Effect of pre-strain and KMnO4 oxidation of carbon nanotubes embedded in polyurethane on strain dependent electrical resistance of the composite

Purpose The synergistic effect of functionalization of multi-walled carbon nanotubes (CNT) using KMnO4 oxidation and initial tensile deformation on the electrical resistance of nanotube network/polyurethane composite subjected to elongation was studied. Design/methodology/approach Though the initial deformation irreversibly changed the arrangement of carbon nanotube network, subsequent cyclic elongation confirmed stable resistance values. The increased strain-dependent resistance of stimulated nanotube network/polyurethane composite was demonstrated by monitoring vibration of tambour leather after a bead impact and finger flexion. Findings The results showed a tenfold composite resistance increase for the composite prepared from KMnO4 oxidized nanotubes, quantified by a so-called gauge factor, from a value of about 20 in comparison to the network prepared from pristine nanotubes. This is a substantial increase, which ranks the stimulated composite among materials with the highest electromechanical response. Originality/value The results in this paper are new and have not been published yet. The paper combines different ideas which are developed together. It presents a new concept of synergistic effect of CNT oxidation and application of pre-strain simulation. Oxidation and pre-strain increases by several times the sensitivity of the tested composites which are predetermined for use as strain sensors of various sizes and shapes.

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Enhanced Electromechanical Properties of Carbon Nanotube/Polyurethan Composite by KMnO4 Oxidation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.605.235 ◽

2014 ◽

Vol 605 ◽

pp. 235-238

Author(s):

Roman Bořuta ◽

Petr Slobodian ◽

Robert Olejnik ◽

Michal Machovsky ◽

Pavel Riha

Keyword(s):

Electrical Resistance ◽

Gauge Factor ◽

Strain Sensing ◽

Sensing Element ◽

Electromechanical Properties ◽

Deformation Strain ◽

High Deformation ◽

Polyurethane Composite ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

The effect of oxidation of multi-walled carbon nanotubes by KMnO4on the electrical resistance of a nanotube network/polyurethane composite subjected to bending has been studied. In this respect, the main achievement is a multiple increase of gauge factor for the evaluating electromechanical properties of the composite after nanotube oxidation with KMnO4. It indicates favorable properties of the composite for its use as a high-deformation strain-sensing element.

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Temperature-Dependent Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets on the Tensile Quasi-Static and Fatigue Properties of Epoxy Nanocomposites

Polymers ◽

10.3390/polym13010084 ◽

2020 ◽

Vol 13 (1) ◽

pp. 84

Author(s):

Yi-Ming Jen ◽

Hao-Huai Chang ◽

Chien-Min Lu ◽

Shin-Yu Liang

Keyword(s):

Carbon Nanotubes ◽

Fatigue Strength ◽

Synergistic Effect ◽

Polymer Nanocomposites ◽

Graphene Nanoplatelets ◽

Temperature Dependent ◽

Epoxy Nanocomposites ◽

Hybrid Fillers ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.

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Water-based polyurethane composite anticorrosive barrier coating via enhanced dispersion of functionalized graphene oxide in the presence of acidified multi-walled carbon nanotubes

Progress in Organic Coatings ◽

10.1016/j.porgcoat.2020.105734 ◽

2020 ◽

Vol 146 ◽

pp. 105734 ◽

Cited By ~ 1

Author(s):

Li-Chao Jing ◽

Tao Wang ◽

Wei-Wei Cao ◽

Jian-Gong Wen ◽

Hui Zhao ◽

...

Keyword(s):

Carbon Nanotubes ◽

Graphene Oxide ◽

Functionalized Graphene ◽

Functionalized Graphene Oxide ◽

Polyurethane Composite ◽

Barrier Coating ◽

Water Based ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

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Synergistic effect of photoanode and photocathode modified with oxygenated multi-walled carbon nanotubes in dye-sensitized solar cells

Korean Journal of Chemical Engineering ◽

10.1007/s11814-021-0859-4 ◽

2021 ◽

Author(s):

Min-Jung Song ◽

Joon-Hyung Jin

Keyword(s):

Carbon Nanotubes ◽

Solar Cells ◽

Synergistic Effect ◽

Dye Sensitized Solar Cells ◽

Dye Sensitized ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Sensitized Solar Cells

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Synergistic effect of multi walled carbon nanotubes and reduced graphene oxides in natural rubber for sensing application

Soft Matter ◽

10.1039/c3sm51978c ◽

2013 ◽

Vol 9 (43) ◽

pp. 10343 ◽

Cited By ~ 109

Author(s):

Deepalekshmi Ponnamma ◽

Kishor Kumar Sadasivuni ◽

Michael Strankowski ◽

Qipeng Guo ◽

Sabu Thomas

Keyword(s):

Carbon Nanotubes ◽

Synergistic Effect ◽

Natural Rubber ◽

Graphene Oxides ◽

Reduced Graphene ◽

Multi Walled Carbon Nanotubes ◽

Sensing Application ◽

Reduced Graphene Oxides ◽

Walled Carbon Nanotubes

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The electrical resistance of electrodes made of multi walled carbon nanotubes is modulated by nIR-laser

Microelectronic Engineering ◽

10.1016/j.mee.2016.09.013 ◽

2016 ◽

Vol 166 ◽

pp. 45-49 ◽

Cited By ~ 5

Author(s):

Juan Bernal-Martínez ◽

Rafael Godínez-Fernández ◽

Manuel Roman-Aguirre ◽

Alfredo Aguilar-Elguezabal

Keyword(s):

Carbon Nanotubes ◽

Electrical Resistance ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Nir Laser

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Electrical and piezoresistive properties of cement composites with carbon nanomaterials

Journal of Composite Materials ◽

10.1177/0021998318764809 ◽

2018 ◽

Vol 52 (24) ◽

pp. 3325-3340 ◽

Cited By ~ 18

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.

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Effects of CNT Doping Level and Water/Cement Ratio on the Piezoresistivity of CNTS/Cement Composites

ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Volume 2 ◽

10.1115/smasis2010-3629 ◽

2010 ◽

Author(s):

Baoguo Han ◽

Xun Yu ◽

Jinping Ou

Keyword(s):

Carbon Nanotubes ◽

Compressive Stress ◽

Electrical Resistance ◽

Doping Level ◽

Experimental Results ◽

Cement Composites ◽

Cement Ratio ◽

Water Cement Ratio ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

The carbon nanotubes (CNTs)/cement composites with different doping levels of multi-walled carbon nanotubes (MWNTs) and water/cement ratios are fabricated. By comparing the responses of electrical resistance of these CNTs/cement composites to compressive stress, the effects of MWNT doping level and water/cement ratio on the piezoresistive sensitivity of composites are investigated. Experimental results indicate that the piezoresistive sensitivities of CNTs/cement composites with 0.05 wt. %, 0.1 wt. % and 1 wt. % of MWNTs firstly increase and then decrease with the increase of CNT doping levels. The electrical resistance of CNTs/cement composites 0.6 water/cement ratio is more sensitive to compressive stress than that of composites with 0.45 water/cement ratio.

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