Fastness Properties Research Articles

Dynamic Metal-Coordinated Adhesive and Self-Healable Antifreezing Hydrogels for Strain Sensing, Flexible Supercapacitors, and EMI Shielding Applications.

Dynamic metal-coordinated adhesive and self-healable hydrogel materials have garnered significant attention in recent years due to their potential applications in various fields. These hydrogels can form reversible metal-ligand bonds, resulting in a network structure that can be easily broken and reformed, leading to self-healing capabilities. In addition, these hydrogels possess excellent mechanical strength and flexibility, making them suitable for strain-sensing applications. In this work, we have developed a mechanically robust, highly stretchable, self-healing, and adhesive hydrogel by incorporating Ca2+-dicarboxylate dynamic metal-ligand cross-links in combination with low density chemical cross-links into a poly(acrylamide-co-maleic acid) copolymer structure. Utilizing the reversible nature of the Ca2+-dicarboxylate bond, the hydrogel exhibited a tensile strength of up to ∼250 kPa and was able to stretch to 15-16 times its original length. The hydrogel exhibited a high fracture energy of ∼1500 J m-2, similar to that of cartilage. Furthermore, the hydrogel showed good recovery, fatigue resistance, and fast self-healing properties due to the reversible Ca2+-dicarboxylate cross-links. The presence of Ca2+ resulted in a highly conductive hydrogel, which was utilized to design a flexible resistive strain sensor. This hydrogel can strongly adhere to different substrates, making it advantageous for applications in flexible electronic devices. When adhered to human body parts, the hydrogel can efficiently detect limb movements. The hydrogel also exhibited excellent performance as a solid electrolyte for flexible supercapacitors, with a capacitance of ∼260 F/g at 0.5 A/g current density. Due to its antifreezing and antidehydration properties, this hydrogel retains its flexibility at subzero temperatures for an extended period. Additionally, the porous network and high water content of the hydrogel impart remarkable electromagnetic attenuation properties, with a value of ∼38 dB in the 14.5-20.5 GHz frequency range, which is higher than any other hydrogel without conducting fillers. Overall, the hydrogel reported in this study exhibits diverse applications as a strain sensor, solid electrolyte for flexible supercapacitors, and efficient material for electromagnetic attenuation. Its multifunctional properties make it a promising candidate for use in various fields as a state-of-the-art material.

Optimizing dyeing parameters for sustainable wool dyeing using quinoa plant components with antibacterial properties

This study focuses on the sustainable utilization of Quinoa plant components, particularly its leaves, as a waste agricultural material for natural dyeing applications. Two distinct Quinoa genotypes, Titicaca and Giza, were selected for their natural dyeing properties. UV-VIS absorption spectra of Quinoa colorant extracts provided insights into their chemical composition, revealing distinctive peaks indicative of betalains (400–450 nm), chlorophyll (600–650 nm), carotenoids (400–500 nm), and aromatic amino acids (250–280 nm). Wool samples dyed with different plant parts such as flowers, leaves, and stalks exhibited distinct yellow hue, with leaves demonstrating the highest color strength. Metal mordants such as iron (II) sulphate, copper sulphate, and tin (II) chloride influenced color outcomes, highlighting their role in tailoring final appearance. Fastness properties of dyed wool samples were evaluated, with leaves showing moderate staining resistance and good light fastness. Additionally, antibacterial properties of leaves of Giza Quinoa variety were assessed, showing promising activity against Staphylococcus aureus. The antibacterial properties of fabrics dyed with the leaf extract by mordanting method with different metal salt mordants, particularly Fe, Cr, and Cu, exhibited significant enhancement. These results highlight the multifaceted benefits of Quinoa plant components in sustainable natural dyeing and textile applications, emphasizing their potential for eco-friendly practices in the textile industry.

Dyeing of banana-silk union fabrics with cochineal using different concentrations of bio-mordant

Banana (Musa × paradisiaca L.) is a lignocellulosic natural fiber that can be processed to produce eco-friendly and biodegradable hybrid fabrics when combined with other fibers. Natural-dyed banana fiber can be utilized in the production of sustainable materials for wearable products, household linens, technical textiles, and apparel. In this study, banana-silk union fabrics, pre-treated with bio-mordant at concentrations of 1%, 2%, 3%, 4%, and 5%, were dyed separately using cochineal insect extract (Dactylopius coccus Costa). To assess the dyeability of the banana-silk union fabric, Anatolian black pine cones (Pinus nigra subsp. pallassiana) were utilized as a bio-mordant, with varying quantities. The CIELab values of the dyeings were measured and compared. Additionally, the chemical composition of the cochineal extract, pinecone mordant, raw fabric, and selected dyed fabrics was analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The washing, light, and rubbing fastness properties of the dyed banana-silk union fabrics were also evaluated and compared. This study developed a method for weaving union fabric by blending two distinct natural yarns, namely banana and silk, to reduce dependence on a single fiber and promote the utilization of agricultural waste.

Applying Giloy Stems Dye to Silk and Lyocell Fabrics to Improve Their Antimicrobial and Fastness Properties Using Bio-Mordant

The investigation of novel strategies to combat harmful bacteria is warranted given the serious threat that antimicrobial resistance poses to world health. Out of all of these, treating textile materials with antimicrobial compounds has attracted a lot of attention due to its potential to stop the spread of infectious diseases. The goal of this study was to evaluate how silk and lyocell materials' inherent antibacterial qualities might be improved by giloy dyeing and lemon mordanting. The goal of mordanting was to improve dye adhesion by using only natural ingredients such as citrus lemon extract. Using dye from Azadirachta indica, which was made by aqueous boiling, Lyocell and Silk materials were dyed under various circumstances. Following Giloy dyeing and Lemon mordanting, the antibacterial efficiency significantly improved, notably against common infections like Klebsiella pneumoniae and Staphylococcus aureus, according to the results. Furthermore, the study assessed washing and perspiration fastness capabilities, which yielded positive results and confirmed the method's feasibility. This method has the potential to considerably improve infection control measures in textiles, particularly in fields focused on public health and cleanliness. Given the serious issue of antimicrobial resistance, adopting new textile treatments like this can help to build effective and sustainable solutions. Future studies can investigate further uses and adjustments, assuring its adaptability and wider adoption across many environments.

Alkoxide-based solvent dyeing: a feasible strategy for pollution minimization and sustainable approach for the reactive dyeing of cellulosic materials

This study aimed to evaluate the feasibility of substituting the conventional inorganic alkalis (Na2CO3) with different organic alkoxide5s to explore the potential of replacing aqueous dyeing medium with environmentally friendly solvents like ethanol (EtOH). The study aimed to assess the dyeing characteristics, such as exhaustion, fixation, fastness qualities, physical properties, and environmental implications when EtOH and water were present, while also examining the impact of alkoxides. Time-gated Raman spectra provide insights into the allomorphic forms of cellulose-II after the alkoxide pretreatment, which significantly influences the overall reactivity of cellulose fibers and their dye absorption capabilities. Notably, organic alkoxide pretreated dyeing demonstrated improved color strength, exhaustion, and fixation efficiency compared to Na2CO3 pretreatment, as one of the work’s key findings. For instance, the conventional dyed fabric exhibits 3.4 times lower color strength than alkoxide-based (RR239 + C2H5ONa 3 g/L + EtOH) dyeing, showing substantial potential for upscaling at commercial level as it requires no chemical auxiliaries (such as NaCl and Na2CO3). Importantly, the alkoxide pretreatment does not significantly alter the physical, mechanical and fastness properties of the fabrics, which are comparable to both the pristine and aqueous dyed fabrics, as confirmed by scanning electron microscopy experiments. The effluent’s color intensity resulting from dyeing with C2H5ONa + EtOH (3 g/L) is approximately 24 times lower (250 Pt/Co) in comparison to the aqueous dyeing using 40 g/L of NaCl and 20 g/L of Na2CO3 in an aqueous medium (6154 Pt/Co). Apart from the color intensity, alkoxide pretreatment and EtOH-based dyeing drastically reduce the COD, BOD, TDS, TSS and total hardness values, which could have cost-saving implications for wastewater treatment plants (WWTPs).

Solution processed high aspect ratio ultra-long vertically well-aligned ZnO nano scintillators for potential X-ray imaging applications

We report the photon (PL), electron (CL) and X-ray (XEL) induced luminescence characteristics of high aspect ratio ultra-long (~ 50 µm) ZnO nanorods (NRs) and discuss the potential for fast X-ray detection based on the consistent and efficient visible emission (~ 580 nm) from ZnO NRs. Nanostructured ZnO scintillators were rearranged to form a vertically well-aligned NR design in order to help light absorption and coupling resulting in luminescent and fast scintillation properties. The design of the nanorod array combines the key advantages of a low-cost growth technique together with environmentally friendly and widely available materials. A low temperature hydrothermal method was adopted to grow ZnO NRs in one cycle growth and their structural, optical and X-ray scintillation properties were investigated. The relatively short (~ 10 µm) ZnO NRs emitting in the near-band-edge region were found to be almost insensitive to X-rays. On the other hand, the higher XEL response of long ZnO NRs, which is a key parameter for evaluation of materials to be used as scintillators for high quality X-ray detection and imaging, along with a decay time response in the order of ns confirmed promising scintillation properties for fast and high-resolution X-ray detector applications.

Accelerated optimization through time-scale analysis of inertial dynamics with asymptotic vanishing and Hessian-driven dampings

ABSTRACT Gradient optimization algorithms can be effectively studied from the perspective of ordinary differential equations (ODEs), where these algorithms are obtained through the temporal discretization of the continuous dynamics. This approach provides a powerful tool to comprehend acceleration phenomena in optimization, thanks to time-scale techniques and Lyapunov analysis. In the context of a Hilbert setting, our study focuses on the rapid optimization properties of inertial dynamics, which combine asymptotically vanishing viscous damping with Hessian-driven damping. These dynamics are derived as high-resolution ODEs from both the Nesterov accelerated gradient method and the Ravine method. For a general differentiable convex function f, choosing the viscous damping coefficient in the form of α / t with 3 $ ]]> α > 3 guarantees an inverse quadratic convergence rate of the values, i.e. o ( 1 / t 2 ) , the weak convergence of trajectories towards optimal solutions, and the fast convergence of gradients towards zero. By carefully scaling the dynamics temporally and based on the tuning of the damping coefficient in front of the Hessian term, we identify the limit dynamic as α becomes large. In particular, we examine the case where the limit dynamic corresponds to the Levenberg-Marquardt regularization of Newton's continuous method. This explanation accounts for the aforementioned fast convergence properties and provides fresh insights into the complexity of these methods, which play a central role in optimization for high-dimensional problems. The interplay between numerical algorithms and continuous-time ODEs plays a fundamental role in our analysis for the design and understanding of accelerated optimization algorithms. Numerical experiments are presented to illustrate and support the theoretical results.

Solvent-assisted salt-free reactive dyeing of cotton fabric

The objective of this study was to establish a solvent-assisted salt-free dyeing method for cotton fabric utilizing commercially available reactive dyes. In this study, the feasibility of substituting water as the dyeing medium with environmentally friendly solvents, specifically ethanol (EtOH), isopropyl alcohol (IPA), and propanol (PrOH), was investigated. Eight commercial reactive dyes, each possessing distinct chemical structures, were examined with various dyeing characteristics including exhaustion, fixation, and fastness properties, in the presence of various alcohols. However, solvent-assisted dyeing exhibited comparable or enhanced color strength (K/S) values, exhaustion, and fixation rates compared to conventional aqueous dyeing. For instance, the RR35 dye demonstrated a substantial increase in K/S values with PrOH, EtOH, and IPA, ranging from 115 to 369% improvement. The substitution of alcohol for water did not affect the wash, rub, and light-color fastness properties, as these properties remained consistently excellent. Solvent-assisted salt-free dyeing of cotton fabrics offers a promising solution to address the environmental impacts of traditional water-based dyeing methods by eliminating the requirement for water and salt. Overall, this study presents a solvent-assisted salt-free dyeing technique and contributes to the field by offering detailed insights into its mechanisms and performance. Our research has the potential to reduce water consumption, eliminate salt usage, and mitigate environmental pollution.

Sugar beet (Beta vulgaris L.) leaves as natural colorant for cotton dyeing using an ecofriendly approach toward industrial progress.

In the industrial sector, vegetable residual materials have received attention in the production of bio-colorant for textile dyeing. The current research endeavor is centered on investigating the possibility of using sugar beet leaves as a natural source of dye for the purpose of dyeing cotton fabrics. Different extraction methods were utilized to isolate the bio-colorant present in sugar beet residual material, and the most favorable colorant yield was obtained using a 5% methanolic KOH solution. For optimal dyeing results, the cotton fabric performed dyeing for a duration of 45 min at a temperature of 60 °C, using a salt solution concentration of 6 g/100 mL and 50 mL of the extracted dye solution. Characterization of dye using Fourier transform infrared spectroscopy analysis confirmed the presence of quercetin in the leaf extract. For the creation of a range of color variations, mordants that were chemical in nature, such as tannic acid, iron sulfate, potassium dichromate, and copper sulfate, as well as mordants that were bio-based, such as onion peel, pomegranate peel, henna, golden shower bark, and turmeric, were employed in harmony. In comparison, the utilization of bio-mordants resulted in darker shades that exhibited enhanced color intensity and superior color fastness properties with the value of 4-5 for wash, 4 for wet rubbing, 4-5 for dry rubbing, and 4-5 for light. The findings of this study hold significant value in terms of ecofriendly waste management and contribute to advancements in the industrial sector by utilizing waste residual materials as a natural source of colorants.

Coloration and functionalization of silk fabric based on silver nanoparticles green synthesized from chitosan

This research develops a novel route for the coloration of silk fabric with green synthesized silver nanoparticles (AgNPs) using chitosan as a natural eco-friendly reducing agent. The formation of AgNPs was characterized by the appearance of LSPR absorption peak at 414–448 nm. Based on a TEM image of spherical particles dominated at a particle size between 5 and 10 nm. The zeta potential shows that the AgNPs synthesized from the chitosan are highly stable. The deposition of AgNPs on the silk fabric surface was analyzed with scanning electron microscopy (SEM). The coloration and fastness properties of fabric were found to be significantly improved, a result related to the surface plasmon resonance of AgNPs. The antibacterial properties of the fabric were also found to be excellent, as a more than 87% bacterial reduction was noticed even after 20 washing cycles. Overall, this silk coloration using green nanoparticles can contribute to the low-cost production of multifunctional textiles.

Enhancement of controllable circular actuator using graphene oxide particles

ABSTRACT This work aims to study the responsive expansion of graphene oxide- acrylic elastomer (GO-Acry ER elastomer) under applied electric field. The GO was synthesized from graphite (GP) by using Hummer’s method based on various the ratios of GP to oxidizing agent namely potassium permanganate. GO-Acry ER elastomer was prepared by painted GO as the polarized particle on circular Acry ER as elastomer matrix. The optimum condition of synthesized GO was 1:2 ratios of GP: oxidizing agent which provided a more crystallinity, smaller particle size, and higher pore volume. The circular actuation response of GO-Acry ER elastomer was stimulated by applying external stimuli under various electric field strengths and GO characteristics. The expansion of the GO-Acry ER elastomer increased with an increasing external electric field strength. The GO-Acry ER elastomer under adding GO of 1:2 ratios was the largest expansion with 50% strain under applied electric field of 300 kV/mm. When the electric field strength was > 300 kV/mm, the ER elastomer shrank owing to electrical breakdown. Thus, GO is a suitable choice due to its ease of preparation and fast electro-responsive properties.

Nonswellable Hydrogel Patch with Tissue-Mimetic Mechanical Characteristics Remodeling In Vivo Microenvironment for Effective Adhesion Prevention.

Postoperative adhesion is a common complication after abdominal surgery, but current clinical products have unsatisfactory therapeutic effects. Here, we present a hydrogel patch formed in a single step through dialysis. The exchange of DMSO into water facilitates hydrophobic aggregate in situ formation and the formation of hydrogen bonds within the hydrogel. Thanks to the optimized component ratio and precise structural design. The hydrogel patch has soft-tissue-like mechanical characteristics, including high strength, high toughness, low modulus similar to the abdominal wall, good fatigue resistance, and fast self-recovery properties. The nonswellable hydrogel patch retains over 80% of its original mechanical properties after 7 days of immersion in physiological saline, with a maximum swelling ratio of 5.6%. Moreover, the hydrophobic biomultifunctionality of benzyl isothiocyanate can self-assemble onto the hydrogel patch during the sol-gel transition process, enabling it to remodel the inflammatory microenvironment through synergistic antibacterial, antioxidant, and anti-inflammatory effects. The hydrogel patch prevents postsurgical adhesion in a rat sidewall defect-cecum abrasion model and outperforms the leading commercial Interceed. It holds promising potential for clinical translation, considering that FDA-approved raw materials (PVA and gelatin) form the backbone of this effective hydrogel patch.

Dyeing of Silk Yarn With Natural Dye from Teak Leaves

Objective: This study investigated the impacts of using teak leaf-derived natural dye for dyeing silk yarn. Theoretical Framework: This research uses a conceptual framework for the development of natural fibers for application in textile production. By testing the properties of dyed fibers obtained from teak trees cultivated in Thailand. which tests the properties of the fibers and the adhesion of colors obtained from teak trees. Method: This research explored two mordanting methods (pre-mordanting and post-mordanting) across varying conditions. The study documented the ideal parameters for dyeing, as well as color values, color strength, and fastness properties of the silk yarn. Results and Discussion: by dyeing at 90°C for 60 minutes with a pH of 3. Silk yarn treated with a mixture of teak leaf extract and a mordant substance displayed a yellowish-brown color, except when dyed with ferrous sulfate, which produced a dark gray-brown shade. The silk yarn exhibited fair color fastness when subjected to washing and perspiration, while its resistance to light was rated as poor–moderate. On the other hand, the results in terms of rubbing and water fastness showed a good to very good level. Research Implications: The fibers obtained from the research process have the properties of fibers and color adhesion on the yarn that are highly resistant to washing. Moreover, dyed yarn is beautiful and durable. Originality/Value: These findings underscore the potential utility of teak leaf extract-based natural dyes for silk yarn dyeing.

Biomimetic nanoporous oxygenation membranes with high hemocompatibility and fast gas transport property

Membrane technology holds great potential for separation applications and also finds critical needs in biomedical fields, such as blood oxygenation. However, the bottlenecks in gas permeation, plasma leakage, and especially hemocompatibility hamper the development of membrane oxygenation. It remains extremely challenging to design efficient membranes and elucidate underlying principles. In this study, we report biomimetic decoration of asymmetric nanoporous membranes by ultrathin FeIII-tannic acid metal–ligand networks to realize fast gas exchange with on plasma leakage and substantially enhance hemocompatibility. Because the intrinsic nanopores facilitate gas permeability and the FeIII-catechol layers enable superior hydrophilicity and electronegativity to original surfaces, the modified membranes exhibit high transport properties for gases and great resistances to protein adsorption, platelet activation, coagulation, thrombosis, and hemolysis. Molecular docking and density functional theory simulations indicate that more preferential adsorption of metal–ligand networks with water molecules than proteins is critical to anticoagulation. Moreover, benefiting from the better antiaging property gave by biomimetic decoration, the membranes after four-month aging present gas permeances similar to or even larger than those of pristine ones, despite the initial permeation decline. Importantly, for blood oxygenation, the designed membranes after aging show fast O2 and CO2 exchange processes with rates up to 28–17 and 97–47 mL m−2 min−1, respectively, accompanied with no detectable thrombus and plasma leakage. We envisage that the biomimetic decoration of nanoporous membranes provide a feasible route to achieve great biocompatibility and transport capability for various applications.

Eco-Dyeing and Functional Finishing of Cotton Fabric Using a Natural Colour Derived From Lotus Seed: Enhanced Fastness Properties with Chitosan

Medicinal plant-based dyeing introduces vibrant colours alongside antibacterial and anti-odor properties, fostering sustainability. Innovations include mass sampling for consistent pigment production. Furthermore, lotus seedpods, rich in bioactive compounds, exhibit potential in diverse fields. Chitosan, a biopolymer derived from chitin, boasts versatility in drug delivery systems, wound healing, and antimicrobial applications. This experimental inquiry delves into the dyeability and antimicrobial efficacy of cotton fabric subjected to treatment with chitosan and dyed using Lotus seeds. The investigation encompasses varied parameters such as dye concentration, duration, and temperature for fabric dyeing. The study elucidates the aqueous extraction methodology for dye from Lotus seeds, the chitosan-based mordanting techniques. Standardized assessments are utilized to gauge colour fastness characteristics, encompassing washing, rubbing, and perspiration fastness, along with assessing the antimicrobial attributes of the treated cotton fabric. The study indicates that the application of chitosan-treated cotton fabric enhances dye intensity and overall dyeing quality, consequently improving the colour fastness property of washing, rubbing, and perspiration. Additionally, the treated cotton fabric exhibits significant antimicrobial activity against common bacteria, highlighting the potential of Lotus seed-derived colourants and chitosan mordant in the development of sustainable and antimicrobial textiles. The future scope lies in optimizing the integration of Lotus seed-derived colourants and chitosan mordant for enhanced sustainability and antimicrobial efficacy in textile applications, leveraging advancements in dyeing technology and antimicrobial formulation techniques.

Analysing the effect of mechanically recycled cotton fibres from pre-consumer wastes on mechanical and fastness properties of knitted fabrics

Analysing the effect of mechanically recycled cotton fibres from pre-consumer wastes on mechanical and fastness properties of knitted fabrics

Cu-doped KTN crystal with controllable, reversible, and fast photochromic properties: A superior electro-optical material for improving beam deflection performance

Improving the deflection performance of a beam deflector is urgently required to acquire optical signals for space laser communication and change the attitude and position of space targets and spacecraft. In this work, a Cu-doped potassium tantalate niobate (Cu-KTN) single crystal with fast photochromic and increased beam deflection properties is synthesized using the top-seeded solution growth method. When a Cu-KTN single crystal is irradiated with 405 nm light or ultraviolet (UV) light, the color changes from pale green to reddish brown. After light irradiation, the color gradually returns to yellowish green. Decolorization is accelerated under irradiation with green light or long-wavelength light, and the color changes to pale green. The origin of reversible photochromism reveals the fast valence change of Cu ions. In addition, ion doping improves the beam deflection angle of the secondary electro-optical effect of Cu-KTN (4.3 mrad, 1000 V) crystal compared with pure KTN (3.2 mrad, 1000 V). This study successfully synthesizes Cu-KTN single crystals with photochromic uses and establishes a new route for beam deflectors with significant deflection angles.

Enhancing color brilliance and fastness of polyester dyeing with antipyrine-derived disperse dyes

Disperse azo dyes are important colorants for dyeing polyester fabrics, but developing optimized disperse azo dyes remains a challenge. This work details the synthesis of seven new disperse azo dyes 3a-g derived from the coupling reaction of 4-aminoantipyrine diazonium salt with various phenolic precursors including phenol (3a), salicylic acid (3b), salicylaldehyde (3c), cresols (3d-f), and resorcinol (3g). The dyes were characterized by spectroscopic techniques. Their UV–visible absorption spectra were studied, revealing bathochromic shifts for 3d-g containing electron-donating methyl and hydroxyl substituents compared to parent dye 3a while dyes 3b-c showed hypsochromic shifts. The impact of acid and base on the absorption spectra indicates azo-hydrazone tautomerism for 3f-g but predominant azo form for 3a-e. The dyes showed excellent dyeing on polyester fabrics with up to 97.86 % dye exhaustion. High wash, light and perspiration fastness was exhibited while fastness to respiration varied. The strongest color yield on polyester was achieved with 3g derived from resorcinol coupler. Density functional theory calculations were performed to elucidate relationships between substituent effects and spectral attributes. Lower energy gaps were computed for 3f-g, consistent with enhanced reactivity. This work expands disperse azo dye precursors while offering fundamental structure-performance insight to guide future design. The potent polyester coloration and good fastness properties warrant ongoing investigation of these dyes.

Enhancing the efficiency of hemp fiber dyeing with natural dyes: Indigo and lac

Hemp fibers dyed with natural dyes are environmentally sustainable, but it is typically difficult to achieve an intense shade and washing durability. In this study, mercerization and cationization using polyelectrolyte, Poly-diallyldimethylammonium chloride (polyDADMAC), were chosen to enhance the dyeing efficiency and mechanical properties. Indigo and lac were chosen as natural dyes due to their widespread use. SEM demonstrated that untreated fibers contained the non-cellulose boundary layer on the surfaces, but after mercerization, the surfaces were smoother, making them suitable for absorbing natural dyes. In agreement with the FT-IR, the spectra of non-cellulose disappeared after mercerizing. Following cationization, the FT-IR spectra confirmed the consequences of using poly-DADMAC. Tensile testing demonstrated that mercerized hemp yarns were 34.1% stronger compared to untreated hemp yarns due to the decrease in non-cellulose content and that the intermolecular attraction of cellulose was not disturbed. The color strength and fastness properties were described by the K/S value. Mercerization considerably affected the K/S of indigo dyeing, while cationization affected lac dyeing significantly. Besides that, both treatments improved fastness properties as well.

Biomordant assisted natural dyeing of cellulosic fibre: a greener approach

ABSTRACT Natural dyes serve as a benign alternative to their synthetic counterparts, offering a sustainable option that directly mitigates the release of toxic chemicals. In this study, cotton fabrics were dyed with neem leaf extract in acidic, neutral and alkaline condition where samples were mordanted with lemon juice. The findings revealed a direct correlation between colour strength (K/S) and pH levels, and optimal fastness properties were achieved under alkaline pH conditions when a mordant was employed. The Energy Dispersive X-ray (EDX) ensured the elemental composition of lemon juice assisted dyed fabric which indicates the effective binding of cotton fabric with neem leaves extracted dye. The Fourier Transform Infrared (FTIR) Spectroscopy analysis also confirmed the interaction of cotton fabric with dye particles. The results indicate that cotton fabric can be successfully dyed with neem leaf extract and lemon juice as the biomordant, presenting an eco-friendly and sustainable approach to dyeing practices.