Effects of Different Mordants on Silk Fabric Dyed with Onion Outer Skin Extracts

Mohammad Gias Uddin

doi:10.1155/2014/405626

Mohammad Gias Uddin

Open Access

https://doi.org/10.1155/2014/405626

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Abstract

At present, a higher demand is put towards the use of natural dyes due to increased awareness of the environmental and health hazards associated with the synthesis and use of synthetic dyes. This research was conducted using onion outer skins as a potential source of natural plant dyes. In this study, extraction of dye was carried out in aqueous boiling method. Premordanting technique was followed using different mordants, namely alum, ferrous sulphate, tin, tannic acid, tartaric acid, and their combinations on silk fabric. Fabric samples dyed without using any mordant were then compared with the dyed samples pretreated with the mordants. The range of colors developed on dyed materials was evaluated by measuring the color values with respect to K/S values and color coordinates. It was concluded that the color values were found to be influenced by the addition of mordants, and thus different fashion hues were obtained from the same amount of dye extract using different mordants. Ferrous sulphate was found as the most influential mordant. ΔEcmc values between unmordanted (Reference dyed) and metallic mordanted fabric samples were found higher than those between unmordanted and nonmetallic mordanted fabric samples. The dyed samples were evaluated for color fastness to washing, light, drycleaning, rubbing, and perspiration. The color fastness properties were found to be satisfactory and improved in many cases. From the fastness results, it was obvious that these dyes can also be applied on silk fabric without using any mordant if required.

Highlights

Natural dyes are noncarcinogenic, produce soothing and exclusive color to the textiles, and have better biodegradability and higher compatibility with the environment [1,2,3,4,5,6]
As wash fastness of dye is influenced by the rate of diffusion of dye molecules and state of dyes inside the fiber, it can be explained that they have a tendency to aggregate inside the fiber
This study demonstrated that onion outer skins can be used as a potential source of dyes for dyeing of silk fabric

Summary

Introduction

Produce soothing and exclusive color to the textiles, and have better biodegradability and higher compatibility with the environment [1,2,3,4,5,6]. Onion outer skins are the most commonly discarded household and commercial food waste which can be used as dyes for coloring natural textile materials. These dyes, which are known as pelargonidin (3,5,7,4-tetrahydroxyanthocyanidin) [7] (see Figure 1), work like acid dyes that can dye the protein fibers at high efficiency [8]. Due to presence of four hydroxy groups (Auxochrome groups) pelargonidin exhibits good dyeing properties for dyeing of natural fibers [7, 9]

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