• Composites Research
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• v.34 no.2
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• pp.82-87
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• 2021

The mechanical properties of carbon fiber-reinforced epoxy composites (CFRPs) are greatly dependent on the interfacial adhesion between the carbon fibers and the epoxy matrix. Introducing nanomaterial reinforcements into the interface is an effective approach to enhance the interfacial adhesion of CFRPs. The main purpose of this work was to introduce graphitic nanofiber (GNFs) between an epoxy matrix and carbon fibers to enhance interfacial properties. The composites were reinforced with various concentrations of GNFs. For all of the fabricated composites, the optimum GNF content was found to be 0.6 wt%, which enhanced the interlaminar shear strength (ILSS) and fracture toughness (KIC) by 101.9% and 33.2%, respectively, compared with those of neat composites. In particular, we observed a direct linear relationship between ILSS and KIC through surface free energy. The related reinforcing mechanisms were also analyzed and the enhancements in mechanical properties are mainly attributed to the interfacial interlocking effect. Such an effort could accelerate the conversion of composites into high performance materials and provide fundamental understanding toward realizing the theoretical limits of interfacial adhesion and mechanical properties.

• Journal of Surface Science and Engineering
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• v.55 no.6
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• pp.308-318
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• 2022

The surface modification and treatment using thermal plasma were reviewed in academic fields. In general, thermal plasma is generated by direct current (DC) and radiofrequency (RF) power sources. Thermal spray coating, a typical commercial process using thermal plasma, is performed by DC thermal plasma, whereas other promising surface modifications have been reported and developed using RF thermal plasma. Beyond the thermal spray coating, physical and chemical surface modifications were attempted widely. Superhydrophobic surface treatment has a very high industrial demand particularly. Besides, RF thermal plasma system for large-area film surface treatment is being developed. Thermal plasma is especially suitable for the surface modification of low-dimensional nanomaterial (e.g., nanotubes) by utilizing high temperature and rapid quenching. It is able to synthesize and modify nanomaterials simultaneously in a one-pot process.

• Advances in nano research
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• v.11 no.6
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• pp.641-648
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• 2021

In this article, the dynamic parameters (frequencies, mode shapes, damping ratios) of the scaled concrete structure and the dynamic parameters (frequencies, mode shapes, damping ratios) of the entire outer surface of titanium dioxide, 80 micron in thickness are compared using operational modal analysis method. Ambient excitation was provided from micro tremor ambient vibration data on ground level. Enhanced Frequency Domain Decomposition (EFDD) was used for the output only modal identification. From this study, a good correlation between mode shapes was found. Titanium dioxide applied to the entire outer surface of the scaled concrete structure has an average of 11.78% difference in frequency values and 10.15% in damping ratios, proving that nanomaterials can be used to increase rigidity in structures, in other words, for reinforcement. Another important result determined in the study was the observation of the adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to concrete structure surfaces was at the highest level.

• Advances in nano research
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• v.12 no.1
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• pp.65-72
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• 2022

The dynamic properties (frequencies, mode shapes, damping ratios) of the scaled WPC warehouse are compared using the operational modal analysis approach to the dynamic parameters (frequencies, mode shapes, damping ratios) of the full outer surface of titanium dioxide, 70 micron in thickness. Micro tremor ambient vibration data on ground level was used to provide ambient excitation. For the output-only modal identification, Enhanced Frequency Domain Decomposition (EFDD) was used. This study discovered a strong correlation between mode shapes. Titanium dioxide applied to the entire outer surface of the scaled WPC warehouse results in an average 14.05 percent difference in frequency values and 7.61 percent difference in damping ratios, demonstrating that nanomaterials can be used to increase rigidity in structures, or for reinforcement. Another significant finding in the study was the highest level of adherence of titanium dioxide and similar nanomaterials mentioned in the introduction to WPC structure surfaces.

• Advances in nano research
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• v.14 no.3
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• pp.235-246
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• 2023

Nanotechnology, like any other revolutionary innovation in materials science, has significantly influenced the level of competition in sports. Nanotechnology provides various benefits and enormous potential to enhance athletic equipment, making players safer, more comfortable, and more agile. Various sporting equipment is being infused with nanomaterials, including carbon nanotubes (CNTs), silica nanoparticles (SNPs), nanoclays fullerenes, etc., to enhance athlete and equipment performance. Each of these nanomaterials gives athletic equipment an extra benefit like high strength and stiffness, longevity, decreased weight, abrasion resistance, etc. This paper mechanically analysis the structural strength of tennis equipment to avoid injury. As a result, the bending forces are applied to the reinforced structures to investigate their durability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.153-154
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• 2017

Graphene is a nanomaterial and is known to have very high mechanical strength, thermal and electrical properties. However, graphene is known to be difficult to disperse among carbon-based materials due to van der Waals force. In this study, to solve the dispersion problem of graphene nanoplatelet, oxidized graphene nanoplatelet was prepared by oxidizing GNP in nitric acid. The prepared GO was dispersed in ethanol and distilled water before incorporation into the epoxy paint to confirm dispersibility. In addition, GNP/Epoxy and GO/Epoxy tensile specimens were prepared by mixing GNP and GO at 0.1, 0.3, 0.5 and 1.0 wt.% In epoxy coatings and tensile stress-strain characteristics were investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.185-186
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• 2023

Recently, a lot of nano-scale material technology development and research have been conducted in construction fields to improve the compressive strength and durability of cement-based Composites. There are some studies that have confirmed the properties and application effects of cement-based complex using each nanomaterial, but development and research using both materials are relatively limited. This study sought to confirm the effect of multi-wall carbon nanotubes (MWCNT) and nanosilica, which are representative construction nanomaterials, on the compressive strength, voids, and microstructure formation of cement. The purpose was to produce a cement composite by changing the mixing rate of the two nanomaterials, and to find the optimal mixing amount considering its mechanical and rheological properties.

• Journal of Surface Science and Engineering
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• v.56 no.6
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• pp.341-352
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• 2023

This paper reviews the potentials of a rotary chemical vapor deposition (RCVD) process for nanomaterial synthesis and coating on powder-based materials. The rotary reactor offers a significant improvement over traditional CVD methods having horizontal and fixed reaction chambers. The RCVD system yields enhanced productivity and surface coating uniformity of nanoparticles applied in various purposes, such as efficient heat dissipation, surface hardness enhancement, and enhanced energy storage performances. The effectiveness of the RCVD system would open up new possibilities in various applications because uniform coating on powder-based materials with massive productivity is inevitable to develop multi-functional materials with high reliability.

• Journal of the Korean Physical Society
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• v.80
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• pp.1035-1041
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• 2022

Nondestructive nano-characterization methods were reviewed with respect to technical aspect and practicability. Micro-photoluminescence, cathodoluminscence and Raman spectroscopy with mapping modes were investigated as optical characterization tools, while electron backscatter diffraction and piezoresponse force microscopy were introduced as monitoring techniques for the crystallographic and electromechanical properties. Especially, the spatial resolution of the data acquisition and analysis was carefully inspected in the representative semiconducting nanomaterial systems. Some of efforts to overcome the limit of these characterizations were also taken into consideration.

• Nanomaterials
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• v.12 no.5
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• pp.758-770
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• 2022

Parkinson's disease is one of the most common degenerative disorders and is characterized by observable motor dysfunction and the loss of dopaminergic neurons. In this study, we fabricated curcumin nanoparticles using human serum albumin as a nanocarrier. Encapsulating curcumin is beneficial to improving its aqueous solubility and bioavailability. The curcumin-loaded HSA nanoparticles were acquired in the particle size and at the zeta potential of 200 nm and -10 mV, respectively. The curcumin-loaded human serum albumin nanoparticles ameliorated Parkinson's disease features in the C. elegans model, including body movement, basal slowing response, and the degeneration of dopaminergic neurons. These results suggest that curcumin nanoparticles have potential as a medicinal nanomaterial for preventing the progression of Parkinson's disease.