• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.125-131
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• 2017

We report organically functionalized Ag nanoparticles spontaneously form two-dimensional (2D) novel superstructures at the air-water interface. Analysis of the superstructures suggests that the 2D assembly of Ag nanoparticles originates from a subtle interplay between characteristic inter-particle interactions that can be readily controlled by changing the sizes of nanoparticle metal core and surfactants. Such structures have potential uses in nanostructured functional materials, catalysis, and device applications.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1085-1087
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• 2009

Bare metal stents which were used to treat coronary artery disease have several biochemical problems. Polymerbased drug-eluting stents (DES) have opened up a new paradigm in the treatment of in-stent restenosis. Many studies and research programmes have proved that DES can prevent restenosis. In our study, paclitaxel-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles have been deposited along the three dimensional scaffold of coronary stents by a method using self-assembling properties of colloidal particles. We found that the nanoparticles were deposited uniformly and closely packed. The amount of paclitaxel was easily controlled by the drug content of the nanoparticles and the deposition count.

• Ceramist
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• v.22 no.2
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• pp.189-197
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• 2019

Direct methanol fuel cells (DMFCs) have found a wide variety of commercial applications such as portable computer and mobile phone. In a fuel cell, the catalysts have an important role and durability and efficiency are determined by the ability of the catalyst. The activity of the catalyst is determined by the structure and shape control of the nanoparticles and the dispersion of the nanoparticles and application system. The surface energy of nanoparticles determines the activity by shape control and the nanostructure is determined by the ratio of bi- and tri-metals in the alloy and core-shell. The dispersion of nanoparticles depends on the type of support such as carbon, graphen and metal oxide. In addition, a hybrid system using both optical and electrochemical device has been developed recently.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.33-41
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• 2018

The manuscript reports synthesis of exceptionally stable gold nanoparticles (GNPs) using Momordica charantia fruit extract. The synthesis approach was optimized by refining three experimental variables including source of the fruit extract (peel, seed, and seed coat), pH of the solution, and temperature of the reaction medium. As synthesized GNPs showed excellent stability against various thiolated compounds (e.g., thioglycolic acid, thiourea, ${\text\tiny{L}}-cystine$, 1-dodecanethiol, and cysteamine hydrochloride). Moreover, these nanoparticles showed distinctive colorimetric responses against $Cd^{2+}$ and thiophenol (TP) from their potential interferences. The limit of detection (LOD) values for $Cd^{2+}$ and TP were determined as 0.186 and $0.154{\mu}M$, respectively.

• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.266-269
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• 2019

In this study, $Ag_2Se$ nanoparticles were synthesized by employing the colloidal method. The synthesized $Ag_2Se$ nanocrystals were spherical in shape with a diameter of approximately 4 nm and had high crystallinity. These attributes of $Ag_2Se$ nanocrystals were determined through images obtained from a high resolution transmission electron microscope. Thin films comprising the synthesized $Ag_2Se$ nanoparticles had an optical band gap of 1.5 eV. Furthermore, fabricated NIR sensors comprising $Ag_2Se$ nanoparticles exhibited a high detectivity of $5.5{\times}10^9$ Jones (above $1{\times}10^9$) at room temperature, leading to low power consumption

• Journal of Electrochemical Science and Technology
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• v.12 no.3
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• pp.308-316
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• 2021

In this work, we report synthesis, characterization and corrosion inhibition properties of cationic thiol surfactant-capped silver (SC-Ag-NPs) and gold (SC-Au-NPs) nanoparticles. SC-Ag-NPs and SC-Au-NPs were characterized using regular techniques include TEM. Corrosion study was carried out using carbon steel (CS) in 3.5% NaCl aqueous solution and characterized using multiple electrochemical techniques. Our results suggest that the paint containing SC-Ag-NPs and SC-Au-NPs endow efficient corrosion protection to the CS. Especially, SC-Au-NPs based paint form a stronger barrier between the metal and the corrosive ions, leading to better inhibition properties.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.481-487
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• 2018

Membrane clogging or fouling of the membrane caused by organic, inorganic, and biological on the surface is one of the main obstacles to achieve high flux over a long period of the membrane filtration process. So researchers have been many attempts to reduce membrane fouling and found that there is a close relationship between membrane surface hydrophilicity and membrane fouling, such that the same conditions, a greater hydrophilicity were less prone to fouling. Nanotechnology in the past decade is provided numerous opportunities to examine the effects of metal nanoparticles on the both hydrophilic and antibacterial properties of the membrane. In the present study the improvement of hydrophilic and antimicrobial properties of the membrane was evaluated by adding nanoparticles of titanium dioxide and copper oxide. For this purpose, 4% copper oxide and titanium dioxide nanoparticles with a ratio of 0, 30, 50, and 70% of copper oxide added to the polymeric membrane and compare to the pure polymeric membrane. Comparison experiments were performed on E. coli PTCC1998 in two ways disc and tube and also to evaluate membrane hydrophilic by measuring the contact angle and diameter of pores and analysis point SEM has been made. The results show that the membrane-containing nanoparticle has antibacterial properties and its impact by increasing the percentage of copper oxide nanoparticles increases.

• Advances in nano research
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• v.2 no.1
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• pp.57-67
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• 2014

This article shows the coarsening behavior of nanoparticle multilayers during heat treatments which produce larger metallic nanostructures with varying shapes and sizes on glass slides. Nanoparticle multilayer films are initially constructed via the layer-by-layer self-assembly of small and monodispersed gold and/or palladium nanoparticles with different compositions (gold only, palladium only, or both gold and palladium) and assembly orders (compounding layers of gold layers over palladium layers or vice versa). Upon heating the slides at $600^{\circ}C$, the surface nanoparticles undergo coalescence becoming larger nanostructured metallic films. UV-Vis results show a clear reliance of the layering sequence on the optical properties of these metal films, which demonstrates an importance of the outmost (top) layers in each nanoparticle multilayer films. Topographic surface features show that the heat treatments of nanoparticle multilayer films result in the nucleation of nanoparticles and the formation of metallic cluster structures. The results confirm that different composition and layering sequence of nanoparticle multilayer films clearly affect the coalescence behavior of nanoparticles during heat treatments.

• Korean Journal of Metals and Materials
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• v.49 no.12
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• pp.950-955
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• 2011

In the present study, the formation of hollow Cu oxide nanoparticles through the oxidation process at temperatures from 200 to $300^{\circ}C$ has been studied by transmission electron microscopy with Cu nanoparticles produced by the plasma arc discharge method. The Cu nanoparticles had a thin oxide layer on the surface at room temperature and the thickness of this oxide layer increased during oxidation in atmosphere at $200-300^{\circ}C$ However, the oxide layer consisted of $Cu_2O$ and CuO after oxidation at $200^{\circ}C$ whereas this layer was comprised of only CuO after oxidation at $300^{\circ}C$ On the other hand, hollow Cu oxide nanoparticles are obtained as a result of vacancy aggregation in the oxidation processes, resulting from the rapid outward diffusion of metal ions through the oxide layer during the oxidation process.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.2
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• pp.201-212
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• 2011

Nanotechnology is the applied science which develops new materials and systems sized within 1 to 100 nanometer, and improves their physical, chemical, and biological characteristics by manipulating on an atomic and molecular scale. This nanotechnology has been applied to wide spectrum of industries resulting in production of various nanoparticles. It is expected that more nanoparticles will be generated and enter to natural water bodies, imposing great threat to potable water resources. However their toxicity and treatment options have not been throughly investigated, despite the significant growth of nanotechnology-based industries. The objective of this study is to provide fundamental information for the management of nanoparticles in water supply systems through extensive literature survey. More specifically, two types of nanoparticles are selected to be a potential problem for drinking water treatment. They are carbon nanoparticles such as carbon nanotube and fullerene, and metal nanoparticles including silver, gold, silica and titanium oxide. In this study, basic characteristics and toxicity of these nanoparticles were first investigated systematically. Their monitoring techniques and treatment efficiencies in conventional water treatment plants were also studied to examine our capability to mitigate the risk associated with nanoparticles. This study suggests that the technologies monitoring nanopartilces need to be greatly improved in water supply systems, and more advanced water treatment processes should be adopted for better control of these nanoparticles.