Silk Research Articles

From Ancient Threads to Colonial Commerce: The Evolution of West Bengals Silk Industry from Mythical Origins to Independence

Silk production, or sericulture, has a rich history that is frequently eclipsed by its modern applications. Sericulture began in ancient China approximately 3000 BC and this was a well held secret until it spread to Korea, India and eventually the West through a variety of causes, including royal intrigue and missionary endeavours. By the Han Dynasty, silk had evolved from a luxury item to a valuable economic asset, impacting trade and culture throughout Asia and Europe. India's silk industry, as documented in ancient scriptures, progressed from early wild silk production in the Himalayan foothills to sophisticated mulberry sericulture by the 2nd century BCE. The Mughal dynasty improved Indian silk traditions by incorporating several weaving techniques and nurturing a thriving business in Kashmir and Bengal. From 1612 to 1858, the East India Company capitalised on Bengal's silk potential by building trading centres and using Piedmontese reeling technology to improve quality. Despite initial hurdles, Bengal silk became a major export commodity, but colonial policies and technological shifts eventually led to its demise. Silk output fell dramatically after independence due to a variety of economic and geopolitical issues. This article investigates the growth of India's silk industry, focussing on Bengal's key role and examines the effects of colonial control, technological advancements and the sector's trajectory up to Independence.

Sustainable Assessment of Bio-Colorant from Bakain Bark (Melia azedarach L.) for Dyeing of Cellulosic and Proteinous Fabric.

The current study proceeded to reduce the environmental hazards spreading worldwide due to synthetic dyes. To overcome these problems, eco-friendly natural dyes are introduced as alternative sources of synthetic dyes. The present study was focused on exploring the bio-colorant of the aqueous and acidic extract of the bark of Melia azedarach L. for the dyeing of both silk and cotton samples. The results of the extraction medium specified that the aqueous extract gave maximum colorant solubility and upon fabric dyeing produced higher color strength in contrast to the acidic medium. The optimization experimentation data showed that excellent color strength of silk fabric was found at 45 min dyeing time duration, in 35:1 mL dye extract, and using 2% salt (NaCl) as an exhausting agent, whereas cotton fabric showed the maximum K/S value at 60 min dyeing time, in a 45:1 mL liquor ratio, and with the use of 2% salt. Bio-mordants produce different shades on both fabrics. Bio-mordanting experiments on silk revealed that pre-mordanting with 2% turmeric and 3% pomegranate, and post-mordanting using 3% turmeric and 2% pomegranate produced a darker shade. In the case of cotton, the pre-mordanted samples with 2% turmeric and 3% pomegranate and the post-mordanted samples with 4% turmeric and 4% pomegranate gave the highest color strengths. All the mordanted samples gave excellent fastness ratings. Overall, it has been found that Bakain bark proved to be an excellent source of tannin. The result of this study showed that it could be a cost-effective and eco-friendly dye source for textile progress.

Silk Fabric Functionalized by Nanosilver Enabling the Wearable Sensing for Biomechanics and Biomolecules.

Integrating biomechanical and biomolecular sensing mechanisms into wearable devices is a formidable challenge and key to acquiring personalized health management. To address this, we have developed an innovative multifunctional sensor enabled by plasma functionalized silk fabric, which possesses multimodal sensing capabilities for biomechanics and biomolecules. A seed-mediated in situ growth method was employed to coat silver nanoparticles (AgNPs) onto silk fibers, resulting in silk fibers functionalized with AgNPs (SFs@Ag) that exhibit both piezoresistive response and localized surface plasmon resonance effects. The SFs@Ag membrane enables accurate detection of mechanical pressure and specific biomolecules during wearable sensing, offering a versatile solution for comprehensive personalized health monitoring. Additionally, a machine learning algorithm has been established to specifically recognize muscle strain signals, potentially extending to the diagnosis and monitoring of neuromuscular disorders such as amyotrophic lateral sclerosis (ALS). Unlike electromyography, which detects large muscles in clinical medicine, sensing data for tiny muscles enhance our understanding of muscle coordination using the SFs@Ag sensor. This detection model provides feasibility for the early detection and prevention of neuromuscular diseases. Beyond muscle stress and strain sensing, biomolecular detection is a critical addition to achieving effective health management. In this study, we developed highly sensitive surface-enhanced Raman scattering (SERS) detection for wearable health monitoring. Finite-difference time-domain numerical simulations ware utilized to analyze the efficacy of the SFs@Ag sensor for wearable SERS sensing of biomolecules. Based on the specific SERS spectra, automatic extraction of signals of sweat molecules was also achieved. In summary, the SFs@Ag sensor bridges the gap between biomechanical and biomolecular sensing in wearable applications, providing significant value for personalized health management.

Molecular dynamics modelling of the stress–strain response of [formula omitted]-sheet nanocrystals

Molecular dynamics simulations were conducted on two model antiparallel β-sheet crystallites [GA]n and [GAS]n to study deformation in chain, sheet stacking, and hydrogen bonding directions under uniaxial loading. In chain direction, both models were mechanically stable, even beyond the 570 K amorphousation temperature of silk fiber; however, [GA]n model displayed higher yield strain, stress, elastic modulus, and resilience than [GAS]n. In transverse directions, they had similar stress–strain behavior and demonstrated significant anisotropic mechanical behavior. Hence, inclusion of an amino acid with a rich side chain group extending between β-sheets reduces the stiffness of crystallite in chain direction. Serine and alanine residues maintained existing H-bonds and established new ones during stretching in chain direction and shrinking in transverse directions which affected the mechanical response near the yield point. Comparison between β-sheet crystallite and PPTA (Kevlar) showed that the mechanical performance of these crystal polymers were very similar in chain direction, but contrarily β-sheet crystallite had higher stiffness in H-bonding and sheet stacking directions than PPTA. This study may provide a guideline in designing of polyaminoacid based biocompatible materials with superior mechanical performance.

Tasar silk fiber waste reinforced polylactic acid composite: Physical, mechanical, and sliding wear characterization

Incorporating natural industrial waste as a reinforcement for the development of sustainable composite is now being extensively practiced to eliminate harmful synthetic fiber. This study exhaustively evaluated the potential of tasar silk fiber waste (TSFW) as a reinforcing agent in a polylactic acid (PLA) matrix to optimize the physical, mechanical, and wear properties. Therefore, PLA-based biocomposites with varying TSFW proportions (0, 2, 4, 6, 8, and 10 by weight) are manufactured and then evaluated for physical (density, voids, water absorption), mechanical (tensile, flexural, impact, and hardness), and sliding wear properties. Results suggested that water uptake of PLA composites increases with the addition of TSFW and becomes saturated after nine days of immersion. The TSFW reinforcement at 8 wt% in PLA yields 32 % and 22 % improvement in tensile strength (66.2 MPa) and flexural strength (103.2 MPa), respectively. A remarkable improvement was observed in the impact strength at similar reinforcement (8 wt%) of TSFW with the observed value of 27.90 kJ/m2. A continuous increase in hardness was obtained by including TSFW in PLA, with the highest value of 86 Shore D recorded for 10 wt% TSFW added biocomposite. The specific wear rate of all samples increased, but the incorporation of TSFW significantly reduced the same. Microscopic examination suggests that microploughing, microcutting and groove formations were the main mechanism of material removal. After examining the results, it is recommended that TSFW be used in bidirectional mat form for further enhancement of mechanical properties and improved bonding between fiber and matrix.

Study on dyeability of silk fabric with anthocyanin extracted from butterfly pea flowers

Study on dyeability of silk fabric with anthocyanin extracted from butterfly pea flowers

The renewed tin-weighting treatment as sustainable and durable flame-retardant approach for protein silk fabric

The facile development of a sustainable and durable flame-retardant approach for protein silk is of interest. Inspired by silk tin-weighting technology, this study developed a novel and sustainable in-situ deposition strategy based on biomass phytic acid to impart durable flame-retardant performance to silk fabrics. The chemical structure of insoluble chelating precipitation, and the surface morphology, thermal stability, combustion behavior, flame-retardant capacity, laundering resistance, and flame-retardant mode of action of the tin-weighting silk samples, were explored. The Sn-, P-, Si-containing insoluble chelating precipitation formed within the fiber interior and combined with silk fibers through electrostatic attraction and metal salt chelation. As a result, the tin-weighting silk displayed excellent self-extinguishing capacity, with the damaged length reduced to 9.2 cm and the LOI increased to 31.6 %; it also achieved self-extinguishing after 30 washing cycles, demonstrating high flame-retardant efficacy and laundering resistance. Moreover, the tin-weighting silk also showed the obvious suppression in smoke and heat generation by 55.6 % and 35.7 %, respectively. The synergistic charring action of phosphate groups, tin metal salts, and silicates was beneficial for enhancing the fire safety of silk. The tin-weighting treatment also displayed a minor impact on mechanical performance of silk fabrics.

Characterization and comparative analysis of sericin protein 150 in Bombyx mori

Lepidopteran silk is a complex mixture of proteins, consisting mainly of fibroins and sericins. Sericins are a small family of highly divergent proteins that serve as adhesives and coatings for silk fibers. So far, five genes encoding sericin proteins have been identified in Bombyx mori. Having previously identified sericin protein 150 (SP150) as a major sericin-like protein in the cocoons of the pyralid moths Galleria mellonella and Ephestia kuehniella, we describe the identification of its homolog in B. mori. Our refined gene model shows that it consists of four exons and a long open reading frame with a conserved motif, CXCXCX, at the C-terminus, reminiscent of the structure observed in a class of mucin proteins. Notably, despite a similar expression pattern, both mRNA and protein levels of B. mori SP150 were significantly lower than those of its pyralid counterpart. We also discuss the synteny of homologous genes on corresponding chromosomes in different moth species and the possible phylogenetic relationships between SP150 and certain mucin-like proteins. Our results improve our understanding of silk structure and the evolutionary relationships between adhesion proteins in the silk of different lepidopteran species.

The effect of weighting on the color appearance of dyed silk fabric

The weighting process may change the color appearance of silk. The objective of the present study is to evaluate the effect of weighting with methyl methacrylate (MMA) on the color appearance of silk fabric using the response surface method. For this purpose, a CCD design was used to investigate the effect of methyl methacrylate monomer concentration and dye concentration on color appearance and percentage of weight gain of silk fabric. Analysis of variance, response surface, and contour plots of the colorimetric characteristics of the weighted silk fabric show that the methyl methacrylate concentration has a significant effect on color parameters such as L*, a*, b*, C*, and hue angle of the weighted silk fabric. The results indicate that the weighting process changes the color of silk fabric.

Fully biobased approach for sustainable flame retardancy, antibacterial and anti-UV modification of silk fabric

The versatile modification of silk fabric using a fully biobased approach is intriguing. In this study, phytic acid and vanillin, which are plant extracts, were utilized to synthesize reactive vanillin phytate ester for modifying silk fabric to achieve durable flame retardancy, antibacterial and anti-UV performance. The multifunctional properties, thermal resistance, smoke and heat suppression capacity, flame-retardant durability and mechanism of modified silk fabrics were investigated. The vanillin phytate ester imparted high antimicrobial and UV resistance to silk fabric, achieving a 97 % inhibition rate against Escherichia coli and reaching an “excellent” level of UV protection. The modified silk fabric also possessed the self-extinguishing capacity, with a limiting oxygen index value as high as 33.5 %. There was also a significant reduction of 71.7 % in peak heat release and 40 % in smoke release compared with those of the original silk. After undergoing 20 washing cycles, the modified silk fabrics also self-extinguished and passed the vertical burning test, and such good washing resistance was achieved by the Schiff base cross-linking of vanillin phytate ester on the silk fabric. An intumescent flame-retardant mechanism was also identified by char residue analyses, which was driven by the synergistic charring action of phosphate groups and aromatic structures.

Therapeutic potential of silkworm sericin in wound healing applications.

Chronic wounds are characterised by an imbalance between pro and anti-inflammatory signals, which result in permanent inflammation and delayed re-epithelialization, consequently hindering wound healing. They are associated with bacterial infections, tissue hypoxia, local ischemia, reduced vascularization, and MMP-9 upregulation. The global prevalence of chronic wounds has been estimated at 40 million in the adult population, with an alarming annual growth rate of 6.6%, making it an increasingly significant clinical problem. Sericin is a natural hydrophilic protein obtained from the silkworm cocoon. Due to its biocompatibility, biodegradability, non-immunogenicity, and oxidation resistance, coupled with its excellent affinity for target biomolecules, it holds great potential in wound healing applications. The silk industry discards 50,000 tonnes of sericin annually, making it a readily available material. Sericin increases cell union sites and promotes cell proliferation in fibroblasts and keratinocytes, thanks to its cytoprotective and mitogenic effects. Additionally, it stimulates macrophages to release more therapeutic cytokines, thus improving vascularization. This review focuses on the biological properties of sericin that contribute towards enhanced wound healing process and its mechanism of interaction with important biological targets involved in wound healing. Emphasis is placed on diverse wound dressing products that are sericin based and the utilisation of nanotechnology to design sericin nanoparticles that aid in chronic wound management.

When the Dead Cry: Crime, Population, and Popular Literature in Early Modern Southwark

Drawing on parish registers, records from the assizes, and an anonymous ballad, this article reconstructs the events surrounding the murder of John Clarke by his own master, silk weaver Richard Price. Price, it turns out, had killed before, and in many respects fits what we would today call a serial killer. The article thus examines the way parish registers might usefully be supplemented by legal and literary texts to get at not only the births, marriages, and deaths of parishioners in the aggregate but also their lived experience, how they responded to tragedy not on the nearby stage but in their neighborhood. The article thus argues for the importance of careful examination of the archives to understand the lives of ordinary people in the early modern period, and the article further suggests a symbiotic relationship between “big data” and microhistory.

Natural Deep Eutectic Solvent-Assisted Construction of Silk Nanofibrils/Boron Nitride Nanosheets Membranes with Enhanced Heat-Dissipating Efficiency.

Natural polymer-derived nanofibrils have gained significant interest in diverse fields. However, production of bio-nanofibrils with the hierarchical structures such as fibrillar structures and crystalline features remains a great challenge. Herein, an all-natural strategy for simple, green, and scalable top-down exfoliation silk nanofibrils (SNFs) in novel renewable deep eutectic solvent (DES) composed by amino acids and D-sorbitol is innovatively developed. The DES-exfoliated SNFs with a controllable fibrillar structures and intact crystalline features, novelty preserving the hierarchical structure of natural silk fibers. Owing to the amphiphilic nature, the DES-exfoliated SNFs show excellent capacity of assisting the exfoliation of several 2D-layered materials, i.e., h-BN, MoS2, and WS2. More importantly, the SNFs-assisted dispersion of BNNSs with a concentration of 59.3% can be employed to construct SNFs/BNNSs nanocomposite membranes with excellent mechanical properties (tensile strength of 416.7MPa, tensile modulus of 3.86GPa and toughness of 1295.4 KJ·m-3) and thermal conductivity (in-plane thermal conductivity coefficient of 3.84 W·m-1·K-1), enabling it to possess superior cooling efficiency compared with the commercial silicone pad.

Investigation of the Structural Changes in Silk Due to Tin Weighting.

In the 19th century, the weighting of silk with metal salts, such as tin, was a common practice to enhance certain properties of silk fabrics and compensate for the weight loss incurred during the degumming process. This technique induces both physical and chemical modifications to the fibres, contributing to their long-term degradation, which requires thorough investigation. This study aims to examine the structural changes in silk fibres caused by the accumulation of metal salts from the tin-weighting process, using mock-up samples prepared through successive loading with weighting agents using a traditional tin-phosphate treatment method. Unweighted and tin-weighted silk samples were compared using scanning electron (SEM) micrographs, which presented the dispersed nanoparticles on the fibres, while through energy-dispersive X-ray spectroscopy (EDS) elemental mapping, the presence and uniform distribution of the weighting agents were confirmed. Fourier-transform infrared spectroscopy (FTIR) analysis revealed structural changes in tin-weighted silk samples compared to untreated ones, including shifts in amide bands, altered water/hydroxyl and skeletal stretching regions, and increased skeletal band intensities suggesting modifications in hydrogen bonding, β-sheet content, and structural disorder without significantly impacting the overall crystallinity index. X-ray diffraction (XRD) analysis of both pristine and tin-weighted silk samples revealed significant alterations, predominantly in the amorphous regions of the silk upon weighting. These structural changes were further examined using small-angle X-ray scattering (SAXS) and small- and wide-angle X-ray scattering (SWAXS), which provided detailed insights into modifications occurring at the nanometre scale. The analyses suggested disruptions in β-sheet crystals and intermolecular packing, especially in the amorphous regions, with increasing amounts of tin-weighting. Contact angle analysis (CA) revealed that the tin-phosphate-weighting process significantly impacted silk surface properties, transforming it from moderately hydrophobic to highly hydrophilic. These changes indicate that the incorporation of tin-phosphate nanoparticles on and within silk fibres could restrict the flexibility of polymer chains, impacting the physical properties and potentially the degradation behaviour of silk textiles. By studying these structural changes, we aim to deepen our understanding of how tin-weighting impacts silk fibre structure, contributing valuable insights into the longevity, conservation, and preservation strategies of silk textiles in the context of cultural heritage.

Spider Silk: Rapid, Bottom‐Up Self‐Assembly of MaSp1 into Hierarchically Structured Fibers Through Biomimetic Processing

AbstractSpider dragline silk's exceptional mechanical performance, coupled with its benign production pathway, have inspired the design of diverse smart materials. Remarkably, relatively little is known about the self‐assembly process of major ampullate spidroin 1 (MaSp1) – the main protein constituent of dragline fiber – during its rapid conversion from soluble precursor protein into hierarchically structured mature silk fibers. Herein, the biomimetic potential of MaSp1 is explored using a new recombinant platform with full domain representation. MaSp1 is found to undergo efficient liquid‐liquid phase separation (LLPS) in response to kosmotropic ions, with notably higher propensity compared to MaSp2, and with MaSp1 exhibiting a more complex solubility profile relative to levels of sodium chloride. To further the understanding of silk spinning, the rapid assembly of mesoscale structures is monitored in real‐time in response to ion and pH gradients, revealing a progression from LLPS droplets toward aligned hierarchical fibers. Furthermore, using this biomimetic system, insoluble macroscopic MaSp1 fibers can be readily generated, wherein the application of mechanical deformation triggers the emergence of β‐sheet secondary structures. The insights gained from this study can have broader application in efforts to mimic the formation of biomaterials with spatially organized features across multiple length scales.

A Review on Medicinal Value of Silkworm Product and By-Products

Sericulture is an agro based industry that includes production of raw silk by breeding, rearing of silkworm and cultivation of their host plants. The manufacture of various types of silk was the only emphasis of the traditional sericulture industry, and leftovers were typically disposed away as trash. Byproducts and products from sericulture can be used medicinally in addition to generating silk. The silkworm is a valuable tool in laboratory research and has been utilised as a model organism in life sciences, environmental monitoring, antimicrobial drug screening, and other applications. Protein extract from silkworm eggs is used to improve memory and assist control weight. The silkworm's larvae are also beneficial medicinally; they include blood glucose-lowering agents and silkworm gut fibre, among other things. Similarly, silkworm pupae, a significant by-product of the silk reeling business, have great nutritional content and potential medical applications including hepatoprotection, anticancer, and anti-aging. They can be utilised as an alternative to conventional dietary supplements. As a result, functional sericulture under a new paradigm has replaced sericulture to produce solely silk fabric, greatly increasing farmer revenue while also relieving patient suffering.

Silk fabric dyeing with Basella alba (Sri Lankan green spinach fruit) natural dyes: Mordant-free dyeing approaches

The rising demand for natural dyes creates opportunities for farmers and artisans, boosting employment and local economies. This research investigates the utilization of a natural colourant derived from Basella alba fruit, commonly recognized as Sri Lankan green spinach, for dyeing silk fabrics without mordants. The methodology involved an aqueous extraction, acidic, and alkaline extraction process of natural dyes. Additionally, in this extraction process, a solution comprising Basella alba fruit extraction and Soy Milk Solution was mixed in ratio 4:1 enriching the dyeing affinity of the natural colourants. Basella alba was chosen as the primary colourant, with investigations conducted on the influence of varying pH levels and extraction temperatures. The results of this study suggest that Basella alba fruit extract can be used as a natural dye for silk fabric dyeing. CIE La*b* and K/S data have revealed excellent reflectance on Silk fabric. The extraction process of Basella alba fruit for natural dyeing showcases the potential to yield natural pastel shades, such as yellow, pink, and purple shades. The dyed samples were assessed for their light and washing fastness, receiving grades ranging from fair to excellent. Notably, the washing fastness 4:1 ratio of Basella alba fruit with Soy Milk Solution with extract dyeing yielded particularly impressive results. It reveals enhanced washing fastness properties particularly in low-temperature (40°C) dyeing processes. This study not only highlights the technical viability of employing Basella alba fruit extract for silk fabric dyeing but also highlights its socioeconomic significance in fostering sustainable livelihoods and niche market.

Study on the performance of Co–Ni sulfide electrocatalysts supported by different fibroin-based carbon precursors

Research on sustainable energy sources is crucial for alleviating environmental issues and addressing energy security concerns. This study investigates the utilization of various silk precursors in the hydrogen evolution reaction. Waste silk fabric, regenerated silk fibroin film, porous silk fibroin, silk cocoon and degummed silk fibroin were used as precursors to prepare HER electrocatalysts. To investigate the influence of precursor form on catalytic perform9ance, a comparative analysis of the morphology, structure and composition of different materials was conducted. Among various catalysts, waste silk fabric based catalysts exhibit the most excellent catalytic activity, with an overpotential of 113 mV at 10 mA cm−2 and a Tafel slope of 30.9 mV/dec. Even After 1000 cycles of testing, it still maintains excellent catalytic activity. This study provides insights into the influence of precursor forms on the electrochemical performance of biomass carbon-based catalysts, aiming to inspire further research in this field.

Horn sheath-inspired lightweight composites with enhanced impact resistance

The natural Caprinae horn sheaths possess excellent mechanical properties due to the synergistic effects of the porous and corrugated lamellar structure. However, research on bioinspired designs based on this structure remains absent. In this work, we attempted to integrate hollow glass microspheres modified by silane coupling agents into A. pernyi silk fabric, and finally fabricate a horn sheath-inspired composite using the vacuum-assisted resin transfer molding. The impact strength of the horn sheath-inspired composite reaches up to 150 kJ m-2 with a low density of 1290 kg m-³. Fracture morphology analysis and finite element simulation confirmed the toughening mechanisms, including crack deflection and interfacial bonding due to the synergistic effects of the porous structure and the corrugated silk fabrics. This study provides a bioinspired strategy to lightweight and tough composites, with significant potential in impact-critical applications.

Exploring the Traditional Turkish Ucetek Entari of the Late Ottoman Era from the Izmir Ethnography Museum Collection

The ucetek entari, üç etek or three-skirt robe, was the main element of traditional Turkish women’s clothing, worn with a chemise and shalwar. The features of this special garment extend to the clothing culture of the ancestors of the Turks who lived in Eurasia. The structure of the ucetek entari is typical Ottoman attire, with a small standup collar, long sleeves open up to the elbows, high slits on each side of the skirt, and triangular pieces added for fullness. This research was conducted in the Izmir Ethnography Museum to analyze the fabrics, embroidery, and pattern-making techniques of the ucetek entari, along with their zero waste and multifunctional design approach. The main fabrics, linings, facings, their yarn count in the warp and weft directions, pattern dimensions, embroidery properties, other surface decorations, and technical drawings of the robes were photographed and examined in detail. The results revealed that ucetek entaris were daily or special occasion wear which were designed using mostly silk and cotton fabrics. The focus of this research is to analyze in depth the ucetek entaris in the Izmir Ethnography Museum.