• 한국전기전자재료학회논문지
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• 제19권3호
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• pp.233-239
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• 2006

Two different nanofluids were prepared by dispersing $Al_{2}O_3$ nanoparticles in transformer oil after hydrophobic surface modification. The agglomerated alumina nanoparticles with diameters from ${\mu}m$ to mm were ball-milled and then treated with surfactants such as lauric acid, stearic acid and oleic acid. The surface characteristics of modified nanoparticles were examined by FTIR spectroscopy. It showed that the hydrophobicity of nanoparticles was caused by esterification between hydroxyl groups on the particle surface and functional groups of surfactant. The shape and size distribution of ball-milled particles were analyzed by TEM and PSA. The results compared with the primary particles indicated that the size distributions of nanoparticles were dependant on milling times. The dispersion stability of modified nanoparticles dispersed in oil was highly dependent on the composition and amounts of surfactants.

• Bulletin of the Korean Chemical Society
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• 제35권10호
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• pp.2979-2984
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• 2014

Silver nanoparticles have been synthesized by liquid-phase and alcohol reduction methods. Silver-doped silica-complex nanoparticles were prepared using a sol-gel process. The formation, structure, morphology, and particle size of the nanoparticles have been studied using several techniques. Silver nanoparticles of size of 30-40 nm were formed successfully by alcohol reduction. TEM images show that both the concentration and the molecular weight of polyvinyl pyrrolidone (PVP) considerably affect the size of the emerging silver nanoparticles. The number of silver-doped silica-complex particles increased by a mercapto-group treatment that showed a narrower size distribution than that of silica treated with amino groups. The silver/polyester and silver-doped silica/polyester masterbatch chips showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli.

• Macromolecular Research
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• 제16권7호
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• pp.604-608
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• 2008

Color dye-doped silk fibroin nanoparticles were successfully fabricated using a microemulsion method. An aqueous silk fibroin solution was prepared by dissolving cocoons (Bombyx mori) in a concentrated lithium bromide solution followed by dialysis. A color dye solution was also mixed with the aqueous silk fibroin solution. The surfactants used for the microemulsion were then removed by methanol and ethanol, yielding color dye-doped silk fibroin nanoparticles, approximately 167 nm in diameter. The secondary structure of the nanoparticles showed a $\beta$-sheet conformation, as characterized by Fourier transform infrared spectroscopy. The morphology of the nanoparticles was determined by field emission scanning electron microscopy, transmission electron microscopy and atomic force microscopy, and their size and size distribution were measured by dynamic light scattering. The color dye-doped silk fibroin nanoparticles were examined by confocal laser scanning microscopy.

• 한국전기전자재료학회논문지
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• 제18권5호
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• pp.478-483
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• 2005

In this paper, we synthesized 10 to 20 nm diameter NiFe nanoparticles and nanoparticle films utilizing supersonic jet deposition of nanoparticle aerosols generated by laser ablation of $30\;to\;45{\mu}m$ diameter permalloy $(Ni_{81}Fe_{19} \;at\;{\%})$ microparticles. The component and composition of the nanoparticles were characterized by an energy dispersive X-ray spectroscopy. The morphology of the nanoparticles and nanoparticle films was analyzed by a high-resolution transmission electron microscopy and a scanning electron microscopy, respectively. The experimental results showed that the nanoparticles and nanoparticle films have remarkable properties with an excellent preservation of the composition of feedstock permalloy microparticles. The purpose of the present work is to present details on the composition and nanostructural characterizations for NiFe nanoparticles and nanoparticle films prepared by laser ablation of microparticles (LAM).

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3530-3538
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• 2010

In this study 1-[4-(2-methoxy benzyl)-6-aryl-pyridazin-3(2H)-ylidene] hydrazines were used for the synthesis of new heterocyclic systems such as thiazolidine, phthalazine, pyrazolo, tetrazolo, hydrazide and new pyridazine derivatives to explore the effect of silver nanoparticles on their biological activity efficiency. Structures of the new heterocycles were characterized by the aid of several analytical techniques including; $^1H$-NMR, FTIR and mass spectra. Silver nanoparticles were synthesized by a simple methodology and the formation of silver nanoparticles was confirmed by transmission electron microscopy (TEM) and UV studies. Most of the new prepared heterocycles were evaluated in vitro as new antimicrobial agents. Combination effects of the silver nanoparticles on the antimicrobial activity of the new heterocycles were investigated using the disk diffusion method. Compound 10a exhibited the strongest enhancing effect of silver nanoparticles solution against Aspergillus flavus and Candida albicans.

• Applied Science and Convergence Technology
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• 제23권5호
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• pp.296-300
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• 2014

The synthesis of pure and rare-earth doped gallium oxide (${\beta}-Ga_2O_3$) nanoparticles is reported. The synthesized nanoparticles are characterized with XRD, TEM, and PL analyses. Strong blue emission is observed from un-doped gallium oxide nanoparticles, while nanoparticles doped with $Eu^{3+}$ and $Tb^{3+}$ give strong red and green emissions, respectively. When doped with $Eu^{3+}$ and $Tb^{3+}$ together, gallium oxide nanoparticles emit white light. The CIE coordinate of the emitted light was found to be (0.33, 0.33), which is well within the white light region.

• Advances in nano research
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• 제16권3호
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• pp.303-311
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• 2024

This paper conducts a thorough economic evaluation of integrating nanoparticles into concrete structures within the construction industry, aiming to elevate the material properties of concrete. Employing the Halpin-Tsai micromechanics theory for deriving the effective material properties of the nanocomposite concrete structure, the research investigates the nuanced impact of nanoparticles on various mechanical properties, including the modulus of elasticity, compressive strength, and their indirect effects on the percentage of reinforcement. Implementing the Euler theory to formulate the governing equation based on Hamilton's principle, the study delves into the pricing dynamics of nanoparticles and their influence on the overall cost structure of concrete structures. Notably, the findings reveal that a measured increase in the volume percentage of nanoparticles, up to 1%, results in a remarkable 78% improvement in elastic modulus and a substantial 142% reduction in armature percentage. Remarkably, from an economic perspective, the incremental cost associated with the integration of nanoparticles is relatively modest (around $1 per ton of concrete), considering the substantial enhancements in mechanical properties achieved.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.283-283
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• 2006

Multigram-scale product exclusively containing magnetic carbon nanoparticles (MNCPs) with uniform size was successfully fabricated without a specific separation process. The iron-doped PPy nanoparticles were synthesized by micelle templating and used as the carbon precursor in order to generate MCNPs. The magnetic carbon nanoparticles possessed a microporous structure and exhibited ferromagnetic properties at room temperature. This approach may be an effective alternative to generate magnetic carbon nanoparticles against the conventional arc-discharge technique.

• 한국균학회지
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• 제43권4호
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• pp.207-215
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• 2015

Nanotechnology, which has become an important area of science, has caused an enormous developmental revolution in many fields. In the last two decades researchers have focused on overcoming the obstacles encountered during the preparation of nanoparticles. This article highlights the nanotechnology, along with a brief description of the manufacturing, concepts and activities of nanoparticles as alternative pesticides against plant pathogens, some methods for evaluation of nanoparticles against phytopathogens in vitro and in vivo, and explains the importance of some common nanoparticle types used in agricultural applications and plant pathology.

• Medical Lasers
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• 제10권2호
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• pp.61-67
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• 2021

Advances in nanobiotechnology have presented numerous possibilities of more effective diagnostic and therapeutic options. In particular, gold nanoparticles have demonstrated the potential for application in molecular imaging and treatment of cancers, including drug delivery system of certain target molecules, enhancement of radiation therapy, and photothermal treatment. This review discusses the properties, mechanism of action, and clinical application of gold nanoparticles. Although the safety of nanoparticles is yet to be ascertained, there is no doubt that in the future, nanotechnology will play an important role in the development and enhancement of a wide range of diagnostic and treatment modalities.