Wet‐spun conductive silk fibroin–polyaniline filaments prepared from a formic acid–shell solution

Abstract

ABSTRACTShell wastes represent a considerable quantity of byproducts in the coastal area. From the viewpoint of ecofriendly and economical disposal, shell wastes are dissolved in formic acid to prepare an ionic liquid at room temperature and dissolve silk fibers to prepare a spinning solution. In this study, we developed conductive filaments made of silk fibroin (SF) and polyaniline (PANI) with wet‐spinning techniques and a water coagulation bath. We then evaluated its surface morphologies and structural, mechanical, and electrical properties. The average diameters of the SF–PANI filaments increased with SF concentration from 8.0 to 14.0 wt % when PANI content was 0.1 wt %. The structure of SF–PANI filaments included the coexistence of silk I and silk II and was not affected by the addition of PANI. Moreover, the stress and strain of the SF–PANI filament were 4.46 ± 0.57 MPa and 16.18 ± 2.35%, respectively. After three drafts, the stress and strain of the SF–PANI filaments reached their maxima: 22.08 ± 0.2 MPa and 63.2 ± 2.56%, respectively. In addition, the electrical properties of the SF–PANI filaments increased with the addition of PANI. Thus, all data in this study suggest that recycled shell wastes can be reused as dissolution systems to prepare SF‐based functional conductive filaments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47127.