Self-regenerated silk fibroin with controlled crystallinity for the reinforcement of silk

How Science Can Contribute to the Remedial Conservation of Cultural Heritage

“…Life‐cycle assessment (LCA), materials modeling, and the use of data platforms are crucial to help decrease the environmental impact of new materials directly from the design stage. According to these criteria, renewable materials derived from nature are being progressively introduced in restoration; examples include chitosan, fibroin, nanocellulose, and castor oil [22,51–53] . Inspiration for the formulation of new solutions might also come from our ancient past: archaeological and paleontological materials that have survived to recent times are a magnificent example of a posteriori extreme resilience to alteration; moreover, many such materials were synthesized in soft chemical ways with low energy resources [54] .…”

“…The cellulose nanofibrils film at the canvas surface, increasing its ductility, SNPs penetrate deeper and reinforce at the fiber scale, increasing stiffness; the two effects are balanced varying the SNP/CNF ratio, in an elegant approach alternative to the traditional relining of canvases with synthetic adhesives, which are prone to yellowing and acidity development [21] . In the case of silk, dispersions of self‐regenerated silk fibroin (SRSF) have been recently used to improve the mechanical behavior of aged silk fibers through a robust approach where SRSF is obtained from waste silk and adhered onto weak fibers [22] . By varying the concentration of the dispersions, films at different degrees of fibroin amorphousness or crystallinity are obtained, which provide different mechanical properties upon adhesion to the silk fibers: crystalline layers produce brittle materials, while amorphous ones increase ductility.…”

“…[21] In the case of silk, dispersions of self-regenerated silk fibroin (SRSF) have been recently used to improve the mechanical behavior of aged silk fibers through a robust approach where SRSF is obtained from waste silk and adhered onto weak fibers. [22] By varying the concentration of the dispersions, films at different…”

Natural flat cocoon materials constructed by eri silkworm with high strength and excellent anti-ultraviolet performance

“…Through conversion by the formula of d = λ/2sinθ (λ = 1.54 Å), the interplanar spacings of these four diffraction peaks are 5.34 Å, 4.41 Å, 3.72 Å, and 2.63 Å, respectively. The literature data show that the interplanar spacings of characteristic diffraction peaks in the X-ray diffraction pattern with the β-sheet structure are 5.30 Å and 4.30 Å; the interplanar spacings of characteristic diffraction peaks in the X-ray diffraction pattern with the α-helix structure are 7.40 Å and 3.70 Å, [46][47][48] which are similar to the interplanar spacings of several kinds of eri silkworm flat cocoon silks, so it can be considered that there are β-sheet and α-helix structures in the eri silkworm flat cocoon silk. From the peak-differentiating and imitating curves ( Figure 4(c)-(f)), it can be clearly seen that the crystallinity of flat cocoon silk fed with nanomaterials is higher than that of flat cocoon silk without nanomaterials.…”

Advanced Materials in Cultural Heritage Conservation

“…Finally, one of the latest applications addresses alterations in the secondary structure of fibroin in silk artifacts, which weaken the mechanical properties of degraded textiles, whose conservation is a challenging operation. The use of self-regenerated silk fibroin, prepared from waste silk, has been recently proposed as a green, effective and compatible consolidant for historical artifacts [ 92 ]. The application of fibroin with different degrees of amorphousness or crystallinity, obtained from diluted or concentrated protein dispersions, results in changes in the mechanical properties of the treated silk fibers, which show brittleness in the presence of crystalline layers and ductility when amorphous fibroin is applied.…”