• Journal of Korean Society for Atmospheric Environment
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• v.25 no.2
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• pp.122-132
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• 2009

Adsorption of toluene by activated carbon fiber (ACF) coated with dielectric heating element and desorption by applying microwave were investigated. In order to prepare adsorbent so that VOC can be desorbed by microwave heating, fine dielectric heating element with nano size was coated on the surface of the ACF using hybrid binder. Eight adsorbents (ACF-DHE, Activated Carbon Fiber coated with Dielectric Heating Element) were prepared with different amount of dielectric heating element, kinds of hybrid binder, and solvent. In order to investigate adsorption characteristics, BET surface area, pore volume, and average pore size were measured for each adsorbent including ACF. Breakthrough experiments with toluene concentration, flow rate, bed length using fixed bed reactor were performed to investigate adsorbality of adsorbent, and results were compared with that of the ACF. Desorption reactor was constructed with modified microwave oven to investigate heating effect on ACF-DHE by applying microwave power. Each adsorbent saturated with toluene were put into desorption reactor. Composition of desorbed gas generated by applying controlled microwave power to reactor was measured. Up to now, hot air desorption method has been used. Experimental results showed that desorption method with new adsorbent prepared by coating dielectric heating element on ACF can be used for industrial application.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.331-340
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• 1995

Microwave (Hybrid) Heating (MHH) was used to oxidize and sinter Al-Al2O3 powder mixture. For 25 v/o Al specimen and 35 v/o Al specimen, the total processing to produce low-shrinkage reaction bonded alumina was carried out within 1 hour even though conventional furnace process took more than 10 hours. Compared with conventional fast firing process, MHH process increased more than 40% oxidation at the same temperature, and these high oxidation rates were thought to be caused by the surface ohmic current on Al particles.

• Korean Journal of Crystallography
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• v.9 no.1
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• pp.44-47
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• 1998

A reduction/oxidation reaction between A1 metal powder and SiO2 powder was performed by Self-propagating High-temperature Synthesis (SHS) reaction induced by microwave energy to produce a composite of Al2O3 and Si powders by using a 2.45 GHz kitchen model microwave oven. A Microwave Hybrid Heating(MHH) method was applied by using SiC powders as a suscepting material to raise the temperature of the disk samples and the heat increase rate of over 100℃/min were obtained before the reaction. The reaction started around 850℃ and the heat increase rate jumped to over 200℃/min after the reaction took place.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.114-117
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• 2003

Conventional heating the heat source cause the molecules to react from the surface toward the center so that successive layers of molecules heat in turn. The product surfaces may be in danger of over heating by the time heat penetrates the material. Microwave, however, produce a volume heating effect. All molecules are set in action at the same time. It also evens temperature gradients and offers other important benefits such as selective heating. (omitted)

• Journal of the Korean Ceramic Society
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• v.39 no.7
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• pp.669-674
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• 2002

Ni-Zn ferrite was sintered by microwave hybrid sintering method using microwave energy of 2.45 GHz, 700 W in the temperature range of 900$^{\circ}C$ ∼ 1070$^{\circ}C$. A high density (98%TD) Ni-Zn ferrite, added Bi$_2$O$_3$ and CuO, with a single phase was obtained by microwave sintering at 970$^{\circ}C$ for 15 min. All the sintered samples showed sintered density over 90% of TD. These results indicate that the processing time and energy consumption can be reduced significantly by microwave hybrid sintering method.

• Journal of Powder Materials
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• v.10 no.4
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• pp.249-254
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• 2003

WC-6wt%Co hard metal powders were sintered by a 2.45 GHz multimode microwave applicator in Ar atmosphere. Microwave sintering of WC-6wt%Co powder lowered the sintering temperature and shortened the processing time in less than two hours than by a conventional method. Microstructures of the sintered specimen were studied with scanning electron microscope (SEM) and no abnormal grain growth was observed. Mechanical properties were similar to the values of the specimens sintered by a conventional method. Specimen sintered at 135$0^{\circ}C$ for 30 minutes ,hewed 99%, 20.5 GPa and 8.1 MPa$\sqrt{m}$ of theoretical density, hardness and fracture strength, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.508-512
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• 1998

The NTC thermistors were sintered by using microwave hybrid heating method at $1100^{\circ}C$~$1300^{\circ}C$ and those electrical properties were investigated. The obtained $B_{25^{\circ}C/85^{\circ}C}$ values from temperature dependence of electrical resisitivity were around 3100~3200 K which were almost the same values as conventionally sintered ones. Compared with conventional sintering process, this process could complete whole sintering process within 20 minutes. This the processing time and energy consumption could be reduced through this rapid heating by using microwave hybrid heating.t there were showed only two peaks, glycolide melting peak and lower molecular weight melting peak without lauryl alcohol. Conversion increased slowly with the reaction time up to 50 minutes, and then gave a sudden increase above that. The reaction time to disappear in glycolide melting peak during polymerization was shortened with the increase of lauryl alcohol content. Zero-shear viscosity of polyglycolic acid decreased with the increase of free acid content in glycolide.ssional energy and bending hysteresis increased. \circled3 Surface characteristics such as friction coefficient and thickness variation of highly shrinkage fabrics became relatively roughened state. \circled4 Since stiffened and roughened characteristics of highly shrinkage fabrics, drapabilities of them were significantly lowered. Additionally thermal insulation property of high shrinkage fabric was higher than that of low shrinkage fabric due to bulky and thickened feature. From the results, it is considered that the silk fabrics with high filling shrinkage have the good bulkiness and heat keeping properties and thus they have the suitable characteristics for high quality men's and women's formal garments.

• Polymer(Korea)
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• v.34 no.2
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• pp.144-149
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• 2010

Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.