Development Of Natural Plant-based Mordant And Its Applications In Wool Dyeing And Functional Finishing

The application of natural dyes can be traced back to the caveman period,which has a long history.However,since the emergence of synthetic dyes in 1856,natural dyes have been gradually replaced by synthetic dyes because of their advantages of complete chromatography,bright color,excellent color fastness and low price.With the gradual improvement of people's demanding for the good environment and health,synthetic dyes because of their toxicity,some synthetic dyes also have carcinogenic,to distortion and other hazards,so that natural dyes return to people's attention.Natural dyes have the advantages of low toxicity,renewable,unique color,wide source and functional,etc.However,in the dyeing process of natural dyes,due to low dyeing rate,it is necessary to add mordant.The commonly used mordant is metal mordant,such as chromium ion plasma is harmful to the environment and human health,not in line with the original intention of environmental protection.Therefore,in order to solve this problem,three natural mordants were selected from agricultural and forestry wastes,and functional finishing was carried out on textiles.The main research contents and conclusions are as follows:1?This study presents an environmentally benign bioactive finishing of wool fabric via the use of unexplored tannin-rich waste/fallen leaves extract of Chinese tallow/Sapium sebiferum L.through simple adsorption technique.Simple aqueous extraction followed by the evaluations of build-up properties on wool fabric using Chinese Tallow(CT)leaves extract were studied in due course of this study.Optimization of extraction and dyeing variables/conditions such as p H,temperature,CT concentration,and time were conducted using UV-Visible and reflectance spectral method.The nature of functional groups of the extracted dye were investigated through FT-IR spectral analysis with further in deepth thermal analyses using TG and DSC measurements.Additionally,the extracted dye was subjected to quantitative analytical tests to check the relative amounts of total phenolics and flavonoid with respect to gallic acid and catechin equivalents,respectively.Build-up properties and fastness characteristics were studied in the presence and absence of mordants(two metal and one biomordant)under corresponding ISO standards.Results showed that wool fabric treated with CT leaves extract exhibit excellent antioxidant activity,good UV protection and high antibacterial activities against E.coli and S.aureus.The use of biomordant to alter the functional properties provide an eco-friendly method for wool finishing.In general,the treated wool fabric in this work has shown a promising future for the preparation of health and hygiene-related textile materials.2?Folium artemisiae argyi(FAA)leaves have a long history of usage as food colorant throughout China but its usage as a bio-colorant for textile substrates has not been fully exploited yet.The present research focused on the extraction of functional components from FAA leaves and their applications for simultaneous coloration and biofunctionalization of wool fabric.Examination of different extracting solvents(Ethanol/water combinations),identification and stability of color components using UV-Visible,FT-IR,TG and DTG;and examination of dyeing methods were successfully carried out during the course of this work.Additionally,the dye extracted in different solvent systems were subjected to total phenolics and flavonoid content analysis and expressed as gallic acid and catechin equivalents,respectively.The different solvent extracts(50%aqueous ethanol in conjunction with small amounts of acid and alkali)gave maximum biocolorant yield at 80 ^oC for 60 min.Wool fabric dyed in different solvent systems gave different colors with good washing fastness.The inadequate fastness characteristics were evidently ameliorated by premordanting with Fe²⁺and Al³⁺salts.An adequate amount of FAA leaves extract on wool fabric exhibited good UV protection and antibacterial behaviors.Premordanting enhanced UV protection,antibacterial and antioxidant behaviors of dyed wool fabric.Wool fabric treated with FAA leaves extracts exhibited diverse color variations(such as green color with alum mordant)and proved great potential for industrial application as a source of natural bio-colorant,as well as a value-adding application for the plant in addition to its normal usage as a food colorant.3?As agricultural waste,fruit seeds have received little attention in producing natural colorant for textile dyeing application.This work uses Eriobotrya japonica L.seed skins(EJSS)as source of natural dye for the coloration and bio-functional finishing of wool fabric.Investigation has been made to the optimal extracting conditions(such as solvent system,p H,temperature and time)and natural dye characterization(chemical components,surface morphology,and thermal stability)using UV-Visible,FT-IR,SEM,EDS,TG and DSC.Flora leaves of C.Tallow,F.Artemisiae Argyi and C.Camphora were used to produce bio-mordants in this work.Pre-mordant fabric dyeing was conducted with comparisons made between bio-mordants and traditional metal ion mordants(ferrous sulfate,potassium aluminium sulfate,and copper sulfate).Results showed that pre-mordant dyeing using EJSS natural dye can produce wool fabric with a variety of shades with enhanced color strength,color fastness,and bio-functions(such as UV protection,antioxidant and antibacterial properties).Fabric mordanted with tannin-rich bio-mordant showed the best color strength and excellent functional behavior due to the high interaction between fiber and dye molecules activated by functional groups(such as phenolic groups).The outcome of this study can provide a potential to the application of agricultural waste to the natural dyeing of textile,as well as to a value-adding green waste management.4?The present study describes the potential use of biocolorants from Ginkgo biloba waste/fallen leaves to develop colored UV-protective and antibacterial wool fabrics in view of growing environmental pollution and to reduce the dependency of textile industry on synthetic antibacterial agents.This study presents a novel method to counteract the growing antibiotic resistance by using G.biloba leaves extract in conjunction with ampicillin against potent gram-negative bacterial strains.Natural colorants were extracted from the powdered waste leaves of G.biloba in 50%aqueous ethanol at 70 ^oC for 60 min under acid conditions of p H 3.Qualitative identification(UV-visible and FT-IR)and thermal stability(TG)of the extracted dye was carried out in due course of this study.The optimal dyeing conditions,dye adsorption(Isotherm parameters),and dye performances were also reported in this study.Pseudo-second order and sips isotherm model provided best fitting of experimental data with high regression coefficient(R²=0.99).Build-up properties and fastness characteristics were studied in the presence and absence of mordants under corresponding ISO standards.A comparative analysis was done regarding the use of metal and biomordants for altering the fastness and functional properties.An adequate amount of G.biloba waste leaves extract on wool fabric exhibited good UV-protective and antibacterial behaviours.Antibacterial potential of G.biloba natural dye was enhanced in combination with ampicillin showing synergetic interactions with significant reduction in the corresponding MIC values.Premordanting with metals salts(Fe²⁺,Al³⁺,and Sn²⁺)demonstrated negative effects on the corresponding functional finishing properties,whereas biomordants showed enhanced UV-protection and antibacterial properties.