Influences of multi-walled carbon nanotube (MCNT) fraction, moisture, stress/strain level on the electrical properties of MCNT cement-based composites

Luo, Jianlin; Zhang, Chunwei; Duan, Zhongdong; Wang, Baolin; Li, Qiuyi; Chung, Kwok L.; Zhang, Jigang; Chen, Shuaichao

doi:10.1016/j.sna.2018.08.010

Cited by 30 publications

(8 citation statements)

References 46 publications

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“…For example, Wen et al [33] found the percolation threshold of 2.6 vol.% in a mixture containing carbon nanotube/carbon black/polypropylene, and obtained a percolation threshold of 0.18 wt.% in the PLA/EVA/rGOs composites. In this study, a percolation threshold of 0.5 wt.% (~0.3 vol.%) was obtained, which is the lowest in all the reported construction-material based nanocomposites (cement, asphalt and other composites) [34]. Such low percolation threshold is mainly due to the high dispersion quality of graphene, as well as the effective reduction method.…”

Section: Resultsmentioning

confidence: 60%

Self-Heating Graphene Nanocomposite Bricks: A Case Study in China

Tang

Gong

et al. 2020

Materials

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In cold climate regions, the energy associated with indoor heating constitutes a large portion of energy consumption. Increasing energy utilization efficiency is critically important for both economic and environmental reasons. Directly converting electrical energy to thermal energy using joule heating construction elements can save energy and investment to the water pipelines which have been extensively used for indoor heating in China. The fired brick has been extensively used to make pavements, walls and other masonry. Taking advantage of the high dispersion quality of graphene oxide (GO) in water, as well as the firing process used to make fired bricks, graphene nanocomposite bricks with excellent electrical properties and improved mechanical performance were prepared in China. The compressive strength of the bricks showed a substantial increase from 3.15 MPa to 7.21 MPa when GO concentration was 0.1 wt.%. Through applying 5 volts of electrical field within 5 minutes, the nanocomposites can be heated from room temperature to 60 °C, 110 °C and 160 °C for the nanocomposite bricks with graphene concentration of 3 wt.%, 4 wt.% and 5 wt.%, respectively, due to the extremely low percolation threshold (~0.5 wt.%) and high conductivity (10 Ω·cm at 1 wt.%). The sheets were connected more tightly when the GO content was increased. The thermal efficiency can reach up to 88% based on the applied voltage, measured resistance and temperature rise curves.

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Section: Resultsmentioning

confidence: 60%

Self-Heating Graphene Nanocomposite Bricks: A Case Study in China

Tang

Gong

et al. 2020

Materials

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“…The conductivity of MWCNTs/CM is not only related to the ionic conductivity of pore solution, but also to the content and distribution of MWCNTs. The effect of MWCNTs content on the electrical conductivity of cement mortar under different water content has been studied by scholars [26,36,37], so we will not repeat it here. The main work of this paper is to explore the effect of MWCNTs size on the electrical conductivity of cement mortar under different water content.…”

Section: The Effect Of Mwcnts Length On Electricalmentioning

confidence: 99%

Effect of Carbon Nanotube Size on Electrical Properties of Cement Mortar under Different Temperatures and Water Content

Cheng

2022

Geofluids

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The effects of temperature and water content on the electrical conductivity of cement mortar with different sizes of carbon nanotubes were studied, and the effect of the size of carbon nanotubes on the electrical conductivity of cement mortar was revealed. The results show that the small diameter carbon nanotubes have the best enhancement effect on the electrical conductivity of cement mortar. The electrical conductivity of cement mortar with different diameters of carbon nanotubes is positively correlated with water content, and with the decrease of the diameter of carbon nanotubes in the sample, the effect of water content on the electrical conductivity of carbon nanotube cement mortar becomes smaller and smaller. With the increase of temperature, the electrical conductivity of cement mortar containing carbon nanotubes of different diameters increases in varying degrees, but the increase of samples with small diameter carbon nanotubes is the smallest, indicating that the electrical conductivity of cement mortars with small diameter carbon nanotubes is less affected by temperature.

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“…Figure 15 shows the PV/YP ratios of all the cement slurries. According to Magzoub et al [33] and Luo et al [34], PV/YP describes the carrying capacity of drilling fluids. Generally, any value of the ratio of YP/PV ≥ 0.75 or PV/YP ≥ 1.3 shows a good carrying capacity of a drilling fluid and can therefore lead to an improved cleaning of the wellbore.…”

Section: Pv/yp Ratiomentioning

confidence: 99%

Experimental Evaluation of the Performance of Fresh Nano Zeolite as an Oil Well Cement Additive

Broni-Bediako¹,

Naatu²

2021

PSE

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Cementing oil and gas wells require materials that, not only meet performance standards but also fairly different from those encountered in conventional processes. The search for alternative materials for cementing oil wells has increased worldwide. It is desirable that these alternative materials make cement sheath stronger, durable, flexible, cost-effective and more resistant to shocks. This research aimed at evaluating the performance of fresh nano zeolite as an additive for shallow oil well cementing operations. Laboratory tests were conducted on a base cement slurry mixed with different concentrations of fresh nano zeolite from 1% bwoc to 3% bwoc at a Bottomhole Circulating Temperature (BHCT) of 80°F (27°C) to determine physical properties such as compressive strength, thickening time, rheology, free fluid, and fluid loss. The results showed that the compressive strength of the cement slurries improved significantly at 12 hours than 24 hours curing period at 87°F (31°C). As the concentration of fresh nano zeolite increases less time was required to reach 50 psi, 100 psi and most importantly 500 psi which is needed to resume drilling operations. An increase in concentration of fresh nano zeolite at 80°F (27°C) resulted in an increase in the thickening time of all the cement slurries. This shows that fresh nano zeolite has a high retardation effect. Generally, the addition of fresh nano zeolite from 1% bwoc to 3% bwoc improved the carrying capacity of all the cement slurries. Test results also showed that increasing the fresh nano zeolite concentrations resulted in a decrease in rheological values which is a characteristic of a dispersant. Plastic viscosity values were observed to have an increasing trend generally with an increasing concentration of fresh nano zeolites. All the cement slurries were below 100 cP and therefore pumpable. The addition of fresh nano zeolite to the base cement slurry increased the free fluid of the cement slurries. The fresh nano zeolite didn't have any effect on fluid loss and therefore does not exhibit characteristics of a fluid loss agent.

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Influences of multi-walled carbon nanotube (MCNT) fraction, moisture, stress/strain level on the electrical properties of MCNT cement-based composites

Cited by 30 publications

References 46 publications

Self-Heating Graphene Nanocomposite Bricks: A Case Study in China

Self-Heating Graphene Nanocomposite Bricks: A Case Study in China

Effect of Carbon Nanotube Size on Electrical Properties of Cement Mortar under Different Temperatures and Water Content

Experimental Evaluation of the Performance of Fresh Nano Zeolite as an Oil Well Cement Additive

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