• 한국자원식물학회지
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• 제24권3호
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• pp.309-313
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• 2011

Houttuynia cordata is used as a raw material of oriental medicine to acquire antioxidant and anti cancer effect and to cure a heart disease. Mechanochemical technology not only reduces the size of the object but also changes the chemical properties of the object. Extraction of functional materials from the Houttuynia cordata after grinding as a pretreatment using the mechanochemical technology was conducted in this study to investigate the effect of grinding on the yields and antioxidant activities of the extract. Houttuynia cordata was ground by the planetary ball mill and the morphology was analyzed by SEM. Yields of functional materials were increased from 6.2 g in the sample without grinding to 7.0, 7.8, 8.8 g after grinding of 30 minutes, 1 hour and 2 hours, respectively. Nitrite scavenging abilities were increased from 57-77% to 69-86% as a result of mechanochemical pretreatment. Also, DPPH scavenging abilities for the methanol extraction were increased from 10.01-40.29% to 11.01-49.29% as a result of mechanochemical grinding.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.315-324
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• 2001

Mechanochemical effects that occurred in the fine grinding process of quartz particles using planetary ball mill was investigated. Quartz particles have been frequently utilized for optical materials, semiconductor molding materials. We determined that grinding for a long time can be create amorphous structures from the crystalline quartz by Mechanochemical effects. But, to be produced nano-composite particles that the critical grinding time reached for composite materials in a short time. Henceforth, a qualitative estimation must be conducted on the filler for EMC(Epoxy molding compound) materials. It can be produced mechanochemically treated composite materials and also an integrated grinding efficiency considering of the nano-composite amorphous structured particles. The mechanochemical characteristics were evaluated based on particle morphology, size distribution, specific surface area, density and the amount of amorphous phase materials into the particle surface. The grinding operation in the planetary ball mill can be classified into three stages. During the first stage, initial particle size was reduced for the increase of specific surface area. In the second stage, the specific surface areas increased in spite of the increase in particle size. The final stage as a critical grinding stage, the ground quartz was considered mechanochemically treated particles as a nano- composite amorphous structured particles. The development of amorphous phase on the particle surface was evaluated by X-ray diffractometry, thermal gravity analysis and IR spectrometer. The amount of amorphous phase of particles ground for 2048 minutes was 85.3% and 88.2% by X-ray analysis and thermal gravity analysis, respectively.

• 한국자원식물학회지
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• 제24권3호
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• pp.314-318
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• 2011

Saururus chinensis is used as a raw material of an anti-rheumatic, poultice, sedative and stomachic. The tea of dried Saururus chinensis leaves has a function of relaxing pains in back and breast and of treating stomach ailments. The plant has the functions of anti-inflammatory, depurative, diuretic, febrifuge and refrigerant. The extraction of functional material is carried out by methanol and ethanol solvents. Mechanochemical grinding is applied as a pretreatment process before extraction to enhance the extraction efficiency by increasing the surface area of the materials while changing the chemical properties of the materials. Extraction of functional materials from the Saururus chinensis after grinding as a pretreatment using the mechanochemical technology was accomplished in this study to investigate the effect of grinding on the antioxidant activities of the extract. Saururus chinensis was ground by the planetary ball mill and the morphology was analyzed by SEM. Mechanochemical pretreatment increased the yields of functional materials from 5.9 g to 6.4, 7.0, and 8.1 g after grinding of 30 minutes, 1 hour and 2 hours, respectively. Nitrite scavenging ability increased from 53.0-71.0% to 61.0-79.0% for the methanol extraction in the solution of pH 1.2. Also, Electron donating abilities were increased from 7.90-33.51% to 11.97-38.51% for the methanol extraction. The extract concentration for the half inhibition of DPPH radicals was reduced from $278{\mu}g/mL$ in the original sample to $263{\mu}g/mL$ in the sample after grinding for the methanol extraction.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.469-471
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• 2001

Dry grinding of a mixture of CaCO$_3$ and Ca(H$_2$PO$_4$)$_2$.$H_2O$ was conducted using a planetary ball mill in order to investigate solid state reaction for a synthesis of hydroxyapatite(Ca$_{10}$(PO$_4$)$_{6}$(OH)$_2$, HAp) through mechanochemical treatment method. The raw materials, which are composed of waste oyster and calcium biphosphate Ca(H$_2$PO$_4$)$_2$.$H_2O$, were mixed and then treated mechanochemically. The synthesis of hydroxyapatite(Ca$_{10}$(PO$_4$)$_{6}$(OH)$_2$, HAp) from the mixture was almost completed by about 60 minute grinding. The formation of HAp monophase in the ground mixture was characterized through X-ray diffraction (XRD) analysis. Moreover, the formation of HAp monophase depending on the grinding time was improved by increasing the grinding time.ime.ime.

• 한국정밀공학회지
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• 제13권6호
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• pp.45-51
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• 1996

Silicon wafers are required to be finished under the roughness of nanometer order for the subsequent chip fabrication processes. Recently, the finish grinding techniques have been researched for the improvement of accuracy and surface roughness simultaneously. Among them, the grinding technique using fine abrasive has been known as an easily accessible method. However, the manufacture of the fine grit grinding wheel has been very difficult because of the coherence of the grits. In this paper, the development of the ultrafine grit silica($SiO_2$) grinding wheel by the combination of the binder coating and the vacuum forming techniques is reported. And, the mechanochemical removal effects of the grinding conditions are discussed. Finally, a successful result of Ra O.4nm. Rmax 4nm in the ground surface roughness of a 6 inch silicon wafer was achieved.

• 반도체디스플레이기술학회지
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• 제3권1호
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• pp.9-13
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• 2004

Carbon nanofibers (CNFs) with uniform diameter and controlled size were prepared from catalytic decomposition of $\textrm{C}_{2}\textrm{H}_{2}$ with Ni-MgO catalyst treated by mechanochemical (MC) process. The properties of Ni catalyst, such as size, distribution and morphology, can be governed by tuning grinding time in MC process. As a result, size and structure of CNFs can be tailored. The effect of grinding time to the as-grown CNFs was studied. CNFs with diameter from 10-70 nm were synthesized. CNFs with bundle formation sharing one tip and twisted CNFs were also synthesized with catalyst treated by MC process.

• 한국재료학회지
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• 제7권2호
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• pp.152-156
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• 1997

본 논문은 분쇄한 dickite의 메카노케미칼 효과에 관해서 연구한 것이다. 유성밀을 사용하여 분쇄한 dickite의 메카노케미칼 효과를 알아보기 위하여, 분쇄시간을 달리하여 얻어진 dickite에 대하여 시차열분속과 X선 동경분포함수를 이용하여 정밀구조분석을 하였다. 분쇄한 dickite에 대하여 동경분포함수 해석 결과, $SiO_{4}$ 사면체는 분쇄한 dickite내에서 국소단위구조로 그대로 잔류하고 있었다. 한편 AI-O의 배위수 및 원자간 거리는 분쇄시간의 증가에 따라 점점 감소하였고, 이에 대한 정량화가 가능했다. 이는 시차열분석 결과의 AI주위의 환경변화와 일치하였다. 따라서, 분쇄함에 따른 dickite의 메카노케미칼 현상은 AI주위의 환경변화에 기인된 것으로 볼 수 있다.

• 한국분말재료학회지
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• 제13권4호
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• pp.243-249
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• 2006

Yttrium aluminum garnet (YAG) powders were synthesized via mechanochemical solid reaction using $Y_2O_3$ with three types of aluminum compounds. $Y_2O_3$ reacted mechanochemically with all A1 compounds and formed YAM (yttrium aluminum monoclinic), YAG and YAP (yttrium aluminum perovskite) phases depending on the starting materials. The ground samples containing ${\gamma}-A1_2O_3$ showed the best reactivity, whereas the ground sample containing A100H, which had the largest surface area, exhibited pure YAG after calcination at $1200^{\circ}C$. The sample containing Al had the least reactivity, producing YAP along with YAG at $1200^{\circ}C$. The types and grinding characteristics of the starting materials and grinding time are believed to be important factors in the mechanochemical synthesis of YAG.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 1999년도 춘계 공동학술발표회
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• pp.267-269
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• 1999

• 자원리싸이클링
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• 제27권4호
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• pp.57-64
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• 2018

알칼리화합물과의 기계화학반응을 통해 산화물로부터 텅스텐(W)과 바나듐(V) 성분의 수 침출 특성을 조사하였다. 기계화학반응은 알칼리화합물의 혼합율과 분쇄시간을 변화시키면서 실시하였고, 그 결과, 수용성 용해특성의 $Na_2WO_4$와 $NaVO_3$가 각각 생성되었으며 수 침출에 의한 W, V의 침출특성은 알칼리화합물의 혼합율과 분쇄시간에 비례하여 증가하였다. 99% 이상의 침출율은 각각 30분 (W), 5 분 (V)의 짧은 기계화학적 처리를 통하여 달성되었다. 이러한 기계화학적 처리를 통하여 텅스텐, 바나듐산화물로부터 수 침출에 의한 추출이 가능하였고, 이 공정은 탈질촉매로부터 텅스텐, 바나듐의 선택적 회수에 적용될 수 있다.