scholarly journals Mechanical, Electrical, and Piezoresistive Sensing Characteristics of Epoxy-Based Composites Incorporating Hybridized Networks of Carbon Nanotubes, Graphene, Carbon Nanofibers, or Graphite Nanoplatelets

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2094 ◽  
Author(s):  
XiaoDong Wang ◽  
JianChao Wang ◽  
Swarup Biswas ◽  
Hyeok Kim ◽  
IlWoo Nam

The present study compared the mechanical, electrical, morphological, and piezoresistive characteristics of epoxy-based sensing nanocomposites fabricated with inclusions of hybridized networks of four different carbon nanomaterials (CNMs), such as carbon nanotube (CNT), graphene, carbon nanofiber (CNF), and graphite nanoplatelet (GNP). Enhancements in elastic modulus and electrical conductivity were achieved by CNT–graphene composites and CNT–CNF composites, and these were explained by the morphological observations carried out in the present study and experimental studies found in the literature. The greatest gauge factor was accomplished by the CNT–GNP composite, followed by the CNT–CNF composite among composites where the CNM networks were sufficiently formed with a content ratio of 3%. The two types of the composites outperformed the composites incorporating solely CNT in terms of gauge factor, and this superiority was explained with the excluded volume theory.

Author(s):  
Rafael Vargas-Bernal

There is enormous interest in carbon nanomaterials, due to their exceptional physical properties, from the perspective of science and engineering of materials applied to the electronics industry. Until now, significant progress has been made towards understanding the mechanisms of electrical conductivity of carbon nanotubes and graphene. However, scientists around the world even today continue studying these mechanisms, for exploiting them fully in different electronic applications with a high technological impact. This article discusses the mechanisms of electrical conductivity of both nanomaterials, analyzes the present implications, and projects its importance for future generations of electronic devices. In particular, it is important to note that different mechanisms may be identified when these nanomaterials are used individually, when they are incorporated as fillers in composite materials or hybrid materials, or even when they are doped or functionalized. Finally, other electrical variables with important role in electrical conductivity of these materials are also explored.


Author(s):  
Rafael Vargas-Bernal

There is enormous interest in carbon nanomaterials due to their exceptional physical properties, from the perspective of science and engineering of materials applied to the electronics industry. Significant progress has been made towards understanding the mechanisms of electrical conductivity of carbon nanotubes and graphene. However, scientists around the world continue studying these mechanisms to exploit them fully in different electronic applications with a high technological impact. This chapter discusses the mechanisms of electrical conductivity of both nanomaterials, analyzes the present implications, and projects its importance for future generations of electronic devices. In particular, it is important to note that different mechanisms may be identified when these nanomaterials are used individually, when they are incorporated as fillers in composite materials or hybrid materials, or even when they are doped or functionalized. Finally, other electrical variables with important role in electrical conductivity of these materials are also explored.


2013 ◽  
Vol 143 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Galip Haznedar ◽  
Sara Cravanzola ◽  
Marco Zanetti ◽  
Domenica Scarano ◽  
Adriano Zecchina ◽  
...  

2018 ◽  
Vol 52 (24) ◽  
pp. 3325-3340 ◽  
Author(s):  
Doo-Yeol Yoo ◽  
Ilhwan You ◽  
Hyunchul Youn ◽  
Seung-Jung Lee

This study investigates the effect of nanomaterials on the piezoresistive sensing capacity of cement-based composites. Three different nanomaterials—multi-walled carbon nanotubes, graphite nanofibers, and graphene oxide—were considered along with a plain mortar, and a cyclic compressive test was performed. Based on a preliminary test, the optimum flowability was determined to be 150 mm in terms of fiber dispersion. The electrical resistivity of the composites substantially decreased by incorporating 1 wt% multi-walled carbon nanotubes, but only slightly decreased by including 1 wt% graphite nanofibers and graphene oxide. This indicates that the use of multi-walled carbon nanotubes is most effective in improving the conductivity of the composites compared to the use of graphite nanofibers and graphene oxide. The fractional change in resistivity of the composites with nanomaterials exhibited similar behavior to that of the cyclic compressive load, but partial reversibility in fractional change in resistivity was obtained beyond 60% of the peak load. A linear relationship between the fractional change in resistivity and cyclic compression strain (up to 1500 με) was observed in the composites with multi-walled carbon nanotubes, and the gauge factor was found to be 166.6. It is concluded that cement-based composites with 1 wt% multi-walled carbon nanotubes can be used as piezoresistive sensors for monitoring the stress/strain generated in concrete structures.


2007 ◽  
Vol 1057 ◽  
Author(s):  
Marianne Kilbride ◽  
Richard Arthur Pethrick ◽  
Steven Ward ◽  
Mark Harriman

ABSTRACTRecently there has been an increase in the use of composite materials for aircraft construction. Composites have significant production and application advantages, but generally suffer from being electrically insulating, and hence are unable to handle a lightening strike in the traditional way that aluminium would. A potential solution to this problem is sought through the use of carbon nanotubes and carbon nanographite. Achieving the correct dispersion of the conducting filler is critical to achieving the desired enhancement in conductivity. Two different methods have been explored to achieve the dispersions; – direct blending and solution dispersion, with a range of concentrations of nanographite being incorporated. In addition, the effect of directly blending graphite nanoplatelets and carbon nanotubes in order to create a hybrid nanocomposite material was studied. The carbon nanotubes were incorporated into a blend with the graphite nanoplatelets with the intention of utilizing their tube structure in order to bridge the gaps between the platelet sheets of nanographite, creating more effective and abundant conductive pathways throughout the composite. In all cases the electrical conductivity was measured using a four point probe technique.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1395 ◽  
Author(s):  
Sung-Hoon Park ◽  
Ji-Hwan Ha

We report the enhanced electromagnetic interference (EMI) shielding properties of hybrid carbon nanotube (CNT) composites consisting of more than two kinds of fillers through the use of segregate conducting networks. An excluded volume was created by micro-sized silica particles that concentrate the CNT network, resulting in improved electrical conductivity and microwave properties. To achieve the optimal dispersion of CNTs and silica particles, high shear force was applied to the pre-cured composite mixture via three-roll milling. Depending on the micro-silica content ratio, we observed improved electrical conductivity and EMI shielding properties. For a quantitative comparison to observe the excluded-volume effects, a CNT composite without micro-silica was measured in parallel with the other sample.


2011 ◽  
Vol 2011 ◽  
pp. 1-21 ◽  
Author(s):  
Ali Mostofizadeh ◽  
Yanwei Li ◽  
Bo Song ◽  
Yudong Huang

In recent years, many theoretical and experimental studies have been carried out to develop one of the most interesting aspects of the science and nanotechnology which is called carbon-related nanomaterials. The goal of this paper is to provide a review of some of the most exciting and important developments in the synthesis, properties, and applications of low-dimensional carbon nanomaterials. Carbon nanomaterials are formed in various structural features using several different processing methods. The synthesis techniques used to produce specific kinds of low-dimensional carbon nanomaterials such as zero-dimensional carbon nanomaterials (including fullerene, carbon-encapsulated metal nanoparticles, nanodiamond, and onion-like carbons), one-dimensional carbon nanomaterials (including carbon nanofibers and carbon nanotubes), and two-dimensional carbon nanomaterials (including graphene and carbon nanowalls) are discussed in this paper. Subsequently, the paper deals with an overview of the properties of the mainly important products as well as some important applications and the future outlooks of these advanced nanomaterials.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1329
Author(s):  
João Restivo ◽  
Olívia Salomé Gonçalves Pinto Soares ◽  
Manuel Fernando Ribeiro Pereira

A large number of methodologies for fabrication of 1D carbon nanomaterials have been developed in the past few years and are extensively described in the literature. However, for many applications, and in particular in catalysis, a translation of the materials to a macro-structured form is often required towards their use in practical operation conditions. This review intends to describe the available methods currently used for fabrication of such macro-structures, either already applied or with potential for application in the fabrication of macro-structured catalysts containing 1D carbon nanomaterials. A review of the processing methods used in the fabrication of macrostructures containing 1D sp2 hybridized carbon nanomaterials is presented. The carbon nanomaterials here discussed include single- and multi-walled carbon nanotubes, and several types of carbon nanofibers (fishbone, platelet, stacked cup, etc.). As the processing methods used in the fabrication of the macrostructures are generally very similar for any of the carbon nanotubes or nanofibers due to their similar chemical nature (constituted by stacked ordered graphene planes), the review aggregates all under the carbon nanofiber (CNF) moniker. The review is divided into methods where the CNFs are synthesized already in the form of a macrostructure (in situ methods) or where the CNFs are previously synthesized and then further processed into the desired macrostructures (ex situ methods). We highlight in particular the advantages of each approach, including a (non-exhaustive) description of methods commonly described for in situ and ex situ preparation of the catalytic macro-structures. The review proposes methods useful in the preparation of catalytic structures, and thus a number of techniques are left out which are used in the fabrication of CNF-containing structures with no exposure of the carbon materials to reactants due to, for example, complete coverage of the CNF. During the description of the methodologies, several different macrostructures are described. A brief overview of the potential applications of such structures in catalysis is also offered herein, together with a short description of the catalytic potential of CNFs in general.


Author(s):  
Felicia Stan ◽  
Nicoleta-Violeta Stanciu ◽  
Adriana-Madalina Constantinescu ◽  
Catalin Fetecau

Abstract This paper reports on the 3D printing of flexible and stretchable parts based on multiwall carbon nanotubes (MWCNTs)/polyester-based thermoplastic polyurethane (TPU) nanocomposites. The rheological properties of the MWCNT/TPU nanocomposites with different wt.% of MWCNTs (0.1–3) were determined and used as guidance for the extrusion and 3D printing processes. MWCNT/TPU filaments were extruded and used for 3D printing of different flexible and stretchable parts. The mechanical, electrical, and piezoresistive response of the MWCNT/TPU nanocomposite filaments and 3D printed parts under static and monotonic loading was studied. The experimental results show that with increasing temperature and shear rate, respectively, the shear viscosity of the MWCNT/TPU nanocomposite decreases, whereas the viscosity increases with increasing wt.% of MWCNTs. With the addition of MWCNTs, the elastic modulus and tensile strength of the feedstock filament all increase, enhancing the printability of TPU by increasing the buckling resistance and the stability of the 3D printed layer. The electrical conductivity of the 3D printed MWCNT/TPU nanocomposites increases with increasing wt.% of MWCNTs and exceeds the conductivity of the filaments. The 3D printed MWCNT/TPU nanocomposites with 3 wt.% show an electrical conductivity about 10 S/m, irrespective of the printing direction. Moreover, the 3D printed MWCNT/TPU nanocomposites exhibit good mechanical properties and high piezoresistive sensitivity with gauge factor (50–600) dependent on both strain and printing direction.


Sign in / Sign up

Export Citation Format

Share Document