Multi-Walled Carbon Nanotubes-Based Sensors for Strain Sensing Applications

The use of multi-walled carbon nanotube (MWCNT)-based sensors for strain–strain applications is showcased in this paper. Extensive use of MWCNTs has been done for the fabrication and implementation of flexible sensors due to their enhanced electrical, mechanical, and thermal properties. These nanotubes have been deployed both in pure and composite forms for obtaining highly efficient sensors in terms of sensitivity, robustness, and longevity. Among the wide range of applications that MWCNTs have been exploited for, strain-sensing has been one of the most popular ones due to the high mechanical flexibility of these carbon allotropes. The MWCNT-based sensors have been able to deduce a broad spectrum of macro- and micro-scaled tensions through structural changes. This paper highlights some of the well-approved conjugations of MWCNTs with different kinds of polymers and other conductive nanomaterials to form the electrodes of the strain sensors. It also underlines some of the measures that can be taken in the future to improve the quality of these MWCNT-based sensors for strain-related applications.

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Fabrication and Characterization of Graphene/Epoxy Nanocomposites

Materials Science ◽

10.5755/j01.ms.25.4.19462 ◽

2019 ◽

Vol 25 (4) ◽

pp. 433-440

Author(s):

Shiuh Chuan HER ◽

Lei Yao CHEN

Keyword(s):

Thermal Properties ◽

Experimental Results ◽

Mechanical And Thermal Properties ◽

Epoxy Nanocomposites ◽

Sem Images ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Thermal Stability Of

Graphene with high electric and thermal conductivities has been widely used as reinforced filler. In this study, graphene loadings in the range between 0.3 and 1.0 wt.% were added to the epoxy to fabricate the nanocomposites. The mechanical and thermal properties of nanocomposites were characterized using tensile test and differential scanning calorimeter (DSC), respectively. Experimental results show that the elastic modulus, yield strength, ultimate strength and glass transition temperature of the graphene reinforced epoxy are increasing with the increase of the graphene, while the fracture strain and toughness are decreasing with the increase of the graphene. Scanning electron microscope (SEM) was employed to investigate the dispersion and separation of graphene in the epoxy based matrix. The SEM images depict that graphene is well dispersed resulting in a significant improvement of the mechanical and thermal properties of the nanocomposites. The mechanical properties and thermal stability of epoxy nanocomposites with graphenes and multi-walled carbon nanotubes additives were then compared. Experimental results show that nanocomposite with graphene additives outperform the multi-walled carbon nanotube additives.

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PIEZORESISTIVE PROPERTIES OF MULTI-WALLED CARBON NANOTUBE–POLY(DIMETHYLSILOXANE) COMPOSITES FOR LOW-PRESSURE-SENSING APPLICATIONS

NANO ◽

10.1142/s1793292012500051 ◽

2012 ◽

Vol 07 (01) ◽

pp. 1250005 ◽

Cited By ~ 5

Author(s):

SU YONG KWON ◽

YON KYU PARK ◽

MIN SEOK KIM

Keyword(s):

Conductive Filler ◽

Low Pressure ◽

Pressure Sensitivity ◽

Pressure Sensing ◽

Sensing Applications ◽

Pressure Sensitive ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Mwcnt Loading

Low-pressure-sensitive composites using multi-walled carbon nanotubes as a conductive filler and poly(dimethylsiloxane) as a polymer matrix have been fabricated, and their electrical and piezoresistive properties have been studied. A large aspect ratio of the MWCNTs was used to achieve good electrical properties of the composite, which led to a significant decrease in the percolation threshold and an increase in the electrical conductivity for very low MWCNT loadings. The piezoresistive properties of the composites at < 1.2 MPa were studied, which showed that the resistance–pressure sensitivity of the composites could be modulated by varying the MWCNT loading in the PDMS matrix.

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Effects of Multi-Walled Carbon Nanotubes (MWCNTS) on the Mechanical and Thermal Properties of Plasticized Polylactic Acid Nanocomposites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.812.181 ◽

2013 ◽

Vol 812 ◽

pp. 181-186 ◽

Cited By ~ 6

Author(s):

Maizatulnisa Othman ◽

Kok Hui Tan ◽

Hashim Mohd Yusof ◽

Khalid Halisanni ◽

Ghazali Ruzaidi ◽

...

Keyword(s):

Mechanical Properties ◽

Carbon Nanotubes ◽

Polylactic Acid ◽

Flexural Properties ◽

Mechanical And Thermal Properties ◽

Dynamic Mechanical Analyzer ◽

Roll Mill ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

A multi-walled carbon nanotube (MWCNT)/plasticized polylactic acid (PLA) composite was prepared using a two-roll mill set at 170°C and 50 rev/min. The material was characterized using dynamic mechanical analyzer (DMA). Characterization works include obtaining mechanical properties, such as tensile and flexural properties of the nanocomposites. Polyethylene glycol (PEG) at 6 wt% was used as the plasticizer for blending with the PLA. It was found that the tensile and flexural strengths of the nanocomposites increased up to 43.8 MPa and 81.4 MPa respectively with the addition of 0.15 wt% MWCNTs. The DMA results revealed that the storage modulus and the glass transition temperature (Tg) of the nanocomposites improved with the addition of 0.15 wt% CNTs, which was previously reduced by the incorporation of PEG.

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Characterization and modeling of the effective electrical conductivity of a carbon nanotube/polymer composite containing chain-structured ferromagnetic particles

Journal of Composite Materials ◽

10.1177/0021998316644846 ◽

2016 ◽

Vol 51 (2) ◽

pp. 171-178 ◽

Cited By ~ 9

Author(s):

Sung-Hwan Jang ◽

Huiming Yin

Keyword(s):

Electrical Conductivity ◽

Carbon Nanotube ◽

Chain Model ◽

Sensing Applications ◽

Effective Electrical Conductivity ◽

Multi Walled Carbon Nanotube ◽

The Matrix ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Ferromagnetic Particles

The effective electrical conductivity of multi-walled carbon nanotube/polydimethylsiloxane composites with chain-structured ferromagnetic particles has been investigated by experiments and micromechanics-based modeling. A multi-scale modeling approach is used to consider different size of fillers of multi-walled carbon nanotubes and particles as well as their distribution in the matrix. At nanoscale, for multi-walled carbon nanotube/polydimethylsiloxane composite, eight-chain model and influence of waviness of multi-walled carbon nanotube are considered to render an effective electrical conductivity. At microscale, ferromagnetic particles are aligned in the matrix made of the multi-walled carbon nanotube/polydimethylsiloxane composite, and an analytical model is established based on representative volume element. The influence of inter-particle distance is evaluated. The proposed analytic results agree well with the experimental results. The present model can be a useful tool for design and analysis of these composites for sensing applications considering their percolation threshold and overall electrical conductivity.

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A New Method for Dispersing Pristine Carbon Nanotubes Using Regularly Arranged S-Layer Proteins

Nanomaterials ◽

10.3390/nano11051346 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1346

Author(s):

Andreas Breitwieser ◽

Uwe B. Sleytr ◽

Dietmar Pum

Keyword(s):

Carbon Nanotubes ◽

Covalent Modification ◽

Silica Layer ◽

Medical Sciences ◽

Lysinibacillus Sphaericus ◽

Wide Range ◽

Catalytic Sites ◽

Multi Walled Carbon Nanotubes ◽

Pristine Mwnts ◽

Walled Carbon Nanotubes

Homogeneous and stable dispersions of functionalized carbon nanotubes (CNTs) in aqueous solutions are imperative for a wide range of applications, especially in life and medical sciences. Various covalent and non-covalent approaches were published to separate the bundles into individual tubes. In this context, this work demonstrates the non-covalent modification and dispersion of pristine multi-walled carbon nanotubes (MWNTs) using two S-layer proteins, namely, SbpA from Lysinibacillus sphaericus CCM2177 and SbsB from Geobacillus stearothermophilus PV72/p2. Both the S-layer proteins coated the MWNTs completely. Furthermore, it was shown that SbpA can form caps at the ends of MWNTs. Reassembly experiments involving a mixture of both S-layer proteins in the same solution showed that the MWNTs were primarily coated with SbsB, whereas SbpA formed self-assembled layers. The dispersibility of the pristine nanotubes coated with SbpA was determined by zeta potential measurements (−24.4 +/− 0.6 mV, pH = 7). Finally, the SbpA-coated MWNTs were silicified with tetramethoxysilane (TMOS) using a mild biogenic approach. As expected, the thickness of the silica layer could be controlled by the reaction time and was 6.3 +/− 1.25 nm after 5 min and 25.0 +/− 5.9 nm after 15 min. Since S-layer proteins have already demonstrated their capability to bind (bio)molecules in dense packing or to act as catalytic sites in biomineralization processes, the successful coating of pristine MWNTs has great potential in the development of new materials, such as biosensor architectures.

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Strain Sensor via Wood Anomalies in 2D Dielectric Array

Nanomaterials ◽

10.3390/nano11041022 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1022

Author(s):

Rashid G. Bikbaev ◽

Ivan V. Timofeev ◽

Vasiliy F. Shabanov

Keyword(s):

Higher Plants ◽

Numerical Study ◽

Reciprocal Lattice ◽

Strain Sensing ◽

Photonic Materials ◽

Sensing Applications ◽

Wide Range ◽

Sensor Structure ◽

Optical Behavior ◽

Chlorophyll Absorption

Optical sensing is one of many promising applications for all-dielectric photonic materials. Herein, we present an analytical and numerical study on the strain-responsive spectral properties of a bioinspired sensor. The sensor structure contains a two-dimensional periodic array of dielectric nanodisks to mimic the optical behavior of grana lamellae inside chloroplasts. To accumulate a noticeable response, we exploit the collective optical mode in grana ensemble. In higher plants, such a mode appears as Wood’s anomaly near the chlorophyll absorption line to control the photosynthesis rate. The resonance is shown persistent against moderate biological disorder and deformation. Under the stretching or compression of a symmetric structure, the mode splits into a couple of polarized modes. The frequency difference is accurately detected. It depends on the stretch coefficient almost linearly providing easy calibration of the strain-sensing device. The sensitivity of the considered structure remains at 5 nm/% in a wide range of strain. The influence of the stretching coefficient on the length of the reciprocal lattice vectors, as well as on the angle between them, is taken into account. This adaptive phenomenon is suggested for sensing applications in biomimetic optical nanomaterials.

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Combining experimental and simulation data of molecular processes via augmented Markov models

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1704803114 ◽

2017 ◽

Vol 114 (31) ◽

pp. 8265-8270 ◽

Cited By ~ 53

Author(s):

Simon Olsson ◽

Hao Wu ◽

Fabian Paul ◽

Cecilia Clementi ◽

Frank Noé

Keyword(s):

Force Field ◽

Structural Changes ◽

Markov Models ◽

Force Fields ◽

Divide And Conquer ◽

Simulation Data ◽

Wide Range ◽

Simulation And Experiment ◽

Kinetics Of

Accurate mechanistic description of structural changes in biomolecules is an increasingly important topic in structural and chemical biology. Markov models have emerged as a powerful way to approximate the molecular kinetics of large biomolecules while keeping full structural resolution in a divide-and-conquer fashion. However, the accuracy of these models is limited by that of the force fields used to generate the underlying molecular dynamics (MD) simulation data. Whereas the quality of classical MD force fields has improved significantly in recent years, remaining errors in the Boltzmann weights are still on the order of a few kT, which may lead to significant discrepancies when comparing to experimentally measured rates or state populations. Here we take the view that simulations using a sufficiently good force-field sample conformations that are valid but have inaccurate weights, yet these weights may be made accurate by incorporating experimental data a posteriori. To do so, we propose augmented Markov models (AMMs), an approach that combines concepts from probability theory and information theory to consistently treat systematic force-field error and statistical errors in simulation and experiment. Our results demonstrate that AMMs can reconcile conflicting results for protein mechanisms obtained by different force fields and correct for a wide range of stationary and dynamical observables even when only equilibrium measurements are incorporated into the estimation process. This approach constitutes a unique avenue to combine experiment and computation into integrative models of biomolecular structure and dynamics.

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Calibration of reaction parameters for the improvement of thermal stability and crystalline quality of multi-walled carbon nanotubes

Journal of Materials Science ◽

10.1007/s10853-009-4001-y ◽

2010 ◽

Vol 45 (3) ◽

pp. 783-792 ◽

Cited By ~ 13

Author(s):

Saveria Santangelo ◽

Giacomo Messina ◽

Giuliana Faggio ◽

Maurizio Lanza ◽

Alessandro Pistone ◽

...

Keyword(s):

Carbon Nanotubes ◽

Thermal Stability ◽

Crystalline Quality ◽

Reaction Parameters ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Effect of nanofiller on fibre laser drilling quality of carbon fibre reinforced polymer composite laminates

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408918812253 ◽

2018 ◽

Vol 233 (4) ◽

pp. 857-870

Author(s):

Dhiraj Kumar ◽

Kalyan Kumar Singh

Keyword(s):

Carbon Nanotubes ◽

Carbon Fibre ◽

Polymer Matrix ◽

Composite Laminates ◽

Reinforced Polymer ◽

Carbon Fibre Reinforced Polymer ◽

Multi Walled Carbon Nanotubes ◽

Fibre Reinforced Polymer ◽

Walled Carbon Nanotubes

Laser machining of carbon fibre reinforced polymer composites is a challenging task due to a significant difference between physical and thermal properties of the constituent materials, i.e. polymer matrix and carbon fibres. This results in extended heat-affected zone (HAZ), taper kerf and poor surface finishing. This paper focuses on an investigation, attempting to minimise the divergence in the decomposition temperature of carbon fibres and epoxy resin by adding multi-walled carbon nanotubes in polymer matrix as a secondary reinforcement. High thermal conductivity of multi-walled carbon nanotubes increases the thermal diffusivity of polymer matrix, which in turn reduces the matrix recession. In addition, laser power and scan speed was also considered as an input parameter and their influence on output responses such as HAZ, taper angle and surface roughness has been studied. To analyse the effect of multi-walled carbon nanotubes on the resultant thermal damage, an innovative technique, i.e. scanning acoustic microscopy was used. This technique provides a ply-by-ply damage analysis. C-scans of the top and bottom surface of the machined holes in the composite were also carried out. Further, micrographs of the holes were taken to analyse the quality of the holes using field-emission scanning electron microscope. The obtained results indicated that HAZ, taper angle and surface roughness of holes decreased by ∼30%, ∼47% and ∼43%, respectively, with 1.5 wt% multi-walled carbon nanotubes doped carbon fibre reinforced polymer laminates, when compared with the results obtained from experiments with neat carbon fibre reinforced polymer composite laminates.

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Multi-Walled Carbon Nanotubes as Electrocatalyst Supports for H2O2 Reduction Reaction

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.831 ◽

2013 ◽

Vol 860-863 ◽

pp. 831-834

Author(s):

Dan Zheng ◽

Ting Fang Yang ◽

Zhang Fei Guo

Keyword(s):

Cyclic Voltammetry Curve ◽

Chemical Reduction ◽

Reduction Reaction ◽

Carbon Substrate ◽

Acid Media ◽

Multi Walled Carbon Nanotube ◽

Multi Walled Carbon Nanotubes ◽

Current Densities ◽

Reaction Activation Energy ◽

Walled Carbon Nanotubes

This work studies the use of Multi-walled carbon nanotube (MWCNT) as catalyst supports for H2O2 electro-reduction in acid media. Using impregnation-chemical reduction method, we prepared Pt-Ag/CNTs, Pt-Co/CNTs, Pt-Ag/C and Pt-Co/C nanocatalysts. Four catalysts were analyzed by XRD and TEM. Their electrochemical performance was studied via cyclic voltammetry curve. The results show that: the nanoparticles have a better dispersion on CNTs substrate than on XC-72 carbon substrate. Comparing with Pt-Ag and Pt-Co on XC-72 carbon substrate, the H2O2 reduction reaction activation energy of catalysts on CNTs substrate is bigger, and the peak current densities of catalysts on CNTs substrate are larger than that on XC-72 carbon.

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