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Abstract The leather industry possesses a prominent place in the fashion industry. However, waste management during leather manufacture is a limiting factor to attaining sustainability by the industry. Tannery hair waste (byproduct of enzymatic dehairing), being a rich source of keratin, remains underutilized. Casein binders are currently used for glaze finishing, which lack sustainability and incur high costs. In the present study, an attempt has been made to extract keratin hydrolysate and use it as a sustainable binder for leather finishing. The extracted keratin hydrolysate from hair waste has been characterized using nuclear magnetic resonance and Fourier transform infrared spectroscopy. Differential scanning calorimetry and thermogravimetric analysis show that the keratin hydrolysate is thermally stable. The finished leathers, characterized for distension of grain, adhesion of finish, and fastness, are found to be within the recommended standards. Gloss, contact angle, and water vapor permeability of the leather finished with a keratin hydrolysate binder show better properties as compared to the reported values for commercial casein binders. Thus, utilizing keratin hydrolysate in leather finishing not only contributes to waste reduction but also aligns with the growing trend toward closed-loop leather processing systems and circular economy practices.
Integrating electrical conductivity and flame-retardant properties into leather is a promising advancement that will enhance its functionality for modern applications. This study attempted an innovative approach utilizing ionic liquid (IL)-assisted in-situ polymerization of aniline to fabricate electrically conductive and flame-retardant leather. The use of imidazolium-based ILs aided in modulating the size of polyaniline (PANI) during the polymerization process, improving its penetration and uniform distribution within the leather matrix. The electrical resistance of control leather was reduced from 389.4 MS2 to 1.5 MS2 after three cycles of in-situ polymerization of aniline. Additionally, PANI-leather demonstrated enhanced flame-retardant properties, with an 82.8 % reduction in flammability degree compared to untreated leather, owing to its high nitrogen content and organic core promoting compact char formation. Characterization through XRD, SEM, and XPS confirmed the uniform distribution of PANI throughout the cross-sectional area of the leather matrix. These findings suggest that IL-assisted PANI deposition offers a scalable, cost-effective method to fabricate smart leathers with multifunctional properties, broadening their applicability in wearable electronics, strategic sectors, automotive interiors, and protective gear.
In pursuit of environmentally sustainable leather processing, this study reports a novel amphoteric copolymeric fatliquor synthesized from allyltrimethylammonium bromide (ATMA) and dimethylaminoethyl methacrylate (DMAEMA) through free radical copolymerization. The copolymer exhibits a dual ionic character that ensures compatibility with both chrome-tanned and chrome-free leather systems. Structural characterizations using FTIR, NMR, GPC, and ESI-MS confirmed the successful incorporation of cationic, anionic, and hydrophobic functionalities. The amphoteric architecture facilitated pH-responsive interactions with collagen, promoting uniform penetration and efficient fixation. In chrome-tanned leather, the copolymer achieved a substantially higher fatliquor uptake (85.2
Precise identification of animal species in leather is pivotal in maintaining biological diversity and protecting consumers from buying illegal trade products. Conventional approaches concerning this research largely rely on leather specialists and physical assessment, often prone to ambiguous judgments. The practical applications of the vision transformer's (ViT) self-attention mechanism to capture global contextual relationships, enabling species-specific texture variations regardless of spatial distance, are explored in this research work. Accordingly, the research presents a comprehensive comparative study of three pre-trained ViT-based deep learning models (ViT-Base, ViTSmall, ViT-Tiny), fine-tuned via transfer learning on a diverse dataset of 10,000 region-specific leather images from four legally permissible animal species. Two data augmentation techniques, horizontal and vertical flipping, are employed during the training. The fine-tuned models demonstrate excellent performance on the challenging unseen dataset comprising 8800 leather images with ideal and non-ideal attributes. Among the three models, ViT-Base shows its superiority in species identification performance with an accuracy of 95.97%, and the other two variants, ViT-Small and ViT-Tiny, show comparable results with an accuracy of 91.78% and 82.61%, respectively. The results in this study highlight the proposed model's effectiveness in identifying the leather species. This, in turn, helps the leather specialists by developing precise species prediction methods.
This study presents a porous, collagen-reinforced nanofibrous scaffold developed using subcritical CO2-mediated expansion to address limitations in conventional 2D electrospun membranes. The 3D-expanded (EXP) architecture significantly increased porosity and fluid retention, enhancing inter-fiber spacing without compromising fiber morphology. Electrospun polyhydroxybutyrate-polyethylene glycol (PHB-PEG) nanofibers were loaded with Lawsone (L), an antioxidant phytochemical, and structurally reinforced with a collagen-alginate gel (COL). Scaffold expansion was achieved via subcritical CO2 exposure under ambient pressure, followed by freeze-drying. The expanded scaffold (EXP-COL-L) exhibited enhanced mechanical strength (2.6 MPa), high crosslinking efficiency (82 %), and a sustained biphasic drug release reaching 66 % over 96 h. In vitro analysis using fibroblast cells confirms the biocompatibility of the matrix. The scaffold also offered cytoprotection under oxidative stress, maintaining 86 % viability after H2O2exposure. ELISA-based cytokine profiling revealed downregulation of IL-6 and Connexin-43, and significant upregulation of IL-10, Collagen III, and Sphingosine kinase-1, highlighting anti-inflammatory and regenerative effects. This subcritical CO2-fabricated scaffold offers a scalable, solvent-free route to engineer biomimetic, cell-responsive wound dressings. These findings demonstrate its potential as a next-generation tissue-mimetic platform for sustained drug delivery and enhanced wound healing
