The textile industry is witnessing a paradigm shift towards sustainability to circumvent ecological dilemmas and human health jeopardies arising from textile processing. Therefore, the review paper herein focuses on the role of green chemistry in synthesizing the natural biological pigments and biomordants for textile substrates such as Sarsasapogenin and soyasaponin from areetha nut extract. Concurrently, the overview aligns the data on the chemical characterization of these plant-based renewable pigments for textile processing that is chlorophyll, carotenoids, flavonoids others. Likewise, the subtle and vital role of bioactive biological compounds in plant pigments for functional textiles applications for example antibacterial, analgesic, and more is succinctly accentuated. The review paper identifies the substantial surplus reserve of plant-based materials that could be conserved for sustainable implications in the textile field. However, there is a prodigious scope of research and development in the same and therefore concludes by citing the multi-disciplinary research as future work to mitigate declared climate emergency for international thrive ability. Likewise, the responsibility of conserving biodiversity, adhering to sustainable development goals, and cradle-to-cradle theories are reinforced in the review paper.

Keywords: Green chemistry, Biological pigments, Bioactive, Functional fabrics, Sustainable textiles.

Climate emergency and human health perils from textile emissions and effluents Today a well-organized and established textile pigment and dye industry exist. However, there are environmental and human health hazards associated with it namely, the emissions of volatile organic compounds (VOCs), Chlorofluorocarbons (CFCs), greenhouse effect gas emissions namely sulfur dioxides and nitrogen oxides. The accumulative consequences are global warming, ozone layer depletion, summer smog, and acid rain which damage vegetation and aquatic life [1]. Ellan MacArthur Foundation affirms that the Emissions from the textile industry alone amounted to 98 million tons of carbon footprints in 2015 and the projected upraise is 300 million tons by 2050; refer to [Figure 1] [2].

Figure 1: Emissions from the Textile industry [4].

Greenpeace international initiated Detox My Fashion campaign in 2011 to ensure that the clothing was free from hazardous chemicals from make to finish. They promulgate transparency from manufactures to be evident to the consumers. Greenpeace International in collaboration with zero discharge of all hazardous chemicals (ZDHC) painstakingly works towards a clean process and safe chemistry [3] The Greenpeace International research findings concluded that the Citarum river, refer to [Figure 2], has chromium and copper-containing dyes of 0,005 mg/l and heavy metals from textile mills resulting in low levels of dissolved oxygen (DO) in the water of 2.45 mg/l. The minimum required DO is 4 mg/l to sustain aquatic life [5]. It took a heavy toll on aquatic life with 60% of fish dead also affecting surrounding flora and fauna. Even more, Greenpeace International investigations on wastewater samples from rivers around textile manufacturing and washing companies in Indonesia and Mexico have revealed the presence of detergents and surfactants 2,4,7,9-tetramethyl-5-decyne-4, 7-diol (TMDD), Nonylphenol (NP), and Nonylphenol ethoxylates (NPEs). These surfactants persistently contaminate the aquatic environment with hormone-disrupting properties [4].

Figure 2: Citarum river water coloured with unsafe textile dye chemicals waste seepage [3].

The well water near Citarum contains 4 times more mercury than recommended safe levels. The effluent water drinking, bathing, and working therein must be the foremost cause of the growing rate of cancer, mental illness, growth inhibition among children, and skin diseases among natives [6]. Also, the European Chemicals Agency (ECHA) and U.S. Environment Protection Agency (EPA) have stringently scrutinized the suspected carcinogens such as synthetic colourant aniline ‘Indigo’, textile additive titanium dioxide, and featured them under the restricted chemical lists (RSLs). They cause skin cancer and skin allergies associated with hypoxia and are toxic to marine life [7]. The clothing being second skin is exposed to textile dyes and additives that are cytotoxic, carcinogenic, genotoxic, and mutagenic causing DNA damage [8].

Greenpeace detox fashion agenda is dedicated to rehabilitating textile toxicity to the environment and human health, refer to [Table 1] for the Manufacturing Restricted Substances List or M-RSL by Greenpeace International, Germany, herein the focus is to substitute and eliminate the top eleven massively hazardous chemicals from the supply chain to mitigate the appalling harm done by the chemicals onto the environment and human health alike [3]. However, not all the synthetic is appalling or could be replaced, those from which, as listed in the M-RSL, resulting in enormous pollution and health problems require to be substituted. The negative impacts of overconsumption, over industrialization, and non-biodegradability due to fossil-based materials in the textile chain is to be addressed. The bio mimicry - and inspirations from nature, could greatly help us in the same.

Table 1: The Manufacturing Restricted Substances List or M-RSL by Greenpeace International [3].

Likewise, due to ozone depletion UV rays are causing skin ailments such as allergies, aging, carcinogenesis, and erythema [9]. Therefore, the Ultraviolet Protective Factor (UPF) of the fabric is calculated; refer to [Table 2]. The Ultraviolet Radiations’ (UVR) are electromagnetic radiations up to 400 nm, they are divided into 3 as per their strength, UVA (315-400 nm), UVB (280-315 nm), and UVC (100-280 nm). UVC and UVB (90%) are absorbed by the ozone layer, water, carbon dioxide, and oxygen in the stratosphere. Therefore, UVB (10%) and UVA reach the earth [10]. They pierce through the human skin and can prove to be detrimental. Ozone depletion has accelerated this process. Textile emission and effluents provide the momentum to ozone depletion. Therefore, it is essential to refute the dangers arising from the textile industry.

Table 2: The ultraviolet protection factor (UPF) [10].

Concurrently, textile materials are vulnerable to microbial bouts as they provide enough surface area and absorb moisture vital for bacterial colonies to multiply. Cellulosic and protein (keratin) fibers provide the indispensable elementary necessities of dampness, oxygen, food, and temperature for bacterial growth and reproduction. These bacteria proliferate repeatedly leading to the unpleasant odor, dermal contagion, product corrosion, allergic comebacks, and other associated ailments [11]. The expansion of eco-friendly and safe to humans, antimicrobial fabric finish is exceedingly vital as clothing stay in direct contact with the human body. The anti-microbial textile application would render the resultant cloth resistant to bacteria, fungi, and yeast attacks. Therefore, enhancing the fabric functionality, visual appeal and medicinal endue of the cloth. It would prevent the biodeterioration of the fabric due to mildew and mold growth and create a protective shield against bed bugs [11].

To render the textile substrate functionally protective against microbes’ wide range of textile goods such as synthetic antimicrobial agent’s triclosan, metallic salts, phenols, and quaternary ammonium compounds are commercially marketed. However, they are not ‘hygienic’ and cause negative side effects. Thus, alternative plant-based biomaterials are sought-after for antimicrobial applications. The natural chitosan and natural dyes are widely utilized for the same. Additionally, herbal extracts namely, aloe Vera, neem, tulsi leaves, tea tree oil, eucalyptus oil are utilized. An upsurge in plant-based bioactive components has opened new boulevards in this area of research for textile healthcare applications [11].

Plant-based bioactive antimicrobial coatings for cotton fabrics are an evolving technology in the production of medical clothes. They impart colour to the fabrics along with functional property. The pigments could be extracted from fungi and bacteria for colouration however they do not impart any functional property to the substrate. There is a huge proportion of humanity on earth they are religiously and ethically prohibited from the killing of any form such as Hindus, Jains, and Buddhists in India following the principle of Ahimsa. These sects could not favor microbial-coloured textiles for example red colour obtained from chiodectonic acid from lichens on textiles or bacterial enzymatic processing of textiles with laccase, amylases others. Hence, the plant-based renewable and exotic colorations would be a good natural alternative [12].

Rationally the synthesis of the literature review distills that the effect of the textile industry on the global environment and human health is an accumulative effect of the chemical, material, process, design, and product life cycle associated with it. Therefore, to mitigate the same the paper emphasizes an inter-disciplinary research approach for holistic sustainable outcomes. Also, in compliance with the above apprehensions, the overview reinforces the role of biological bioactive pigments for sustainable and functional textiles. Cohesively, the role of green chemistry is accentuated. The relevant and recent research studies are cogently cited to justify the same. Likewise, on critical analysis, the identified gaps in knowledge are intermittently specified as anticipated for future work.

Sustainable Measures

There are manifold strategies adopted by the textile research and development segment for an imperative shift towards sustainable alternatives for global benefits. In this overview, the approaches most relevant to the topic are discussed as follows.

Green chemistry

The United States Environment Protection Agency (EPA) defines green chemistry or sustainable chemistry as the strategy for chemical substances and methods to decrease or remove the usage and production of harmful elements. It mandatorily covers the entire life cycle of a chemical material. Green chemistry principally involves exerting at the iota scale of chemistry across all disciplines including textile chemistry. Green chemistry originates from the Pollution Prevention Act of 1990 in the USA and primarily emphasizes source reduction [13].

The twelve ideologies contented by Sustainable green chemistry are listed herein [13].

• Generate no waste material.
• Utilize the whole of the chemical.
• Produce no toxic chemical.
• Synthetizes safe chemical.
• Utilize safe additives and auxiliaries.
• Perform reactions at room temperature and pressure.
• Utilize renewable raw materials.
• Eliminate modifications and postulates.
• Utilize catalysts.
• Design degradable chemicals at the molecular stage itself
• Analyze on time and remove the formation of lethal by-products.
• Analyze, foreknow and eliminate the chemical accidents potentially poisonous to the environment and human health.

The research studies cited hereafter represent plant-based green chemistry in textile processing that would prodigiously propel the sustainability agenda with functional textiles. For example, herbal saponins from Areetha nut and Shikakai would be a sustainable alternative that would benefit the textile manufacturing and washing companies, refer to [Table 3]. They are not only biodegradable and renewable sources of surfactants, but also aromatic, soft to the skin, and functionally healing as investigated by Thakker, refer to [Figures 3 and 4] illustrating green chemistry [14].

Table 3: Bioactive herbal saponins from areetha nut and Shikakai for sustainable and functional textiles [Thakker A].

Figure 3: Functionally efficient saponins from areetha nut and shikakai extracts [14].

Figure 4: Functionally efficient saponins from Areetha nut and Shikakai extract [14].

Concurrently, an inter-disciplinary study is envisaged wherein the author investigates on anti-microbial and anti-fungal properties of banana, bamboo, and merino wool fibers treated with natural biomaterials Syzygium aromaticum (Cloves), Curcuma amada (Mango ginger/Amba Haldi), and Juglans nigra (Walnut leaves) for prospective implications in medical textiles and day-to-day protection from ubiquitous pathogens. The three herbs in research are hypothesized to be strongly functional and aromatic. They also impart colour to the fibers as shown in [Figures 5-8] [15]. The sustainable chemical structures of bioactive chemical components that impart functional properties and coloration to textiles substrates are also illustrated below [15].

Figure 5: Original fibers – (a) Merino wool, (b) Banana and (c) Bamboo [15].

Figure 6: (a) Merino wool, (b) Banana, and (c) Bamboo fibers treated with an anti-microbial extract solution of Syzygium aromaticum and its bioactive chemical structures [15].

Figure 7: (a) Merino wool, (b) Banana, and (C) Bamboo fibers treated with an anti-microbial extract solution of and Curcuma amada and its bioactive chemical structures [15].

Figure 8: (a) Merino wool, (B) Banana, and (C) Bamboo fibers treated with an anti-microbial extract solution of and Juglans nigra and its bioactive chemical structures [15].

Significantly biomordants are the subject of profound interest in recent times to meet up to the sustainability criteria and accomplish as safe additives for herbal colouration. This would avert the depletion of mineral ores. The cited studies manifest it. Manimozhi and Kanakarajan, utilized eco-friendly natural dye Torenia spp. Bark, refer to [Figure 9] and likewise sustainable biomordant tannin obtained from Peltophorum pterocarpum bark and Tamarindus indica seed coat for silk yarns colouration. The optimum dye extraction was obtained at room temperature at neutral pH. An increase in temperature made the pigment unstable disintegrating it from violet to pale brown colour. The dye exhaustion percentage as determined on UV-visible spectrophotometer was calculated as given in Equation 1 below [16].

Wherein E% is the dye exhaustion percentage, A0 is the absorption of dye before colouration, and A1 is the absorption of dye after dyeing. The coloured silk yarns were examined for perspiration fastness by ISO 105 E04-2013 test method. Likewise, light fastness and wash fastness were investigated by ISO 105 B02-2013 and ISO 105C-06-2010 test methods, respectively [16]. Silk yarns before and after dyeing with Torenia sp Bark wherein (a) Tamarindus indica seed coat tannin mordanted (b) Peltophorum pterocarpum bark tannin mordanted are given in figure 10. The best dyeing was obtained at 50?C, at pH 9, for 30 minutes at a material to liquor ratio of 1:20 as given in [Figures 10 and 11] [16].

Figure 9: Torenia sp bark for natural dyeing of silk yarns [16].

Figure 10: Silk yarns before (a) and after natural dyeing (b) with Torenia sp bark [16].

The phytochemical analysis of Torenia sp Bark extracts solution revealed the presence of Alkaloids, Glycosides, Carbohydrates, Proteins and Amino acids, Phenols, Flavonoids, Tannins, and Terpenoids. Thin-layer chromatography parted anthocyanin violet pigment at a retention value (RF) of 0.88.

Figure 11: Effect of pH on the Torenia sp Bark dye uptake on bio mordanted silk yarns [16].

The UV-spectral analysis showed the highest peaks at 604 nm which corresponds to the violet band of colour. The colour imparting part of the iota is called a chromophore. The functional group attached to the chromophore is called auxochrome [16]. The FTIR analysis of the extract identified the functional -OH hydroxyl groups broad peak at 3400-3600 cm-1 it is an auxochrome. The C=C, C=O, and CH aromatics ring peaked at 1553 cm-1, 1627 cm-1 and 2930 cm-1 respectively. A good wash, light, and perspiration fastness were obtained on Torenia dyed silk yarn’s biomordanted with Tamarindus indica seed coat tannin mordanted as compared to Peltophorum pterocarpum bark tannin biomordanted silk yarns [16].

The above-mentioned study is an appropriate example of an ecological approach for sustainable textiles with green chemistry. The research experimentation involves eco-friendly herbal materials and is low on energy and water demand as optimal extraction and dyeing are obtained at relatively low temperatures and material to liquor ratio. However, the research is limited in approach as it does not elaborate on the functionality of the obtained fabrics. The green colour was obtained on the silk yarns as shown in Figure 10, however, the scientific characterization of colour including the calorimetric values remains to be evaluated. Similarly, Lohtander, Arola, and Laaksonen dyed microcrystalline cellulose (MCC), and Lyocell types Ioncell-F (IC) fibers with willows bark extract solution (WBE). Carboxylic acid-containing biomordants namely tannic acid, citric acid, and oxalic acid have experimented with metallic mordant alum as standard, refer to [Figure 12] [17].

Figure 12: Dye exhaustion percentage of Willow bark extract on MCC and IC fibers [17]. The polyphenolic dye demonstrated a higher dye exhaustion percentage of 50-80 % on MCC fibers as compared to 44-57% for IC fibers, refer to figure 12. Also, MCC fibers dye uptake was enhanced with biomordants than the standard metallic mordant alum however the opposite trend was observed for IC fibers. However, there is no account of the fastness and functional properties in the given study. The MCC fibers (Top row) and IC fibers (Bottom row) dyed with willow bark extract solution are presented in [Figure 13] [17].

Figure 13: MCC fibers in the top row and IC fibers in the bottom row, dyed with Willow bark natural dye [17].

Interestingly Singh et al. performed pre-mordanting of wool fabric with biomordant tannin extracted from the tamarind seed coat and naturally coloured it with kapok flower extract. The fabric-biomordant-dye complex formation is given in [Figure14].

Figure 14: Wool peptide-tannic acid hydroxyl-anthocyanin hydroxyl complex formation [18].

The K/S colour measurement was calculated with Equation 2 as follows [18].

Wherein K/S is the ratio of the absorption coefficient to the scattering coefficient, and R is reflectance. The anti-bacterial functional property of the resultant fabric was calculated with Equation 3 as follows for E. coli and S. aureus strains of gram-negative and gram-positive bacteria, respectively [18].

The antioxidant functionality of the end fabric was determined in terms of radical scavenging activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay method, refer to [Table 4] [18]. Tannin-mordanted wool fabrics demonstrated a fastness rating of 4-5 for both wet-dry rub and wash fastness property. Also, an excellent light fastness rating of 5 was obtained on the biomordanted wool fabrics [18]. Wool fabric samples were treated with 30 % kapok Bark dye extract for anti-bacterial assessment. The anti-bacterial evaluation is given in [Table 5] [18].

    Table 4: Antioxidant activity % of the untreated and treated wool fabric samples [18].

Table 5: Anti-bacterial activity of tannin and kapok flower extracts treated wool fabric samples [18].

The bacterial reduction percentage of 99.87 % and antioxidant activity of 94.55 % were observed, refer to Tables 4 and 5 respectively. Therefore, kapok Bark extract coloured wool fabrics pre-mordanted with tamarind seed coat extract tannin were concluded to be sustainable and functionally efficient fabrics. Further investigation with regards to life cycle assessment would be valuable [18]. Also, Pinheiro et al. investigated Acacia mearnsii sawdust as a biomordant for colour fixation on banana fibers naturally coloured with Camellia sinensis, Hibiscus sabdariffa, and Curcuma longa [19]. The banana fibers were cold biomordanted for 24 hours and were left for 12 hours in each natural dye bath at room temperature for colouration. The banana fibers biomordanted with Acacia mearnsii had high colour intensity as compared to banana fibers mordanted with alum and Acacia mearnsii as remarkedly indicated in [Figures 15 and 16] each coloured with natural dye Hibiscus sabdariffa and Curcuma longa.

Figure 15: Demonstrate banana Prata fibers (a) mordanted with Alum and Acacia Mearnsii (b) biomordanted with Acacia Mearnsii and coloured with natural dye Hibiscus sabdariffa [19].

Figure 16: Demonstrate banana Prata fibers (a) mordanted with Alum and Acacia mearnsii (b) biomordanted with Acacia mearnsii and coloured with natural dye Curcuma longa [19].

The study devised a sustainable biomaterial and ecological processing with natural colouration. However, details with regards to dye exhaustion percentage and calorimetric values remain to be diagnosed. The wash, rub, and light fastness are yet to be measured. Also, the chemical and ecological characterization would propel commercial applications as synthesized above the green chemistry is an imperative aspect for future sustainable textiles [19].

Currently, to meet the zero emissions and zero effluents target set by “Registration, Evaluation, Authorization & Restriction of Chemicals” (REACH) and “U.S. Environmental protection agency” (EPA) for 2050, and “Sustainable Global Development Goals” (SDG’s) agenda, refer to [Figure 17], set by UN for 2035, these governing bodies encourage the plant-based textiles additives and colourant to be utilized for sustainable global textile future. Successively, 11% of market growth demand for natural dyes, pigments, and additives is predicted for 2025 [20].

Figure 17: Sustainable development goals (SDGs) [21].

Cradle to Cradle® theory postulated by Professor. Michael Braungart, William McDonough, and EPEA Hamburg in the 1990s promulgate ecological footprints in the Biosphere and Techno sphere, a remarkable step towards sustainable textiles; refer to [Figure 18] [22].

Figure 18: Cradle-to-cradle theory [22].

The product standards are assessed in 5 groups namely [22]: Material safety Energy consumption Water utilization Social fairness Recyclability Smart chemistry with character (CHT) group of companies emphasizes sustainable solutions for textile productions, finishing, and care. They provide a range of textile auxiliaries, dyes, and pigments that are cradle-to-cradle certified. For example, their Bezema range of colors for textiles is claimed to be highly exhaustive with excellent fastness properties. They require minimum input of water, energy, and electrolytes. They are suitable for cellulosic fibers and their blends. However, their origin and composition are not evident to consumers [23]. Similarly, herbal materials adhere to cradle-to-cradle theory in every aspect as discussed herein.

Plant-based renewable materials for textile applications

The review paper concentrates on herbal biomaterials for application on natural textile substrates for colouration and or functionality as discussed henceforth.

Carotenoids, any of a class of mainly yellow, orange, or red fat-soluble pigments, including carotene, which gives colour to plant parts such as ripe tomatoes and autumn leaves. They are terpenoids based on a structure having the formula C??H??. Carotenoids are characterized chemically by a long aliphatic polyene chain composed of eight isoprene units [27,28]. The main constituent is crocetin in saffron, refer to [Figure 21], gardenin in cape jasmine, refer to [Figure 22], bixin and norbixin in annatto, curcumin in turmeric others are exemplars of highly prevalent carotenoids [25]. Also, refer to [Figure 28].

Flavonoids, any of a large group of typically biologically active water-soluble plant compounds (such as the anthocyanin’s and flavones) that include pigments ranging in color from yellow to red to blue and occur especially in fruits, vegetables, and herbs (such as grapes, citrus fruits, peppers, and dill), also flavanols are any of the various hydroxy derivatives of flavone [27,28]. Yellow dye plants belonging to the flavonoid group are rabbit bush accumulating flavonoids aglycones, tickseed contain flavonoid colourants aka anthochlors occurring in pairs of chalcones and aurones. For the chalcones, these are coreopsin, a butein glucoside, marein, refer to [Figure 23], and lanceolin. The aurones are sulfurein, a sulfuretin glucoside, maritimein, a glucoside of maritimein, and leptosin, a glucoside of leptosidin, refer to [Figure 24] [25]. Also, refer to Figures 29 to 70 and Figures 80 to 83. Red, blue, purple, and violet dye plants belonging to the flavonoid group are anthocyanin and anthocyanidins.

Anthocyanins, a plant pigment (as cyanidin, delphinidin, or pelargonidin) formed by the hydrolysis of anthocyanin and characterized by the same ring structure as the flavones and flavanol’s but having no ketone group [27,28]. Roselle calycle’s yield red anthocyanins Hybiscin and gossypicyanin as illustrated in [Figures 25 and 26]. Also, refer to Figures 71 to 79.

Quinones, either of two isomeric cyclic yellow, orange, or red crystalline compounds that are derivatives of benzene with chemical formula C?H?O? [27,28] for example, safflower containing carthamin [25]. Refer to Figures 84.

Benzoquinone, a yellow crystalline quinonoid compound related to benzene but having two hydrogen atoms replaced by oxygen with chemical formula C?H?O?. There are two isomers, with the oxygen atoms on the opposite (1, 4-benzoquinone) or adjacent (1, 2-benzoquinone) carbon atoms [27,28] for example, Echinofuran B and C [25]. Refer to Figures 85, 86, and 87.

Naphthoquinones, each of six isomeric compounds with chemical formula C?? H? O?, notionally obtained by replacing two of the ?CH groups of naphthalene by carbonyl groups, specifically (more fully "1,4-naphthoquinone", "α-naphthoquinone") for example the shikon roots contains naphthoquinones violet pigments in high proportions. The chief colourant present is the dextrorotatory optical isomer of alkannin and shikonin, refer to Figures 88 to 108 for chemical structures of naphthoquinones.

The biological pigments detailed herein are bioactive and therefore functional. The encompassed therapeutic and healing benefits could be entrapped within the microfibrillar fabric structure and transferred onto the wearer. [Table 6] further characterizes the plant pigments with their chemical structures with an emphasis on the application of natural fibers for functionality. The further characterization of the biological pigments for textile application would be covered in another part of the paper in the future.

Table 6: Biological pigments in plants for functionality on natural textile substrate [25,26,29,31].

The table enumerates circular materials that propel zero carbon footprints [32]. It is imperative to utilize surplus, therefore, protect the ecosystem and regenerate the surplus for applications on textiles.

Sustainable – the new normal was first defined by our common futures in the 1987 Brundtland report on environment and development: "Sustainable development is the development that meets the needs of the present without compromising the ability of future generations to meet their own needs."[35]. The overview presented here emphasizes the same. Sustainable-the new normal was first defined by our common futures in the 1987 Brundtland report on environment and development: "Sustainable development is the development that meets the needs of the present without compromising the ability of future generations to meet their own needs."[35]. The overview presented here emphasizes the same.

Conclusion

To sum up, in November 2018, the UK declared a climate emergency. The intention is to make it motion-led than just legislative, with the target of going down to net-zero carbon emissions. United Kingdom Climate Projections [UKCP18] ecological forecast demonstrates significant climate shifts, for example, a 5.4? increase in summer temperatures by 2070, 50% chances of hot summers by 2050, as experienced in 2018, and 1.15 meters increase in sea levels of London by 2100. We are almost there to experience intense floods, heat waves, erosion, volcanoes, and hurricanes in short timescales from now. A worldwide collaborative approach as devised by SDGs would provide resilient strategies to combat the global climate crisis and protect mother earth. UK’s net-zero GHG (Greenhouse gases) and F-gases (Fluorinated gases) target area 2050 and Scotland are 2045 [36]. Concurrently, microfibres and microplastics are hidden culprits. Microfibres, as defined by the textile institute, are a fiber or filament of linear density below 1 decitex. Research from the Coastal Ocean Research Institute in Vancouver revealed 878 tons of textile microfibres washed into North America waterways every year from day-to-day laundering clothes. Wastewater treatment plants (WWTP) strains 99% of these pollutants as sewage sludge. They are spread onto the farmlands and find their way into the human food chain. A similar applies to microplastics. Research scientist at Plymouth University UK, fathomed 1/3rd of the fish studied with at least 1 microplastics. The 75% of which was synthetic derived PET fibers, within their gut. Canadian scientists found aquatic zooplankton-consuming microfibres in the North Pacific Ocean. The Salmon in British Columbia feeds on this zooplankton with pollutants [37]. Figure 34 Illustrates PET microfibre effluent anarchy [2].

A review synthesized above distills that the aftermaths experienced as above are the cumulative effects of predominately materials and chemistry interacting with the environment and humans therefore bringing together the corresponding field to combat the crisis arising out of it would be copiously essential and beneficial. Hence the relative inter-disciplinary research studies are highly recommended at international, national, and individual levels. The aforementioned examples cited cohesively adjoin the field of textiles, environment, technology, and medicine to resolve the conflicts for holistic affirmative outcomes.

Future work

To refute the existing challenges as discussed above the future research and developments cohort their lens to align as elaborated ahead for sustainable and functional outcomes.

DuPont, Lenzing, and others have aligned their lens to integrate sustainability with performance textiles. Wherein clothing enhances the wellbeing by infusing nutrients to the wearer by the bio-delivery mechanism of the fibers. Cited here are recent inspirations from nature implemented for functional eco-smart textiles, Cannabidiol [CBD] is a marijuana plant extract infused in Acabada, USA, Proactive Wear range of women’s sportswear by microencapsulation. The bioactive hemp plant phytochemical Cannabidiol interacts with the human body system and induces relief from pain and insomnia. It has anti-inflammatory properties that speed up recovery after exercise. Technically 25 g of CBD is infused in the sportswear garment and is designed to withstand 40 wear and wash cycles, thereafter they can be up cycled [38]. Successively, research is envisaged to investigate the herbal bio-ink formulations with healing properties for printing cotton fabrics. Wherein the Cotton, Wool, and Bamboo fabrics would be printed with innovative herbal inks with digital ink-jet printer Epson sure colour P600. The printed fabrics would be tested for their anti-microbial efficiency against gram-positive and gram-negative bacterial cultures. Fourier-transform infrared spectroscopy (FTIR) would identify the peak intensities to magnify the healing bio-active components present in bio-inks. Thus, the objective to make our day-to-day textiles functional and protective against pathogens would be accomplished in an innovative and eco-friendly mechanism, refer to Figure 35. The research herein impels textiles circular economy and multi-disciplinary research for global sustainable Thriveability, the said aspects are elaborated further.

Biomimicry

Biomimicry an inspiration from nature would assist in solving problems to meet the “needs” sustainably it impels plant-based renewable sources to circumvent depleting fossil fuels creatively and harmoniously. In the words of Sir A. Einstein, “Look deep into nature and you will understand everything better”. A lot is derived from the ancient traditional knowledge of healing from plant-based resources from nature and replanting them for protecting biodiversity, accentuating the saying “From nature back to nature”. And with inspiration from Sir Hippocrates appropriately goes the quote, “Let clothes be the medicine, let medicine be the clothes”. Therefore, for the future, it is suggested to perform multidisciplinary and nature-inspired research and development for sustainability in future fashion factories.

Disclosure Statement

No potential conflict of interest was reported by the author.

Orchid: https://orcid.org/0000-0001-7084-1639

The author is grateful to the anonymous funder for sponsoring sustainability-based research for global cause and benefits.

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Corresponding author: Alka Madhukar Thakker, School of Textiles and Design, Heriot-Watt University, United Kingdom.

Copyright: © 2021 All copyrights are reserved by Alka Madhukar Thakker, published by Coalesce Research Group. This work is licensed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.