scholarly journals Effect of Multi-Walled Carbon Nanotubes on Strength and Electrical Properties of Cement Mortar

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 79
Author(s):  
Elena Cerro-Prada ◽  
Rosalía Pacheco-Torres ◽  
Fernando Varela

This work aims to investigate the effects of multi-walled carbon nanotubes (MWCNTs) on the strength and electrical properties of cement mortar. MWCNTs were added to cement mortar in four different concentrations: 0.00 wt.%, 0.01 wt.%, 0.015 wt.%, and 0.02 wt.% by the mass of cement. The consistency, density, setting time and compressive and flexural strength of mixes were tested and analyzed at 28 and 90 days curing time. Mechanical performance tests confirm an increase of 25% and 20% in the ultimate compressive and flexural strength respectively, which results from MWCNT 0.02 wt.% loading at 90 days curing time. The resistivity measurements in mortars with 0.01 and 0.015 wt.% MWCNT loading result up to 10% decrement at both 28 and 90 days curing. Activation energy calculations show fully accordance with these statements, resuming that 0.01 wt.% MWCNT appears to be the most effective loading scheme to produce certain conductivity enhancement in cement mortar.

2019 ◽  
Vol 11 (4) ◽  
pp. 119-124
Author(s):  
Ekaterina Karpova ◽  
Gintautas Skripkiūnas ◽  
Grigory Yakovlev ◽  
Asta Kičaitė

It is well known that organic waste materials deteriorate the performance of concrete. The impregnation of organic aggregates and their application in combination with other chemical admixtures and mineral additives are used in order to improve the concrete properties in case of their modification by organic components. The current research is focused on the evaluation of impact of multi-walled carbon nanotubes (MWCNT) on the properties of cement systems prepared based on wood sawdust extract (WSE). The setting time, density, consistency, flexural and compressive strength, water absorption tests were undertaken. The retardation effect of (WSE) on the initial and final setting time of cement paste was observed. The additional modification of cement paste with WSE by MWCNT in the dosage of 0.005% by weight of cement (bwoc) did not show the significant changes in initial and final setting time. The application of MWCNT in the dosage of 0.005% bwoc contributed to the increase of early strength of cement mortar prepared with WSE.


2016 ◽  
Vol 711 ◽  
pp. 232-240 ◽  
Author(s):  
Ling Shi Meng ◽  
Christopher K.Y. Leung ◽  
Geng Ying Li

This paper studies the effects of multi-walled carbon nanotubes (MWCNTs) on the mechanical properties and durability of polymer latex-modified cement mortar. Latex-modified cementitious materials possess many advantages. However, reduction of mechanical properties due to the introduction of an amorphous structure within the cement composite has limited its application. In this study, multi-walled carbon nanotubes functionalised with carboxyl group (MWCNTs-COOH), ranging from 0% to 0.15% by weight, are added into mortar modified with 0.6 wt.% polyvinyl alcohol (PVA) latex. Mechanical properties including compressive strength and flexural strength are measured. Water absorption test and rapid chloride diffusion test are performed to assess durability performance. Results indicate considerable increase of compressive strength and flexural strength, as well as improvement in durability, by the addition of MWCNTs-COOH. With Scanning Electron Microscopy conducted on both the latex solution and cement composite, the microstructural changes resulted from MWCNT addition are revealed.


2018 ◽  
Vol 33 (5) ◽  
pp. 543-557 ◽  
Author(s):  
Jianfei Cao ◽  
Yue Lu ◽  
Hechun Chen ◽  
Lifang Zhang ◽  
Chengdong Xiong

Poly(etheretherketone) exhibits good biocompatibility, excellent mechanical properties, and bone-like stiffness. However, the natural bio-inertness of pure poly(etheretherketone) hinders its applications in biomedical field, especially when direct bone-implant osteo-integration is desired. For developing an alternative biomaterial for load-bearing orthopedic application, combination of bioactive fillers with poly(etheretherketone) matrix is a feasible approach. In this study, a bioactive multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite was prepared through a compounding and injection-molding process for the first time. Bioactive calcium polyphosphate was added to polymer matrix to enhance the bioactivity of the composite, and incorporation of multi-walled carbon nanotubes to composite was aimed to improve both the mechanical property and biocompatibility. Furthermore, the microstructures, surface hydrophilicity, and mechanical property of multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite, as well as the cellular responses of MC3T3-E1 osteoblast cells to this material were investigated. The mechanical testing revealed that mechanical performance of the resulting ternary composite was significantly enhanced by adding the multi-walled carbon nanotubes and the mechanical values obtained were close to or higher than those of human cortical bone. More importantly, cell culture tests showed that initial cell adhesion, cell viability, and osteogenic differentiation of MC3T3-E1 cells were significantly promoted on the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite. Accordingly, the multi-walled carbon nanotubes/calcium polyphosphate/poly(etheretherketone) composite may be used as a promising bone repair material in dental and orthopedic applications.


2007 ◽  
Vol 444 (4-6) ◽  
pp. 304-308 ◽  
Author(s):  
Carlos E. Cava ◽  
Ricardo Possagno ◽  
Mariane C. Schnitzler ◽  
Paulo C. Roman ◽  
Marcela M. Oliveira ◽  
...  

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