Enhanced dielectric properties of polymer composite films induced by encapsulated MWCNTs with a one core‐two shell structure

• Published in: Journal of polymer science. Part B, Polymer physics Polymer physics, 2017-06, Vol.55 (12), p.948-956
• Main Authors: Yu, Shuangmin, Wang, Gengchao
• Format: Article
• Language: English
• Subjects: carbon nanotubes; Core-shell structure; Dielectric loss; dielectric materials; Dielectric properties; Dispersion; Encapsulation; Multi wall carbon nanotubes; Permittivity; poly(vinylidenefluoride‐hexaflouropropylene); polyaniline; Polyanilines; Polymer films; Polymer matrix composites; Self-assembly
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.24341

ABSTRACT Multiwalled carbon nanotubes (MWCNTs) can endow high dielectric constant to polymer‐based composites. However, the accompanying poor dispersion of MWCNTs and high dielectric loss for composites severely limit their application in dielectric field. Herein, a modified acid‐treated MWCNTs encapsulated by the polyaniline/poly(sodium 4‐styrenesulfonate) layers (aMWCNTs@PANI‐PSS) with a one core‐two shell structure was fabricated by in situ polymerization followed by electrostatic self‐assembly technique. Furthermore, the composite films based on aMWCNTs@PANI‐PSS/poly(vinylidenefluoride‐hexaflouropropylene) (PVDF‐HFP) were fabricated by a solution‐casting method. An ultrathin insulating PSS shell is wrapped onto aMWCNTs@PANI, resulting in the improvement of dispersibility for aMWCNTs@PANI and the decrease of dielectric loss for composite films. When the content of aMWCNTs@PANI‐PSS is 5.0 wt %, the dielectric constant of aMWCNTs@PANI‐PSS/PVDF‐HFP reaches 430 (100 Hz), which is about 55 times of pure PVDF‐HFP and 1.7 times of aMWCNTs@PANI/PVDF‐HFP (247). Besides, the responding dielectric loss of aMWCNTs@PANI‐PSS/PVDF‐HFP composite film is only 0.67, much lower than that of aMWCNTs@PANI/PVDF‐HFP (25) and aMWCNTs/PVDF‐HFP (3185). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 948–956 The one core‐ two shell structured aMWCNTs@PANI‐PSS nanofiber has been fabricated, and its PVDF‐HFP based composite film shows a high dielectric constant and relatively low dielectric loss. The approach in this study may be extended to the fabrication of similar hybrid composites with excellent mechanical and dielectric performance, which can be beneficial for applications in electronic devices.