Spinning Angora Rabbit Wool‐Like Porous Fibers from a Non‐Equilibrated Gelatin/Water/2‐Propanol Mixture

Abstract

Due to their porous structure, angora rabbit fibers make for some of the highest quality wool. The application of these fibers on a technical scale is not feasible due to their limited availability and high price. Here, a robust fiber preparation method is reported based on an unusual spinning process, where a non‐equilibrated, ternary system of protein, solvent, and non‐solvent is continuously processed into strong fibers with minimal energy input and harmless solvents. Gelatin—the degradation product of collagen—is chosen as the protein component because of its immense availability from slaughterhouse waste. Due to the sponge‐like structure of the ternary gelatin/water/2‐propanol spinning mixture, fibers with internal cavities are produced. The porous nature of these fibers resembles the morphology of angora rabbit fibers. Despite their high porosity, the here‐obtained gelatin fibers show clear re‐orientation of the fibrous protein and attain a mechanical performance similar to other bio‐ (e.g., wool, tendon collagen) and synthetic polymers (e.g., polytetrafluoroethylene, polyamide 6). These promising results motivate for broader investigations on the spinning of non‐equilibrium protein mixtures and suggest the use of porous gelatin fibers in textiles.

Fibers Mechanically Similar to Sheep Wool Obtained by Wet Spinning of Gelatin and Optional Plasticizers

“…Gel spinning of gelatin in ethylene glycol yielded higher mechanical properties (up to 400 MPa tensile strength) but only after extraction of ethylene glycol during several days which is impractical for a large‐scale application. In comparison to dry spun gelatin fibers prepared in a previous work (elastic modulus: 2.6 GPa; engineering tensile strength: 85 MPa; true tensile strength: 160 MPa), the here presented wet spun gelatin fibers have superior mechanical properties.…”

Effects of Wnt10b on dermal papilla cells via the canonical Wnt/β‐catenin signalling pathway in the Angora rabbit

“…The Angora rabbit is a typical rabbit used for wool. The Angora rabbit fibres are among the highest quality animal fibres used in the textile industry, because of their sheen, small fibre diameter and the presence of a lattice‐type medulla (Stoessel et al, ). Despite their extraordinary properties, the Angora rabbit fibres are not suited for application on a technical scale because of limited availability, with its global production being only about 10,000 tons per year.…”

Elaborate ultrastructure of the Hirudo (Annelida: Hirudinae) cocoon surface

“…The d ‐spacing, for each peak using d = 2 π /q formula (Birkholz, ) are d 1 of 0.45 nm (2θ = 20 ο ), d 2 of 0.98 nm (2θ = 9 ο ), and d 3 = 0.40 nm (22 ο ). The spacing d 1 corresponds to the backbone spacing (distance between neighboring peptides chains; Stanton et al, ), which is common in all proteins (Stoessel et al, ). The spacing d 2 represents the intermolecular distance, corresponding to the lateral packaging distances of α‐helices (Stoessel et al, ).…”

“…The spacing d 1 corresponds to the backbone spacing (distance between neighboring peptides chains; Stanton et al, ), which is common in all proteins (Stoessel et al, ). The spacing d 2 represents the intermolecular distance, corresponding to the lateral packaging distances of α‐helices (Stoessel et al, ). The d ‐spacing at 0.40 nm represents the interplanar distance across fiber axes corresponding to the correlation distance between amino acid residue sequences (Charvolin & Sadoc, ).…”

“…Small holes were present on the surface of proximal branches and these enlarged distally, thereby requiring 3-4 branches to surround it ( Figure 5, inset). Stanton et al, 2017), which is common in all proteins (Stoessel et al, 2014). The spacing d 2 represents the intermolecular distance, corresponding to the lateral packaging distances of a-helices (Stoessel et al, 2014).…”