Silk Research Articles

The Photothermal Conversion and UV Resistance of Silk Fabrics Being Achieved through Surface Modification with C@SiO2 Nanoparticles.

With the improvement in people's living standards, the development and application of smart textiles are receiving increasing attention. In this study, a carbon nanosurface was successfully coated with a SiO2 layer to form C@SiO2 nanomaterials, which improved the dispersion of carbon nanomaterials in an aqueous solution and enhanced the absorption of light by the carbon nanoparticles. C@SiO2 nanoparticles were coupled on the surface of silk fabric with the silane coupling agent KH570 to form C@SiO2 nanosilk fabric. The silk fabric that was subjected to such surface modification was endowed with a special photothermal function. The results obtained with scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and infrared spectroscopy (FTIR) showed that C@SiO2 nanoparticles were successfully modified on the surface of the silk fabric. In addition, under the irradiation of near-infrared light with a power of 20 W and a wavelength of 808 nm, the C@SiO2 nanosilk fabric experienced rapid warming from 23 °C to 60 °C within 30 s. After subjecting the functional fabric to hundreds of photothermal experiments and multiple washes, the photothermal efficiency remained largely unchanged and proved to be durable and stable. In addition, the thermogravimetric (TG) analysis results showed that the C@SiO2 nanoparticles contributed to the thermal stability of the silk fabric. The UV transmittance results indicated that C@SiO2 nanofabric is UV-resistant. The silk modification method developed in this study is low-cost, efficient, and environmentally friendly. It has some prospects for future applications in the textile industry.

Durable Radiative Cooling Multilayer Silk Textile with Excellent Comprehensive Performance

AbstractPassive radiative cooling without energy consumption is increasingly being explored as an eco‐friendly alternative to electric cooling for mitigating heat stress caused by global warming. Incorporating radiative cooling into personal thermal management has garnered widespread interest. However, existing sub‐ambient radiative cooling textiles face challenges related to inferior solar reflectance, poor outdoor durability, or health concerns. Here, a durable multilayer silk textile (MST) is developed that achieves excellent comprehensive performance for the first time, including both ultrahigh solar reflectance (96.5%) and ultrahigh infrared emittance (97.1%), safety, air and moisture permeability, high mechanical strength, washability, abrasion resistance, surface hydrophobicity, and UV resistance. The MST achieves a remarkable sub‐ambient temperature drop of 5.1 °C under 892.4 W m−2 of ultra‐strong solar radiation and surpasses both commercial silk and cotton textiles at noon with temperature reductions of 6.0 and 8.3 °C, respectively. For proof of concept, a hat using the MST is fabricated, which shows improved cooling performance compared to commercial hats. Considering its outstanding cooling performance, durability, zero energy consumption, abundant raw materials, and scalable production ability, it is believed that the radiative cooling MST holds great promise for practical applications in daytime personal thermal management.

Thermally reversible hydrogels printing of customizable bio-channels with curvature

Replicating intricate bio-channels, akin to expansive vascular networks, offers numerous advantages including self-repair, replacing damaged bio-channels, testing drugs, and biomedical devices. But, crafting multi-sized, editable bio-channels with specific curvatures, particularly using natural polymer-based bio-inks, poses a significant challenge. To address this, this study introduces a temperature-driven indirect printing method, exemplified by the diploic vein. Here, K-carrageenan (kca)-silk fiber (SF)-hyaluronic acid (HA)/hFOB 1.19 (SV40 transfection of human osteoblasts) and kca-collagen-HA/HUVECs (human umbilical vein endothelial cells) are employed to fabricate vascular-like walls and lumens, utilizing their thermoreversible properties to create multi-stage bifurcated lumens. Precise spatial curvature was generated by heating the vascular network wrapped in poly(N-isopropyl acrylamide) (PNIPAAm)-poly(ethylene glycol) diacrylate (PEGDA). Since temperature is specific to the thermal material carrying the cells, the rheological properties of bioinks, modeling temperature parameters, and their impact on printing size was explored. Additionally, mechanical properties and curvature response were characterized to determine the necessary process parameters for achieving the desired size. Ultimately, in vitro bioprinting experiments involving HUVECs and hFOB 1.19 demonstrate cell viability, adhesion, proliferation, and migration within the intraluminal hydrogel scaffold. This approach allows for customizing bio-channel content and controlling curvature programming, providing new prospects for in vitro biochannel production, with potential benefits for pathology research.

ADDRESSING CLASS IMBALANCE FOR TRAINING A MULTI-TASK CLASSIFIER IN THE CONTEXT OF SILK HERITAGE

Abstract. Collecting knowledge in the form of databases consisting of images and descriptive texts that represent objects from past centuries is a fundamental part of preserving cultural heritage. In this context, images with known information about depicted artifacts can serve as a source of information for automated methods to complete existing collections. For instance, image classifiers can provide predictions for different object properties (tasks) to semantically enrich collections. A challenge in this context is to train such classifiers given the nature of existing data: Many images do not come along with a class label for all tasks (incomplete samples) and class distributions are commonly imbalanced. In this paper, these challenges are addressed by a multi-task training strategy for a classifier based on a convolutional neural network (SilkNet) that requires images with class labels for the tasks to be learned. The proposed approach can deal with incomplete training examples, while implicitly taking interdependencies between tasks into account. Extensions of the training approach with a focus on hard examples during training as well as the use of an auxiliary feature clustering are developed to counteract problems with class imbalance. Evaluation is conducted based on a dataset consisting of images of historical silk fabrics with labels for five tasks, i.e. silk properties. A comparison of different variants of the classifier shows that the extensions of the training approach significantly improve the classifier’s performance; the average F1-score is up to 5.0% larger, where the largest improvements occur with underrepresented classes of a task (up to +14.3%).

Maintaining Mandar Silk Fabric Through Addressing and Marketing as a Supporter of Marital Tourism at Polewali Mandar

Maintaining Mandar Silk Fabric Through Addressing and Marketing as a Supporter of Marital Tourism at Polewali Mandar

Structure and Properties of Cationic Chitosan Derivative Modified Bombyx mori

Abstract Cationic modification of silk fabric can highly improve its antibacterial property, but cationic modification may change the microstructure of silk fiber, and further affect its properties, thus O-methyl acrylamide quaternary ammonium salt of chitosan (NMA-HTCC), which is a kind of strong cationic chitosan derivative, was used for the modification on Bombyx mori silk fiber. The combination structure between NMA-HTCC and silk fiber was characterized by FT-IR. The surface morphology and structure of silk fiber after being treated by NMA-HTCC were investigated by SEM and XPS analysis. The crystalline structure and thermal stability of silk fibers before and after being treated were determined by XRD and DSC analysis, respectively. Then the breaking strength, breaking elongation and antibacterial properties of the silk yarns were also determined. The results indicated that the NMA-HTCC modified silk fiber clearly showed two characteristic absorption peaks at 1535 cm-1 and 1670 cm-1 due to the N-H bending and C=O stretch of the secondary amide in the acrylamidomethyl group of the NMA-HTCC molecule. The successful combination of NMA-HTCC and silk fiber was also confirmed by XPS and SEM analysis. Compared with the untreated silk sample, the diffracted intensity of the characteristic absorption peak and crystallinity of the NMA-HTCC modified silk fiber were both increased; the internal aggregation structure of the silk fiber treated with NMA-HTCC was much closer and its thermal stability was enhanced obviously. The breaking strength and elongation of silk fibers after being treated with NMA-HTCC were also significantly increased. Silk fibers treated with NMA-HTCC had excellent durable antibacterial properties against S. aureus and E. coli, even after 50 repeated launderings, with the bacterial reduction rate of the silk fibers maintained at over 95 %. The results in this research can provide the theoretical basis for the application of NMA-HTCC in the modifications of silk fabric.

Introducing Antibacterial Property to Silk Fabric by Chemical Grafting of [2-(methacryloyloxy)ethyl] Trimethyl Ammonium Chloride (MAETC)

Introducing Antibacterial Property to Silk Fabric by Chemical Grafting of [2-(methacryloyloxy)ethyl] Trimethyl Ammonium Chloride (MAETC)

The Venetian Community in Byzantine Thebes (1072–1204): A Prosopographical Study

Thebes is among the best-documented Venetian colonies in Byzantium, with records dating back to 1072. While it is widely acknowledged that Venetians played a crucial role in the development of Byzantine Thebes, the details about the Venetian community of the city remain largely unexplored, which has hindered a deeper understanding of the true extent of the Venetian impact on Thebes. To address this scholarly gap, the article examines the community using Venetian documentary sources, focusing on the works of R. Morozzo della Rocca and A. Lombardo. The study adopted a prosopography methodology, reconstructing and analysing the biographies of individuals and families in groups. The investigation covers the community’s leading families and individuals, as well as clergy and ecclesiastical establishments of special interest. Following this vein, the author of the article concludes with a more detailed picture of the Venetian community. It seems to have played a notable and persistent role in Thebes. Ecclesiastical establishments and the clergy constituted the basis of Venetian activities. Bolstered by reliable and sustainable sources of income, these institutions fulfilled the basic religious and administrative needs of the Venetian community. Apart from possible industrial and agricultural engagements, the community members predominantly emerge as active participants in commercial ventures, linking in particular to the renowned Theban silk textiles. While Venetians did form matrimonial and commercial alliances amongst themselves, their assimilation with the native Byzantine populace of the city seems to have been minimal.

Photostability of Mannich‐type dyed silk fibroin with pyrazolone‐containing aromatic primary amine dyes

AbstractMannich‐type dyeing of silk fibroin with aromatic primary amine dyes (APADs) is a novel reactive dyeing method that requires mild conditions and exhibits high selectivity and good wet fastness. However, the primary amine group in the APADs significantly decreases the photostability of Mannich‐type dyed silk fabrics. To reveal the structure–activity relationship and photofading mechanism of the APADs by Mannich‐type dyeing, six pyrazolone‐containing APADs with similar structures were designed and synthesised. Variation in amino electron density among the dye analogues was related to differences in colour fixation of the Mannich‐dyed fabrics, as determined from the calculated Mulliken charge densities. Using mass spectrometry to monitor the photodecomposition of the dyed silk, it is demonstrated that the Mannich‐type dyed silk fabrics undergo photooxidative fading, in contrast to the conventional acidic‐type dyed fabrics that undergo photoreductive fading. Furthermore, it is shown that the Mannich‐type dyed silk fabric has a higher light fastness than conventional acidic‐type dyed fabrics using the same pyrazolone‐containing APADs. Evaluation of dye dipole moment and Mannich‐type dyeing shows that the APADs with increased dipole moments generally demonstrated increased light fastness.

Enhancing flame retardant and wrinkle-resistant performances of silk fabric with bio-based Maillard reaction products between glucose and poly(glutamic acid)

Bio-based materials have garnered considerable attention in the flame retardant field due to their inherent safety and environmental benefits. This study introduces a novel and eco-friendly flame retardant prepared through the Maillard reaction between glucose and poly(glutamic acid) for treating silk fabric. The study elucidates the synthesis of Maillard reaction products (MRPs) and verifies their deposition onto the silk fabric surface by observing changes in surface morphology, functional groups, and charged characteristics. The flammability tests demonstrate that MRPs treated silk fabrics had a high limiting oxygen index of over 27 % and a charred length of less than 12 cm, indicating effective flame retardancy. Moreover, the introduction of MRPs led to a significant decrease in smoke release when silk fabric underwent combustion. This observation can be attributed to the enhanced char formation and increased thermal degradation temperature of MRPs treated silk fabric. The electrostatic interaction between silk fiber and MRPs contributed to the fabric's resistance to repeated washing. Moreover, MRPs treated silk fabric retained their tensile properties and showed enhanced wrinkle-resistant performance. Generally, this research opens up a new path for the green preparation of halogen-free and phosphorus-free flame retardant protein fibers.

Rapid production of chimeric silkworm/spider silk with improved mechanical properties by infection of nonpermissive Bombyx mori with recombinant AcMNPV harboring native-size of spidroin genes

Spider silks with excellent mechanical properties attract more attention from scientists worldwide, and the dragline silk that serves as the framework of the spider's web is considered one of the strongest fibers. However, it is unfeasible for large-scale production of spider silk due to its highly territorial, cannibalistic, predatory, and solitary behavior. Herein, to alleviate some of these problems and explore aneasy way to produce spider fibers, we constructed recombinant baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) simultaneously expressing Trichonephila clavipes native ampullate spidroin 2 (MaSp-G) and spidroin 1 (MaSp-C) driven by the promoters of silkworm fibroin genes, to infect the nonpermissive Bombyx mori larvae at the fifth instar. MaSp-G and MaSp-C were co-expressed in the posterior silk glands (PSGs) of infected silkworms and successfully secreted into the lumen of the silk gland for fibroin globule assembly. The integration of MaSp-G and MaSp-C into silkworm silk fibers significantly improved the mechanical properties of these chimeric silk fibers, especially the strength and extensibility, which may be caused by the increment of β-sheet in the chimeric silkworm/spider silk fiber. These results demonstrated that silkworms could be developed as the nonpermissive heterologous host for the mass production of chimeric silkworm/spider silk fibers via the recombinant baculovirus AcMNPV.

Physical Properties of the Second Type of Aciniform Spidroin (AcSp2) from Neoscona theisi Reveal a pH-Dependent Self-Assembly Repetitive Domain.

Orb-weaving spiders can use an array of specialized silks with diverse mechanical properties and functions for daily survival. Of all spider silk types, aciniform silk is the toughest silk fiber that combines high strength and elasticity. Although aciniform spidroins (AcSp) are the main protein in aciniform silks, their complete genes have rarely been characterized until now. Moreover, the structural and physical properties of AcSp variant proteins within the species are also unclear. Here, we present three full-length AcSp genes (named AcSp1A, AcSp1B, and AcSp2) from the orb-weaving spider Neoscona theisi and investigate the structural and mechanical features of these three AcSp repetitive domains. We demonstrate that all three AcSp proteins have mainly α-helical structural features in neutral solution and high thermal stability. Significantly, the AcSp2 repetitive domain shows a pH-dependent structural transition from α to β conformations and can self-assemble into amyloid fibrils under acidic conditions, which is the first reported AcSp repetitive domain with pH-dependent self-assembly capacity. Compared with the other two AcSp spidroins, AcSp2 demonstrated the lowest expression level in the aciniform gland but had the highest strength for its silk fiber. Collectively, our findings provide new insight into the physical properties of each component of aciniform silk and expand the repertoire of known spidroin sequences for the synthesis of artificial silk materials.

AN EARLY CONSUMER REVOLUTION IN HISPANIC AMERICA? CONSUMPTION OF ASIAN GOODS BY THE COMMONERS IN 18TH-CENTURY MEXICO

ABSTRACTWas there an early consumer revolution in Hispanic America? This article presents varied evidence supporting an affirmative answer to this question, especially regarding the case of New Spain. The inauguration of the Manilla Galleon trade route across the Pacific Ocean in 1565 was decisive in this respect. It made it possible that Asian goods (more or less finished silk and cotton textiles, porcelain, lacquerware, ivory religious images, furniture and spices, mainly) experienced an early diffusion throughout New Spain after arriving in Acapulco. This innovation in consumption patterns was adopted first by the elites, not much later, by the intermediate classes and, rather soon than not, by the commoners. Primary (i.e. Avalúos of the galleons' cargo) and secondary sources permit quantitatively exploring the possibilities of consumption of Asian goods by unprivileged segments of New Spain's population. We find that a non-negligible number of those goods were accessible to Mexico City labourers. Thus, it may be inferred that upper segments of society accessed it earlier and more easily. Therefore, New Spain should be included in any global narrative of the changes in consumption during the Early Modern Era.

Effect of eIF6 on the development of silk glands and silk protein synthesis of the silkworm, Bombyx mori

The silkworm is a lepidopteran domesticated from the wild silkworm, mostly valued for its efficient synthesis of silk protein. This species' ability to spin silk has supported the 5500-year-old silk industry and the globally known “Silk Road”, making the transformation of mulberry leaves into silk of great concern. Therefore, research on the silk-related genes of silkworms and their regulatory mechanisms has attracted increasing attention. Previous studies have revealed that domestic silk gland cells are endoreduplication cells, and their high-copy genome and special chromatin conformation provide conditions for the high expression of silk proteins. In this study, we systematically investigate the expression pattern of eukaryotic initiation factors (eIFs) and identified the eIF6 as a eukaryotic translation initiation factor involved in the synthesis of silk proteins. We generated an eIF6 gene deletion mutant strain of silkworm using the CRISPR/Cas9 system and investigated the function of eIF6 in silk gland development and silk protein synthesis. The results showed that deletion of eIF6 inhibited the individual development of silkworm larvae, inhibited the development of silk glands, and significantly reduced the cocoon layer ratio. Therefore, we elucidated the function of eIF6 in the development of silk glands and the synthesis of silk proteins, which is important for further elucidation of the developmental process of silk glands and the mechanism underlying the ultra-high expression of silk proteins.

Development of Eco-Friendly Method for Degumming of Eri Cocoons

In this study, a new eco-friendly degumming technique was developed for Eri cocoons without any chemicals. A newly developed eco-Eri degumming process was tried at 110 °C, 120 °C, 130 °C and 140 °C temperatures for 10, 20 and 30 min with soft and hard water. The novel eco-friendly degumming method was compared with the existing method of degumming viz. Soap-soda along with the enzymatic method. After degumming, weight loss per cent, changes in the fibre surface morphology concerning SEM imaging and fibre properties concerning tensile strength and elongation were studied. The eco-Eri degumming method at 130 °C for 30 min using soft water removed the maximum sericin content (degumming loss 15.7%) from Eri cocoon shells and had optimum degumming efficiency. In the eco-Eri degumming method, the degummed Eri cocoons were uniformly softened. The soap soda method of degumming resulted in 14.5% weight loss whereas enzymatic degumming resulted in a maximum of 13% weight loss (12% dosage). Enzymatic degumming significantly reduced the tensile strength but no results found in the tensile properties of Eri silk fibres were observed in new eco-friendly and soap-soda methods. SEM images indicated optimal fibre surface with the smoother surface until 130 °C, but fibre damage and fibrillation occurred at 140 °C and also with the Soap-soda method. An optimal condition for degumming Eri cocoons with the new eco-Eri degumming process is 130 °C for 30 min using soft water. The eco-Eri degumming method is better compared to other methods used presently in the industry.

Synthesis, Characterization, Antibacterial Activity, and Applications of New Reactive Disperse Rhodanine Dyes for Silk and Nylon Fabrics

Synthesis, Characterization, Antibacterial Activity, and Applications of New Reactive Disperse Rhodanine Dyes for Silk and Nylon Fabrics

A novel application of synthesised based squarylium dyes on nylon 6, and silk woven fabrics

Abstract Squarylium dyes were synthesized and characterized by different spectrometric techniques using FT-IR, UV-visible and GC–MS, the dyes gave molar extinction coefficient values greater than 5.2812 × 105 L mol−1 cm−1. Their fastness properties in respect to wash, light, perspiration and hot pressing on nylon 6, and silk fabrics were analyzed, effects of time, temperature, carrier concentration and pH was also investigated and reported. The dyed fabrics showed good to very good wash, light fastness, and perspiration good to very good hot pressing on nylon 6 and good to very good on silk fabric, respectively. The dye-bath exhaustion was found to be between 76 and 92% on nylon 6 and 57 and 85% on silk, respectively. The percentage exhaustion on nylon 6 was found to be very good to excellent but on silk it was found to be good to very good. These studies showed that squarylium dyes can be applied to nylon 6 and silk fabrics, but better performance was found on nylon 6 than silk fabric.

Polyphosphate-loaded silk fibroin membrane as hemostatic agent in oral surgery: a pilot study

PurposePost-interventional hemorrhage can result in serious complications, especially in patients with hemostatic disorders. Identification of safe and efficient local hemostatic agents is important, particularly in the context of an ageing society and the emergence of new oral anticoagulants. The aim of this in vitro study was to investigate the potential of silk fibroin membranes coated with the inorganic polymer polyphosphate (polyP) as a novel hemostatic device in oral surgery.MethodsCocoons of the silkworm Bombyx mori were degummed and dissolved. Varying amounts of long-chain polyP (2–2000 µg/mm2) were adsorbed to the surface of silk fibroin membranes. Analysis of the procoagulant effect of polyP-coated silk membranes was performed using real-time thrombin generation assays in human plasma. Increasing concentrations of polyP (0.15–500 µg/ml) served as a positive control, while uncoated silk fibroin membranes were used as negative control.ResultsPolyP-coated silk fibroin membranes triggered coagulation when compared to plasma samples and pure silk fibroin membranes. A polyP-dose-dependent effect of thrombin generation could be found with a maximum (ETP = 1525.7 nM⋅min, peak thrombin = 310.1 nM, time to peak = 9.8 min, lag time = 7.6 min.) at 200 µg/mm2 of polymer loading on the silk fibroin membrane surface.ConclusionsIn this study, it was demonstrated that silk fibroin membranes coated with polyP have the potential to act as a promising novel hemostatic device.Graphical

Combination of bio-based tannic acid, sophora flower extract and metal salts: A facile route towards improving durable flame retardancy and UV resistance of silk fabrics

Environmental engineering placed green demands on the functional modification of textiles. Here, the combination of bio-based tannic acid, sophora flower extract and metal salts was used to manufacture silk fabrics with flame retardancy and UV resistance via a facile impregnation strategy. With different metal salts treated, the modified silk fabrics named silk/TA/SFE-TE, silk/TA/SFE-Fe and silk/TA/SFE-Cu achieved self-extinguishing in the vertical burning test, with limiting oxygen index values of 31.7 ± 0.4 %, 30.2 ± 0.2 % and 30.9 ± 0.3 %, respectively. In the cone calorimetry test, the peak heat release rate values of the three silk fabrics modified with metal salts were all significantly suppressed, and the total smoke production values of silk/TA/SFE-TE and silk/TA/SFE-Fe were reduced from the original 0.178 m2 to 0.126 m2 and 0.138 m2, respectively. Furthermore, silk/TA/SFE-TE, silk/TA/SFE-Fe and silk/TA/SFE-Cu displayed high ultraviolet protection factor values and thus had good UV resistance, owing to the presence of tannic acid and sophora flower extract. Most importantly, the flame retardancy and UV resistance of the three silk fabrics modified with metal salts were still superior to those of the original silk fabrics after 30 washing cycles. In short, this facile route for the preparation of functionalized silk fabrics provides a novel idea for the development of advanced textiles.

Sericulture in Rural Assam: A Key Aspect for Entrepreneurship Development

The current global scenario certainly presents enormous opportunities for the Indian silk industry. Agriculture and agro-based industries are crucial to the growth of rural economies in developing nations such as India. Sericulture is a traditional agro-based economic activity that has historically been important in terms of job creation and income generation. Given the industry's off-farm and on-farm employment possibilities, it has the potential to offset the seasonality impact on the rural economy. The need for relatively little initial investment makes this industry more appealing to rural entrepreneurs. Mulberry, Oak Tasar, Muga, and Eri are the four different types of silk that are uniquely produced in the North East India. Assam produces more eri and muga silk than mulberry and tasar. Women are better suited to the sericulture sector because it relies heavily on in-house or off farm activities. To understand the scope of employment generation and the growth of different silk cultures in Assam a decadal analysis has been done considering the number of families engaged in sericulture and production of silk yarn from 2011-2021. It has been observed that ericulture has grown in popularity over time since it is comparatively cheap and generates more income than other forms of sericulture. Moreover the growth of sericulture industry in terms of families engaged and production of silk yarn was not always stable over the years. Price fluctuations, lack of proper market, lack of transportation and storage facilities, poor finance, lack of technology penetration, low productivity, and the industry's rural nature are the key obstacles that are holding back the industry to grow to its full potential.