| In China,cotton fibre is the main raw material for the textile industry and is widely used in the medical and health care,textile and clothing industries.Most of the dyes used in textile printing and dyeing processing works are synthetic,which can cause environmental pollution and endanger human health.With the growing concept of sustainable development,the use of synthetic dyes has been restricted.Compared to synthetic dyes,natural dyes are more environmentally friendly.They are widely available,pose no health hazards,have little chemical reactivity,are biocompatible and also have certain health benefits.In recent years,natural dyes have also been favoured by researchers in the dyeing of cotton fabrics due to their excellent natural properties.F.Artemisiae argyi(FAA)as a natural dye,comes from the plant Artemisia absinthium.Artemisia annua is a wild perennial herb of the Asteraceae family,which is highly adaptable and has a wide distribution of resources.It also has a long history of medicinal use,with antibacterial and antiviral properties,and has potential applications in the functional finishing of textiles.The use of natural dyes has certain limitations when dyeing cotton fabrics.Because cellulose is negatively charged in aqueous solution and most natural dyes are anionic,there is Coulomb repulsion between negatively charged cotton fiber and dye anions,which makes it difficult for natural dyes to dye on cotton fabrics.The fabric has low dye absorption and low colour fastness.In order to overcome these shortcomings,the surface of cotton fabric was modified by green and environmental protection before dyeing with FAA natural dye.While the affinity between cotton fabric and natural dye,it was endowed with wettability,colour fastness and other functions(UV resistance,oxidation resistance and antibacterial properties)of cotton textile substrate.The main research contents and conclusions are as follows:(1)In order to optimise the extraction conditions and extraction efficiency of FAA dyes,a resource-saving and eco-friendly water infusion method was used for the rapid extraction of the pigments from FAA.The process parameters(ethanol content,extraction time,extraction temperature,solvent p H)affecting the extraction process were systematically investigated.The extraction of natural dyes from FAA was characterized and tested using UV absorption spectroscopy and Fourier transform infrared analysis(FTIR).The content of polyphenols and flavonoids in natural dyes of FAA extracted by three solvent systems: water/ethanol,water/ethanol/acid and water/ethanol/alkali,was determined by gallic acid and catechins equivalent method.The results showed that the best conditions for extracting the natural dyestuff from mugwort leaves are 50 % ethanol,a little acetic acid to p H=4 and a water bath at 80 °C for 70 min.Comparing the three solvent systems,the water/ethanol solvent system contained the highest amount of polyphenols and the water/ethanol/acid solvent system contained the highest amount of flavonoids.The use of eco-friendly reagents for the extraction solvents further optimised the eco-friendly extraction process of the FAA natural dyes.The analysis of the TG and DTG curves showed that the mugwort dyestuff had excellent thermal stability under the optimal extraction conditions,indicating that the dyestuff could be suitable for subsequent textile dyeing and finishing processes.(2)As a clean technology,ultrasonics has been widely explored in textile dyeing.Mordant dyeing process is usually to achieve efficient textile dyeing,but there are few reports on the application of ultrasound in mordant dyeing process.This part discusses the influence of ultrasonic chemical mordant dyeing on the subsequent fabric dyeing effect.Because of their natural compatibility and biological characteristics,soybean protein and wormwood leaf are used as mordants and natural dyes.The mordant dyeing effects of soybean protein under ultrasonic bath,traditional water bath and magnetic stirring bath were compared.Results showed that while soy mordanting in water bath can significantly increase fiber natural dye uptake,the dye affinity can be enhanced further when ultrasonic irradiation was applied.Ultrasonic mordanting was found to be able to produce higher fabric color strength(K/S)while consuming less soy protein when compared with other mordanting baths.Less weight increase as a result of ultrasonic irradiation can also provide cotton fabric with softer handle than those processed in traditional water bath.UV protection of dyed fabrics was found to be significantly improved from the control sample,with samples processed with ultrasonics showing the greatest improvement.In addition to improving the affinity of the dyestuff,this chapter successfully achieves an antibacterial functional finishing of the fabric.(3)Cotton is the most commonly used natural fiber with natural properties applicable to next-to-skin textile.This study uses plasma fiber surface modification with soy protein coating in an attempt to improve cotton natural dyeing ability and functional finish from herbal plant of FAA as source of natural dye and bio agent.Results showed that while soy coating alone can significantly increase fiber natural dye uptake,fabric dyeing ability can be enhanced further when plasma pretreatment was applied.When plasma pretreatment is applied to fiber surface and at a soy concentration of above 3%,traditional water bath coating can exceed ultrasonic bath in its effectiveness in attracting natural dye in the subsequent dyeing process.Plasma pretreatment followed by soy sonic coating can provide cotton with soft handle whilst achieving an improved color strength and UV protection.This study demonstrated a successful process of applying bio medicinal agent to cotton substrate,which can provide cotton with antioxidant properties and super powerful antibacterial(against S.aureus)ability with bactericidal rate of 95-100%.The strong antibacterial activity can remain as powerful after 8 month of storage.All materials used in this work are natural based and are within easy access.The main achievement of this study is that by using low cost natural compatible materials and green surface modification,traditional cotton material can widen its way in practical medical/healthcare application.(4)FAA is rich in biologically active components and its potential as a natural dye for functional finishing of textiles has not been fully exploited.Wool,silk and modified cotton were dyed using FAA natural dyes.The performance of the dyed and finished textiles was evaluated by testing the colour depth(K/S),L* a* b* value,Colour fastness,UV resistance,antioxidant properties and antibacterial properties of the samples.In order to evaluate the storage stability of the natural dyes of FAA,the textiles were tested after 8 months for a range of functional changes.The results show that the colour properties of the wool and silk fabrics are better than those of the modified cotton fabrics,as they are protein-based fibres.All dyed fabrics specifically had good UV protection,anti-oxidation and anti-bacterial properties.The functionality of the dyed fabrics remained largely unchanged after a period of storage.It is worth noting that textiles dyed and finished with natural dyestuff of FAA exhibit excellent durable antibacterial properties and even improved antibacterial properties. |
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