Bending Property of Sandwich Beams with MWNTs/Polymer Nanocomposites as Core Materials

2007 ◽  
Vol 345-346 ◽  
pp. 1265-1268 ◽  
Author(s):  
Meng Kao Yeh ◽  
Tsung Han Hsieh
Keyword(s):  
Failure Mechanism ◽  
Polymer Nanocomposites ◽  
Sandwich Beams ◽  
Phenolic Resins ◽  
Weight Percentage ◽  
Bending Property ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes ◽  
Press Method ◽  
Core Materials

The bending property and failure mechanism of sandwich beams were investigated. The multi-walled carbon nanotubes (MWNTs) were used as the reinforcement in the MWNTs/polymer nanocomposites and the epoxy and phenolic resins were used as the matrix. The MWNTs/polymer nanocomposites were used as the core materials of sandwich beams, which had faces made by graphite/epoxy laminates. In experiment, the hot press method was applied to fabricate the MWNTs/polymer nanocomposites and graphite/epoxy laminates. The weight percentage of MWNTs in core materials and the fiber orientation of face laminates were varied to assess their effects on the bending properties of the sandwich beams. The failure mechanism of sandwich beams with two kinds of polymer core materials was investigated. In analysis, the finite element method was used to obtain the bending behavior of the sandwich beams. The numerical results were in good agreement with the experimental ones.

The rheological behaviour and thermal ageing characteristics of PP/MWCNT/glass fibre multiscale composites

2021 ◽  
pp. 096739112199290
Author(s):  
N Rasana ◽  
K Jayanarayanan ◽  
Krishna Prasad Rajan ◽  
Aravinthan Gopanna
Keyword(s):  
Hybrid Composites ◽  
Rheological Behaviour ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Thermal Ageing ◽  
Multiwalled Carbon ◽  
Weight Percentage ◽  
Fixed Weight ◽  
Multiscale Composite ◽  
The Matrix

Multiscale hybrid composites were prepared using varying weight percentages (0 to 5) of multiwalled carbon nanotubes (MWCNTs) as nanofiller and a fixed weight percentage (20) of short glass fibres as micro filler (in polypropylene (PP) matrix. The shear and extensional viscosity of the composites was measured using a capillary rheometer. It was observed that even at higher shear rates the synergism of micro and nanofillers in the matrix significantly enhanced the melt viscosity. The complex nanotube network entanglement with micro fillers and PP chains imparted restrictions to the polymer chain movements. The prepared samples were subjected to thermal ageing at 100°C for 4 days in hot air oven. After ageing, multiscale composite with 3 wt% MWCNTs exhibited 28.57% enhancement in strain at break, whereas the tensile strength and modulus reduced by 6.8% and 8% respectively. The fracture toughness properties like strain energy release rate and critical stress intensity factor were not affected for multiscale composite at the optimum content of 3 wt% MWCNT, even after thermal ageing.

scholarly journals A Novel Composite with Structural Health Monitoring Functionality via 2D and 3D Impedance Mapping Topography

2021 ◽  
Vol 11 (4) ◽  
pp. 1647
Author(s):  
Georgios Foteinidis ◽  
Alkiviadis S. Paipetis
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Carbon Fabric ◽  
Structural Health ◽  
The Matrix ◽  
Junction Points ◽  
Sinusoidal Electric Field ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We report the transformation of a conventional composite material into a multifunctional structure able to provide information about its structural integrity. A purposely positioned grid of carbon fabric strips located within a glass fibre laminate in alternating 0/90 configuration combined with a ternary nanomodified epoxy matrix imparted structural health monitoring (SHM) topographic capabilities to the composite using the impedance spectroscopy (IS) technique. The matrix was reinforced with homogenously dispersed multi-walled carbon nanotubes (MWCNTs) and carbon black (CB). A sinusoidal electric field was applied locally over a frequency range from 1 Hz to 100 kHz between the junction points of the grid of carbon fabric strips. The proposed design enabled topographic damage assessment after a high-velocity impact via the local monitoring of the impedance. The data obtained from the IS measurements were depicted by magnitude and phase delay Bode plots and Nyquist plots. The impedance values were used to create a 2D and a multi-layer (3D) contour topographical image of the damaged area, which revealed crucial information about the structural integrity of the composite.

scholarly journals The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix

2011 ◽  
Vol 13 (2) ◽  
pp. 62-69 ◽  
Author(s):  
Maria Wladyka-Przybylak ◽  
Dorota Wesolek ◽  
Weronika Gieparda ◽  
Anna Boczkowska ◽  
Ewelina Ciecierska
Keyword(s):  
Carbon Nanotubes ◽  
Surface Modification ◽  
Epoxy Resin ◽  
Epoxy Matrix ◽  
Mechanical Mixing ◽  
Weight Percentage ◽  
Homogeneous Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Mixing Method ◽  
Walled Carbon Nanotubes

The effect of the surface modification of carbon nanotubes on their dispersion in the epoxy matrix Functionalization of multi-walled carbon nanotubes (MWCNTs) has an effect on the dispersion of MWCNT in the epoxy matrix. Samples based on two kinds of epoxy resin and different weight percentage of MWCNTs (functionalized and non-functionalized) were prepared. Epoxy/carbon nanotubes composites were prepared by different mixing methods (ultrasounds and a combination of ultrasounds and mechanical mixing). CNTs modified with different functional groups were investigated. Surfactants were used to lower the surface tension of the liquid, which enabled easier spreading and reducing the interfacial tension. Solvents were also used to reduce the liquid viscosity. Some of them facilitate homogeneous dispersion of nanotubes in the resin. The properties of epoxy/nanotubes composites strongly depend on a uniform distribution of carbon nanotubes in the epoxy matrix. The type of epoxy resin, solvent, surfactant and mixing method for homogeneous dispersion of CNTs in the epoxy matrix was evaluated. The effect of CNTs functionalization type on their dispersion in the epoxy resins was evaluated on the basis of viscosity and microstructure studies.

scholarly journals Temperature-Dependent Synergistic Effect of Multi-Walled Carbon Nanotubes and Graphene Nanoplatelets on the Tensile Quasi-Static and Fatigue Properties of Epoxy Nanocomposites

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 84
Author(s):  
Yi-Ming Jen ◽  
Hao-Huai Chang ◽  
Chien-Min Lu ◽  
Shin-Yu Liang
Keyword(s):  
Carbon Nanotubes ◽  
Fatigue Strength ◽  
Synergistic Effect ◽  
Polymer Nanocomposites ◽  
Graphene Nanoplatelets ◽  
Temperature Dependent ◽  
Epoxy Nanocomposites ◽  
Hybrid Fillers ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Even though the characteristics of polymer materials are sensitive to temperature, the mechanical properties of polymer nanocomposites have rarely been studied before, especially for the fatigue behavior of hybrid polymer nanocomposites. Hence, the tensile quasi-static and fatigue tests for the epoxy nanocomposites reinforced with multi-walled carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were performed at different temperatures in the study to investigate the temperature-dependent synergistic effect of hybrid nano-fillers on the studied properties. The temperature and the filler ratio were the main variables considered in the experimental program. A synergistic index was employed to quantify and evaluate the synergistic effect of hybrid fillers on the studied properties. Experimental results show that both the monotonic and fatigue strength decrease with increasing temperature significantly. The nanocomposites with a MWCNT (multi-walled CNT): GNP ratio of 9:1 display higher monotonic modulus/strength and fatigue strength than those with other filler ratios. The tensile strengths of the nanocomposite specimens with a MWCNT:GNP ratio of 9:1 are 10.0, 5.5, 12.9, 23.4, and 58.9% higher than those of neat epoxy at −28, 2, 22, 52, and 82 °C, respectively. The endurance limits of the nanocomposites with this specific filler ratio are increased by 7.7, 26.7, 5.6, 30.6, and 42.4% from those of pristine epoxy under the identical temperature conditions, respectively. Furthermore, the synergistic effect for this optimal nanocomposite increases with temperature. The CNTs bridge the adjacent GNPs to constitute the 3-D network of nano-filler and prevent the agglomeration of GNPs, further improve the studied strength. Observing the fracture surfaces reveals that crack deflect effect and the bridging effect of nano-fillers are the main reinforcement mechanisms to improve the studied properties. The pullout of nano-fillers from polymer matrix at high temperatures reduces the monotonic and fatigue strengths. However, high temperature is beneficial to the synergistic effect of hybrid fillers because the nano-fillers dispersed in the softened matrix are easy to align toward the directions favorable to load transfer.

ADDITIVE MANUFACTURING OF HIGH-LOADING POLYMER NANOCOMPOSITES WITH MULTISCALE ALIGNMENT

2021 ◽  
Author(s):  
SOYEON PARK ◽  
KUN (KELVIN) FU
Keyword(s):  
Additive Manufacturing ◽  
Polymer Nanocomposites ◽  
High Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
High Productivity ◽  
Macro Scale ◽  
The Matrix ◽  
Multiscale Structures ◽  
Printing Direction

Polymer nanocomposites have advantages in mechanical, electrical, and optical properties compared to individual components. These unique properties of the nanocomposites have attracted attention in many applications, including electronics, robotics, biomedical fields, automotive industries. To achieve their high performance, it is crucial to control the orientation of nanomaterials within the polymer matrix. For example, the electric conductivity will be maximized in the ordered direction of conductive nanomaterials such as graphene and carbon nanotubes (CNTs). Conventional fabrication methods are commonly used to obtain polymer nanocomposites with the controlled alignment of nanomaterials using electric or magnetic fields, fluid flow, and shear forces. Such approaches may be complex in preparing a manufacturing system, have low fabrication rate, and even limited structure scalability and complexity required for customized functional products. Recently, additive manufacturing (AM), also called 3D printing, has been developed as a major fabrication technology for nanocomposites with aligned reinforcements. AM has the ability to control the orientation of nanoparticles and offers a great way to produce the composites with cost-efficiency, high productivity, scalability, and design flexibility. Herein, we propose a manufacturing process using AM for the architected structure of polymer nanocomposites with oriented nanomaterials using a polylactic acid polymer as the matrix and graphite and CNTs as fillers. AM can achieve the aligned orientation of the nanofillers along the printing direction. Thus, it enables the fabrication of multifunctional nanocomposites with complex shapes and higher precision, from micron to macro scale. This method will offer great opportunities in the advanced applications that require complex multiscale structures such as energy storage devices (e.g., batteries and supercapacitors) and structural electronic devices (e.g., circuits and sensors).

scholarly journals Micro Hardness and Erosive Wear Behavior of Tungsten Carbide Filled Epoxy Polymer Nano Composites

2020 ◽  
Vol 5 (3) ◽  
pp. 405-415
Author(s):  
M. Kameswara Reddy ◽  
V. Suresh Babu ◽  
K. V. Sai Srinadh
Keyword(s):  
Tungsten Carbide ◽  
Polymer Nanocomposites ◽  
Adhesive Bonding ◽  
Epoxy Polymer ◽  
Wear Behavior ◽  
Erosive Wear ◽  
Nano Composites ◽  
Erosion Wear ◽  
Wear Properties ◽  
The Matrix

The present work studies the tribological performance of Tungsten Carbide (WC) nanoparticles reinforced epoxy polymer nanocomposites. Polymer nanocomposites are prepared by hand lay-up method. Erosive wear and hardness tests were conducted to examine the physical and wear properties of epoxy/WC nanocomposites. Addition of WC nanoparticles led to significant reduction in erosion rate. In addition to that, incorporation of WC nanoparticles enhanced the hardness of epoxy nano composites. At 2% weight of WC nano filler, nanocomposites showed better performance in erosion wear properties and also in hardness. While at 3wt% of WC filler, least performance in hardness was caused by the weak adhesive bonding between the matrix and filler. The nature of erosion wear behavior was observed. Finally worn surfaces of nanocomposites were inspected using a “scanning electron microscope (SEM)”.

Simultaneous Determination of Eight New Generation Amide Insecticide Residues in Complex Matrix Agri-food by Multi-walled Carbon Nanotube Cleanup and UPLC-MS/MS

2021 ◽  
Author(s):  
Tao Lin ◽  
Xinglian Chen ◽  
Li Wang ◽  
Haixian Fang ◽  
Maoxuan Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Simultaneous Determination ◽  
High Performance ◽  
Rapid Determination ◽  
Complex Matrix ◽  
Limit Of Quantification ◽  
Relative Standard ◽  
The Matrix ◽  
Multi Walled Carbon Nanotubes

Abstract The simultaneous determination method of 8 amide pesticides by multi-walled carbon nanotubes (MWCNs) cleanup, combined with QuEChERS method and ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry has been developed and successfully applied in complex matrix such as green onions, celery, leeks, citrus, lychees, avocado. The matric effect of MWCNs is optimized and compared with QuEChERS materials. The results show that MWCNs can effectively reduce the matrix effect in sample extraction. The mass spectrometry is optimized, through their chemical structure skeletons, the ESI+ and ESI- mode are simultaneously scanned in the method. The coefficient (r) is greater than 0.9990, the limit of quantification ranges from 0.03 to 0.80 μg/kg, the recovery rate ranges from 71.2% to 120%, and the relative standard deviation (RSD) ranges from 3.8% to 9.4%. The method is fast, simple, sensitive, and has good purification effect. It is suitable for the rapid determination of amide pesticides in complex matrix agri-food.

Effect of Composition of Fibers on Properties of Hybrid Composites

2017 ◽  
Vol 7 (4) ◽  
pp. 28-43
Author(s):  
R. Panneer
Keyword(s):  
Glass Fiber ◽  
Hybrid Composites ◽  
Low Cost ◽  
Natural Fibers ◽  
Absorption Capacity ◽  
Weight Percentage ◽  
Specific Strength ◽  
The Matrix ◽  
Potential Applications ◽  
Weight Design

Fibers embedded in the matrix of another material are the best example of modern day composite materials. Hybrid Composites made out of an amalgamation of Natural Fibers such as banana, jute, and coir along with glass fiber embedded in polymers have potential applications in automotive, aircraft and marine industries for their unique characteristics like high specific strength, light weight, design flexibility, corrosion resistance, biodegradability and low cost. In this work, epoxy hybrid composites reinforced with glass fiber mats and banana, jute, coir fibers of random lengths between 10-25 mm are prepared by varying their compositions in terms of weight percentage. The composites are fabricated by hand lay-up process and cut into test specimens as per ASTM Standards. Their mechanical characteristics such as Tensile Strength, Flexural Strength, Impact Strength, Hardness, Density and Water Absorption Capacity are evaluated and analysed.

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