Search Results (142)

Acid Orange 3 (AO3) is a widely used azo dye in leather, paper, and textile dyeing. Untreated direct discharge into water bodies severely threatens human health and aquatic ecosystems, yet efficient degradation remains challenging for conventional technologies. In this work, RuO₂/CeO₂ heterostructure was synthesized and immobilized on a Ti substrate via controlled hydrothermal and annealing treatments, yielding RuO₂/CeO₂@Ti electrode. The electrode showed electrocatalytic activity for the oxygen evolution reaction (OER) over a wide pH range. Under optimized conditions (47 mA/cm², pH 6, 0.25 M NaCl), 150 mg/L AO3 was degraded by 95.89% within 180 min. The degradation mechanism was elucidated by GC-MS and DFT (density functional theory) calculations. The degradation process was dominated by indirect oxidation, sequentially involving azo bond cleavage, heterocyclic ring opening, desulfurization, denitrification, benzene ring cleavage, and mineralization of small molecules into H₂O and CO₂. Full article

The town of Guano, located in the province of Chimborazo, Ecuador, is a canton renowned for its concentration of cultural expressions related to traditional artisanal techniques, such as the production of garments and leather goods, tanning, textile weaving, products made from cabuya or totora reeds, and knotted rugs. These artisanal practices are embedded in a long-standing historical and symbolic framework, linked to processes of cultural transmission and identity reinterpretation. Furthermore, Guano has been a pivotal site in Ecuadorian archaeological history thanks to the studies of Jacinto Jijón y Caamaño (1927), who identified six cultural phases of the Puruhá culture through ceramic and stratigraphic analysis. The province has earned recognition as the “Cradle of Ecuadorian Nationality” due to its valuable archaeological heritage. However, much of the interpretation of this legacy has been constructed from colonial-era archaeological approaches, which have limited the understanding of the Puruhá worldview and generated interpretive shifts in the cultural attribution of its iconography. This research analyzes, from a semiotic and decolonial perspective, the semiotic codes present in the iconography of the Puruhá culture, observable in archaeological ceramic pieces and their reinterpretation in the Guano rugs, understood as living cultural artifacts. The analysis of the denotative and connotative levels of the graphic motifs integrates the iconographic study, Andean fractal design, and the examination of contemporary artisanal discourses. The results demonstrate the existence of a structured symbolic system, based on principles of duality, complementarity, cyclicality, and the tripartite division of the cosmos, as well as the persistence of patterns such as spirals and zoomorphic figures in current textile production. The study identifies that, despite this symbolic continuity, those who possess this knowledge often attribute these symbols to external cultural frameworks, primarily the Inca culture, which limits their potential as a resource for identity, culture, and tourism. In this sense, the research provides a situated and non-hegemonic interpretive framework that contributes to the cultural reinterpretation of the Guano knotted carpets, offering input for safeguarding intangible cultural heritage, strengthening local identity, and designing sustainable cultural interpretation strategies. Full article

This study examines the accounting determinants of the capital structure of Portuguese firms in the textile, clothing, and leather sectors, based on a sample of 6469 firms over the period 2010–2022, using panel data models. The relevance of this study lies in its focus on specific industrial sectors characterized by a high predominance of small and medium-sized enterprises (SMEs) and a strong dependence on bank financing. In addition to the traditional analysis of leverage determinants, this study introduces a conditional approach to accounting variables based on firms’ structural characteristics, namely size and age. Robustness checks and data treatment procedures were conducted to mitigate the potential impact of outliers in the financial variables. The results show that profitability, liquidity, and risk negatively affect indebtedness, whereas asset structure and growth exert positive effects. The effective tax rate has a negative impact on debt. Firm size and age significantly condition the relationship between variables. SMEs’ financing decisions exhibit differentiated patterns depending on firm size and age. The findings support the predictions of the Pecking Order Theory and, to a lesser extent, the Trade-Off Theory. The study highlights the importance of considering firm heterogeneity when designing financing policies and strategies for Portuguese SMEs. Full article

The development of bio-based inks represents a promising strategy to reduce the environmental impact of digital printing technologies. This study investigates the formulation and performance of water-based inks incorporating two renewable pigments: a fermentation-derived indigo pigment and a plant-extracted yellow pigment. Special attention was given to dispersion optimization of the poorly water-soluble indigo pigment. Extended mechanical dispersion (115 h in a ball mill) proved critical to achieve colloidal stability, enabling the preparation of inks that met standard rheological and physicochemical criteria for inkjet printing with piezoelectric printheads. Both inks were applied on a variety of substrates, including cotton, polyester, leather, and kraft paper, pre-treated, in the case of the textiles, with either a cationic biopolymer or a synthetic polyurethane-based binder. Colorimetric evaluation confirmed effective deposition and uniformity, with the indigo ink producing deep blue hues and superior overall fastness than the yellow ink, particularly in washing and rubbing tests. The yellow pigment ink showed good stability but once applied to the fabric, the resulting print exhibited poor fastness, particularly against light exposure, indicating limited durability of the coloration on the textile. Shelf-life analysis of the indigo ink revealed a decline in viscosity and surface tension over time, though the colour and particle size remained stable, particularly under room temperature conditions. These findings confirm the potential of fermentation-derived indigo as a robust bio-based alternative to synthetic dyes and its superior performance in relation to other nature extracted pigments, which, although facilitating ink preparation due to their higher water solubility, result in lower-fastness prints. Full article

Developing environmentally friendly, multifunctional waterproof and breathable membranes (WBMs) has attracted extensive attention and is of great significance but remains challenging. Herein, an environmentally friendly and multifunctional waterborne polyurethane WBM with self-healing and self-cleaning properties is developed in two steps. Firstly, by using polydimethylsiloxane (PDMS) as a hydrophobicity giver and tannic acid (TA) as a crosslinker, a dual-modified waterborne polyurethane (PTWPU) is prepared, which has high surface hydrophobicity due to the surface enrichment of siloxane segments and self-healing performance from the formation of a dynamic phenolic carbamate network. Secondly, by incorporating titanium dioxide (TiO₂) photocatalyst nanoparticles to increase internal porosity and establish hydrophilic pathways, a multifunctional waterborne polyurethane WBM (TPTWPU) is developed. This membrane features further enhanced surface hydrophobicity from generated micro-roughness and effective self-cleaning performance, because TA acts as an electron trap to promote the photocatalytic activity of TiO₂. The TPTWPU membrane shows good hydrophobicity (water contact angle of 115.3°) and satisfactory moisture permeability of 135.0 g/(m²·24 h), which is 61.2% higher than unmodified membranes. Furthermore, it exhibits efficient self-healing, with a recovery rate exceeding 80% within 2 h. This feasible strategy will provide guidance for materials design in multifunctional coatings for textiles and leather. Full article

Azo dyes represent the largest and most extensively used class of synthetic dyes in industries such as textiles, leather, paper, food, cosmetics, and pharmaceuticals. Due to their complex aromatic structures and the presence of azo (–N=N–) bonds, these dyes exhibit high chemical stability and resistance to degradation, leading to their persistent discharge into the environment through industrial wastewater. This review provides a comprehensive overview of the chemistry, sources, environmental fate, and toxicological impacts of azo dyes, with a particular focus on microbial remediation strategies. The roles of bacteria, fungi, algae, and microbial consortia, along with their enzymatic mechanisms and influencing factors, are critically discussed. The presence of azo dyes in aquatic and terrestrial ecosystems causes severe environmental problems, including reduced light penetration, disruption of photosynthetic activity, and deterioration of water quality. Moreover, the reductive cleavage of azo dyes can result in the formation of toxic, mutagenic, and carcinogenic aromatic amines, posing significant risks to ecological and human health. Conventional physicochemical treatment methods, although effective in decolorization, suffer from limitations such as high cost, energy demand, sludge generation, and incomplete mineralization. This review identifies key strategies for achieving scalable and eco-friendly solutions for industrial wastewater management. Full article

Growing demand for sustainable materials has intensified research into eco-friendly alternatives to conventional and synthetic leathers. Traditional bovine leather and its chromium-tanning process heavily contribute to water pollution, toxic waste generation, and carbon emissions, while synthetic leather derived from Polyvinyl Chloride (PVC) and polyurethane (PU) presents challenges related to fossil fuel dependence and non-biodegradability. This review explores bio-based and sustainable leather substitutes that are made of plants, microbial cellulose, and mycelium fungi. Plant-based leather substitutes such as Vegea^®, Desserto^®, and Piñatex^® use agricultural waste products to create durable, partially biodegradable composites. Microbial cellulose from kombucha fermentation offers material with good physical and aesthetic properties. Mycelium leather, derived from fungal biomass, demonstrates potential for scalable and low-impact production. Comparative analyses of mechanical and physical properties show that mycelium composites are approaching industrial standards, though challenges remain regarding tensile strength, water resistance, and process standardization. Despite current limitations, bio-based leathers, particularly mycelium composites, offer a promising way toward circular material innovation and carbon-neutral manufacturing in fashion, automotive, design and other industries. Full article

Filamentous fungi are among the most significant biological agents responsible for the biodeterioration of organic cultural heritage materials preserved in archives, libraries, and museums. Cellulose-based substrates—such as paper, papyri, and plant-derived textiles—as well as protein-based materials, including parchment and leather, provide favourable conditions for fungal colonization due to their chemical composition and hygroscopic behaviour. Once activated, fungi contribute to deterioration through a combination of mechanical penetration and biochemical processes, including the secretion of hydrolytic enzymes, organic acids, and pigmented metabolites, which progressively compromise the structural integrity and visual appearance of heritage objects. This review aims to critically synthesize current knowledge on the mechanisms of fungal biodeterioration affecting organic heritage materials, with particular attention to material-specific vulnerabilities, indoor environmental drivers, and implications for preventive conservation. Recent advances in fungal ecology have highlighted the presence of xerophilic and extremotolerant taxa capable of persisting under conditions traditionally considered unfavourable for microbial growth, posing new challenges for conservation management. Rather than attributing biodeterioration directly to global climate change, this review explicitly emphasizes the role of indirect and building-mediated climate-related stressors—such as increased frequency of moisture intrusion events, infrastructure vulnerability, and microclimatic instability within buildings—in shaping fungal risk in indoor heritage environments. The integration of environmental monitoring, microbiological diagnostics, and predictive risk-assessment tools emerges as a key strategy for early detection and mitigation. By consolidating interdisciplinary evidence from microbiology, materials science, and heritage conservation, this work underscores the need to shift from reactive restoration toward anticipatory, risk-based preventive approaches to ensure the long-term preservation of organic cultural heritage materials. Full article

This study investigates the application of soybean peroxidase (SBP), an enzyme extracted from a soybean processing byproduct, for the decolourization and oxidative treatment of three industrial azo dyes: Acid Orange 7 (AO7), Acid Orange 20 (AO20), and Reactive Black 5 (RB5), each at a concentration of 50 µM. These dyes are widely used in textile, paper, and leather industries and persist in wastewater. Optimization experiments were conducted at room temperature (approximately 22 °C) to examine the effects of pH, SBP activity, and hydrogen peroxide (H₂O₂) concentration. Optimal degradation conditions were identified as: pH 3.5, 0.075 U/mL SBP, and 0.0375 mM H₂O₂ for RB5; pH 3.0, 0.5 U/mL SBP, and 0.0375 mM H₂O for AO7; and pH 3.0, 0.0025 U/mL SBP (200-fold less than for the isomeric AO7) and 0.0625 mM H₂O₂ for AO20. Under these conditions, dye conversion was very rapid, reaching >97% decolouration in 30 s. The initial first-order rate constants and half-lives were ≥10.7 min⁻¹ and ≤0.065 min (AO7), ≥7.3 min⁻¹ and ≤0.095 min (AO20), and ≥8.5 min⁻¹ and ≤0.081 min (RB5). When normalized to enzyme activity, AO7 showed the highest catalytic efficiency. These findings support the use of SBP as a low-cost, eco-friendly, and effective biocatalyst for the rapid treatment of dye-containing industrial wastewater. Full article

Effective management of Environmental, Social, and Governance (ESG) practices within the framework of transparency and accountability in businesses is crucial for enhancing their compliance capacity in the face of regulatory pressures and contributing to the early detection of environmental and social risks. This study aims to evaluate the ESG disclosure-based performance of businesses operating in the textile, clothing, and leather sectors in Turkey by examining their ESG indicators from a transparency and accountability perspective. The CRITIC (Criteria Importance Through Intercriteria Correlation) method was used to determine the relative importance levels of the indicators, while the MABAC (Multi-Attributive Border Approximation Area Comparison) and COPRAS (Complex Proportional Assessment) methods were used to rank the performance of businesses within the framework of these indicators. Finally, clustering analysis was used to classify businesses with similar characteristics. The findings show that corporate governance principles are the most important indicator, and that Kordsa Teknik Tekstil A.Ş. and Söktaş Tekstil Sanayi ve Ticaret A.Ş. exhibit a significant and positive difference in terms of transparency and accountability in their ESG practices compared to other businesses. The combined use of CRITIC, MABAC, COPRAS, and cluster analysis offers an innovative, robust decision-making approach and holistic methodological integration for assessing ESG disclosure-based performance in the context of transparency and accountability for businesses. Full article

Acid violet 19 (AV19) dye is used in many fields, including photographic film, inks, leather, and textiles. Potassium ferrate (VI) (Fe(VI)) represents a novel oxidant, notable for its strong oxidative capabilities, stability, and environmental sustainability. This research investigates the decolorization and mineralization of AV19 through the application of Fe(VI), with a particular emphasis on essential parameters, including pH, molar ratios, and temperature variations. The study ascertained that the optimal conditions for AV19 oxidation are a pH of 7.0, a molar ratio of AV19: Fe(VI) of 1:5, and a temperature of 45 °C with a reaction time of 12 min. The decolorization efficiency achieved was approximately 98%, and the mineralization was 31%. The degradation process yielded intermediates, such as sulfonic acid derivatives, benzoic acid, benzene, and cyclohexane compounds, which were further oxidized into acetic acid, carbon dioxide, and water. Comprehensive computational toxicity evaluations confirmed that both the intermediates and the final products are non-toxic. Full article

This study focused on the development of a new concept for ablative thermal protection material, using a relatively new polymer matrix based on polysiloxane resin, which exhibits high-performance thermal properties. As a reinforcing element, graphite felt (GF/UHT) was selected. These new ablative materials were tested and characterized to evaluate their thermal properties through comparison with established/standard ablative materials based on phenolic resin and graphite felt (GF/Isophen). To evaluate them, two distinct types of thermal tests were performed. The first consisted of subjecting the ablative materials to a temperature of 1100 °C for a total duration of 10 min (with three different dwell times: 30 s, 120 s, and 300 s). A mass loss of 31% was recorded for the GF/UHT ablative material samples compared to the GF/Isophen material, where the mass loss reached approximately 68%. The second test consisted of exposure to an oxyacetylene flame at a temperature of 1600 °C. The GF/UHT samples had an improved behavior compared to the GF/Isophen samples, the latter being completely penetrated at the end of the test. Additionally, differential scanning calorimetry (DSC) tests were performed and characterized by FTIR spectroscopy and scanning electron microscopy. Full article

Proteases play key roles in many industrial processes and account for the majority of global enzyme sales. Geobacillus isolates from extreme environments such as marine hydrothermal vents are capable of producing high yields of proteases with thermophilic properties. Many proteases produced by Geobacillus species have been extensively studied, some of which have been purified and characterized. In addition, the high thermal stability largely depends on structural stability. Based on X-ray crystallography, several factors have been found to affect the structural stability of the thermostable proteases of Geobacillus. Moreover, the thermostable proteases of Geobacillus have a wide range of biotechnological applications, such as in detergent, food, bioremediation, leather-processing and textile industries. Therefore, this review focusses on the thermostable proteases of Geobacillus, including their characteristics, structural stability mechanisms and biotechnological applications. It will help the development of utilizing thermostable protease resources and enhancing their suitability for use in various industrial applications. Full article

Using renewable D-gluconic acid δ-lactone as the starting material, two novel glucosamide-based organosilicon quaternary ammonium surfactants (2/3SiDDGPBH) were synthesized through an environmentally friendly three-step process involving amidation, hydrophobic modification, and quaternization. Comprehensive characterization demonstrated their exceptional performance: surface tension reduction to 33.4 mN/m (2SiDDGPBH) and 33.64 mN/m (3SiDDGPBH), uniform spherical micelles (1–10 nm and 30–100 nm) were formed, and outstanding foam properties with 3SiDDGPBH developed, showing superior foamability and stability. Material modification tests on polymethyl methacrylate (PMMA) plates, mature acacia leaves, oilpaper, vegetable-tanned top-grain leather, and melamine-formaldehyde resin (MFR) faced with plywood revealed excellent spreading performance and durability, particularly for 3SiDDGPBH-treated MFR plywood, which maintained excellent spreading performance even after 80 washing cycles. Scanning electron microscopy (SEM) analysis confirmed that the Si wt% of MFR plywood treated with 2/3SiDDGPBH and scrubbed MFR plywood both exhibited a significant increase, and the 3SiDDGPBH-treated MFR plywood demonstrated superior bonding properties. These surfactants combine low surface tension, excellent foaming properties, and outstanding spreading performance, demonstrating broad application prospects in fields such as pesticide adjuvants, industrial and household cleaning agents, cosmetics, oilfield extraction, textile printing and dyeing, and functional coatings. Full article

A mycelium is a network of hyphae that possesses the ability to self-assemble and grow into various shapes, acting as a natural binder that minimises the need for intensive chemical and energy processes, making it an alternative capable of forming structures that may eventually outperform traditional fibres such as animal leather and polyester. In this work, two mycelium mats were created, and their thickness, water absorption, coverage, and tear strength for the sewing process were determined. Fibre mats were grown in vitro or on a jute substrate. The mats were treated with salt, tannin or citric acid solutions, then air- or oven-dried. In general, the treatment that least modified the colour and appearance of the mycelium mats was citric acid, and when dried by airflow, the thickness averaged 1.4 mm. The highest tear strengths were 10.55 N/mm and 12.7 N/mm for the mycelium mats treated with citric acid without and with jute, respectively. A high percentage of water absorption was observed, reaching 267% (mycelium mats treated with tannins and dried at 65 °C) and 28% (mycelium mats treated with citric acid and air-dried). In general, all mycelium mats can be sewn, except for those treated with citric acid, which have a viscous texture and require slow sewing to prevent the mycelium from breaking. The Trametes fungus can be utilised in the production of mycelial materials, allowing for the optimisation of growth conditions to obtain mycelial mats that meet the requirements for use as an environmentally friendly alternative in the textile and related industries. Full article