Polyvinyl alcohol covalently grafted CNT for free-standing, flexible, and high-performance thermoelectric generator film. (7th February 2019)

• Record Type: Journal Article
• Authors: Ha, Jae Un; Cho, Jangwhan; Yoon, Seongwon; Jang, Min Su; Hassan, Syed Zahid; Kang, Min Gyun; Chung, Dae Sung
• Is Part Of: Nanotechnology. Volume 30:Number 14(2019)
• Publication Date: 2019-02-07
• Subjects: organic thermoelectric generator -- grafted single-walled carbon nanotube -- flexible device; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/1361-6528/ab0121
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We introduce a strategic approach to synthesize covalntly cross-linked carbon nanotube (CNT)-polymer nanocomposites, which can be applied as a free-standing and flexible organic thermoelectric generator film. Esterification of polyvinyl alcohol (PVA) to render PVA-COOH followed by an amide reaction with single-walled CNTs (SWCNTs) functionalized with amino groups (SWCNT-NH2 ) yielded a covalently grafted PVA/SWCNT composite film with an excellent dispersion of SWCNTs within the polymer matrix as confirmed using Fourier-transform infrared spectroscopy and scanning electron microscopy. This amide reaction could be further optimized with the addition of a small amount of Triton™ X-100, which resulted in a better dispersion of SWCNT prior to the amide condensation reaction. Consequently, a covalently cross-linked PVA/SWCNT composite film showed better Seebeck coefficients than those of previously reported non-covalently, physically wrapped polymer/CNT composite films, resulting in a high power factor up to 275 μ W m −1 K −2 . Furthermore, a covalent amide-linking between PVA and SWCNT yielded a free-standing film (30 × 30 mm) with excellent flexibility and notable shelf stability as confirmed by negligible changes in thermoelectric parameters after bending test for 10 000 times with a bending radius of 2 mm and also shelf stability test in ambient condition without any passivation layer for 30 d.