Electrical and piezoresistive properties of cement composites with carbon nanomaterials

2018 ◽  
Vol 52 (24) ◽  
pp. 3325-3340 ◽  
Author(s):  
Doo-Yeol Yoo ◽  
Ilhwan You ◽  
Hyunchul Youn ◽  
Seung-Jung Lee
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Carbon Nanomaterials ◽  
Peak Load ◽  
Compressive Load ◽  
Gauge Factor ◽  
Fractional Change ◽  
Graphite Nanofibers ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

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.

scholarly journals Load Sensing Capability of Cementitious Matrixes—Nanomodified Cement Versus Carbon Nanotube Dispersion

Proceedings ◽  
2019 ◽  
Vol 34 (1) ◽  
pp. 19
Author(s):  
Buasiri ◽  
Habermehl-Cwirzen ◽  
Krzeminski ◽  
Cwirzen
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Properties ◽  
Carbon Nanomaterials ◽  
Compressive Load ◽  
Weight Changes ◽  
Load Sensing ◽  
Carbon Nanotube Dispersion ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A cement-based matrix incorporating conductive materials such as carbon nanotubes and carbon nanofibers can have self-sensing capability. Both nanomaterials are characterized by excellent physical, mechanical and electrical properties. A disadvantage is that due to their hydrophobic nature it is very difficult to ensure uniform dispersion throughout the cementitious matrix. To overcome this problem a new nanomodified cement containing in-situ attached CNFs was developed leading to a very homogenous and conductive binder matrix. This study aimed to compare the piezoresistive responses of two types of matrixes, one based on the nanomodified cement and the second containing multi-walled carbon nanotubes. Several mortars were prepared containing either MWCNTs or the nanomodified cement, which partially replaced the untreated cement. The effective amount of the carbon nanomaterials was the same for both types of mixes and ranged from 0 wt.% to 0.271 wt.%, calculated by the all binder weight. Changes in the electrical properties were determined while applying compressive load. The results showed that the binders based on the nanomodified cement have significantly better load sensing capabilities and are suitable for applications in monitoring systems.

A comparative study of cellular uptake and cytotoxicity of multi-walled carbon nanotubes, graphene oxide, and nanodiamond

2012 ◽  
Vol 1 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Xiaoyong Zhang ◽  
Wenbing Hu ◽  
Jing Li ◽  
Lei Tao ◽  
Yen Wei
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Cellular Uptake ◽  
Hela Cells ◽  
Carbon Nanomaterials ◽  
Toxicity Assessment ◽  
Cell Uptake ◽  
Multi Walled Carbon Nanotubes ◽  
Living Organisms ◽  
Walled Carbon Nanotubes

Abstract Investigations of the interactions between carbon nanomaterials (CNMs) and living organisms and their subsequent biological responses are of fundamental significance for toxicity assessment and further biomedical applications. In this work, the cellular uptake and cytotoxicity of multi-walled carbon nanotubes (MWCNTs), graphene oxide (GO) and nanodiamond (ND) were examined and compared. We demonstrated that all of the CNMs were readily internalized by HeLa cells through nonspecific cellular uptake. Their cell uptake ratios showed significant differences in the following order: ND > MWCNTs > GO. A series of biological assays were used to evaluate the cytotoxicity of CNMs. It was found that CNMs showed dose- and time-dependent cytotoxicity to HeLa cells. However, cytotoxicity of CNMs was not associated with their cell uptake ratios. Among them, ND exhibited the highest cell uptake ratio and the least cytotoxicity. To the best of our knowledge, this is the first study which has quantitatively determined and compared the cell uptake ratios and cytotoxicities of MWCNTs, GO and ND. And we expect that these results described here could provide useful information for the development of new strategies to design efficient drug delivery nanocarriers and therapeutic systems as well as deep insights into the mechanism of CNMs' cytotoxicity.

Controllable Fabrication of Flexible Multi-Walled Carbon Nanotubes/Reduced Graphene Oxide Hybrid Ultrathin Films

2015 ◽  
Vol 748 ◽  
pp. 175-178
Author(s):  
Wen Xiu Yu ◽  
Su Jie Qin ◽  
Zuo Ping Xiong ◽  
Zhong Qiang Ren ◽  
Xue Wen Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Carbon Nanomaterials ◽  
Low Cost ◽  
Layer By Layer ◽  
Hybrid Films ◽  
Reduced Graphene ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes/reduced graphene oxide (MWCNT/rGO) hybrid films have attracted increasing massive attention due to their unique advantages such as high conductivity, superior mechanical property and thermal properties. In this work, a novel, facile and low cost method was developed to fabricate the MWCNT/rGO flexible ultrathin hybrid films with the thickness of about 55 nm. These hybrid films can be fabricated repeatedly through layer-by-layer exfoliation on the surface of liquids, and transferred to various substrates. The devices based on MWCNT/rGO hybrid films offer a unique platform for integrating carbon nanomaterials for advanced electronics, energy, and sensor applications.

scholarly journals The Effect of Combinations of Carbon Nanomaterials on the Microhardness of the Chromium Galvanic Coating

2020 ◽  
pp. 056-063
Author(s):  
M. Nasraoui ◽  
◽  
Yu.V. Litovka ◽  
V.Yu. Dolmatov ◽  
◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Service Life ◽  
Crystal Lattice ◽  
Carbon Nanomaterials ◽  
Single Walled Carbon Nanotubes ◽  
Galvanic Coating ◽  
Single Walled Carbon ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A method to increase the microhardness of the chromium galvanic coating by adding a mixture of carbon nanomaterials (nanodiamonds, single-walled and multi-walled nanotubes, graphene oxide) into a standard chromium galvanic coating electrolyte was proposed. The increase in the microhardness of the chromium galvanic coating was revealed and explained. This is due to a combination of two mechanisms: the introduction of nanodiamonds into the crystal lattice of the coating metal and the appearance of additional crystallization centers on defects in carbon nanotubes. The method of obtaining parts with a higher service life when using traditional chromium galvanic coating, as well as when using multi-walled carbon nanotubes, single-walled carbon nanotubes, nanodiamonds, and graphene oxide separately, was demonstrated. The best result was obtained using a mixture of nanodiamonds and multi-walled carbon nanotubes. The microhardness of the nanomodified chromium galvanic coating was measured, and it was found to increase by 27 %.

Multi-Walled Carbon Nanotubes/Graphene Oxide Composites for Humidity Sensing

2013 ◽  
Vol 13 (12) ◽  
pp. 4749-4756 ◽  
Author(s):  
Xiaoyu Li ◽  
Xiangdong Chen ◽  
Yao Yao ◽  
Ning Li ◽  
Xinpeng Chen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Humidity Sensing ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Oxide Composites

Development of a Polymeric Carbon Nanocomposite Hollow-Fiber Membrane for Wastewater Treatment

2021 ◽  
Vol 21 (7) ◽  
pp. 3711-3715
Author(s):  
Jeongdong Choi ◽  
Eun-Sik Kim
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Hollow Fiber ◽  
Hollow Fiber Membranes ◽  
Permeate Flux ◽  
Fiber Membranes ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Polymeric Carbon ◽  
Carbon Nanocomposite

This study investigated experimental parameters to fabricate polymeric carbon nanocomposite hollow-fiber membranes with graphene oxide and multi-walled carbon nanotubes. This case was different from that of flat-sheet type membranes in that the characteristics of the hollow-fiber type membranes were affected by the structure of the spinneret, the flow rate of the injected polymer and draw solution, and the mixing ratio. The membranes were characterized in terms of mechanical strength, porosity, hydrophilicity, and permeate flux using different solutions. The results reveal a mechanical strength of the carbon nanocomposite hollow-fiber membranes that is about 47.8% higher than that of hollow-fiber membranes without carbon nanomaterials. The porosity and surface hydrophilicity changed to produce more applicable membranes for water and wastewater treatment. As for the permeate flux, the nanocomposite membrane with graphene oxide showed a higher flux compared to the multi-walled carbon nanotubes membrane, which could be influenced by structural effects of the carbon materials.

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