• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1379-1385
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• 2008

Highly efficient synthesis of substituted benzo[1,4]oxazin-3-ones and pyrido[1,4]oxazin-2-ones under microwave irradiation via Smiles rearrangement is reported. Substituted benzo[1,4]oxazin-3-ones and pyrido[1,4]oxazin-2-ones were obtained by treatment of substituted 2-chlorophenols or 2-chloropyridols with N-substituted 2-chloroacetamide in the presence of potassium carbonate in MeCN and subsequent exposure to cesium carbonate in DMF. All the reactions which take 2-10 hours under conventional condition were completed successfully within a few minutes under microwave irradiation giving moderate to excellent yields.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1489-1495
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• 2010

A porous coordination solid of nickel(II) dihydroxyterephthalate has been synthesized by the microwave-assisted (MW) method. The synthesized nickel(II) dihyroxylterephthalate was designated by the general formula of [$Ni_2$(dhtp) $(H_2O)_2]{\cdot}8H_2O$ (where, dhtp = 2,5-dihydroxyterephthalate, denoted by Ni-DHTP). The effect of microwave-irradiation temperature and time of irradiation on the porosity and morphological changes in the solids have also been investigated. The catalytic performance of Ni-DHTP synthesized by MW method has been studied in the oxidation of cyclohexene with aqueous $H_2O_2$, which gave cyclohexene oxide as the primary product and 2-cyclohexene-1-ol as a major product.

• Journal of the Korean Chemical Society
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• v.56 no.6
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• pp.706-711
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• 2012

Hindered phenols and alcohols were protected as their corresponding ethers using different alkylating agents in presence of KOH/DMSO under microwave irradiation. $$R-OH\;{KOH/DMSO,\;R^{\prime}-X,\;MW \\{\vec{10-15\;Mins,\;80%-90%\;Yield}}}\;R^{{/}^O{\backslash}}R^{\prime}$$.

• Elastomers and Composites
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• v.53 no.3
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• pp.124-130
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• 2018

Recently, microwaves have been used for desulfurization because they can selectively dissociate C-S and S-S bonds present in vulcanized rubber. In this study, we investigated the changes in structural and physical properties of EPDM (Ethylene propylene diene monomer) rubber by irradiating it with microwaves for different durations. The surface chemical composition of the irradiated EPDM rubber was analyzed by FT-IR, XPS, and EDS analyses. It was confirmed by XPS that C-S and S-S S2p peak heights greatly decreased when microwave irradiation was performed for more than 5 min. In the EPDM sample irradiated with microwaves for 10 min, the number of S-O bonds significantly increased owing to oxidation. As the microwave irradiation time was increased, SEM images showed cracks and voids on the EPDM surface. The 20% decomposition temperature of the EPDM rubber sample was investigated by TGA, and it was found to be about $435.23^{\circ}C$ for the EPDM rubber irradiated for 10 min. The crosslinking density of the EPDM rubber was determined by measuring the degree of swelling, and the highest value was observed for the E5 sample irradiated for 5 min. The degree of swelling of the E10 sample irradiated for 10 min was lower than that of the E5 sample. These results indicate that when irradiated with microwaves for more than a certain time, desulfurization occurs and the side chain of the EPDM rubber dissociates and forms additional crosslinking bonds.

• 한국초전도학회:학술대회논문집
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• v.16
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• pp.49-49
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• 2006

• Journal of the Korean Vacuum Society
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• v.20 no.4
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• pp.294-299
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• 2011

In this study, single-walled carbon nanotubes (SWCNTs) were synthesized on a Fe/$Al_2O_3$/Si layer by thermal chemical vapor deposition. Metallic SWCNTs were selectively removed by microwave irradiation. Electrical and structural characterizations of the SWCNTs clearly revealed that the metallic SWCNTs were almost removed by microwave irradiation for 120 sec. The remained semiconducting SWCNTs with a high crystalline structure were obtained over 95%. This method would provide useful information for applications to SWCNTs-based field effect transistors and multifaceted nanoelectronics.

• Elastomers and Composites
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• v.40 no.1
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• pp.45-52
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• 2005

Synthesis or fullerene oxides[$C_{60}(O)_n$] ($n=1{\sim}4$ or n=1) by fullerene[$C_{60}$] and several oxidants such as 3-chloroperoxy benzoic acid, benzoyl peroxide, trichloroisocyanuric acid, and chromium(VI) oxide took place under microwave irradiation. The reactivity in solid state of fullerene[$C_{60}$] with various oxidants under same microwave rendition increased in order or 3- chloroperoxy benzoic acid > benzoyl peroxide > trichloroisocyanuric acid $\simeq$chromium(VI) oxide. The MALDI-TOF-MS, UV-visible spectra and HPLC analysis confirmed that the products of fullerene oxidation were [$C_{60}(O)_n$] ($n=1{\sim}4$ or n=1).

• Elastomers and Composites
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• v.39 no.4
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• pp.309-317
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• 2004

Synthesis of fullerene oxides [$C_{70}O_n$] ($n=1{\sim}3$ or n=1) in solid state by fullerene [$C_{70}$] and several oxidants such as 3-chloroperoxy benzoic acid, chromium(VI) oxide, benzoyl peroxide, and trichloroisocyanuric acid was taken place under microwave irradiation. The reactivity in solid state oi fullerene [$C_{70}$] with various oxidants under same microwave condition increased in the order of 3-chloroperoxy benzoic acid > chromium(VI) oxide > trichloroisocyanuric acid ${\simeq}benzoyl$ peroxide. The MALDI-TOF-MS, UV-visible spectra and HPLC analysis confirmed that the products of fullerene oxidation were [$C_{70}O_n$] ($n=1{\sim}3$ or n=1).

• Composites Research
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• v.33 no.1
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• pp.19-24
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• 2020

In this paper, the microwave irradiation process was conducted during the Poly(vinylidene fluoride) (PVDF) nano-composite film fabrication process to analyze how the β-crystalline is increased. TiO₂ was added as a nanoparticle reinforcement to further improve the β-crystalline conformation of the PVDF films by van der Waals force due to the difference of electronegativity between PVDF and the metal oxide nanoparticle. The crystalline conformation of the fabricated films was analyzed by X-ray diffraction and Fourier transform infrared spectroscopy. According to these analysis results, it was confirmed that the microwave irradiation process during the solvent evaporation process increases the crystallinity of the PVDF films, and more β-crystalline can be obtained after additional film stretching process. It was also found that the PVDF nano-composite films with the metal oxide have relatively higher β-crystalline conformation rather than the neat PVDF films.

• Resources Recycling
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• v.25 no.3
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• pp.49-54
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• 2016

In this study, zircon sand is separated into zirconia and silica by using the Ar-$H_2$ arc plasma refining. And then silica is removed from it by the microwave leaching method to produce a high pure zirconia. Plasma melting consist of two sequential processes; reduction process with Ar gas only followed by refining process with Ar-$H_2$ gas. After cooling in chamber. The solid phase obtained at $240^{\circ}C$ were found to be composed of 20% sulfuric acid solution. The solution was used as a leaching solution with microwave irradiation to obtain a high purity zirconia.