Little information regarding the utilization of algal-based pigments in textile industry is available despite their abundance in aquatic ecosystems, varying color nature, and relatively fast-growing ...habit than other photosynthetic organisms. The aim of the current study is to optimize the conditions in order to harness the colorants from selected marine algal species and evaluating their dye yielding potential for fabric dyeing. Cotton fabrics were dyed with aqueous, alkaline, acidic or organic extracts of four algal species, the brown algae
Iyengaria stellata
,
Sargassum muticum
,
Colpomenia sinuosa
, and the red alga
Laurencia obtusa
under varying conditions of temperature, pH, and exhausting agent concentration. Results showed that 4% KOH and 80% acetone extraction produced maximum color strength of dyed cotton fabric. Among the four species of algae used in the study,
L. obtusa
showed the highest yield of colorant. However, all four species extract behaved differently to dyeing conditions. Mordanting experiments results revealed that iron sulphate and tannic acid were excellent pre- and post-mordanting agents for producing darker color shades of cotton fabrics dyed with all the four algal species used in the study. FTIR analysis indicated that the dominant coloring agents in all four algal species were phenolics in nature. The fabric dyed with extract of
I. stellata
,
C. sinuosa
, and
L. obtusa
showed creamy white shade, while
S. muticum-
treated fabric produced light brown shade. Pre- and post-mordanting of algal powder dyed fabric with chemical mordants, particularly the tannic acid produced other shades, such as light and dark brown.
Mulberry anthocyanins are natural pigments that are readily available and sourced inexpensively. However, the color characteristics of mulberry dyed silk fabric are significantly influenced by ...process conditions, leading to a limited color gamut. This study aims to broaden the color gamut of mulberry anthocyanin-dyed silk fabric by optimizing both the extraction process of anthocyanins from mulberry and the dyeing process. Single-factor experiments and orthogonal experiments were used to optimize the extraction process of mulberry anthocyanins. The factors investigated include the material-to-liquid ratio, extraction temperature, extraction time, and pH value. The dye extract was then used for direct dyeing of silk fabric, and color characteristic values were measured. The dyeing temperature, dyeing time, and dye bath pH value were evaluated using single-factor experiments and orthogonal experiments to determine the optimal dyeing process of mulberry anthocyanins on silk fabric. We further explored the two main factors: dyeing pH and mordant, to expand the color gamut. The color-gamut range, hue style, color value, and color fastness of the dyed fabrics were studied. The results indicated that the optimal extraction parameters were a material-to-liquid ratio of 1:10 (g/mL), an extraction temperature of 60 °C, an extraction time of 60 min, and an extraction pH of 4. The optimal dyeing process was a dyeing temperature of 60 °C, a dyeing time of 40 min, and a dye bath pH of 3. Under different dyeing pH and mordanting conditions, the obtained color-gamut ranges were
a
*
(− 9.66 to 19.16),
b
*
(− 12.04 to 11.58),
L
*
(30.42 to 85.78),
C
*
(0.62 to 19.16), and
h°
(0° to 2.8°) and (5.7° to 360°). The dyed fabrics fell into six major color-tone categories: simplicity and delicacy, elegance and gentleness, sweetness and romance, naturalness and simplicity, and dignity and grandeur. Compared with Pantone colors, 52 colors were identified, demonstrating international applicability. Through the variation of dyeing pH values and mordanting processes, the color-gamut range of dyed fabrics was effectively expanded, presenting promising applications of mulberry anthocyanins in silk-fabric dyeing. In addition, the mulberry anthocyanin-dyed silk fabric exhibited excellent UV resistance and satisfactory color-fastness properties.
A vast array of colorants obtained from natural sources such as plants, insects/animals and microbes have been scrutinized in recent past for their use in different kinds of applications. Research ...into new natural dyes sources along with eco-friendly, robust and cost-effective technologies for their processing and application have greatly aided in widening the scope of natural dyes in various traditional and advanced application disciplines. This review encompasses a summary of research performed in last 15 years (1998–2013) in different arenas of applications of natural dyes, with specific reference to technological development in natural textile dyeing and use of natural dyes in functional finishing of textiles, food coloration and dye-sensitized solar cells. In addition, some newly discovered applications of natural dyes have also been discussed.
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•Many different kinds of applications of natural dyes are under active study.•Reports technological developments in natural textile dyeing and finishing.•Natural dye-sensitized solar cells have been critically discussed.•Special attention has been given to recent developments in natural food colorants.•Some newly discovered applications of natural dyes have also been highlighted.
In a strangulation case, when a necktie is used as a murder weapon, the dyed silk single fiber becomes an important evidence sample to solve the crime. Dyed silk single fibers contain elements, such ...as Cr and Co, which are obtained from dyeing using metal mordants. Currently, there are no nondestructive and sufficiently sensitive elementary analytical methods for the forensic analysis of single fibers. Therefore, in this study, eight commercially available red silk samples were collected and used for total reflection X‐ray fluorescence (TXRF) and synchrotron radiation X‐ray fluorescence (SR‐XRF) spectrometry. Benchtop TXRF detected both S in the silk protein and Cl and Ca, which are elements absorbed from the environment by silkworms, but also Cr, which is a dyeing derivative for metal mordants. The presence of Cr and Zn, in addition to the Zn/Cr signal intensity ratios, was reported to be particularly useful identifiers. In SR‐XRF, the presence of Cr, Co, Zn, and Br and the Zn/Cr signal intensity ratios were reported to be useful discriminating indicators. In this study, the nondestructive discrimination capabilities of TXRF and SR‐XRF measurements for the samples were found to be 85.7% and 100%, respectively. Therefore, we propose a combination of TXRF and SR‐XRF as a new nondestructive single fiber identification method for forensic science. Moreover, if partial destruction of a single fiber is allowed, the observation of the cross section and micro‐Fourier‐transform infrared spectroscopy measurements is useful for identifying red silk fibers.
In the present study, cotton, silk and polyester yarns were dyed with the aqueous extracts of natural dyes from the pink leaves of
and red sepals of
. The dyeing was performed with mordants (Alum, ...Acetic acid, Copper sulphate and Lemon juice) and without mordant. UV-visible spectral analysis of natural dyes was determined. The selected dyed samples were assessed in terms of dye absorption percentage (E%), colour values (CIELAB), colour strength (K/S) and fastness properties. Various shades of ash-green and pink colours were obtained from the aqueous extracts of
leaves and
sepals. Fastness results showed good to very good grades. It was observed that multiple colours were produced with different mordants from a single source; therefore, the dyes extracted from the above plants are polygenetic in nature.
The resurgence of natural dyes is gaining fame in textile industry due to eco-friendly nature. The present study was done
to investigate the Coconut coir as natural dye (tannin) for silk dyeing under ...Microwave (MW) treatment following the
optimization of experimental parameters. Isolation of colorant was carried out in aqueous, acidic and organic media
(methanol) under influence of MW treatment up to 6 minutes. Dyeing of silk was carried out having irradiated and
unirradiated extracts. Good colour strength was achieved by dyeing unirradiated silk using methanolic extract under MW
treatment for 4 minutes at 75°C. The optimal dyeing was achieved at 75 minutes at pH 8 while keeping fabric liquor ratio
1:25 having 5 g/100 ml table salt as an electrolyte. For development of shades, salts of Al and Fe and Tannic acid were
used as pre- and post-chemical mordants and Acacia, Pomegranate, Turmeric and Henna as pre- and post-biomordents. Acacia (6%) as pre-bio mordant and Turmeric (6%) as post-bio mordant considerably improved the colour
strength at optimal conditions utilizing irradiated extract of coconut coir (tannin) and un-irradiated silk under MW
treatment at 4 minutes. ISO-standard shows good colour fastness and colour strength at optimal conditions using Acacia
and Turmeric as bio-mordents. This research work gives information about tannin extracted from Coconut coir has great
potential to dye silk fabric to produce reddish-brown colour under the influence of microwave treatment. FTIR spectral
study revealed chemical changes in the silk fabric treated with microwave radiations.
•The dyes and mordants of ancient Chinese textiles were identified by multi-techniques.•For the first time Rhamnus davurica. has been detected in a textile sample.•The data of dyes and mordants ...combined with the ancient records can be successfully used to explore the ancient dyeing techniques.
In this research, two pieces of textiles from the Qing dynasty (1644–1910) were studied to character the dyeing techniques using appropriate Eco-friendly analysis. The dye was identified by UHPLC-Q-Tof-MS, which improved sensitivity and resolution significantly when compared with LC-MS. The mordant in the textile dyeing process was determined by SEM-EDX. The results showed that Gardenia jasminoides Ellis was used in dyeing the yellow silk thread, Polygonum tinctorium was the source of the plant for the blue silk thread, and the plant source of green fabric most likely turned out to be Rhamnus davurica pall., which was first detected in ancient textiles. Iron and aluminum ions were detected as the metal ions in the mordant. Combined with all this information, the original dyeing process used for these textiles can be inferred. The results allow us to understand the dyeing techniques in the Qing dynasty, and to provide scientific support for conservation and restoration of the precious cultural heritage.
An important concern has been reached a growing interest in natural dyes in the textile dyeing industry for coloring fabrics due to growing environmental consciousness of preventing toxic synthetic ...dyes. Moreover, the use of metallic mordants does not make them entirely eco-friendly. Being aware of this, this report examines cotton knit fabric dyeing with natural mordants with dyes derived from onion skin executed using aqueous boiling technique. Diverse mordants, e.g., alum, ferrous sulphate, iron water, myrobalan, eucalyptus bark, and their combinations on cotton knit fabrics were used for pre-mordanting and together mordanting procedures. Several techniques and different types of equipment were used to measure various results. As a result, the mordanting techniques were reported to impact the outcomes of the dyeing procedure. That diverse mordants and mordanting techniques influenced the colour values produced a wide variety of gentle colors; thus, intermixing of natural and synthetic mordant gave the best result in together mordantation. Also, the pre-mordanting method gave averagely better results and dyeing properties than together mordanting, but eucalyptus gave the best results in together mordantation. Fading was found a little dissatisfactory in washing in case of natural mordants, yet staining properties were quite impressive. For other dyeing properties, satisfactory results were found for both natural and synthetic mordants. Their intermixing also contributed better results. Hence, it was evident that eucalyptus bark might be used as a suitable natural mordant for onion skin dyeing since eucalyptus showed the best result as an individual mordant or intermixing with synthetic mordant.
Phytochemicals, obtained from natural sources, have high importance for their practical implications owing to their inherent biological characteristics. Naphthoquinone compounds (alkannin and ...shikonin) from
Alkanna tinctoria
are well known for antioxidant and coloring properties. Here, naphthoquinone-rich dyeing solution was obtained by aqueous extraction of alkanet roots and applied on protein-based fabrics, i.e., wool. Bioactive colored fabrics were characterized for UV protection, antioxidant activity, and color characteristics. Ultraviolet (UV) protection ability was measured in terms of UV transmittance and UPF (UV protection factor) values, and antioxidant activity in percentage. Some non-hazardous metal salts in permissible concentrations were used as mordants, and their effects on coloration and bioactivities were studied. These salts significantly improved color characteristics and broadened the shade range, while it had little effect on bioactivities. Control dyeing with alkanet extract showed great potential for UV protection and antioxidant activity owing to the conjugated systems in naphthoquinone compounds. Polar functional groups of naphthoquinones were responsible for adsorption on fabric surfaces via chemical interactions.
In this study, we explore the dyeing properties of the extract of sappan wood natural dye for coloration of wool yarn to find the potential use of natural dyed wool yarn in the development of ...eco-friendly textiles. Different characterizations were used to know the chemistry of sappan wood dye and its interaction with metal salts and wool. Interestingly, we found that metal salts, which are called as mordants in reference to unmordanted dyed sample, play an important role in fixing the dye molecule on wool as well as in creating different shades with a variety of hues and tones. The typical color of fabric dyed with extracts of sappan wood without mordant varies from yellowish to red. Light yellowish shades were obtained in case of aluminum sulfate-mordanted samples, whereas yellowish shades were obtained in case of ferrous sulfate mordant. Light colorfastness of the premordanted dyed samples was relatively better than that of the unmordanted dyed samples. The wash fastness of all samples mordanted as well as unmordanted shows color change fairly good to good level, whereas the color staining on wool and cotton was found to be negligible.
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