scholarly journals Improved Performance of an Epoxy Matrix as a Result of Combining Graphene Oxide and Reduced Graphene

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
L. Ramos-Galicia ◽  
L. N. Mendez ◽  
Ana Laura Martínez-Hernández ◽  
A. Espindola-Gonzalez ◽  
I. R. Galindo-Esquivel ◽  
...  

We present an easy and effective way to improve the mechanical properties of an epoxy matrix by reinforcing it with a combination of graphene oxide (GO) and reduced graphene oxide (RGO). These nanocomposites were prepared with different load of nanofillers: 0.1, 0.4, 0.7, 1.0 wt% and a neat epoxy. Ratios of graphene oxide and reduced graphene (GO : RGO) employed were: 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0. Results show that with only 0.4 wt% and a ratio 0.2 : 0.75 of GO : RGO, tensile strength and tensile toughness are 52% and 152% higher than neat epoxy while modulus of elasticity was improved~20%. The obtained results suggest that it is possible achieve advantageous properties by combining graphene in oxidized and reduced conditions as it shows a synergic effect by the presence of both nanofillers.

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Truc T. Ngo ◽  
James G. Kohl ◽  
Tawni Paradise ◽  
Autumn Khalily ◽  
Duane L. Simonson

Two different thermoset biocomposite systems are experimented in this study with the hope to improve their mechanical properties. Fiberglass and hemp, in form of fabrics, are used to reinforce the thermoset polymer matrix, which includes a traditional epoxy resin and a linseed oil-based bioresin (UVL). The fiber/polymer matrix interface is modified using two different approaches: adding a plant-based oil (pine or linseed) to the polymer matrix or coating the fibers with 3-(aminopropyl)triethoxysilane (APTES) prior to integrating them into the polymer matrix. Epoxy resin is cured using an amine-based initiator, whereas UVL resin is cured under ultraviolet light. Results show that hemp fibers with APTES prime coat used in either epoxy or UVL matrix exhibit some potential improvements in the composite’s mechanical properties including tensile strength, modulus of elasticity, and ductility. It is also found that adding oil to the epoxy matrix reinforced with fiberglass mostly improves the material’s modulus of elasticity while maintaining its tensile strength and ductility. However, adding oil to the epoxy matrix reinforced with hemp doubles the material’s ductility while slightly reducing its tensile strength and modulus of elasticity.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 317 ◽  
Author(s):  
Guang-jie Yuan ◽  
Jie-Fei Xie ◽  
Hao-Hao Li ◽  
Bo Shan ◽  
Xiao-Xin Zhang ◽  
...  

Thermally reduced graphene oxide/carbon nanotube (rGO/CNT) composite films were successfully prepared by a high-temperature annealing process. Their microstructure, thermal conductivity and mechanical properties were systematically studied at different annealing temperatures. As the annealing temperature increased, more oxygen-containing functional groups were removed from the composite film, and the percentage of graphene continuously increased. When the annealing temperature increased from 1100 to 1400 °C, the thermal conductivity of the composite film also continuously increased from 673.9 to 1052.1 W m−1 K−1. Additionally, the Young’s modulus was reduced by 63.6%, and the tensile strength was increased by 81.7%. In addition, the introduction of carbon nanotubes provided through-plane thermal conduction pathways for the composite films, which was beneficial for the improvement of their through-plane thermal conductivity. Furthermore, CNTs apparently improved the mechanical properties of rGO/CNT composite films. Compared with the rGO film, 1 wt% CNTs reduced the Young’s modulus by 93.3% and increased the tensile strength of the rGO/CNT composite film by 60.3%, which could greatly improve its flexibility. Therefore, the rGO/CNT composite films show great potential for application as thermal interface materials (TIMs) due to their high in-plane thermal conductivity and good mechanical properties.


Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1726 ◽  
Author(s):  
Denesh Mohan ◽  
Mohd Shaiful Sajab ◽  
Hatika Kaco ◽  
Saiful Bahari Bakarudin ◽  
An’amt Mohamed Noor

The recognition of nanocellulose has been prominent in recent years as prospect materials, yet the ineffectiveness of nanocellulose to disperse in an organic solvent has restricted its utilization, especially as a reinforcement in polymer nanocomposite. In this study, cellulose has been isolated and defibrillated as cellulose nanofibrils (CNF) from oil palm empty fruit bunch (EFB) fibers. Subsequently, to enhance its compatibility with UV-curable polyurethane (PU)-based resin, the surface hydrophilicity of CNF has been tailored with polyethylene glycol (PEG), as well as reduced graphene oxide (rGO). The dispersibility of reinforced modified CNF in UV-curable PU was examined through the transmittance interruption of resin, chemical, and mechanical properties of the composite printed using the stereolithographic technique. Evidently, the enhanced compatibility of modified CNF and UV-curable PU was shown to improve the tensile strength and hardness of the composites by 37% and 129%, respectively.


2020 ◽  
Vol 12 (8) ◽  
pp. 3154 ◽  
Author(s):  
Hedelvan Emerson Fardin ◽  
Adriana Goulart dos Santos

This research aimed to investigate the mechanical and physical properties of Roller Compacted Concrete (RCC) used with Recycled Concrete Aggregate (RCA) as a replacement for natural coarse aggregate. The maximum dry density method was adopted to prepare RCC mixtures with 200 kg/m³ of cement content and coarse natural aggregates in the concrete mixture. Four RCC mixtures were produced from different RCA incorporation ratios (0%, 5%, 15%, and 30%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, and modulus of elasticity, porosity, density, and water absorption tests were performed to analyze the mechanical and physical properties of the mixtures. One-way Analysis of Variance (ANOVA) was used to identify the influences of RCA on RCC’s mechanical properties. As RCA increased in mixtures, some mechanical properties were observed to decrease, such as modulus of elasticity, but the same was not observed in the splitting tensile strength. All RCCs displayed compressive strength greater than 15.0 MPa at 28 days, splitting tensile strength above 1.9 MPa, flexural tensile strength above 2.9 MPa, and modulus of elasticity above 19.0 GPa. According to Brazilian standards, the RCA added to RCC could be used for base layers.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fakhim Babak ◽  
Hassani Abolfazl ◽  
Rashidi Alimorad ◽  
Ghodousi Parviz

We investigate the performance of graphene oxide (GO) in improving mechanical properties of cement composites. A polycarboxylate superplasticizer was used to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1–2 wt% GO and 0.5 wt% superplasticizer was measured and compared with that of cement prepared without GO. We found that the tensile strength of the cement mortar increased with GO content, reaching 1.5%, a 48% increase in tensile strength. Ultra high-resolution field emission scanning electron microscopy (FE-SEM) used to observe the fracture surface of samples containing 1.5 wt% GO indicated that the nano-GO flakes were well dispersed in the matrix, and no aggregates were observed. FE-SEM observation also revealed good bonding between the GO surfaces and the surrounding cement matrix. In addition, XRD diffraction data showed growth of the calcium silicate hydrates (C-S-H) gels in GO cement mortar compared with the normal cement mortar.


2019 ◽  
Vol 163 ◽  
pp. 77-85 ◽  
Author(s):  
Faisal Nazeer ◽  
Zhuang Ma ◽  
Lihong Gao ◽  
Fuchi Wang ◽  
Muhammad Abubaker Khan ◽  
...  

2008 ◽  
Vol 1 (2) ◽  
pp. 113-120 ◽  
Author(s):  
A. C. Marques ◽  
J. L. Akasaki ◽  
A. P. M. Trigo ◽  
M. L. Marques

In this work it was evaluated the influence tire rubber addition in mortars in order to replace part of the sand (12% by volume). It was also intended to verify if the tire rubber treatment with NaOH saturated aqueous solution causes interference on the mechanical properties of the mixture. Compressive strength, splitting tensile strength, water absorption, modulus of elasticity, and flow test were made in specimens of 5cmx10cm and the tests were carried out to 7, 28, 56, 90, and 180 days. The results show reduction on mechanical properties values after addition of tire rubber and decrease of the workability. It was also observed that the tire rubber treatment does not cause any alteration on the results compared to the rubber without treatment.


2016 ◽  
Vol 36 (4) ◽  
pp. 399-405 ◽  
Author(s):  
Khalid Nawaz ◽  
Muhammad Ayub ◽  
Noaman Ul-Haq ◽  
M.B. Khan ◽  
Muhammad Bilal Khan Niazi ◽  
...  

Abstract Large area graphene oxide sheets were synthesized, dispersed in water and used as nanofiller for mechanical improvement in terms of Young’s modulus and ultimate tensile strength (UTS) of polyvinyl alcohol (PVA) at low loading. The molecular level dispersion and interfacial interactions between the graphene oxides and polymeric matrix PVA were the real challenges. An excellent improvement in mechanical properties at 0.35 wt% loading was observed. Modulus improved from 1.58 GPa to 2.72 GPa (~71% improvement), UTS improved from 120 MPa to 197 MPa (~65% improvement), and in spite of these improvements, interestingly, there was no fall in elongation at break at this loading.


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