Micro- and Nano-Indentation of a Hydroxyapatite-Carbon Nanotube Composite

2008 ◽  
Vol 8 (8) ◽  
pp. 3936-3941 ◽  
Author(s):  
Catherine S. Kealley ◽  
Bruno A. Latella ◽  
Arie van Riessen ◽  
Margaret M. Elcombe ◽  
Besim Ben-Nissan
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Carbon Nanotube ◽  
Composite Materials ◽  
Graphite Phase ◽  
Biomedical Implant ◽  
The Matrix ◽  
Nanotube Composites ◽  
Synthetic Hydroxyapatite ◽  
Carbon Nanotube Composite

The mechanical properties of pure synthetic hydroxyapatite and hydroxyapatite-carbon nanotube composites were examined. Vickers microhardness and nanoindentation using a Berkovich tipped indenter were used to determine the hardness, fracture toughness and Young's modulus of the pure hydroxyapatite matrix and the composite materials. Microscopy showed that for the composites produced the carbon nanotubes were present as discrete clumps. These clumps induced a detrimental effect on the hardness of the materials, while the fracture toughness values were not affected. This would be undesirable in terms of using the material for biomedical implant applications. It should be noted that the carbon nanotubes used contained free graphite. As the properties of the composite materials studied were not greatly improved over the matrix, it is speculated that if the graphite phase were removed from the reagent, this could in-turn enhance the properties of the material.

The Microstructure, Mechanical and Dielectric Properties of CNTs/Mullite Ceramics Composites

2006 ◽  
Vol 313 ◽  
pp. 145-150 ◽  
Author(s):  
Jing Wang ◽  
Hua Min Kou ◽  
Yu Bai Pan ◽  
Jing Kun Guo
Keyword(s):  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Carbon Nanotube ◽  
Bending Strength ◽  
Composite Powders ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mullite Ceramics ◽  
Dissipative Factor

Carbon nanotube-mullite (Al2O3/SiO2=3/2) composites have been prepared by hot-pressing the corresponding composite powders, in which the multi-walled carbon nanotubes(1~10 vol%) are homogeneously dispersed between the mullite grains. The microstructure of the specimens has been studied and discussed in relation to the properties of the matrix, the bending strength and the fracture toughness, the dielectric constant and the dissipative factor. Carbon nanotube-mullite composites are potential electromagnetic wave absorbers owing to the percolation of the carbon nanotubes.

Prediction of mechanical properties of MWCNT-reinforced composites using the RVE model

2018 ◽  
Vol 32 (18) ◽  
pp. 1850196 ◽  
Author(s):  
Seung-Hyun Park ◽  
Hong-Kyu Jang ◽  
Yunjeong Park ◽  
Sung-Yong Hong ◽  
Jae-Boong Choi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Mechanical Design ◽  
Relative Distribution ◽  
Single Walled Carbon Nanotube ◽  
Polymer Resin ◽  
The Matrix ◽  
Nanotube Composites ◽  
Prediction Of Mechanical Properties

Carbon nanotube (CNT) composites have mechanical, thermal, and electrical properties superior to those of conventional polymer resin materials. In particular, multi-walled carbon nanotube (MWCNT) composites have higher mechanical strength than single-walled carbon nanotube composites. This work investigates the methods for analytically evaluating and predicting the mechanical properties of MWCNT-reinforced nanocomposites to enable their effective mechanical design. First, the correlation between the thickness of the interphase region (between the carbon nanotubes and the polymer matrix) and the mechanical properties of the MWCNT-reinforced composite was studied. Next, the effect of the relative distribution of carbon nanotubes in the matrix on the mechanical properties of nanocomposites fabricated by injection molding was evaluated. Finally, the effect of agglomerate size on the mechanical properties of nanocomposites was investigated, and a critical size for carbon nanotube agglomerates was analytically proposed.

scholarly journals Optical detection of charge dynamics in CH3NH3PbI3/carbon nanotube composites

Nanoscale ◽  
2017 ◽  
Vol 9 (45) ◽  
pp. 17781-17787 ◽  
Author(s):  
Hajnalka M. Tóháti ◽  
Áron Pekker ◽  
Pavao Andričević ◽  
László Forró ◽  
Bálint Náfrádi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Lead Iodide ◽  
Charge Dynamics ◽  
Nanotube Composites ◽  
Efficient Charge ◽  
Carbon Nanotube Composites ◽  
Induced Charge ◽  
Carbon Nanotube Composite ◽  
Methylammonium Lead Iodide

This spectroscopic study of light-induced charge transfer in the methylammonium lead iodide/carbon nanotube composite confirms that carbon nanotubes can form efficient charge-transporting layers in organic perovskite based devices.

Characterization of cubic tumbler rod milled dispersed carbon nanotubes–Aluminum composites

2018 ◽  
Vol 52 (28) ◽  
pp. 3973-3985
Author(s):  
Sandeep Alanka ◽  
Chanamala Ratnam ◽  
Balla Srinivasa Prasad
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Load Transfer ◽  
Pure Aluminum ◽  
Aluminum Matrix ◽  
Aluminum Carbide ◽  
Multiwalled Carbon Nanotube ◽  
Multiwalled Carbon ◽  
Nanotube Composites ◽  
Carbon Nanotube Composite

In this work, cubic tumbler rod milling was used to disperse X wt% multiwalled carbon nanotubes (X = 0.5, 0.75, 1.0) in an aluminum matrix. Dispersed precursor of aluminum–multiwalled carbon nanotube composite was subsequently consolidated by cold compaction followed by sinter-forged process. Microstructural and mechanical behaviors of as-produced aluminum–multiwalled carbon nanotube composites with different concentration were investigated. Findings revealed that the as-produced Al–0.75 wt% carbon nanotube sinter-forged composite exhibits homogenous distribution and embedded nanotubes confirmed by the scanning electron microscope and the properties were observed to be increased significantly up to addition of 0.75 wt% of carbon nanotubes concentration than the pure aluminum as well as extruded composite and decrease to 1.0 wt% carbon nanotube due to the agglomeration of multiwalled carbon nanotube. However, enhancement of hardness, tensile strength, and Young’s modulus of the nanocomposites, compared with pure aluminum are 48.5, 83.8, and 30%, respectively. The tensile fractography of sinter-forged composite shows carbon nanotubes act like a bridge and barring the crack growth of aluminum matrix, remaining are pullout. Hence, it can be concluded that aluminum carbide phase starting from 0.75 wt% carbon nanotube and a strong interfacial bonding in as-produced aluminum–carbon nanotube composite has been observed which gives effective load transfer between aluminum matrix and carbon nanotubes.

scholarly journals Supramolecular ionic polymer/carbon nanotube composite hydrogels with enhanced electromechanical performance

2020 ◽  
Vol 9 (1) ◽  
pp. 478-488 ◽  
Author(s):  
Yun-Fei Zhang ◽  
Fei-Peng Du ◽  
Ling Chen ◽  
Ka-Wai Yeung ◽  
Yuqing Dong ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Ion Mobility ◽  
Artificial Muscles ◽  
Ionic Polymer ◽  
Composite Hydrogels ◽  
The Matrix ◽  
Electromechanical Performance ◽  
Carbon Nanotube Composite ◽  
Robotic Devices

AbstractElectroactive hydrogels have received increasing attention due to the possibility of being used in biomimetics, such as for soft robotics and artificial muscles. However, the applications are hindered by the poor mechanical properties and slow response time. To address these issues, in this study, supramolecular ionic polymer–carbon nanotube (SIPC) composite hydrogels were fabricated via in situ free radical polymerization. The polymer matrix consisted of carbon nanotubes (CNTs), styrene sulfonic sodium (SSNa), β-cyclodextrin (β-CD)-grafted acrylamide, and ferrocene (Fc)-grafted acrylamide, with the incorporation of SSNa serving as the ionic source. On applying an external voltage, the ions accumulate on one side of the matrix, leading to localized swelling and bending of the structure. Therefore, a controllable and reversible actuation can be achieved by changing the applied voltage. The tensile strength of the SIPC was improved by over 300%, from 12 to 49 kPa, due to the reinforcement effect of the CNTs and the supramolecular host–guest interactions between the β-CD and Fc moieties. The inclusion of CNTs not only improved the tensile properties but also enhanced the ion mobility, which lead to a faster electromechanical response. The presented electro-responsive composite hydrogel shows a high potential for the development of robotic devices and soft smart components for sensing and actuating applications.

Neuron-like polyelectrolyte–carbon nanotube composites for ultra-high loading of metal nanoparticles

2014 ◽  
Vol 38 (10) ◽  
pp. 4799-4806 ◽  
Author(s):  
Md. Shahinul Islam ◽  
Won San Choi ◽  
Tae Sung Bae ◽  
Young Boo Lee ◽  
Ha-Jin Lee
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Metal Nanoparticles ◽  
Multiwalled Carbon Nanotubes ◽  
High Loading ◽  
Multiwalled Carbon ◽  
Simple Protocol ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites

We report a simple protocol for the fabrication of multiwalled carbon nanotubes (MWCNTs) with a neuron-like structure for loading ultra-high densities of metal nanoparticles (NPs).

The Humidity Sensitive Behavior of Poly(Ethyleneimine)/Multiwall Carbon Nanotube Composite Films

2012 ◽  
Vol 531-532 ◽  
pp. 588-591
Author(s):  
Tao Zhu ◽  
Guang Zhong Xie ◽  
Ya Dong Jiang ◽  
Jian Liao ◽  
Hui Ling Tai
Keyword(s):  
Carbon Nanotube ◽  
Relative Humidity ◽  
Composite Films ◽  
Multiwall Carbon Nanotube ◽  
Sensing Material ◽  
Nanotube Composites ◽  
Interdigitated Microelectrode ◽  
Carbon Nanotube Composite ◽  
Multiwall Carbon ◽  
Sensitive Behavior

In this paper, a novel humidity sensor based on polymer-carbon nanotube composites was prepared and characterized. Two different methods were adopted to fabricate the humidity-sensing film for these sensors. The surface of the films was observed by a scanning electron microscope (SEM). The sensing material made up of poly(ethyleneimine) and multiwall carbon nanotube was sprayed on the interdigitated microelectrode pairs(IDTs). The resistance between the two electrodes was measured at different relative humidity levels at 19°C. The data shows that the resistance increases with the rise of the relative humidity over the range of 5-90% RH and that, the resistance increases almost linearly in the range of 5-71% RH. The response of the sensors to NO2 and NH3 were also examined, and the results reveal that the sensor is not sensitive to both of them.

Mechanical Properties Of Polyaniline / Multi-walled Carbon Nanotube Composite Films

2003 ◽  
Vol 791 ◽  
Author(s):  
P. C. Ramamurthy ◽  
W. R. Harrell ◽  
R. V. Gregory ◽  
B. Sadanadan ◽  
A. M. Rao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Composite Films ◽  
Weight Percent ◽  
Organic Electronic Devices ◽  
Multiwalled Carbon ◽  
Multi Walled Carbon Nanotube ◽  
Contact Devices ◽  
Carbon Nanotube Composite

ABSTRACTHigh molecular weight polyaniline / multi-walled carbon nanotube composite films were fabricated using solution processing. Composite films with various weight percentages of multiwalled carbon nanotubes were fabricated. Physical properties of these composites were analyzed by thermogravimetric analysis, tensile testing, and scanning electron microscopy. These results indicate that the addition of multiwalled nanotubes to polyaniline significantly enhances the mechanical properties of the films. In addition, metal–semiconductor (composite) (MS) contact devices were fabricated, and it was observed that the current level in the films increased with increasing multiwalled nanotube content. Furthermore, it was observed that polyaniline containing one weight percent of carbon nanotubes appears to be the most promising composition for applications in organic electronic devices.

Magnesium and Aluminium Carbon Nanotube Composites

2010 ◽  
Vol 425 ◽  
pp. 245-261 ◽  
Author(s):  
C.S. Goh ◽  
Manoj Gupta ◽  
Anders W.E. Jarfors ◽  
Ming Jen Tan ◽  
J. Wei
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Detrimental Effect ◽  
Industrial Applications ◽  
Nanosized Materials ◽  
Nanotube Composites ◽  
Slip Planes ◽  
Carbon Nanotube Composites ◽  
Hcp Structure ◽  
Strength And Stiffness

Carbon nanotubes are one of the most exciting discoveries of nanosized materials in the 20th century. Challenges to create materials applicable for industrial applications involve both the incorporation of the carbon nanotubes into the material and to ensure that they do not agglomerate. Aluminium and magnesium based materials are among the metals that can benefit from the incorporation of carbon nanotubes. The fabrication of Aluminium carbon nanotube composites has challenges from reactivity and degradation of the carbon nanotube additions; hence the powder metallurgy route is preferred. Magnesium based materials on the other hand do not have this limitation and both the powder metallurgical route and the casting route are viable. Among the benefits of adding carbon nanotubes are increased yield strength and stiffness. Here is important that the effect is significant already at very low addition levels. This makes it possible to increase strength without having a significant detrimental effect on ductility. In fact, for magnesium alloys ductility can be improved due to the activation of additional slip planes improving the normally low ductility of HCP structure materials.

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