Natural dyeing with anthocyanins from Hibiscus rosa sinensis flowers

Abstract

A new approach for natural dyeing with anthocyanin has been discussed along with a convenient method of extraction. Anthocyanin from Hibiscus flowers has been extracted by developing a method using methanolic solution of 4% citric acid. The new method gave better yield of anthocyanin as compared with methanolic solution of 0.1% hydrochloric acid. It has been also shown that pH of the extract plays an important role on the dye, thus by adjusting the pH of the extract at 4, dyeing of cotton and silk together with metal mordanting gave different colors. The best dyeing results were obtained for stannous mordanted fabrics in terms of fastness properties. The role of metal ion complexation of stannous salt with the dye extract has been confirmed through UV-Vis and FTIR spectra. Antioxidant activity of the anthocyanin extract seemed to have contributed to enhance the fastness properties of the dyed fabrics.

Natural Dyeing with Black Carrot: New Source for Newer Shades on Silk

“…This coloring phytochemical which is generally present in red, blue, and purple fruits, berries and flowers, is an important food color too (Francis and Markakis 1989). Anthocyanin can be a good fabric dye as can be understood from their structure ( Figure 5) (Vankar and Shukla 2011). Anthocyanin from black carrot can be classified as acid dye (natural pH of dye 6.06) which can play an important role in dyeing fabric especially protein fibers and thus adheres well on silk giving good shades.…”

Metal mordanting in dyeing with natural colourants

“…The changes in colour depth vs light fastness grades in dyeings mordanted with aluminium (), tin (), iron (), chromium (), and copper () salts . Quadrants are indicated by Roman numerals in part (a) of the figure.…”

“…The metric hue differences are plotted against the corresponding light fastness changes in Figure 2c Figure 1 The changes in colour depth vs light fastness grades in dyeings mordanted with aluminium ( ), tin ( ), iron ( ), chromium ( ), and copper ( ) salts [9,11,16,17,[35][36][37][38][39][40][41][42][43][44][45][46][47][48]. Quadrants are indicated by Roman numerals in part (a) of the figure.…”

“…The changes in colour (lightness, brightness, and hue) vs light fastness grades in dyeings mordanted with aluminium ( ), tin ( ), iron ( ), chromium ( ), and copper ( ) salts [11,16,17,29,[35][36][37][38][39][40][41][42][43][44][45]47,[49][50][51][52][53][54] remain unclear. The photostability generally improves with molecular size (or weight) and also with symmetry in colourant structure [2,8,26].…”

Colorimetric and fastness studies and analysis by reversed‐phase high‐performance liquid chromatography with diode‐array detection of the dyeing of silk fabric with natural dye Helichrysum arenarium

“…Natural fibres are obtained from some dye plants and dye animals in nature, and, until the mid-to late-nineteenth century, they were the primary colour source for textiles [3]. Natural dyes have a wide range of shades that can be obtained from various plant parts, including roots, bark, leaves, flowers, skin, fruits, and shells of plants [4][5][6][7][8][9][10][11]. These considerations have led to the publication of several studies on natural dyes from a number of sources [12][13][14][15][16][17] .…”