Comparative Study of Strain-Dependent Structural Changes of Silkworm Silks: Insight into the Structural Origin of Strain-Stiffening

Chengchen Guo; Jin Zhang; Xungai Wang; Anh Tuan Nguyen; Xiang Yang Liu; David L Kaplan

doi:10.1002/smll.201702266

Comparative Study of Strain-Dependent Structural Changes of Silkworm Silks: Insight into the Structural Origin of Strain-Stiffening

Small. 2017 Dec;13(47). doi: 10.1002/smll.201702266. Epub 2017 Oct 27.

Authors

Chengchen Guo¹, Jin Zhang², Xungai Wang², Anh Tuan Nguyen³, Xiang Yang Liu³, David L Kaplan¹

Affiliations

¹ Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA.
² Australian Future Fibres Research and Innovation Centre, Institute for Frontier Materials, Deakin University, VIC, 3216, Australia.
³ Department of Physics, University of Singapore, Singapore, 117542, Singapore.

PMID: 29076647
DOI: 10.1002/smll.201702266

Abstract

Structure-property relationships of silk is an intriguing topic for silk-based biomaterials research since these features are related to biomimicking the processing in natural silk fiber formation which results in excellent mechanical properties. Strain-stiffening is common for spider silks and nonmulberry silkworm silks. However, the structural origin of strain-stiffening remains unclear. In this paper, the strain-dependent structural change of Antheraea pernyi silkworm silk is studied by X-ray fiber diffraction and Fourier transform infrared spectroscopy under stretching. Based on a combination of mechanical and structural analysis, the molecular origins of strain-stiffening in A. pernyi silk were determined. The relatively high content of the β-sheets within the amorphous domains in A. pernyi silk is responsible for strain-stiffening, where "molecular spindles" enhance the extensibility and toughness of the fiber.

Keywords: silkworm silk; strain-stiffening property; structure-property relationship.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.