Cement paste with well-dispersed multi-walled carbon nanotubes: Mechanism and performance

Zhang, Jinyuan; Ke, Yu; Zhang, Jinrui; Han, Qinghua; Dong, Bo‐Qing

doi:10.1016/j.conbuildmat.2020.120746

Cited by 45 publications

(8 citation statements)

References 48 publications

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“…The interaction between microfine coal particles was analyzed on the basis of EDLVO theory. − Therefore, the total interaction energy ( V T ) was demonstrated by the following equation V normalT = V normalW + V normalE + V normalH + V normalS where the van der Waals force action energy ( V w , J) was determined by the Hamaker constant and radius of particles, as performed in eq ; the electrostatic repulsion energy ( V E , J) could be calculated in eqs 5–7, which was mainly determined by the charge potential and radius of the particles; the hydrophobic interaction energy ( V H , J) was determined by the acid–base free energy and radius of particles, and it was performed using eqs 8–12; and the steric hindrance energy ( V S , J), which could be obtained from eqs 13 and , was usually influenced by thickness of the adsorption layer and dispersant property V normalW = prefix− false( A 11 − A 22 false) 2 R 12 H where A 11 and A 22 are the Hamaker constants of coal particles and water in a vacuum, which equaled to 6.1 × 10 –20 and 3.7 × 10 –20 J, respectively; , R is expressed as the median size of microfine coal particles in the slurry, m ; and H is denoted as the distance between coal particles, nm. V normalE = π ε ε 0 R φ 2 ( ln true[ 1 + exp nobreak0em.25em⁡ false( <...…”

Section: Methodsmentioning

confidence: 99%

Insights into the Dispersion Mechanism of Microfine Coal Particles Modified with Naphthalene Sulfonate Formaldehyde Based on EDLVO Theory

et al. 2023

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Coal water slurry (CWS) fuel prepared using microfine coal particles with a size distribution of 1–10 μm is a promising way to cleanly utilize solid resources in engines, even catering a popular application for clean coal technology. In an attempt to address the problems in coal aggregation in microfine coal water slurry (MCWS), dispersants are used to improve the dispersing status of microfine coal particles. Based on the experimental results and extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory calculations, the role of naphthalene sulfonate formaldehyde (NSF) in MCWS performance was explored. The measurement of the slurry ability of microfine coals demonstrated that the apparent viscosity and yield stress of MCWS were decreased significantly with 1.5% NSF addition, which was consistent with the saturated adsorption value of NSF on microfine coals. Furthermore, the ζ-potential and contact angle of microfine coals were both decreased as a function of the NSF dosage, indicating that a larger electrostatic repulsion force and better wetting ability of the coal surface would be obtained in the presence of NSF. The thickness calculation results showed that the thickness is increased with NSF addition, which is attributed to that the NSF molecule extends into the surrounding solution to form a hydrophilic film. The EDLVO calculations illustrated that the total interaction was turned from an attractive force into a repulsive force in the case of NSF, noting that the better dispersion of microfine coals mainly resulted from the better hydrophilicity of the coal surface modified with NSF. The findings might provide guidance for MCWS preparation by revealing the interaction mechanism of microfine coals modified with NSF.

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Section: Methodsmentioning

confidence: 99%

Insights into the Dispersion Mechanism of Microfine Coal Particles Modified with Naphthalene Sulfonate Formaldehyde Based on EDLVO Theory

et al. 2023

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“…In this work, datasets represent the collection of experimental data given in the literature [ 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 ]. Experimental investigations were chosen according to the content of the mixture, type of the nanofiller, and fabrication and testing procedures.…”

Section: Prediction Of Properties Of Self-sensing Concrete Using Annsmentioning

confidence: 99%

“…The data presented in this study are openly available in reference number [ 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 ].…”

mentioning

confidence: 99%

Application of Artificial Neural Networks for Prediction of Mechanical Properties of CNT/CNF Reinforced Concrete

Kekez

Kubica

2021

Materials

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Prominence of concrete is characterized by its high mechanical properties and durability, combined with multifunctionality and aesthetic appeal. Development of alternative eco-friendly or multipurpose materials has conditioned improvements in concrete mix design to optimize concrete production speed and price, as well as carbon footprint. Artificial neural networks represent a new and efficient tool in achieving optimal concrete mixtures according to its intended function. This paper addresses concrete mix design and the application of artificial neural networks (ANNs) for self-sensing concrete. The authors review concrete mix design methods and the development of ANNs for prediction of properties for various types of concrete. Furthermore, the authors present developments and applications of ANNs for prediction of compressive strength and flexural strength of carbon nanotubes/carbon nanofibers (CNT/CNF) reinforced concrete using experimental results for the learning process. The goal is to bring the ANN approach closer to a variety of concrete researchers and possibly propose the implementation of ANNs in the civil engineering practice.

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“…proved that the strength of a paste mortar containing CNTs was not significantly improved either by increasing the amount of CNTs or imposing sonication in mixing suspension . The phenomenon that CNTs with excellent mechanical properties do not significantly improve the performance of a cement-based material is mainly attributed to two reasons: (1) the high van der Waals interaction energy results in poor dispersion of CNTs and (2) the inert CNTs cannot form strong interfacial bonding with cement-based materials. , To solve these problems, Li et al used a mixture of a H 2 SO 4 and HNO 3 solution for surface oxidation treatment (carboxylation) of CNTs to improve the hydrophilicity of CNTs . The cement-based materials modified with CNTs-COOH can resist the erosion of harmful ions .…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Cement Paste with Carboxylated Carbon Nanotubes and Poly(vinyl alcohol)

Zhao

Zhang

Qiao

et al. 2022

ACS Appl. Nano Mater.

Self Cite

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Cement has been a major consumable material for construction in the world since its invention, but its low flexural strength is the main defect affecting the service life of structures. To adapt cement-based materials to a more stringent environment, carboxylated carbon nanotubes (CNTs-COOH) and poly(vinyl alcohol) (PVA) are proposed to enhance the mechanical properties of cement paste. This study systematically verifies the synergistic effect of CNTs-COOH/PVA on the performance of cement paste. First, UV–Vis spectroscopy and FTIR spectroscopy prove that CNTs-COOH can provide attachment sites for PVA and PVA can improve the dispersion and stability of CNTs-COOH in water, which demonstrates the feasibility of synergistically enhancing cement paste. When a 0.015% CNTs-COOH suspension with 0.1% PVA is added, the flexural strength of the cement paste increases by 73, 32, and 42% compared with control specimens at curing ages of 3, 7, and 28 days, respectively. The strength enhancement mechanism is revealed from the aspects of cement matrix enhancement and interface enhancement. Thermogravimetric (TG) analysis and mercury intrusion porosimetry (MIP) prove that CNTs-COOH can enhance the hydration degree of the cement matrix and fill the pores introduced by PVA. Based on the fact that PVA can improve the dispersibility and the nucleation site effect of CNTs-COOH in cement paste, molecular dynamics simulation confirms that PVA can bridge CNTs-COOH and C–S–H to enhance the interfacial bonding by 64.1%.

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Cement paste with well-dispersed multi-walled carbon nanotubes: Mechanism and performance

Cited by 45 publications

References 48 publications

Insights into the Dispersion Mechanism of Microfine Coal Particles Modified with Naphthalene Sulfonate Formaldehyde Based on EDLVO Theory

Insights into the Dispersion Mechanism of Microfine Coal Particles Modified with Naphthalene Sulfonate Formaldehyde Based on EDLVO Theory

Application of Artificial Neural Networks for Prediction of Mechanical Properties of CNT/CNF Reinforced Concrete

Enhancement of Cement Paste with Carboxylated Carbon Nanotubes and Poly(vinyl alcohol)

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