Natural flat cocoon materials constructed by eri silkworm with high strength and excellent anti-ultraviolet performance

Bin Zhou,Ke Wang,Huiling Wang,Hongtao Zhou,Shudong Wang

doi:10.1177/1558925020978652

Bin Zhou, Ke Wang + Show 3 more

Open Access

https://doi.org/10.1177/1558925020978652

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Abstract

Eri silkworm is easy to be raised and has high cocoon yield, the cocoon fails to be continuously reeled due to a loose structure, a large part of cocoon coat and an eclosion hole. In this work, a fifth instar larvae of eri silkworm was provided with only a flat cocooning place to spin to produce a flat cocoon, it was fed with the castor leaves sprayed with nano-TiO2 and graphene oxide (GO), Compared with the flat cocoon obtained without nanomaterials, the silk was not found to change in morphology and structure significantly. Nanomaterials promoted the transformation of the random coil/α-helix conformation of the silk to the β-sheet conformation to a certain extent, which formed a stable crystallization. Thus its strength value could increase by 15%–17%, the ultraviolet protection factor ( UPF) value of the flat cocoon with nanomaterials increased significantly, and the silk obtained made up for the lack of the strength in natural eri silkworm silk and poor resistance to sunlight. The flat cocoon features a stable structure, good formation, uniform thickness, and manual control. It can be directly used as raw material for processing flat textile products, which provides a feasible idea for the high-value utilization of the eri silkworm cocoon.

Highlights

The eri silkworm is the third largest in the world, behind the mulberry silkworm and the tussah
Nano TiO2 and graphene oxide (GO) are mixed into the castor leaves separately or together, which are absorbed and transformed by the eri silkworm itself to produce modified natural silk with a stable combination, excellent mechanical properties and anti-ultraviolet functionality and at the same time eri silkworm was provided with only a flat cocooning place to spin, which changes the spinning path of the eri silkworm to produce the flat cocoon material that can be directly used as a raw material for processing flat textile products to make up for the structural limitations of the cocoon itself to its industrial development
No addition of nanomaterials was found to affect the eating speed of the silkworms, or cause the growth retardation and death of silkworms, indicating that the feeding of TiO2 and GO would not affect the normal growth of eri silkworms

Summary

Introduction

The eri silkworm is the third largest in the world, behind the mulberry silkworm and the tussah. Nano TiO2 and GO are mixed into the castor leaves separately or together, which are absorbed and transformed by the eri silkworm itself to produce modified natural silk with a stable combination, excellent mechanical properties and anti-ultraviolet functionality and at the same time eri silkworm was provided with only a flat cocooning place to spin, which changes the spinning path of the eri silkworm to produce the flat cocoon material that can be directly used as a raw material for processing flat textile products to make up for the structural limitations of the cocoon itself to its industrial development.

Results

Conclusion