaves of the leaves is quite good as a natural textile dye. [ABSTRACT FROM AUTHOR]

The application of Indigofera tinctoria as natural dyes in textile industries has its own limitation. Exposure to sunlight can promote color fading in the fabric because ultra violet (UV) rays contained in the sunlight can damage the chromophore group in dye structure, especially for natural dye which has less stability structure compared to the synthetic dyes. Nano ZnO/TiO2 photocatalyst is a semiconductor material which has band gap that proportional to the wavelength of UV rays. This property makes this material is suitable for UV absorber. This study aims to improve the resilience of Indigofera tinctoria dye towards UV rays by utilizing nano ZnO/TiO2 as an additive. Methods of this research include the manufacture of nano ZnO/TiO2 by sonication method carried out in atmospheric pressure at temperature of 30°C for 30 minutes. The obtained ZnO/TiO2 nanoparticle was diluted in ethanol and applied on Indigofera tinctoria colored cotton fabric using simple dipping method. The independent variables in this study were variation of ZnO/TiO2 weight ratio (20, 21 and 22%), time of sonication ZnO/TiO2 (10, 20 and 30 minutes), and concentration of ZnO/TiO2 applied on fabric (75, 150, and 300 ppm). ZnO/TiO2 nanoparticle was characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDX). Evaluation of dye degradation on Indigofera tinctoria dye fabric was done by color strength analysis. The data obtained was analyzed by Response Surface Method (RSM) assisted by minitab18 software. Optimum operation condition were found to be 20% ZnO in ZnO/TiO2, 30 minutes of sonication, and 300 ppm ZnO/TiO2. The results from this study showed that nano ZnO/TiO2 were successfully synthesized and could be a potential candidate as an additive to increase the color stability of the dye. [ABSTRACT FROM AUTHOR]