Rainbow of Natural Dyes on Textiles Using Plants Extracts: Sustainable and Eco-Friendly Processes

Indians have been considered as forerunners in the art of natural dyeing. Although indigenous knowledge system has been practiced over the years in the past, the use of natural dyes has diminished over generations due to lack of documentation and precise knowledge of the extracting and dyeing techniques. As a result, natural dyes are not commercially successful. Presently, all environmentally unfriendly synthetic compounds are used for dyeing textile materials. They are non-biodegradable, carcinogenic and generate water pollution as well as waste disposal problems. Natural dyes provide a reasonable solution to these problems. Thus, it is imperative to develop technology for extraction of natural dyes and for their application on textile materials. In this study, attempt has been made to extract natural dyes from a variety of plants sources (such as rhizomes of turmeric, Curcuma longa;fruits of harda, Terminalia chebula;petals of safflower, Carthamus tinctorius;roots of barberry, Berberis lycium etc.) using specific techniques. These dyes were tested for their dyeing potential on different textile materials (cotton, silk and wool). Dyeing was done using three different dyeing techniques (pre-, simultaneous- and post-mordanting) wherein different mordants such as alum, copper sulphate and ferrous sulphate etc., were used to fix dye on to the textile material. A rainbow of natural dyes was obtained with varied shades of each colour. Shade cards were prepared for each dye and the colour obtained varied depending on the type of the mordant applied and the mordanting technique used.

Extraction and Application of Natural Mordant Dyes from Eichhornia Crassipes(Water Hyacinth)

Metallic salts are often added as extra mordant when dyeing the fabrics with natural dyes. Eichhornia crassipes,namely water hyacinth( WH),is an environmentally problematic aquatic weed with high affinity for metals. In this paper,WH was selected as the source of natural mordant dyes,and extracted by absolute ethyl alcohol using a soxhlet apparatus. The colorants in WH were extracted and separated by column chromatography and thin layer chromatography( TLC). UV-visible spectrophotometer( UV-VIS),mass spectrometry, chemical identification with chromogenic reaction,and Fourier transform infrared spetroscopy( FTIR) were used to identify the main components of each pigment band. The total metal contents before and after extracting of the WH were determined by using an inductively coupled plasma atomic emission detector. The WH extracts were then used to dye wool fabric. The dyeing properties of WH extracts with and without metal mordant were investigated and compared. The results show that the main components of WH extracts are pheophytin and phyllins. The major metallic elements identified in WH are magnesium, manganese,zinc,and iron. Samples dyed with WH extracts without metal mordant exhibits high K / S values and good dyeing properties. This study indicates that the WH extracts can be used as a natural mordant dye on wool fabrics directly.

Study on the Camouflage-Protective and Dyeing Properties of Natural Dye Indigo

There are two major camouflage protections in modern military tactics:UV-protection and near infrared camouflage.However,not all natural and composite dyestuffs provide the mentioned properties.In this study,the cotton fabric was dyed with natural indigo and the natural indigo dyeing process was optimized.Green leaves were chosen as the simulating object,and the camouflage properties of the dyed cotton fabric were evaluated.It was observed that the dyed cotton fabric had good UV-protection and near-infrared camouflage properties.The UV-protection effect was strongly dependent on the absorption characteristics of natural indigo for UV radiation.The near infrared camouflage effect was mainly dependent on the reflection spectrum characteristics of natural indigo in the near infrared waveband.

APPLICATION OF BLUE 2~# REACTIVE DYE ON NATURAL SILK WAX PRINTING

The optimum processing parameters of silk wax printing with Biue 2# reactive dye( vinyl- sulfone) at 40℃were deter-mined through orthogonal tests on its dyeing properties.The parameters were adopted in designing a wax printing process,which proved practical for actual production with a dye utility as 60% ,a Grade V side wet fastness and a decrease of only 2-4.1%in fabric strength. Also,some feasible measures are put forward in this paper on the major steps of the wax printingprocess.

Photoelectric Characterization of Dye Sensitized Solar Cells Using Natural Dye from Pawpaw Leaf and Flame Tree Flower as Sensitizers

Natural dyes from flame tree flower, Pawpaw leaf and their mixtures were used as sensitizers to fabricate dye-sensitized solar cells (DSSC). The photoelectrochemical performance of the Flame tree flower dye extract showed an open-circuit voltage (VOC) of 0.50 V, short-circuit current density (JSC) of 0.668 mA/cm2, a fill factor (FF) of 0.588 and a conversion efficiency of 0.20%. The conversion efficiency of the DSSCs prepared by pawpaw leaf extract was 0.20%, with VOC of 0.50 V;short-circuit current density, JSC of 0.649 mA/cm2 and FF of 0.605. The conversion efficiency for the flame tree flower and pawpaw leaf dye mixture was 0.27%, with VOC of 0.518 V, JSC of 0.744 mA/cm2 and FF of 0.69. Although the conversion efficiencies, Jsc and the Voc of the prepared dye cells were lower than the respective 1.185%, 7.49 mA/cm2 and 0.64V reported for ruthenium, their fill factors (FF) were higher than that of ruthenium (0.497). It was also observed that both the short-circuit current density and the fill factors of the cells were enhanced using mixed dye.

Assemble of Dye Sensitized Solar Cell Based on Locally Available Natural Dye

Due to the availability, non-toxicity and cost-effectivity, natural dyes are becoming popular day by day. This study explains the fabrication method of dye-sensitized solar cells (DSSCs) using natural dyes containing anthocyanins extracted from pomegranate, blackberry and beetroot. Doctor blade method was employed to prepare TiO2 film as photoanode on FTO glass. The structural and morphological properties of photoanode was studied using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The extracted dye absorption was evaluated by UVVis- NIR spectroscopy. The fabricated cells have efficiency in the range of 0.015-0.042% which has been measured by sun simulator.

Investigation of a Simple and Cheap Source of a Natural Indicator for Acid-Base Titration: Effects of System Conditions on Natural Indicators

This study investigated a natural indicator for acid-base titration which is extracted from guinea corn leaves popularly called “waakye leaves” in Ghana. Four types of acid-base titration were studied: strong acid versus (v/s) strong base, strong acid versus weak base, weak acid versus strong base, and weak acid versus weak base. The indicator color change, pH range and the average titre values were determined for each type of acid-base titration. These values were comparable to those obtained from three standard indicators: methyl orange, methyl red and phenolphthalein. Total flavonoids (TF) and condensed tannin (CT) from the crude leaves extract were determined which might be the major reasons for the activity of the extract as an indicator for simple acid-base titration. The authors suggest that the natural indicator is cheap, available, simple to extract, user and environmentally friendly and could be an excellent replacement for standard indicators.

Isolation of a Microorganic Strain for the High Volume Degradation of Aniline Blue and Its Application in Natural Sewage Treatment

Aniline blue, one of the triphenylmethane dyes, is the most commonly produced and used of these dyes yet it is also the most dangerous and the most serious cause of pollution amongst them. An exploration of aniline blue degradation is likely to facilitate an understanding of the degradation mechanism for a range of related dyes. In this study, we managed to isolate a particular strain of microorganism, identified to be Lysinibacillus fusiformis N019a, which showed a significant capacity for aniline blue degradation in both laboratory tests and natural sewage treatment. In analysis aided by a UV-Visible spectrophotometer, we found that 96.7% of aniline blue had degraded within 24 hours under laboratory conditions. When treating natural sewage, 80.1% of the aniline blue was removed after just 16 hours. Further analysis has shown that Lysinibacillus fusiformis N019a has a strong resistance to Cu2+, Mn2+, Zn2+, and Pb2+. We also found that the degradation product of aniline blue by Lysinibacillus fusiformis N019a was of reduced toxicity to plants and microbes.

Matching Dyeing and Properties of Silk Fabrics with Natural Edible Pigments

The silk fabrics were matching dyed with three natural edible pigments(red rice red,ginger yellow and gardenia blue).By investigating the dyeing rates and lifting properties of these pigments,it was observed that their compatibilities were excellent in the dyeing process:dye dosage 2.5%(omf),mordant alum dosage 2.0%(omf),dyeing temperature 80℃and dyeing time 40 min.The silk fabrics dyed with secondary colors exhibited vibrant and vivid color owing to the remarkable lightness and chroma of ginger yellow.However,gardenia blue exhibited multiple absorption peaks in the visible light range,resulting in significantly lower lightness and chroma for the silk fabrics dyed with tertiary colors,thus making it suitable only for matte-colored fabrics with low chroma levels.In addition,the silk fabrics dyed with these three pigments had a color fastness that exceeded grade 3 in resistance to perspiration,soap washing and light exposure,indicating acceptable wearing properties.The dyeing process described in this research exhibited a wide range of potential applications in matching dyeing of protein-based textiles with natural colorants.

火龙果果皮天然色素提取及羊绒纤维染色

从火龙果果皮中提取天然色素并对羊绒纤维进行染色,通过调整火龙果果皮天然色素用量、染色温度、染色时间、染液pH、媒染剂用量与媒染方法等进行工艺优化。结果表明,当火龙果果皮天然色素体积分数为8%,染色温度55℃,染色时间40 min,染液pH为5,采用2%(omf)硫酸铝为媒染剂的后媒染法染色,羊绒纤维上染率最高。染色羊绒纤维颜色接近火龙果紫红色色光,上染率在75%以上,耐皂洗色牢度达到4级,纤维机械性能符合可纺性要求。

南湖菱壳色素在大麻织物上的染色工艺

为探讨菱壳色素对大麻织物的染色工艺,采用阳离子改性剂KR、壳聚糖、明胶、改性剂BS对大麻织物进行改性,并对未改性、改性后大麻织物用菱壳色素进行染色。探讨改性剂对菱壳色素直接染色效果的影响;媒染剂单宁酸、明矾、草木灰、柠檬酸对未改性、改性大麻织物菱壳色素染色效果的影响。结果表明:菱壳色素染色的大麻织物具有一定紫外线吸收功能,在可见光中最大波长为380 nm,对应的吸光度是0.067。改性剂BS改性大麻织物直接染色法、未改性大麻织物明矾后媒染、水溶性壳聚糖改性大麻织物明矾后媒染、明胶改性大麻织物明矾后媒染、改性剂BS改性大麻织物草木灰同浴媒染、改性剂BS改性大麻织物明矾后媒染的K/S值均在在3.990以上,染色牢度均在3级及以上。除BS改性剂改性大麻织物直接染色法工艺湿摩擦色牢度为3级外,其他各种工艺的色牢度都在3~4级及以上,耐光色牢度最高达到5级。

天然染料染色综述

目前天然染料染色的研究基础薄弱,呈碎片化。基于此,本文介绍了常见天然染料的化学结构,根据染料结构选择正确的染色方法(包括直接染色法、还原染色法和媒染法)并进行优化,同时比较媒染法中预媒染法、同浴媒染法和后媒染法的特点,指出后媒染法最合理、最常用。

染整工艺对麻纤维抗菌性能的影响

从麻纤维自身形态结构、化学组成出发,分析了影响麻纤维自身抗菌性的因素。概述了染整加工工艺中脱胶、染料种类和染料助剂对麻纤维抗菌性能的影响,总结了麻织物的物理抗菌整理和化学抗菌整理方式。认为:在麻纤维自身具备抗菌性的基础上,采用添加天然抗菌剂、物理抗菌整理、植物染料染色等方法,可有效降低麻纤维生产加工过程中抗菌成分的流失,进一步提高麻织物的抗菌性能。

姜黄和黑米染料对柞蚕丝的拼色染色

为提高柞蚕丝织物的抗紫外线性能,同时获得较为齐全的色谱,采用天然姜黄染料及黑米染料对柞蚕丝进行同浴拼色染色,研究两种染料配比及FeSO_(4)后媒染处理对柞蚕丝颜色及抗紫外线性能的影响。结果表明,将姜黄染料和黑米染料进行拼色可以得到从黄色到暗红色等一系列色泽的染色柞蚕丝,FeSO_(4)媒染可进一步丰富柞蚕丝的色谱,得到暗黄、黄绿、暗蓝等一系列色泽;FeSO_(4)媒染试样染色牢度达到3级以上。与单一染料染色试样相比,同浴拼色染色试样的紫外线防护性能更佳,且FeSO_(4)媒染可以进一步提高试样的UPF指数,最高可达到45.88。

茜草色素对生物基聚酰胺56的染色性能

为探讨天然染料用于生物基聚酰胺56(PA56)的染色可行性,实现PA56的环保染色工艺,通过单因素实验,以染色后织物K/S值为指标,优化了茜草上染PA56织物的染色工艺条件。采用准一级和准二级动力学模型,研究了茜草上染PA56的染色动力学特性,分析了染液pH值及添加剂对染色动力学参数的影响。结果表明:当染液的pH值为4.2,染色温度为80℃时,染色保温40 min后可获得一定染色深度的茜草上染PA56织物;经不同金属离子媒染后,染色织物的色牢度和K/S值均有提高;茜草色素在PA56纤维上的染色吸附过程符合准二级动力学模型,随着染色温度的升高,染料平衡吸附量增加,半染时间缩短,扩散系数增大;在染色中加入元明粉或平平加O,或采用预媒染色,都不会改变茜草上染PA56的准二级动力学特征。

再生角蛋白凝胶对纺织退浆废水中浆料分子的吸附性能

为实现废弃角蛋白纤维资源的高值化循环利用,在采用“还原预处理-甲酸”溶解法获取角蛋白多肽并引入α-硫辛酸进行化学改性基础上,制备再生凝胶材料用于纺织退浆废水中浆料分子的吸附处理。借助扫描电子显微镜、傅里叶红外光谱等测试技术对角蛋白凝胶的结构和性能进行表征。针对聚乙烯醇(PVA)和淀粉2种浆料,探究凝胶对不同浆料分子的吸附规律及机制。结果表明:角蛋白凝胶具有均匀的三维孔隙结构,其化学组成和官能团结构与原纤维基本一致,且结晶程度较高;该凝胶对溶液体系中PVA分子的吸附量和去除率分别为16.278 mg/g和30.013%,对淀粉浆料则可达到133.234 mg/g和28.868%;此外,吸附动力学和热力学研究显示,角蛋白凝胶对2种浆料的吸附规律均符合准二级动力学模型,其中对PVA分子主要为物理吸附作用,而对淀粉则可能存在化学吸附效果。

姜黄素与木犀草素对蚕丝的拼色及功能改性

从姜黄中提取天然多酚类姜黄素化合物作为色素,对提取物进行结构鉴定和表征,并将其与木犀草素拼染,探讨了拼染的协同效应与机理。结果表明:姜黄提取物的主要成分为姜黄素类化合物;将其与木犀草素拼混对蚕丝织物进行染色,可呈现出与直接染色不同的黄色色泽;拼染蚕丝织物的各项色牢度可达3级以上;抗氧化、抗紫外和抑菌性能均有明显提升。1%(omf)姜黄素类化合物和2%(omf)木犀草素拼色染色的蚕丝织物抗氧化性达90%以上,UPF值为191.44,抑菌带宽度为0.45 cm以上。

多酚氧化酶催化马齿苋提取物对真丝织物的染色

为开发天然染料生态染色体系,选用漆酶、酪氨酸酶催化的马齿苋提取物对真丝织物进行染色。探讨生物酶种类、酶催化温度及染色参数对织物K/S值及色牢度的影响,综合运用多种表征手段分析染色过程及机理。结果表明,漆酶在40℃下催化提取物1 h即可提高织物的染色深度。在染色温度80℃、pH为7的条件下染色3 h,所得丝织物的K/S值为2.639,耐皂洗和耐摩擦色牢度达到4级及以上。漆酶催化提取物对丝织物的上染过程符合准二级动力学模型,属于化学吸附;电子鼻传感器响应雷达图显示提取物经漆酶催化后染得的织物散发出非常浓郁的芳香气味。