Obtaining high mechanical performance silk fibers by feeding purified carbon nanotube/lignosulfonate composite to silkworms

Abstract

Silkworm fibers have attracted widespread attention for their superb glossy texture and promising mechanical performance.

Advances on Emerging Materials for Flexible Supercapacitors: Current Trends and Beyond

“…Although this report did not discuss the graphene‐based electrode materials, owing to the properties of ultrastretchability of the carbonated silk and the reports on the possibility of converting the fibroin into the graphitic carbons suggests that this substrate can be used either to grow the graphene or process for the graphene coating and could be studied for energy storages, which might open an idea to work on ultrastretchable graphene‐coated electrode. [ 43 ] Supporting this statement, Hou et al., [ 44 ] graphitized the silk by activating them using the ZnCl 2 and then carbonizing at 900 °C to get the carbon. The authors referred to the final product as the nitrogen‐doped as the entire process was carried out under nitrogen atmosphere.…”

Mechanical and structural properties of major ampullate silk from spiders fed carbon nanomaterials

“…GS formed into CNTs have been shown to be the strongest synthesized material, with a strength two orders of magnitude greater than steel at only 1/6 th the weight [1,3,4]. The ability to combine the strongest known synthesized material (e.g., graphene and nanotubes) with the toughest known biological materials in nature (e.g., silkworm silk, spider silk) could lead to the creation of remarkable new bio-synthetic super materials [3,[6][7][8]. However, most of this research is still at the preliminary stages of proof of concept and results vary between experiments.…”

“…Silk from Mulberry Silkworm (i.e., Bombyx mori) cocoons and spider silk have been a focus for material science because of their incredible tensile properties and biocompatibility [3,6,7,[9][10][11][12]. The unique mechanical properties are a result of the combination of protein structures that include semi-amorphous α-helix regions that contribute to the silk's elasticity and crystalline β-sheets that give the material its strength [9,[13][14][15][16][17].…”

“…B. mori have been domesticated for thousands of years and the ability to collect silk at industrial scales makes this a popular biomaterial for creating nanocomposites [9,17]. For an example, after feeding B. mori larva mulberry leaves coated with solutions containing carbon nanotubes (CNTs), silk from their cocoons was found to have double the toughness [6][7][8] and showed an increase in conductivity by more than 70% [7]. However, the drag line silk of orb-weaving spiders, known as major ampullate (MA) silk, has an even higher tensile strength of around 1000-1400 Mpa and an elasticity of around 20-30% [9-12, 16, 17].…”

“…Two methods used to combine spider silk fibers with carbon nanomaterials have been by either coating the exterior of the silk [ 11 , 12 ] or incorporating the carbon nanomaterials into the silk by having spiders ingest a solution containing GS or CNTs [ 7 ]. For an example, in a study by Steven et al (2013), major ampullate silk from Nephila clavipes spiders was coated with amine-functionalized multi-walled carbon nanotubes (f-NTS-SS) through the process of hydrating the silk and mechanically shearing the two materials together.…”