A study on nanofiber‐reinforced thermoplastic composites (II): Investigation of the mixing rheology and conduction properties

Abstract

This article is portion of a comprehensive study on the development of nanofiber-reinforced polymer composites for electrostatic discharge materials and structural composites. Vapor-grown carbon fibers with an average diameter of 100 nm were used as a precursor and model fiber system for carbon nanotubes. These nanofibers were purified and functionalized to provide for an open network of high-purity nanofibers. Banbury-type mixing was used to disperse the nanofibers in the polymer matrix. Rheological and microscopic analysis showed that the high shear processing of the polymer/nanofiber mixture led to a homogeneous dispersion of nanofibers with no agglomerates present and no shortening of the nanofibers. The shear thinning behavior of polymeric materials helps in the mixing of the nanofibers to form the composites. A percolation threshold for electrical conduction of 9 -18 wt % was observed for the highly dispersed nanofiber networks. The electrical behavior of these materials was not affected by changes in humidity. Microscopic analysis showed highly dispersed nanofibers with no indications of porosity. These conducting polymers are well suited for electrostatic discharge applications, and might well become multifunctional materials for strength/ electrical applications.

Transitional behaviour in the transformation from active end planes to stable loops caused by annealing

“…The characteristics of these edge sites, especially for the form of tubular-type carbon (carbon nanotubes) [4]- [13], make it possible to utilize them in the fabrication of absorbent materials [14], catalyst-supports [15,16], field emitters, gas storage components [17] and polymer composites [18,19]. It is well known that highly reactive edge sites are transformed into stable multi-loops when heat treated at higher temperatures [5,12,20,21].…”

Relationship between structural evolution and rheological measurements for polymer + organoclay nanocomposites

“…The degree of shear thinning and the increase in viscosity, which represents the dispersion quality of a filler in a matrix polymer or the interaction between polymer and filler, can become a criterion for a rheological percolation threshold, indicating the onset of the formation of a physical network [24,25]. The existence of a rheological critical point at the electrical percolation threshold has been previously reported [22,26]. As shown in Fig.…”

Influence of Polymer Coating on the Electrode Properties of Fe₃O₄/Carbon Nano-fiber Composite in Alkaline Electrolyte

“…[8][9][10][11][12][13] Particularly, the authors have made attempts to carbon nanofiber (CNF) having high conductivity and mechanical strength along the fiber axis. 14 Iron utilization has been improved up to 400 mAh per unit mass of iron: half of the theoretical capacity, by the optimum design of composite electrodes of nano-sized iron species loaded on a CNF surface, and the fabrication of such composites using sol-gel precipitation or ultrasonic-aided mixing of nano-sized magnetite (Fe 3 O 4 ) and CNF. 15,16 Such composites have rather high surface area, and thus hydrogen evolution by-reaction is unavoidable.…”