Doubling the Mechanical Properties of Spider Silk by C60 Supersonic Molecular Beam Epitaxy

Maria F Pantano,Lucrezia Aversa,Roberto Verucchi,Roberta Tatti,Nicola M Pugno

doi:10.3389/fmats.2020.00197

Abstract

Spider silk is one of the most fascinating natural materials, owing to its outstanding mechanical properties. In fact, it is able to combine usually self-excluding properties, like strength and toughness that synthetic fibers fail to replicate. Here, we report a method to further enhance the already excellent mechanical properties of spider’s silk, producing nanocomposite fibers where the matrix of spider silk is reinforced with C60 molecules. These are deposited by Supersonic Molecular Beam Epitaxy (SuMBE) and are able to efficiently interact with silk, as evidenced by XPS analysis. As a consequence, upon proper adjustment of the fullerene kinetic energy the treated fibers show improved strength, Young modulus and toughness.

Highlights

Spider silk is one of the most fascinating structural materials offered by nature owing to its unique capability of combining usually self-excluding properties, like load standing and energy dissipation
In order to verify the beneficial effects that the addition of C60 molecules can play on the mechanical properties of spider silk, we took 18 samples from the dragline silk produced by the same spider that belongs to Meta menardi species
It is common to observe a certain variability across the stress-strain curves of spider silk fibers belonging to the same sample [as visible from the curves reported in Figure S1A or in other previous reports (Madurga et al, 2016)], which causes variability in the values of the mechanical properties extracted from such curves

Summary

Introduction

Spider silk is one of the most fascinating structural materials offered by nature owing to its unique capability of combining usually self-excluding properties, like load standing (e.g., strength) and energy dissipation (e.g., toughness). In order to overcome issues related to upscaling of spiders farming to a massive industrial level (Altman et al, 2003), transgenic silkworms were created encoding chimeric silkworm/spider silk genes able to produce composite fibers with improved mechanical properties (Teule et al, 2012). Another example was a recombinant protein that allowed mixing of the mechanical properties of spider silk with the capability of controlled nucleation and hydroxyapatite growth typical of dentin (Huang et al, 2007)

Methods

Results

Conclusion