An Effective Strategy to Achieve Ultralow Electrical Percolation Threshold with CNTs Anchoring at the Interface of PVDF/PS Bi‐Continuous Structures to Form an Interfacial Conductive Layer

Abstract

Conductive composites based on polymers and conductive nanofillers are widely studied as a promising material. The rational design of 3D conductive networks in composites is crucial to improve their electrical conductivity and reduce the dosage of nanofillers. Herein, poly(vinylidene fluoride) (PVDF) and polystyrene (PS) bi-continuous structures with modified carbon nanotubes (CNTs) tailored to anchor at the interface are designed to achieve an ultralow electrical percolation threshold because of the formation of a thin interfacial conductive layer. In this work, the modification of CNTs with poly(methyl methacrylate) (PMMA), which contributes to the improvement of the compatibility between PVDF and CNTs, is effective to control the distribution of CNTs in composites. It promotes the migration of CNTs from the PS phase to the interface of PVDF and PS. Consequently, the interfacial conductive layer is formed at a low CNT content, and the electrical percolation threshold of PVDF/PS/CNTs-PMMA nanocomposites is only 0.07 vol%, having a great decrease of about 50% compared with that of PVDF/PS/CNTs nanocomposites. Thus, it is demonstrated that the distribution of CNTs can be tailored to anchor at the interface by proper chemical modification to form an interfacial conductive layer and a decrease of percolation threshold can also be achieved.

Electrical Double Percolation of Polybutadiene/Polyethylene Glycol Blends Loaded with Conducting Polymer Nanofibers

“…Therefore, the percolation threshold ϕ c II was estimated to be 0.02, which was considerably smaller than ϕ c I . Generally, anisotropic fillers with small diameters and high aspect ratios, such as CNTs, are reported to exhibit a low percolation threshold from 0.08 to 3 wt% in CPC with a blended matrix [8][9][10][11][12][13][14]. Furthermore, in our previous studies on composite films of P3HT nanofibers in polymethacrylate (PMMA), a significant amount of conductivity was measured for the ratio of P3HT/PMMA at approximately 5 wt% [28].…”

“…Conductive polymer composites (CPC) that comprise immiscible polymer blends and conductive fillers are novel composite materials, featuring advantages of both polymer blends and conductive fillers. Generally, by loading conductive fillers such as carbon black (CB) [1][2][3][4][5][6][7][8], carbon nanotubes (CNTs) [9][10][11][12][13][14], and graphene [5], it was reported that the resultant mechanical strength and electrical properties can be drastically modified. In particular, the conductivity can be changed from that of an insulator to that of a conductor by increasing the amount of fillers.…”

“…In particular, the conductivity can be changed from that of an insulator to that of a conductor by increasing the amount of fillers. Furthermore, fillers have been reported to be located selectively in a specific phase [1][2][3]5,7,10,11,13,14] or at the interface of the macro-phase separations [1,4,6,8,9,12]. This selective localization of conductive fillers contributes to reducing the amount of fillers required for obtaining conductive properties.…”

A review concerning the main factors that interfere in the electrical percolation threshold content of polymeric antistatic packaging with carbon fillers as antistatic agent

“…[96][97][98] The selective distribution of the filler particles in the interfacial region or in a single phase of co-continuous polymeric blends (generating a network of conductive particles) and the formation of a conductive network of filler-rich polymeric phase inside the composite is designated as double percolation. [99] This phenomenon was firstly described by Sumita et al [100] for HDPE/PP and PMMA/PP blend-based CB composites. [101] Figure 8 shows the effect of the selective localization of carbon filler particles on the electrical percolation threshold of blend-based polymer composites.…”

“…Yang et al [99] produced PVDF/ polystyrene (PS) (45/55) blends with different volume content (0.05, 0.09, 0.18, and 0.36 vol%) of pristine CNT or CNT grafted with PMMA chains (CNTs-PMMA). The authors verified that non-modified CNT was selectively distributed on the PS phase of PVDF/PS blend.…”