Nanomechanical and tribological characterization of silk and silk-titanate composite coatings. (June 2020)

• Record Type: Journal Article
• Authors: Arsecularatne, Joseph A.; Colusso, Elena; Della Gaspera, Enrico; Martucci, Alessandro; Hoffman, Mark J.
• Is Part Of: Tribology international. Volume 146(2020)
• Publication Date: 2020-06
• Subjects: Silk coating -- Silk-titanate composite coating -- Tribological characterization -- Nanomechanical characterization; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2020.106195
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: This paper investigates the tribological and mechanical properties of silk-based nanocomposite coatings which are finding applications in optics, biomedicine and dentistry, thanks to the exceptional mechanical/optical properties and associated biocompatibility of silk. Three different nanocomposite formulations were synthesized, and thin films were prepared by spin coating at different thicknesses and with different post-deposition annealing processes. Ellipsometry, FTIR spectroscopy, AFM, nanoindentation, scratch testing, continuous/reciprocating wear testing, confocal microscopy and SEM were used to characterize the coatings. The results reveal that their hardness and elastic modulus are in the range 0.56–1.30 GPa and 23.6–55.4 GPa, respectively, which are much higher than those reported for other silk films in literature. Incorporation of titanate nanosheets also improved coatings' scratch resistance. Highlights: Presents a nanomechanical/tribological characterization of nanocomposite coatings made of silk fibroin and titanates Results are presented for three different formulations of nanocomposite coatings with different post-deposition annealing The measured nanomechanical properties are higher than those reported for graphene-silk composite films in the literature. Incorporation of titanates nanosheets improved the scratch resistance of a composite coating.