• Advanced Composite Materials
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• v.18 no.4
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• pp.365-379
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• 2009

Epoxy/S2-glass reinforced composites (SGRPs) infused with Cloisite 30B nanoclays were manufactured using the vacuum assisted resin infusion molding (VARIM) process. Prior to infusion, the matrix and clays were thoroughly mixed using a direct mixing technique (DMT) and a high shear mixing technique (HSMT) to ensure uniform dispersion of the nanoclays. Structures with varying clay contents (1-3 wt%) were manufactured. Both pristine and SGRP nanocomposites were then subjected to mechanical testing. For the specimens manufactured by DMT, the tensile, flexural, and compressive modulus increased with increasing the clay content. Similarly, the tensile, flexural, compressive, interlaminate shear and impact strength increased with the addition of 1 wt% clay: however the trend reversed with further increase in the clay content. Specimens manufactured by HSMT showed superior properties compared to those of nanocomposites containing 1 wt% clay produced by DMT. In order to understand these phenomena a morphological study was conducted. Transmission electron microscopy (TEM) micrographs revealed that HSMT led to better dispersion and changed the nanoclay structure from orderly intercalation to disorderly intercalation giving multi-directional strength.

• Fire Science and Engineering
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• v.22 no.3
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• pp.300-304
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• 2008

The flame retardancy was evaluated to present as the fundamental data to decrease the fire hazard of polymers and life losses according to the addition of clay. The combustion characteristics were examined to increase flame retardancy and to decrease smoke yield of epoxy by the addition of clay such as montmorillonite in this study. For this study, the experiments of flame retardancy were conducted the measurement of the limiting oxygen index (LOI), char yield, and smoke density. As MMT concentration increased, LOI and char yield increased. This result showed that the flame retardancy of epoxy/MMT composite was improved. On the contrary, smoke density increased.

• Nuclear Engineering and Technology
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• v.49 no.7
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• pp.1563-1570
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• 2017

In order to perform dry interim storage and transportation of the spent-fuel assemblies of the Bushehr Nuclear Power Plant, dual-purpose casks can be utilized. The effectiveness of different neutron-shield materials for the dual-purpose cask was analyzed through a set of calculations carried out using the Monte Carlo N-Particle (MCNP) code. The dose rate for the dual-purpose cask utilizing the recently developed materials of $epoxy/clay/B_4C$ and $epoxy/clay/B_4C/carbon$ fiber was less than the allowable radiation level of 2 mSv/h at any point and 0.1 mSv/h at 2 m from the external surface of the cask. By utilization of $epoxy/clay/B_4C$ instead of an ethylene glycol/water mixture, the dose rates on the side surface of the cask due to neutron sources and consequent secondary gamma rays will be reduced by 17.5% and 10%, respectively. The overall dose rate in this case will be reduced by 11%.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.615-619
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• 1999

Polyether-clay nanocomposite was not polymerized with stearyltrimethylammonium ion exchanged montmorillonite, but it was self-polymerizable when heated with both stearyltrimethylammpmoim and m-phenylenediammonium ions intercalated montmorillonite to form polyether-clay nanocomposites. Molcular disperion of montmorillonite within the crosslinked epoxy matrix verified using X-ray diffraction and transmission electron microscopy found that the final product contains a uniform dispersion of exfoliated $10{\AA}$ thin clay layers seperated by $250{\sim}500{\AA}$of polyether polymer, thus verifying the nanocomposite structure.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1572-1578
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• 2008

The effect of the organoclay_10A nanoparticles on the DSC and Structural and Dielectrics Properties(1Hz-1MHz) for epoxy/Organoclay_10A Nanocomposites has been studied. Dielectric properties of epoxy-Organoclay nanocomposites were investigated at 1, 3, 5, 7, 9 filler concentration by weight. Epoxy nanocomposites samples were prepared with good dispersion of layered silicate using power ultrasonic method in the particles. As structural analysis, the interlayer spacing have decreased with filled nanoparticles contents increase using power ultrasonic dispersion. The maximum increase interlayered spacing was observed to decease for above 5wt% clay loading. The other hand, as decrease with concentration filler of the layered silicate were increased dispersion degree of nanoparticles in the matrix. The interesting dielectric properties for epoxy based nanocomposites systems are attributed to the large volume fraction of interfacesin the bulk of the material and the ensuring interactions between the charged nanoparticle surface and the epoxy chains.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.6
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• pp.538-543
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• 2008

Nanostructured materials are attracting increased interest and application. Exciting perspectives may be offered by electrical insulation. Epoxy/Organoclay nanocomposites may find new and upgraded applications in the electrical industry, replacing conventional insulation to provide improved performances in electric power apparatus, e.g, high voltage motor/generator stator winding insulation, dry mold transformer, etc. In the paper work, the electrical and thermal properties of epoxy/organoclay nanocomposites materials were studied. The electrical insulation characteristics were analyzed through the permittivity characteristics. by analyzing the permittivity spectra, it was found that dielectric constant becomes smaller with increase frequency and becomes larger with increase temperature. This indicates restriction of molecular motion and strong bonds at the epoxy/organoclay nanocomposites. The morphology of nanocomposites obtained was examined using TEM and X-ray diffraction. It has been shown that the presence of polar groups leads to an increased gallery distance and partial exfoliation. Nevertheless, full exfoliation of clay platelets has not been achieved.

• Elastomers and Composites
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• v.49 no.3
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• pp.204-209
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• 2014

Sodium-montmorillonite ($Na^+$-MMT) was introduced into single wall carbon nanotube (SWCNT)/epoxy composite to investigate the effect of MMT size and MMT/SWCNT ratio on the mechanical and electrical properties of composite. Three different sizes of MMTs were used and all were found to function as effective dispersion aids for SWCNTs. Mechanical properties of SWCNT/epoxy composite increased with MMT content; tending to decrease once the MMT content reached a critical level. However, the surface electrical resistance decreased with increasing MMT content and tended to increase after the critical content was reached. Critical MMT/SWCNT ratio for maximum mechanical properties and minimum electrical resistivity was strongly dependent on the MMT size. Critical MMT/SWCNT ratio was decreased with MMT size.

• Corrosion Science and Technology
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• v.22 no.2
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• pp.99-107
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• 2023

Layered silicate clay montmorillonite (MMT) has been used in nanocomposite coating to improve corrosion protection by reinforcing the barrier property. The better dispersion of MMT in the coating produces a higher barrier effect. Pretreatment with MMT could favor the delamination of clay platelets, facilitating MMT dispersion in the coating. In the present work, a montmorillonite/silica (MMT/Si) composite was prepared by the in situ sol-gel method. x-ray diffraction measurements and field-emission scanning electron microscopy observations showed silica crystal formation and increased basal spacing between the MMT platelets. Composite MMT/Si particles were introduced in an epoxy resin to reinforce the corrosion protection of the coating applied on the AA2024 surface. Electrochemical impedance spectroscopy (EIS) was performed to characterize the protective property of the coating. The results demonstrated the high barrier effect of the coating containing 5 wt% of MMT/Si. Adhesion evaluation after a salt spray test exhibited a high adherence to the epoxy coating containing MMT/Si.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.87-87
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• 2010

Epoxy/mica has been used as the material of high-voltage rotator stator winding due to its high insulation performance, mechanical strength, and thermal stability. In recent years, however, it shows frequent changes in the load of generators and frequent automatic stops due to the significant increase in peak loads from the increase in the applied load of power facilities according to the introduction of advanced and high-technology equipments. Thus, it is necessary to develop new materials that highly develop the conventional insulation materials. Nanotechnology introduced in the present time has become an alternative plan that overcomes such technical limitations. In addition, the nano-scaled intercalation composite has been known as the material that represent excellent electrical, mechanical, and thermal characteristics compared to the conventional materials. This study investigated the dielectric dispersion and relaxation characteristics of the nanocomposite, which was fabricated by mixing epoxy matrix with nano-scaled intercalation mica and clay, according to changes in frequencies and temperatures.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1585-1590
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• 2023

In this study, halloysite nanoparticles-doped epoxy resin was synthesised using the casting method. The MH-300A density metre revealed that the density of the fabricated composites changed from 1.132 to 1.317 g/cm³ as the halloysite nanoparticle concentration increased. The Fourier transform infrared was recorded for the synthesised composites. Furthermore, the γ-ray shielding properties of the synthesised composites were evaluated using Monte Carlo simulation and a theoretical programme, XCOM. The linear attenuation coefficient of the epoxy resin increased by 43% (at γ-energy of 15 keV) and 14% (at γ-photon energy of 662 keV) when the concentration of the halloysite nanoparticles was increased from 0 wt% to 40 wt%, respectively.