scholarly journals Improved Mechanical and Moisture-Resistant Properties of Woven Hybrid Epoxy Composites by Graphene Nanoplatelets (GNP)

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1249 ◽  
Author(s):  
Jesuarockiam Naveen ◽  
Mohammad Jawaid ◽  
Edi Syams Zainudin ◽  
Mohamed Thariq Hameed Sultan ◽  
Ridwan Yahaya
Keyword(s):  
Hybrid Composites ◽  
Cocos Nucifera ◽  
Crystallinity Index ◽  
Moisture Diffusion ◽  
Graphene Nanoplatelets ◽  
Strong Interactions ◽  
Diffusion Analysis ◽  
Significant Difference ◽  
Modified Epoxy ◽  
Moisture Resistant

This research investigated the effect of adding different wt.% (0, 0.25, 0.50, and 0.75) of GNP (graphene nanoplatelets) to improve the mechanical and moisture resistant properties of Kevlar (K)/cocos nucifera sheath (CS)/epoxy hybrid composites. The laminates were fabricated with different K/CS weight ratios such as 100/0 (S1), 75/25 (S2), 50/50 (S3), 25/75 (S4), and 0/100 (S5). The results revealed that the addition of GNP improved the tensile, flexural, and impact properties of laminated composites. However, the optimal wt.% of GNP varies with different laminates. A moisture diffusion analysis showed that the laminates with a 0.25 wt.% of GNP content efficiently hindered water uptake by closing all the unoccupied pores inside the laminate. Morphological investigations (SEM and FE-SEM (Field Emission Scanning Electron Microscope)) proved that the addition of GNP improved the interfacial adhesion and dispersion. Structural (XRD and FTIR) analyses reveals that at 0.25 wt.% of GNP, all the hybrid composites showed a better crystallinity index and the functional groups presents in the GNP can form strong interactions with the fibers and matrix. A statistical analysis was performed using One-way ANOVA, and it corroborates that the mechanical properties of different laminates showed a statistically significant difference. Hence, these GNP-modified epoxy hybrid composites can be efficiently utilized in load-bearing structures.

Effect of graphene nanoplatelets on the ballistic performance of hybrid Kevlar/Cocos nucifera sheath-reinforced epoxy composites

2019 ◽  
Vol 89 (21-22) ◽  
pp. 4349-4362 ◽  
Author(s):  
J Naveen ◽  
M Jawaid ◽  
ES Zainudin ◽  
Mohamed TH Sultan ◽  
R Yahaya
Keyword(s):  
Energy Absorption ◽  
Laminated Composites ◽  
Cocos Nucifera ◽  
Graphene Nanoplatelets ◽  
Epoxy Composites ◽  
Ballistic Limit ◽  
Ballistic Performance ◽  
Gas Gun ◽  
Significant Difference ◽  
Ballistic Properties

This study investigated the effect of graphene nanoplatelets (GnPs) on the ballistic performance of Kevlar/ Cocos nucifera sheath-reinforced epoxy composites. GnPs with different wt. % (0%, 0.25%, 0.50%) were integrated into epoxy resin through ultra-sonication. Laminated composites were fabricated by incorporating Kevlar and Cocos nucifera sheath layers into the epoxy/GnP mixture by the hand lay-up method followed by hot pressing. Nine- and 12-layered laminates were fabricated with different numbers of Kevlar and Cocos nucifera sheath plies. Ballistic tests were conducted using a single-stage gas gun experimental setup with an 8 mm hemispherical stainless steel projectile. The results showed that the addition of GnPs improved the energy absorption by 8.5% (nine plies) and 12.88% (12 plies) and the ballistic limit by 4.28% (nine plies) and 6.17% (12 plies), respectively of Kevlar/epoxy/GnP composites at 0.25 wt. %. However, hybrid Kevlar/ Cocos nucifera sheath/epoxy/GnP composites and Cocos nucifera sheath/epoxy/GnP laminated composites decreased the energy absorption and ballistic limit after the addition of GnPs. This is because the addition of GnPs improved the interfacial interactions between the fiber and GnP modified epoxy matrix, which is inappropriate to absorb and dissipate the kinetic energy of the projectile. Statistical analysis was carried out using one-way analysis of variance and it was shown that there is a statistically significant difference between the obtained ballistic properties of the laminates.

The role of SEBS in tailoring the interface between the polymer matrix and exfoliated graphene nanoplatelets in hybrid composites

2015 ◽  
Vol 163 ◽  
pp. 182-189 ◽  
Author(s):  
Jyotishkumar Parameswaranpillai ◽  
George Joseph ◽  
K.P. Shinu ◽  
P.R. Sreejesh ◽  
Seno Jose ◽  
...  
Keyword(s):  
Polymer Matrix ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Exfoliated Graphene

The Contact Diffusion of Linguistic Practices

2015 ◽  
Vol 5 (2) ◽  
pp. 169-201 ◽  
Author(s):  
Jürgen Bohnemeyer ◽  
Katharine T. Donelson ◽  
Randi E. Moore ◽  
Elena Benedicto ◽  
Alyson Eggleston ◽  
...  
Keyword(s):  
Language Contact ◽  
Language Use ◽  
Reference Frames ◽  
Indigenous Languages ◽  
Spatial Reference ◽  
Diffusion Analysis ◽  
Significant Difference ◽  
Education Levels ◽  
Spatial Reference Frame ◽  
Using Data

We examine the extent to which practices of language use may be diffused through language contact and areally shared, using data on spatial reference frame use by speakers of eight indigenous languages from in and around the Mesoamerican linguistic area and three varieties of Spanish. Regression models show that the frequency of L2-Spanish use by speakers of the indigenous languages predicts the use of relative reference frames in the L1 even when literacy and education levels are accounted for. A significant difference in frame use between the Mesoamerican and non-Mesoamerican indigenous languages further supports the contact diffusion analysis.

Si3N4/Graphene binary particles reinforced hybrid titanium composites and their characterization

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tugba Mutuk ◽  
Mevlüt Gürbüz
Keyword(s):  
Hybrid Composite ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Compressive Behavior ◽  
Titanium Matrix ◽  
Wear Properties ◽  
Titanium Matrix Composites ◽  
Matrix Density

Abstract This study reports on silicon nitride (Si3N4) and graphene nanoplatelets binary powder reinforced hybrid titanium composites obtained by a powder metallurgy method. Si3N4 powder was added at 3 wt.% and graphene nanoplatelets were added in various amounts (0.15, 0.30, 0.45, 0.60 wt.%) in the titanium matrix. Density, micro-Vickers hardness, compressive behavior, wear properties and microstructure of the hybrid composites were evaluated. Addition of different percentages of graphene nanoplatelets and 3 wt.% Si3N4 to the titanium matrix composites significantly enhanced mechanical properties. The highest hardness (634 HV) and compressive strength (1458 MPa) values were measured for 0.15 wt.% graphene nanoplatelets and 3 wt.% Si3N4 added titanium hybrid composite. The lowest mass loss and wear rate (Δm = 4 mg, W = 6.1×10–5 mm3 (N m)–1) values were measured for the same 0.15 wt.% graphene nanoplatelets and 3 wt.% Si3N4 added titanium hybrid composite compared with pure Ti.

COMPUTATIONAL MODELING OF EPOXY-BASED HYBRID COMPOSITES REINFORCED WITH CARBON FIBERS AND FUNCTIONALIZED GRAPHENE NANOPLATELETS

2021 ◽  
Author(s):  
HASHIM AL MAHMUD ◽  
, MATTHEW RADUE ◽  
WILLIAM PISANI ◽  
GREGORY ODEGARD
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Hybrid Composites ◽  
Graphene Nanoplatelets ◽  
Pristine Graphene ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Aspect Ratios ◽  
The Impact ◽  
Nanoscale Level

The impact on the mechanical properties of unidirectional carbon fiber (CF)/epoxy composites reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and Functionalized Graphene Oxide (FGO) are investigated in this study. The localized reinforcing effect of each of the graphene nanoplatelet types on the epoxy matrix is predicted at the nanoscale-level by molecular dynamics. The bulk-level mechanical properties of unidirectional CF/epoxy hybrid composites are predicted using micromechanics techniques considering the reinforcing function, content, and aspect ratios for each of the graphene nanoplatelets. In addition, the effect of nanoplatelets dispersion level is also investigated for the pristine graphene nanoplatelets considering a lower dispersion level with four layers of graphene nanoplatelets (4GNP). The results indicate that the shear and transverse properties are significantly affected by the nanoplatelet type, loading and aspect ratio. The results of this study can be used in the design of hybrid composites to tailor specific laminate properties by adjusting nanoplatelet parameters.

Halloysite nanotube reinforcement endows ameliorated fracture resistance of seawater aged basalt/epoxy composites

2020 ◽  
Vol 54 (20) ◽  
pp. 2761-2779 ◽  
Author(s):  
Hasan Ulus ◽  
Halil Burak Kaybal ◽  
Volkan Eskizeybek ◽  
Ahmet Avcı
Keyword(s):  
Shear Strength ◽  
Hybrid Composites ◽  
Tensile Tests ◽  
Halloysite Nanotubes ◽  
Interlaminar Shear Strength ◽  
Epoxy Composites ◽  
Halloysite Nanotube ◽  
Fiber Reinforced Polymer Composites ◽  
Interlaminar Shear ◽  
Modified Epoxy

Seawater aging-dominated delamination failure is a critical design parameter for marine composites. Modification of matrix with nanosized reinforcements of fiber-reinforced polymer composites comes forward as an effective way to improve the delamination resistance of marine composites. In this study, we aimed to investigate experimentally the effect of halloysite nanotube nanoreinforcements on the fracture performance of artificial seawater aged basalt–epoxy composites. For this, we introduced various amounts of halloysite nanotubes into the epoxy and the halloysite nanotube–epoxy mixtures were used to impregnate to basalt fabrics via vacuum-assisted resin transfer molding, subsequently. Fracture performances of the halloysite nanotubes modified epoxy and basalt/epoxy composite laminated were evaluated separately. Single edge notched tensile tests were conducted on halloysite nanotube modified epoxy nanocomposites and the average stress intensity factor (KIC) was increased from 1.65 to 2.36 MPa.m1/2 (by 43%) with the incorporation of 2 wt % halloysite nanotubes. The interlaminar shear strength and Mode-I interlaminar fracture toughness (GIC) of basalt–epoxy hybrid composites were enhanced from 36.1 to 42.9 MPa and from 1.22 to 1.44 kJ/m2, respectively. Moreover, the hybrid composites exhibited improved seawater aging performance by almost 52% and 34% in interlaminar shear strength and GIC values compared to the neat basalt-epoxy composites after conditioning in seawater for six months, respectively. We proposed a model to represent fracture behavior of the seawater aged hybrid composite based on scanning electron microscopy and infrared spectroscopy analyses.

scholarly journals Characterization on thermal properties of glass fiber and kevlar fiber with modified epoxy hybrid composites

2020 ◽  
Vol 9 (3) ◽  
pp. 3158-3167 ◽  
Author(s):  
Vivekanandhan Chinnasamy ◽  
Sampath Pavayee Subramani ◽  
Sathish Kumar Palaniappan ◽  
Bhuvaneshwaran Mylsamy ◽  
Karthik Aruchamy
Keyword(s):  
Thermal Properties ◽  
Glass Fiber ◽  
Hybrid Composites ◽  
Kevlar Fiber ◽  
Modified Epoxy

scholarly journals Potential of Distilled Liquid Smoke Derived from Coconut (Cocos nucifera L) Shell for Traumatic Ulcer Healing in Diabetic Rats

2019 ◽  
Vol 13 (02) ◽  
pp. 271-279 ◽  
Author(s):  
Meircurius Dwi Condro Surboyo ◽  
Ira Arundina ◽  
Retno Pudji Rahayu ◽  
Dieni Mansur ◽  
Taufan Bramantoro
Keyword(s):  
Ulcer Healing ◽  
Cocos Nucifera ◽  
Coconut Shell ◽  
Diabetic Rat ◽  
Natural Food ◽  
Necrosis Factor Alpha ◽  
Liquid Smoke ◽  
Tnf Α ◽  
Significant Difference ◽  
Cocos Nucifera L

Abstract Objective Distilled liquid smoke (DLS) is a result of coconut processing by-product that not only serves as a natural food preservative but also has a promising therapeutic effect. The healing potential of DLS derived from coconut (Cocos nucifera L) shell was investigated on a traumatic ulcer with the diabetic rat. Materials and Methods DLS was analyzed the component by gas chromatograph mass spectrometry. Diabetic condition was induced by alloxan in 55 male Wistar rats. Ten mm of traumatic ulcer was made along the labial fornix incisive inferior after the diabetic condition was confirmed. Then DLS coconut shell, benzydamine hydrochloride, and sterile distilled water were applied topically for 3, 5, and 7 days. The potential healing was evaluated based on the expression of nuclear factor kappa beta (NFκB) and tumor necrosis factor alpha (TNF-α) on macrophages using immunohistochemical staining and the amount of collagen using Masson Trichome staining. The difference between each group was analyzed using one-way analysis of variance. The least significant difference test is used to determine the significant difference (p < 0.05). Results The major compounds found were phenol (36.6%), 2-methoxyphenol (guaiacol) (25.2%), furfural (17.8%), and 4-ethyl-2-methoxyphenol (3.5%) with 28 other minor constituents. The lowest NFκB and TNF-α expression on macrophage was observed by topical application of DLS derived from coconut shell for 3, 5, and 7 days of treatment. The amount of collagen was increased and indicated by the highest result of DLS compared to others. Conclusion The DLS derived from coconut (Cocos nucifera L) shell was able to improve traumatic ulcer healing in a person with diabetes.

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