An electrochromic alginate fiber based on a W18O49/PEDOT:PSS composite layer

• Published in: International journal of biological macromolecules 2025-03, Vol.296, p.139680, Article 139680
• Main Authors: Liu, Yongjiao, Sun, Ning, Duan, Jingzhong, Liu, Xiaoxuan, Dong, Jinfeng, Wang, Tian, Long, Xiaojing, Nie, Zhaoguang, Wang, Bingbing, Xia, Yanzhi
• Format: Article
• Language: English
• Subjects: Alginate fibers; Conductive fibers; Electrochromic; W18O49 nanowires
• ISSN: 0141-8130; 1879-0003; 1879-0003
• DOI: 10.1016/j.ijbiomac.2025.139680

In this experiment, we studied a technique that permits the continuous fabrication of electrochromic alginate fibers because there hasn't been much research on electrochromic alginate fibers. Therefore, it's important to investigate ways to increase the application areas of alginate fibers. AgNP‑calcium alginate fibers with high electrical conductivity were prepared by Ag+ substitution method. Electrochromic alginate fibers were successfully prepared by sequentially coating the fibers with PEDOT:PSS, W18O49, and PVDF:HFP to form a W18O49/PEDOT:PSS composite color-changing layer and a PVDF:HFP stable electrolyte layer. Fifty electrochromic alginate fibers with a length of 7 cm were tested, and their resistance values ranged from 2 to 12 Ω, of which 78 % were between 3 and 8 Ω, providing excellent electrical conductivity. In the electrolyte from 0.1 V to −0.7 V, the color of the fiber changes from the original state to the colored state in only 5 s. Ten minutes after the voltage is disconnected, the color changes to the original color of the AgNP-Calcium Alginate fibers and the color change are reversible. The solid fibers can change from light blue to dark blue and the color change is uniform in the upright and bent state. This study lays a solid research foundation for the industrial production and intelligent application of electrochromic alginate fibers. AgNP‑calcium alginate fibers with good electrical conductivity were prepared by Ag+ substitution method. Electrochromic AgNP‑calcium alginate fibers were prepared by sequentially coating PEDOT:PSS, W18O49 and PVDF:HFP coatings onto AgNP‑calcium alginate fibers. The fibers changed from the original color state to the coloring state at a voltage of −0.7 V to 0.1 V. After switching off the voltage, the color changed back to the original color and the process of color change was reversible. The properties of electrochromic AgNP‑calcium alginate fibers were investigated by UV absorption spectroscopy, and the transmittance of the fibers was 35.97 % before color change and 22.28 % after color change. In the solid state, the fibers can change from light blue to dark blue, and the transmittance of the fibers before and after discoloration is 36.34 % and 23.10 %, respectively. [Display omitted] •Electrochromic AgNP-Calcium Alginate fibers have good electrical conductivity with resistance values between 2 and 12 Ω.•The electrochromic fibers can be prepared continuously as long fibers.•Electrochromic fibers have pro