Synergistic effect in improving the electrical conductivity in polymer nanocomposites by mixing spherical and rod-shaped fillers

Soft Matter ◽  
2020 ◽  
Vol 16 (46) ◽  
pp. 10454-10462
Author(s):  
Fan Qu ◽  
Wei Sun ◽  
Bin Li ◽  
Fanzhu Li ◽  
Yangyang Gao ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Synergistic Effect ◽  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Tunneling Distance

φNR0 and φNS0 are volume fraction of nanorods and nanospheres in the system respectively. TD = The NR–NS tunneling distance.

scholarly journals Correction: Synergistic effect in improving the electrical conductivity in polymer nanocomposites by mixing spherical and rod-shaped fillers

Soft Matter ◽  
2021 ◽  
Author(s):  
Fan Qu ◽  
Wei Sun ◽  
Bin Li ◽  
Fanzhu Li ◽  
Yangyang Gao ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Synergistic Effect ◽  
Polymer Nanocomposites ◽  
Soft Matter

Correction for ‘Synergistic effect in improving the electrical conductivity in polymer nanocomposites by mixing spherical and rod-shaped fillers’ by Fan Qu et al., Soft Matter, 2020, 16, 10454–10462, DOI: 10.1039/D0SM00993H.

scholarly journals Calculation of the Electrical Conductivity of Polymer Nanocomposites Assuming the Interphase Layer Surrounding Carbon Nanotubes

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 404 ◽  
Author(s):  
Yasser Zare ◽  
Kyong Yop Rhee
Keyword(s):  
Electrical Conductivity ◽  
Polymer Nanocomposites ◽  
Volume Fraction ◽  
Tunneling Effect ◽  
Interphase Layer ◽  
Conductive Network ◽  
Effective Volume ◽  
Effective Volume Fraction ◽  
Filler Fraction ◽  
High Fraction

The interphase layer surrounding nanoparticles can reflect the tunneling effect as the main mechanism of charge transferring in polymer/carbon nanotube (CNT) nanocomposites (PCNT). In this paper, the percolation threshold, effective volume fraction of CNT, and the portion of percolated filler after percolation are expressed by interphase and CNT waviness. Moreover, the developed terms are used to suggest the influences of CNT dimensions, interphase thickness, and waviness on the electrical conductivity of PCNT by conventional and developed models. Thin and long CNT, thick interphase, and low waviness obtain a high fraction of percolated CNT. However, the highest level of effective filler fraction is only calculated by the thinnest CNT and the thickest interphase. Furthermore, both models show that the thinnest and the longest CNT as well as the thickest interphase and the least CNT waviness cause the highest conductivity in PCNT, because they positively contribute to the formation and properties of the conductive network.

Nanotube Networks in Polymer Nanocomposites:  Rheology and Electrical Conductivity

2004 ◽  
Vol 37 (24) ◽  
pp. 9048-9055 ◽  
Author(s):  
Fangming Du ◽  
Robert C. Scogna ◽  
Wei Zhou ◽  
Stijn Brand ◽  
John E. Fischer ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Polymer Nanocomposites

Dual percolations of electrical conductivity and electromagnetic interference shielding in progressively agglomerated CNT/polymer nanocomposites

2021 ◽  
pp. 108128652110214
Author(s):  
Xiaodong Xia ◽  
George J. Weng
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Percolation Threshold ◽  
Polymer Nanocomposites ◽  
Electromagnetic Interference ◽  
Effective Medium Theory ◽  
Scale Model ◽  
Shielding Effectiveness ◽  
Emi Shielding

Recent experiments have revealed two distinct percolation phenomena in carbon nanotube (CNT)/polymer nanocomposites: one is associated with the electrical conductivity and the other is with the electromagnetic interference (EMI) shielding. At present, however, no theories seem to exist that can simultaneously predict their percolation thresholds and the associated conductivity and EMI curves. In this work, we present an effective-medium theory with electrical and magnetic interface effects to calculate the overall conductivity of a generally agglomerated nanocomposite and invoke a solution to Maxwell’s equations to calculate the EMI shielding effectiveness. In this process, two complex quantities, the complex electrical conductivity and complex magnetic permeability, are adopted as the homogenization parameters, and a two-scale model with CNT-rich and CNT-poor regions is utilized to depict the progressive formation of CNT agglomeration. We demonstrated that there is indeed a clear existence of two separate percolative behaviors and showed that, consistent with the experimental data of poly-L-lactic acid (PLLA)/multi-walled carbon nanotube (MWCNT) nanocomposites, the electrical percolation threshold is lower than the EMI shielding percolation threshold. The predicted conductivity and EMI shielding curves are also in close agreement with experimental data. We further disclosed that the percolative behavior of EMI shielding in the overall CNT/polymer nanocomposite can be illustrated by the establishment of connective filler networks in the CNT-poor region. It is believed that the present research can provide directions for the design of CNT/polymer nanocomposites in the EMI shielding components.

scholarly journals Elastic wave velocity and electrical conductivity in a brine-saturated rock and microstructure of pores

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Tohru Watanabe ◽  
Miho Makimura ◽  
Yohei Kaiwa ◽  
Guillaume Desbois ◽  
Kenta Yoshida ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Elastic Wave ◽  
Wave Velocity ◽  
High Pressures ◽  
Seismic Velocity ◽  
Volume Fraction ◽  
Elastic Wave Velocity ◽  
Fluid Volume ◽  
Sem Observation ◽  
Wide Aperture

AbstractElastic wave velocity and electrical conductivity in a brine-saturated granitic rock were measured under confining pressures of up to 150 MPa and microstructure of pores was examined with SEM on ion-milled surfaces to understand the pores that govern electrical conduction at high pressures. The closure of cracks under pressure causes the increase in velocity and decrease in conductivity. Conductivity decreases steeply below 10 MPa and then gradually at higher pressures. Though cracks are mostly closed at the confining pressure of 150 MPa, brine must be still interconnected to show observed conductivity. SEM observation shows that some cracks have remarkable variation in aperture. The aperture varies from ~ 100 nm to ~ 3 μm along a crack. FIB–SEM observation suggests that wide aperture parts are interconnected in a crack. Both wide and narrow aperture parts work parallel as conduction paths at low pressures. At high pressures, narrow aperture parts are closed but wide aperture parts are still open to maintain conduction paths. The closure of narrow aperture parts leads to a steep decrease in conductivity, since narrow aperture parts dominate cracks. There should be cracks in various sizes in the crust: from grain boundaries to large faults. A crack must have a variation in aperture, and wide aperture parts must govern the conduction paths at depths. A simple tube model was employed to estimate the fluid volume fraction. The fluid volume fraction of 10−4–10−3 is estimated for the conductivity of 10−2 S/m. Conduction paths composed of wide aperture parts are consistent with observed moderate fluctuations (< 10%) in seismic velocity in the crust.

Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
Author(s):  
Xin Lan ◽  
Jin Song Leng ◽  
Yan Ju Liu ◽  
Shan Yi Du
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Recovery Process ◽  
Thermomechanical Properties ◽  
Electrically Conductive ◽  
New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

scholarly journals Temperature-Dependent Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets on the Tensile Quasi-Static and Fatigue Properties of Epoxy Nanocomposites

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 84
Author(s):  
Yi-Ming Jen ◽  
Hao-Huai Chang ◽  
Chien-Min Lu ◽  
Shin-Yu Liang
Keyword(s):  
Carbon Nanotubes ◽  
Fatigue Strength ◽  
Synergistic Effect ◽  
Polymer Nanocomposites ◽  
Graphene Nanoplatelets ◽  
Temperature Dependent ◽  
Epoxy Nanocomposites ◽  
Hybrid Fillers ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.

COMPUTATIONAL DESCRIPTION OF THE GEOMETRY OF ALIGNED CARBON NANOTUBES IN POLYMER NANOCOMPOSITES

2021 ◽  
Author(s):  
STEPAN V. LOMOV ◽  
JEONYOON LEEJEONYOON LEE ◽  
BRIAN L. WARDLE ◽  
NIKITA A. GUDKOV ◽  
ISKANDER S. AKHATOV ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polymer Nanocomposites ◽  
Finite Element Modelling ◽  
Volume Fraction ◽  
Voronoi Tessellation ◽  
Geometrical Model ◽  
Limiting Factor ◽  
Full Paper ◽  
Aligned Carbon Nanotubes ◽  
Curvature And Torsion

The paper considers nanocomposites, reinforced with aligned carbon nanotubes (A- CNTs). Nominally aligned, the CNTs in the forest are wavy, which has important consequences in downgraded mechanical properties, and influences electric and thermal performance. The most detailed geometrical model of A-CNTs was proposed by Stein and Wardle (Nanotechnology, 27:035701, 2015). It creates a centerline trajectory of a CNT in steps, each step defining a section of the CNT, growing in the alignment direction with certain deviations. The paper, starting from this framework, formulates a model of the CNT geometry, which is based on the concept of correlation length of the CNT waviness and maximum admissible CNT curvature and torsion. The value of the maximum curvature can be linked to the buckling criteria for CNTs, or derived from ab initio and finite element modelling. It is used as a limiting factor for the growth, defining the waviness and tortuosity of the CNTs. The CNTs in the forest are placed in a random non-regular way, using Voronoi tessellation. The full paper includes investigation of the proposed algorithm for several values of the CNT volume fraction (in the range 0.5%…8%), the dependency of the modelled geometry on the curvature, and the apparent twist of the CNT centerlines. The modelling results are compared with experimental observations in 3D TEM imaging.

Copolymer-Nanoparticles Mixture in a Cylindrical Pore

NANO ◽  
2017 ◽  
Vol 12 (04) ◽  
pp. 1750045
Author(s):  
Jun-Xing Pan ◽  
Yu-Qi Guo ◽  
Yu-Fang Han ◽  
Min-Na Sun ◽  
Jin-Jun Zhang
Keyword(s):  
Phase Transition ◽  
Electrical Conductivity ◽  
Polymer Nanocomposites ◽  
Diblock Copolymer ◽  
Large Diameter ◽  
Small Diameter ◽  
Confinement Effect ◽  
Cylindrical Pore ◽  
Disorder Phase Transition ◽  
Novel Structures

Computer simulation is carried out for investigating the effect of nanoparticles on diblock copolymer morphology under cylindrical confinement. The phase diagrams of polymer nanocomposites with nanoparticle-block wetting strength and concentration of nanoparticles are obtained in different nanopores. In small diameter nanopore, there is almost no influence of nanoparticles on the diblock copolymer morphology because of the stronger confinement effect; in middle diameter nanopore, the system can self-assemble into various novel structures due to the interaction between confinement effect and nanoparticles effect; in large diameter nanopore, due to the stronger effect of nanoparticles, a disorder-order-disorder phase transition occurs with the wetting strength and concentration of nanoparticles increasing. This result can be useful in designing new nanocomposites with advanced electrical conductivity and/or mechanical strength.

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