Flexible and electrically conductive composites based on 3D hierarchical silver dendrites

Soft Matter ◽  
2020 ◽  
Vol 16 (29) ◽  
pp. 6765-6772
Author(s):  
Bo Song ◽  
Xueqiao Wang ◽  
Shiv Patel ◽  
Fan Wu ◽  
Kyoung-sik Moon ◽  
...  

This work presents flexible and highly conductive composites using 3D hierarchical silver dendrites (SDs) as conductive fillers, which demonstrate a low percolation threshold and excellent electromechanical characteristics.

2020 ◽  
Vol 92 (10) ◽  
pp. 1441-1450
Author(s):  
Igor Lesiuk ◽  
Andrzej Katunin

Purpose This paper aims to present a numerical analysis and comparison of two types of conductive fillers of polymeric composites subjected to lightning strikes. Design/methodology/approach Two types of conductive fillers were considered in the developed numerical models of electrically conductive composites: carbon nanotubes and polyaniline. For these fillers, the representative volume elements were developed to consider distribution of the particles that ensures percolation and homogenization of the materials within the Eshelby-based semi-analytical mean-field homogenization approach. The performed numerical analyses allowed determination of effective volume fractions of conducting particles, resistivity and conductivity tensors, and finally the current density for the simulated materials subjected to lightning strike. Findings The obtained results allowed for comparison of electrical conductivity of two simulated materials. It was observed that besides fair results obtained in the previous studies for intrinsically conducting polymers as fillers of composites dedicated for lightning strike protection, the composites filled with carbon nanotubes reveal much better conductivity. Practical implications The presented simulation results can be considered as initial information for further experimental tests on electrical conductivity of such materials. Originality/value The originality of the paper lies in the proposed design and simulation procedures of conductive composites as well as the comparison of selected composites dedicated for lightning strike protection as the most intensively developed materials for this purpose.


2020 ◽  
Vol 19 ◽  
pp. 121-126 ◽  
Author(s):  
Miao Tang ◽  
Peng Zheng ◽  
Yingjie Wu ◽  
Pengli Zhu ◽  
Yajie Qin ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 518
Author(s):  
Hasan Borke Birgin ◽  
Antonella D’Alessandro ◽  
Simon Laflamme ◽  
Filippo Ubertini

Multifunctional structural materials are very promising in the field of engineering. Particularly, their strain sensing ability draws much attention for structural health monitoring applications. Generally, strain sensing materials are produced by adding a certain amount of conductive fillers, around the so-called “percolation threshold”, to the cement or composite matrix. Recently, graphite has been found to be a suitable filler for strain sensing. However, graphite requires high amounts of doping to reach percolation threshold. In order to decrease the amount of inclusions, this paper proposes cementitious materials doped with new hybrid carbon inclusions, i.e., graphite and carbon microfibers. Carbon microfibers having higher aspect ratio than graphite accelerate the percolation threshold of the graphite particles without incurring into dispersion issues. The resistivity and strain sensitivity of different fibers’ compositions are investigated. The electromechanical tests reveal that, when combined, carbon microfibers and graphite hybrid fillers reach to percolation faster and exhibit higher gauge factors and enhanced linearity.


2021 ◽  
Vol 321 ◽  
pp. 171-176
Author(s):  
Jana Majerová ◽  
Rostislav Drochytka

The electrical conductivity of concrete can be achieved by adding steel wires or functional fillers. Commonly used fillers are nanotubes, carbon black, nickel powder and so on. These fillers are expensive, but there is a possibility to use waste materials. This is the subject of this experiment. The conductive properties of conductive sand, sludge from the wire drawing process, iron grinding dust waste and waste carbon were verified. From these fillers, waste carbon showed the best electrical properties (impedance). The impedance of the waste carbon was 0.31 Ω and the impedance of the cement composite containing 70% of the weight of waste carbon was less than 670 Ω.


2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Cheng Yang ◽  
Xiaoya Cui ◽  
Zhexu Zhang ◽  
Sum Wai Chiang ◽  
Wei Lin ◽  
...  

2018 ◽  
Vol 60 (5) ◽  
pp. 678-682
Author(s):  
B. Ch. Kholkhoev ◽  
A. S. Buinov ◽  
S. A. Bal’zhinov ◽  
V. G. Makotchenko ◽  
V. E. Fedorov ◽  
...  

2011 ◽  
Vol 2011 (1) ◽  
pp. 000090-000098 ◽  
Author(s):  
Michelle Velderrain ◽  
Matthew Lindberg

Silicones have been used for decades in aerospace and other harsh environments where temperature extremes are common. As the level of sophistication increases for electronic devices to serve these industries where failure is not an option, the material supplier has to also be able to meet these needs. Silicones are polymeric materials composed primarily of repeating silicon and oxygen bonds, known as siloxanes, which can be optimized for various chemical and physical properties by incorporating different organic groups onto the silicon atom. Employing advanced processing techniques to the siloxane system can also greatly reduce mobile siloxane molecules to reduce contamination that can cause electronic failures during assembly or operation. Siloxane based polymeric systems are also unique polymers compared to standard organic based materials in that they have a large free volume that imparts a low modulus which absorbs stresses during thermal cycling as well as not degrading at continuous operating temperatures up to 250 C. They are also slightly polar which allows the incorporation of fillers to impart a variety of unique properties. Filler technology is also a rapidly growing enterprise where fillers with various particle sizes and shapes can be added to silicones to impart key properties such as maintaining electric conductivity at elevated temperatures. This paper will explain fundamentals of silicone chemistry and processing related to getting the optimal performance in harsh environments. A case study comparing two different electrically conductive fillers and how they can influence the electrical conductivity at elevated temperatures will be presented.


Sign in / Sign up

Export Citation Format

Share Document