scholarly journals Propiedades mecánicas de morteros de cemento con adiciones de fibras de carbono, nanotubos de carbono y grafeno = Mechanical properties of cement mortars with additions of carbon fibres, carbon nanotubes and graphene

2017 ◽  
Vol 3 (3) ◽  
pp. 12
Author(s):  
María Ursúa Goicoechea
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Carbon Fibers ◽  
Carbon Materials ◽  
Carbon Fibres ◽  
Cement Mortars ◽  
Different Types ◽  
Cement Matrices ◽  
Cement Compounds

El carbono es uno de los elementos más abundantes de la naturaleza. Su particular estructura hace que pueda tener hasta cinco tipos distintos de alótropos. Durante los últimos años se han producido grandes avances en el estudio de estos materiales de carbono. Las fibras de carbono (CF), los nanotubos de carbono (CNTs) y el grafeno y óxido de grafeno (GO), en función de su estructura y su escala, presentan unas propiedades notablemente diferenciadas. Este estudio pretende comparar y determinar los efectos de estas características en matrices de cemento. Las características de estos materiales son difíciles de transmitir de forma exacta a los compuestos de cemento y hormigones, principalmente por las dificultades que presentan los nanomateriales en su dispersión. Por ello, los datos obtenidos en distintos estudios muestran resultados muy variables. Sin embargo, se ha demostrado que, para mejoras medias, los nanomateriales resultan ser más eficientes.AbstractCarbon is one of the most abundant elements of nature. Its particular structure has to have up to five different types of allotropes. During the last years there have been great advances in the study of these carbon materials. Carbon fibers (CF), carbon nanotubes (CNT) and graphene and graphene oxide (GO), depending on their structure and scale, have remarkably different properties. This study aims to compare and determine the effects of these characteristics on cement matrices. The characteristics of these materials are difficult to transmit accurately to concrete and cement compounds, mainly due to the difficulties presented by nanomaterials in their dispersion. Therefore, the data obtained in different studies, results, very variable. However, it has been shown that, for average improvements, nanomaterials are more efficient.

An effective approach for modifying carbonaceous materials with niobium single sites to improve their catalytic properties

2015 ◽  
Vol 44 (46) ◽  
pp. 19956-19965 ◽  
Author(s):  
A. S. Bozzi ◽  
R. L. Lavall ◽  
T. E. Souza ◽  
M. C. Pereira ◽  
P. P. de Souza ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Activated Carbon ◽  
Carbon Materials ◽  
Catalytic Properties ◽  
Carbonaceous Materials ◽  
Simple Route ◽  
Catalytically Active

In this paper we show a very simple route for the incorporation of catalytically active niobium species on the surface of carbon materials, such as graphene oxide, carbon nanotubes and activated carbon.

Electronic and Mechanical Properties of Super Carbon Nanotube Networks

2006 ◽  
Vol 963 ◽  
Author(s):  
Vitor R. Coluci ◽  
Socrates O. Dantas ◽  
Ado Jorio ◽  
Douglas s Galvao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Tight Binding ◽  
Deformation Mechanisms ◽  
Different Types ◽  
Dynamics Simulations ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanotube Networks ◽  
Main Deformation

ABSTRACTEletronic and mechanical properties of ordered carbon nanotube networks are studied using molecular dynamics simulations and tight-binding calculations. These networks are formed by single walled carbon nanotubes (SWNT) regularly connected by junctions. The use of different types of junctions (“Y”-, “X”-like junctions, for example) allows the construction of networks with different symmetries. These networks can be very flexible and the elastic deformation was associated with two main deformation mechanisms (bending and stretching ) of the constituents SWNTs. Rolling up the networks, “super” carbon nanotubes can be constructed. These super-tubes share some of the main electronic features of the SWNT which form them but important changes are predicted (e.g. reduction of bandgap value). Simulations of their deformations under tensile stress have revealed that the super-tubes are softer than the corresponding SWNT and that their rupture occur in higher strain values.

scholarly journals Polymethyl Methacrylate-Based Bone Cements Containing Carbon Nanotubes and Graphene Oxide: An Overview of Physical, Mechanical, and Biological Properties

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1469 ◽  
Author(s):  
Sanaz Soleymani Eil Bakhtiari ◽  
Hamid Reza Bakhsheshi-Rad ◽  
Saeed Karbasi ◽  
Mohamadreza Tavakoli ◽  
Mahmood Razzaghi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Polymethyl Methacrylate ◽  
Biological Properties ◽  
Bone Diseases ◽  
Bone Cements ◽  
Bone Fixation ◽  
Primary Bone ◽  
Carbon Based

Every year, millions of people in the world get bone diseases and need orthopedic surgery as one of the most important treatments. Owing to their superior properties, such as acceptable biocompatibility and providing great primary bone fixation with the implant, polymethyl methacrylate (PMMA)-based bone cements (BCs) are among the essential materials as fixation implants in different orthopedic and trauma surgeries. On the other hand, these BCs have some disadvantages, including Lack of bone formation and bioactivity, and low mechanical properties, which can lead to bone cement (BC) failure. Hence, plenty of studies have been concentrating on eliminating BC failures by using different kinds of ceramics and polymers for reinforcement and also by producing composite materials. This review article aims to evaluate mechanical properties, self-setting characteristics, biocompatibility, and bioactivity of the PMMA-based BCs composites containing carbon nanotubes (CNTs), graphene oxide (GO), and carbon-based compounds. In the present study, we compared the effects of CNTs and GO as reinforcement agents in the PMMA-based BCs. Upcoming study on the PMMA-based BCs should concentrate on trialing combinations of these carbon-based reinforcing agents as this might improve beneficial characteristics.

scholarly journals Effect of Graphene Oxide on Mechanical Properties of Cement Mortar and its Strengthening Mechanism

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3753 ◽  
Author(s):  
Yahui Wang ◽  
Jiawen Yang ◽  
Dong Ouyang
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Cement Hydration ◽  
Strengthening Mechanism ◽  
Cement Composites ◽  
Working Mechanism ◽  
Cement Pastes ◽  
Cement Mortars ◽  
Binder Ratio ◽  
Growth Space

The effects of the water–binder ratio and different graphene oxide (GO) sizes on the mechanical properties of GO-cement composites were systematically studied by preparing GO-cement mortars. The scanning electron microscopy observation (SEM) of the surface and fracture surface of cement pastes was carried out to study the morphology of cement hydration crystals in GO-cement systems under different space conditions. It was found that GO nanosheets significantly improved the compressive, flexural, and tensile strengths of cement mortars. When the dosage of GO nanosheets was 0.03% by weight of cement, the compressive, flexural, and tensile strengths at 28 days increased by 21.37%, 39.62%, and 53.77%, respectively, but GO was not found to be able to regulate the formation of flower-like cement hydration crystals. It was only shown that the growth space had an important influence on the morphology of hydrates. A possible working mechanism was proposed by which GO nanosheets prevented the expansion of microcracks in the cement pastes via a shield effect, thus enhancing the strength and toughness of the cement composites.

scholarly journals Mechanical Properties of C3N Nanotubes from Molecular Dynamics Simulation Studies

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 894 ◽  
Author(s):  
Azam Salmankhani ◽  
Zohre Karami ◽  
Amin Hamed Mashhadzadeh ◽  
Mohammad Reza Saeb ◽  
Vanessa Fierro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Simulation Studies ◽  
Different Types ◽  
Carbon Based Nanomaterials ◽  
C60 Fullerenes ◽  
Carbon Based

Although the properties of carbon nanotubes (CNTs) are very well-known and are still extensively studied, a thorough understanding of other carbon-based nanomaterials such as C3N nanotubes (C3NNTs) is still missing. In this article, we used molecular dynamics simulation to investigate the effects of parameters such as chirality, diameter, number of walls, and temperature on the mechanical properties of C3N nanotubes, C3N nanobuds, and C3NNTs with various kinds of defects. We also modeled and tested the corresponding CNTs to validate the results and understand how replacing one C atom of CNT by one N atom affects the properties. Our results demonstrate that the Young’s modulus of single-walled C3NNTs (SWC3NNTs) increased with diameter, irrespective of the chirality, and was higher in armchair SWC3NNTs than in zigzag ones, unlike double-walled C3NNTs. Besides, adding a second and then a third wall to SWC3NNTs significantly improved their properties. In contrast, the properties of C3N nanobuds produced by attaching an increasing number of C60 fullerenes gradually decreased. Moreover, considering C3NNTs with different types of defects revealed that two-atom vacancies resulted in the greatest reduction of all the properties studied, while Stone–Wales defects had the lowest effect on them.

A comparative study of Ni–Mn layered double hydroxide/carbon composites with different morphologies for supercapacitors

2016 ◽  
Vol 18 (43) ◽  
pp. 30068-30078 ◽  
Author(s):  
M. Li ◽  
F. Liu ◽  
X. B. Zhang ◽  
J. P. Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Comparative Study ◽  
Layered Double Hydroxide ◽  
Electrode Materials ◽  
Carbon Materials ◽  
Carbon Composites ◽  
Reduced Graphene ◽  
Double Hydroxide

A variety of carbon materials varying from 0D to 2D, i.e. 0D nanoparticles, 1D carbon nanotubes (CNTs) and 2D reduced graphene oxide (rGO) are selected to in situ combine with Ni–Mn layered double hydroxide (LDH) to prepare electrode materials for supercapacitors.

Enhanced mechanical properties of cement paste by hybrid graphene oxide/carbon nanotubes

2017 ◽  
Vol 134 ◽  
pp. 336-345 ◽  
Author(s):  
Cheng Zhou ◽  
Fangxian Li ◽  
Jie Hu ◽  
Mengmeng Ren ◽  
Jiangxiong Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Cement Paste
Sign in / Sign up

Export Citation Format

Share Document