Adsorption and Kinetic Study of Lac Dyeing on Silk Improving Dyeing

Dye

Improving dyeing properties of silk grafted with methyl methacrylate and methacrylamide

The chemists at King Mongkut’s Percentage dye uptake increased with the perspiration fastness remained unchanged Institute of Technology, Ladkrabang, presence of polymethyl methacrylate or for curcumin dyeing without and with the Bangkok, Thailand worked on degummed polymethacrylamide in the silk fibroin presence of the mordant. Also, the low- Bombyx mori silk to improve its dyeing structure regardless of the types of the light resistances of the degummed and and colourfastness properties, by a grafting dyestuffs. Furthermore, compared to the grafted silks dyed by curcumin dyestuff technique with either methyl methacrylate degummed silk, the colourfastness to were notably improved by the MMA and (MMA) monomer or methacrylamide washing of the MMA-grafted and MAA- MAA grafting technique[Prachayawarakorn (MAA) monomer. Both commercial grafted silks dyed with acid, basic and Jutarat and Kryratsamee Watthana, Dyeing synthetic dyes, that is, acid and basic dyes, curcumin dyestuffs were greatly improved. properties of Bombyx mori silks grafted with J Appl and natural dyes extracted from turmeric, Colourfastness to both acid and basic methyl methacrylate and methacrylamide, Polym Sci, 2006, 100(2), 1169-1175]. without and with potassium aluminum perspirations with acid and basic dyestuffs sulfate mordant, were used in this study. was slightly improved, whereas

Adsorption and kinetic study of lac dyeing on silk

Lac dye is a natural reddish Adsorption and kinetic studies of values of the enthalpy (∆H#) and entropy dyestuff extracted from stick lac which is lac dyeing of silk were investigated by of activation (∆S#) were 44.7 kJ/mol and a secretion of the insect Coccus laccae scientists of Thailand and Australia using, −175.7 J/mol K, respectively. The free (Laccifer lacca Kerr). The insect C. as optimal conditions, a pH of 3.0, a energy of activation (∆G#) at 30°C was laccae is often found in South and material to liquor ratio (MLR) of 1:100, 97.9 kJ/mol. The activation parameters Southeast Asia, especially in Thailand and an initial dye concentration of 450 mg/ with and without erythrolaccin in the lac India. In Thailand, the lac insect grows litre and 60 min contact time. The dye were similar, consistent with most commonly on the Rain tree, progress of dye adsorption was monitored erythrolaccin only having a slight effect

Samanea saman (Jacq.) Merr. (syn. at λmax 487 nm by visible spectroscopy. on the lac dyeing of silk. The free energy Pithecellobium saman Benth.). Lac dye The experimental data fitted well to the (∆G), enthalpy (∆H) and entropy (∆S) is used extensively as a natural food Langmuir and Freundlich isotherms with terms for the lac dyeing were also additive, in cosmetics and as a colourant a high correlation coefficient (R2). The determined and the negative values of ∆G for silk and cotton dyeing. In the North pseudo second-order kinetic model was and ∆H obtained indicated that the lac and the Northeast of Thailand, it is used indicated with the activation energy of 47.5 dye adsorption process is a spontaneous as a natural red dyestuff for cotton and kJ/mol. It is suggested that the overall rate and an exothermic one. The results from silk dyeing but the fastness properties and of lac dye this kinetic study will assist in gaining a reproducibility to give consistency in adsorption is better understanding of the adsorption production are still problems to be solved. likely to be mechanism of this dyeing process [Chairat As part of the approach to tackle these controlled by Montra, Rattanaphani Saowanee, Bremner John B problems, fundamental physical studies the chemical and Rattanaphani Vichitr, An adsorption and Dyes Pigments on the dyeing process are important. process. The kinetic study of lac dyeing on silk, , Lac dye 2005, 64(3), 231-241].

184 Natural Product Radiance CYANMAGENTAYELLOWBLACK

Dye

Natural dyes as photosensitizers for dye-sensitized solar cell

Dye-sensitized TiO2 solar cell extract and the TiO2 film on cathode in (DSC) has become an attractive and cheap DSC. The blue-shift phenomenon from device for the conversion of solar light absorption spectrum to photoaction into electrical energy since Grätzel and spectrum of DSC sensitized with black rice O’Regan firstly reported the prototype of extract is due to the intensity and gap this solar cell in 1991. DSC is assembled energy match of incidence light. Because with an anode of conductive glass coated of the simple preparation technique, with platinum, a cathode of TiO2 porous widely available and low cheap cost film on a conductive glass substrate natural dye as an alternative sensitizer for anchored a monolayer of dyes and an dye-sensitized solar cell is promising [Hao electrolyte of certain organic solvent Rosa xanthina Sancun, Wu Jihuai, Huang Yunfang and Lin containing a redox couple, such as iodide/ Jianming, Natural dyes as photosensitizers for dye- has been emphasized by many researches sensitized solar cell, Solar Energy, 2006, 80 triiodide. Many efforts have focused on to obtain useful dyes as photosensitizers (2), 209-214]. sensitizer dyes, since dye plays a key role for DSC from natural products. The scientists of China investigated natural dyes extracted from black rice, capsicum, Erythrina variegata Linn. flower, Rosa xanthina Lindl., and kelp, the interaction between the dye molecule (the core molecular groups of natural dyes)

and TiO2 porous film. The dye-sensitized solar cells (DSC) were assembled by using these Erythrina variegata natural dyes as sensitizers. The ISC from

1.142 mA to 0.225 mA, the VOC from 0.551 in harvesting sunlight and transferring V to 0.412 V, the fill factor from 0.52 to solar energy into electric energy. So far, 0.63, and Pmax from 58 µW to 327 µW several organic dyes and organic metal were obtained from the DSC sensitized complexes have been employed to sensitize with natural dye extracts. Based on nanocrystalline TiO2 semiconductors, and investigation on the structure and one of the most efficient sensitizer is properties of dye molecules, it was found transition metal coordination compound that black rice extract possesses the best (ruthenium polypyridyl complex). In photosensitized effect in the extracts of nature, the fruit, flower and leaf of plants five kinds of natural dyes chosen, which show various colour from red to purple is due to the better interaction between and contain various natural dyes which the carbonyl and hydroxyl groups of can be extracted by simple procedure. It anthocyanin molecule on black rice

Vol 5(3) May-June 2006 185 Dye

Quinone and flavonoid dyes as insect feeding deterrents for wool Wool (obtained from different Natural dyes would provide an alternative was used in which the specimens were breeds of sheep) is susceptible to insect to synthetic insecticides, which are more mordanted prior to dyeing. The dyestuffs damage from clothes moths and carpet detrimental to the health and safety of included three naturally occurring beetle larvae. Continuous damage can humans and the environment. By properly quinones (cochineal, madder and black result in significant economic losses, selecting the dyestuffs for wool textiles that walnut) and six flavonoids (chestnut, especially in warehouses and showrooms. have inherent resistance to insects, the fustic, indigo and logwood). Some insect larvae eat wool to obtain need for insecticidal chemicals could be The insect resistance of eight sulfur, which is an essential factor in insect greatly reduced. It also would reduce the naturally occurring quinones and growth. Several conditions, including cost of manufacturing because flavonoids dyes applied to wool with five food, temperature, and moisture, conventional insect repellency treatments mordanting agents was studied in detail influence the growth of the insects, would not be needed. Therefore, the by using laboratory-reared black carpet especially larvae. scientists at Department of Apparel, beetles. The anthraquionone dyes, such There are two major approaches Textiles and Interior Design, Kansas State as cochineal and madder, were found to to controlling clothes moths and carpet University Manhattan, Kansas evaluated be very effective in protecting the wool beetles: (1) no-chemical methods and (2) eight natural dyes and the combination fabric against black carpet beetles. chemical methods. No-chemical methods of dyes and mordanting agents for insect Madder resulted in the lowest weight loss use extremely high temperature or repellency and/or insecticidal effect and the best effect of insect deterrence electromagnetic radiation frequencies to against black carpet beetle, Attagenus against black carpet beetles. Among the kill insects. Chemical methods include the megatoma F. Seven of the natural dyes flavonoids, chestnut, fustic, logwood and use of several natural and synthetic were applied in conjunction with five indigo dye when used on wool will not insecticides, biological control, chemical mordanting agents, whereas the indigo provide insect resistance. Among modification of wool, laundering with was applied by a conventional reduction/ mordanting agents, alum, copper and iron strong soap solutions, and dry-cleaning. oxidation method. can be used with the eight dyes without Chemical methods are more popular, For the experiment the fabric increasing insect susceptibility of the dyed common and easy to apply. used was a medium-weight (g/m2) wool wool products. Using chrome or tin as a Another important category of flannel which was prescoured prior to mordanting agent for dyeing wool with natural products that have potential use mordanting and dyeing processes to cochineal is not recommended as it is natural dyes, such as chestnut, remove surface impurities that would increases insect susceptibility. Thus, the cochineal, fustic, indigo, madder, influence treatment and/or insect testing. naturally occurring mordant dyes provide logwood and walnut, which comes from The scouring solution contained 0.1% (w/ an alternative to insecticides in protecting plant’s leaves, roots and flowers, and w) AATCC soap and 10% (w/w) sodium wool textiles from insect attack [Park Jung insects. Natural dyes can be dyed on wool carbonate. The five mordanting agents Hwa, Gatewood Barbara M and Ramaswamy Gita to provide brilliant colours, and they are selected for evaluation were aluminum N, Naturally occurring quinones and flavonoid dyes for wool: Insect feeding deterrents, J Appl Polym related quinones- and flavonoids- (aluminum sulfate), chrome (potassium Sci, 2005, 98(1), 322-328]. containing products. Naturally occurring dichromate), copper (copper sulfate), quinones and flavonoids are known to have iron (iron oxide) and tin (stannous insecticidal or insect-repellent properties. chloride). A premordanting procedure

186 Natural Product Radiance Dye

Dyeing wool with lac Recently, a revival interest in the (Ziziphus mauritania Lam.). The use conventional heating at low temperature use of natural dyes in textile coloration of lac dye in the dyeing of silk and leather and short time. The effects of dye bath has been growing. This is a result of the seems to have been known to the Chinese pH, salt concentration, ultrasonic power, stringent environmental standards some 4000 years ago. Lac is a mixture of dyeing time and temperature were studied imposed by many countries in a response at least five closely related laccaic acids, and the resulting shades obtained by to the toxic and allergic reactions which are water soluble red dyes of dyeing with ultrasonic and conventional associated with synthetic dyes. anthraquinoid type structure. techniques were compared. Colour Conventional wisdom leads to the belief Researchers at National Research strength values obtained were found to be that natural dyes are friendlier to the Centre, Textile Research Division, El- higher with ultrasonic than with environment than their synthetic Behos St. Dokki, Cairo, Egypt conducted conventional heating. The results of counterparts. Natural dyes can exhibit a study to investigate the dyeing and fastness properties of the dyed fabrics were better biodegradability and generally have fastness properties of wool fibres using fair to good. Dyeing kinetics of wool fibre a higher compatibility with the lac as a natural dye. Different factors with lac dye using conventional and environment. affecting dyeability and fastness properties ultrasonic conditions was also compared. Lac is a unique dye material of were thoroughly investigated by both The time/dye-uptake isotherms revealed animal origin being the secretion of a tiny conventional and ultrasonic techniques. the enhanced dye-uptake in the second insect Laccifer lacca Kerr thriving on The extractability of lac dye using power phase of dyeing (diffusion phase) [Kamel certain host plants such as, Palas ultrasonic was also evaluated in MM, El-Shishtawy Reda M, Yussef BM and Mashaly [Butea monosperma (Lam.) comparison with conventional heating. H, Ultrasonic assisted dyeing III. Dyeing of wool Kuntze], Kusum [Schleichera The results of dye extraction indicated that with lac as a natural dye, Dyes Pigments, 2005, 65 (2), 103-110]. oleosa (Lour.) Oken.] and Ber power ultrasonic is rather effective than

Characterization of anthocyanin extracts from maize kernels The researchers at Mexico four maize samples contained anthocyanin 6”-dimalonylglucoside). Anthocyanin worked on the characterization of the in both the pericarp and aleurone layer. extracts showed similar behaviour in pigments present in the kernel of four Total anthocyanin content among samples solutions with different pH. From pH 1-6 native maize varieties related to the races ranged from 54mg/100g to 115 mg/100g lambdamax values were maintained Arrocillo, Conico, Peruano and Purepecha of sample. Anthocyanin profiles were almost constant; however, above this pH to determine their possible use as natural almost the same among the four samples. value, a marked increase was observed in dyes. Total anthocyanin content was Differences were observed only in the the bathochromic shifts, but the bluish determined by a conventional relative percentage of each anthocyanin. colour did not continue to change above spectrophotometric method and The anthocyanins identified are: cyanidin- pH 8 [Moreno YS, Sanchez GS, Hernandez DR anthocyanin analysis by high-performance 3-glucoside, pelargonidin-3-glucoside, and Lobato NR, Characterization of anthocyanin liquid chromatography. The stability of the peonidin-3-glucoside, cyanidin-3-(6” extracts from maize kernels, J Chromatogr Sci, pigment at pH was also evaluated. The malonylglucoside) and cyanidin-3-(3”, 2005, 43(9), 483-487].

Vol 5(3) May-June 2006 187 Dye

Extraction of natural dyes from coloured plant wastes The production of natural dyes released from the food and beverage complete dyestuff from natural resources has been found to industry and considered plant materials extraction. Samples be costly, hence, new strategies are derived from Raspberries, Sour cherries, were collected required to establish technically and Black elder, Blackcurrant, Grapes, Red during extraction at commercially competitive processes and beet, Onions, Rhubarb, Black tea and intervals of 10 resources. The use of cheap by-products Black carrots. During experiment a minutes. from other agricultural activities, e.g. bark weighed amount of plant material was Onions The extracts from the timber industry or leaves from extracted with distilled water in a beaker. were applied as abundantly available plants like deodar, In the standard procedure the ratio mass direct dyes and in the presence of iron(II) jackfruit and eucalyptus and use of of waste:volume of liquid was set at 1:20. or alum mordants. The results prove the dyestuff-containing wastes released from The extraction was performed for potential of such wastes as a source for the food and beverage industry free of approximately 60 min at 95°C. Photometry natural dyestuff for woolen textiles. To charge has been suggested by researchers. was used to quantify the extractable obtain textile dyeing with acceptable In the traditional natural dyeing of textiles amount of coloured material and to fastness properties, however, rigorous an important part of red/yellow dyes had estimate the minimum time required to selection of dyes and development of been extracted from fruits and vegetables. suitable processes is required. A The considerable number of red natural dyes scientists at Institute need further research to optimise the low for Textile Chemistry level of fastness to light [Thomas Bechtold, and Textile Physics Rita Mussak, Amalid Mahmud-Ali, Erika and Institute for Ganglberger and Susanne Geissler, Extraction of natural dyes for textile dyeing from coloured plant Applied Ecology, wastes released from the food and beverage Austria worked on industry, J Sci Food Agric, 2006, 86(2), various wastes Red beet Black carrot 233-242]. Improving light fastness of natural dyes on cotton yarn Researchers from France (woad) colours in European, American comparison with synthetic ones is conducted studies to evaluate the light and even Asian textiles until the 19th established beyond question. Nevertheless, fastness of selected natural dyes [aerial century. The photofading rate curves of the use of some additives can improve this parts of Weld (Reseda luteola Linn.) madder and weld fixed on cotton default of natural dyes. In all the cases, and Woad (Isatis tinctoria Linn.) and correspond to Type II fading rate curves the use of UV absorbers or antioxidants Madder roots (Rubia tinctoria Linn.)] described by Giles. These results are in improved the light fastness of dyed fabrics. and the effect of some commonly used concordance with those of Cox-Crews. The The most effectives were the vitamin C and antioxidants and UV absorbers on the light woad presents a Type III fading rate curve, the gallic acid [Cristea Daniela and Vilarem fastness of these dyes. These dyes were similar to the indigo fading rate curve Gerard, Improving light fastness of natural dyes on selected because they were widely used presented by Cox-Crews. A poor light cotton yarn, Dyes Pigments, 2006, 70(3), for red (madder), yellow (weld) and blue fastness of the three natural dyes in 238-245].

188 Natural Product Radiance