A comparative study of particle size analysis in fine powder: The effect of a polycomponent particulate system

최희규,Woong Lee,김동욱,샤런드라쿠마르,Jonghak Ha,Seongsoo Kim,Jungeun Lee 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.1

We report the particle size distribution of poly component particulate systems studied in three kinds of experimental methods. Six analyzers, such as Mastersizer Microplus (Malvern Instruments Ltd., UK), LS230 (Coulter Electronics Ltd., USA) LMS30 (Seishin, Japan), Analysette22 (Fritsch, Germany), HELOS (Sympatec, Germany) based on a laser diffraction and scattering method, and the SKC-2000S (Seishin Co., Ltd., Japan) based on the centrifugal sedimentation method, were used to study the particle size distribution. The results do not show reasonably good agreement between the different analyzers and different sample systems. There is a discrepancy regarding the absolute values, which can be explained by the fact the techniques used are based on different measuring principles. The results of the present study reflect that the investigator must carefully select the particle size analyzer for a particular application. Therefore, we suggest that it is necessary to measure the particle size distribution by using at least two types of analyzers or more of different makers.

The Grinding Behavior of Ground Copper Powder for Cu/CNT Nanocomposite Fabrication by Using the Dry Grinding Process with a High-speed Planetary Ball Mill

최희규,Amgalan Bor,Shiori Sakuragi,Jehyun Lee,임형태 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.1

The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

입자경과 분쇄소비동력의 고찰에 의한 교반볼밀 분쇄특성의 정량적 연구

최희규,왕림,Choi, Hee-Kyu,Wang, Lin 한국재료학회 2007 한국재료학회지 Vol.17 No.10

A series of wet grinding experiments have been carried out using a stirred ball mill to systematically investigate consideration of grinding characteristics. The particle size distribution and median diameter of the grinding consumption power for a given grinding time were considered. Also, the effect of grinding aids on particle size and grinding consumption energy defined as the summation of grinding power was investigated. The grinding aids had influence on the smaller products size and decrease grinding consumption energy because the function of grinding aids were to be attribute to the prevention of agglomeration and ball and grinding chamber wall coating of sample powder. The grinding process seemed to be controlled by the force of agglomeration of the ground products. It was demonstrated that the particle size and grinding consumption energy could be more decreased by the addition of grinding aids.

제한절편 길이 다형성(RFLP) 분자마커를 이용한 납자루아과 담수어류 3종의 난과 치어 종 동 정 기법 개발

최희규,이혁제 한국환경생물학회 2018 환경생물 : 환경생물학회지 Vol.36 No.3

본 연구는 PCR 기반 RFLP (Restriction Fragment Length Polymorphism; 제한절편 길이 다형성) 분자기법을 활용하여 난 및 치어 대상 납자루아과 어류 3종의 동정을 좀 더 빠르고 정확하게 파악하고 납자루아과 어류의 종별 산란양상 및 번식생태 이해에 대한 기여가 목적이다. 본 연구를 위해 기존 선행된 문헌자료를 확인하고 납자루아과 어류가 2종 이상 동서하고 있는 지역을 확인하여 현지조사를 수행하였다. 현지조사 결과 확인된 납자루아과 어류는 묵납자루 (Acheilognathus signifer), 줄납자루 (A. yamatsutae) 및 각시붕어 (Rhodeus uyekii)로 총 3종이 확인되었으며, 확인된 납자루아과 어류와 동서하고 있는 숙주조개 (작은말조개; Unio douglasiae sinuolatus)를 채집하여 숙주조개 속 납자루아과 어류의 난 및 치어를 확보하였다. 현지조사 결과 확인된 납자루아과 어류 3종을 대상으로 미토콘드리아 DNA COI과 cyt b 유전자 염기서열을 비교하여 각각 종별로 특이성을 지닌 부위 (단일염기변이; Single Nucleotide Variation: SNV)에 맞는 제한효소를 선정하였고, 숙주조개 속 난 및 치어를 대상으로 genomic DNA를 추출하여 PCR-RFLP 실험을 수행한 결과 현지조사 시 확인된 납자루아과 어류 3종의 독특한 제한절편 길이 양상을 전기영동을 통하여 확인하였다. 본 연구를 통해 묵납자루, 줄납자루 및 각시붕어의 종을 판별할 수 있는 RFLP 마커를 개발하였으며, 숙주조개 난 및 치어를 대상으로 정확한 종의 동정을 보다 빠르고 효과적으로 수행하여 각각 납자루아과 종별 산란양상을 보다 정확히 규명하고 향후 이들 자연개체군의 효과적인 유지, 관리 및 보전 방법 개발에 유용하게 활용될 수 있을 것으로 판단된다. This study aimed to develop a species identification method for the egg and fry of the three Korean bitterling fishes (Pisces: Acheilognathinae), including Acheilognathus signifer, Acheilognathus yamatsutae and Rhodeus uyekii based on the PCR-based Restriction Fragment Length Polymorphism (RFLP) markers. We conducted a field survey on the Deokchicheon River from the North Han River basin, where the three Acheilognathinae species co-occur, and also analyzed the existing sequence dataset available from the GenBank. We found coexistence of the three species at the study site. The egg and fry were obtained from the host mussels (Unio douglasiae sinuolatus) by hand from May to June 2015 and in May 2017. To develop PCR-based RFLP markers for species identification of the three Acheilognathinae fish species, restriction enzymes pinpointing species-specific single nucleotide variation (SNV) sites in mitochondrial DNA COI (cytochrome oxidase I) and cyt b (cytochrome b) genes were determined. Genomic DNA was extracted from the egg and fry and RFLP experiments were carried out using restriction enzymes Apal I, Stu I and EcoR V for A. signifer, A. yamatsutae and R. uyekii, respectively. Consequently, unambiguous discrimination of the three species was possible, as could be seen in DNA band patterns from gel electrophoresis. Our developed PCR-based RFLP markers will be useful for the determination of the three species for the young and would assist in studying the spawning patterns and reproductive ecology of Acheilognathinae fishes. Furthermore, we believe the obtained information will be of importance for future maintenance, management and conservation of these natural and endangered species.

학회참관기 : 제7회 세계분체기술학술대회 (The 7th World Congress on Particle Technology, WCPT7)를 마치고

최희규 한국화학공학회 2014 NICE Vol.32 No.3

매체교반형 미분쇄기에 의한 무기분말의 초미분쇄 기구에 관한 연구

최희규,최우식 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.4

최근 신소재 개발과 관련하여 분쇄실험을 행하는데 있어서, 서브미크론(submicron) 영역의 초미분쇄가 주목을 받고 있다. 특히, 미분쇄에서 초미분쇄 영역까지 널리 사용되고, 상업적으로도 많이 이용되는 매체형 교반밀에 의한 연구가 많이 발표되고 있다. 본 연구에서는 방해석, 납석, 활석 같은 무기분말의 시료와 수직형 교반불밀을 사용한 일련의 실험에서 교반불밀의 분쇄메커니즘(mechanism)을 밝히는 것을 목적으로 하였다. 에너지특성을 조사하기 위해 실험조작조건과 관련지어 분쇄와 에너지투입과의 상관관계를 해석하기 위해 분쇄기의 소비 동력을 측정하였고, 각 실험조작인자에 대한 상관관계를 통계적으로 해석하여 모델식을 제안하였다. 그리고, 각 실험조건에서 분쇄에너지 효율을 검토하여 분쇄조제가 분쇄효율의 개선에 미치는 영향을 조사하여, 분쇄조제를 사용하였을 때, 분쇄조제를 사용하지 않고 최적의 효율을 나타내었던 실험조작조건 보다 분쇄효율이 약 13.1% 개선된 것을 알 수 있었다. 또한, 얻어진 데이터에 분쇄속도론을 적용, 분쇄속도상수에 미치는 회전속도, 슬러리 농도 및 분쇄조제 첨가의 영향을 실험적으로 검토하여, 실험재료의 물성이 달라지거나 실험조작조건을 달리했을 경우에 실험조작인자가 분쇄속도에 미치는 영향을 분쇄속도상수의 변화를 통해 알 수 있었고, 분쇄조제를 사용하지 않았을 때에 비해 최대 25.6%의 분쇄속도가 빨라짐을 알았다. Recently in various industrial processes, the need for fine particles especially submicron particles has been increased in preparation field of raw powders such as fine ceramics and high technical products. The grinding by a stirred ball mill to submicron range has been achieved commercially in many cases. A series of grinding experiments using a vertical stirred grinding media mill and inorganic powders such as calcite, pyrophyllite and talc as test samples were carried out to clarify the grinding mechanism of the stirred grinding media mill. The effect of experimental conditions such rotation speed of stirrer, ball filling ratio, ball diameter and slurry concentration on the power inputted in the stirred media mill were measured and the quantitative relationship between them was proposed with multiple regression analysis. The relationship between the experimental factors and the comminution consumption power could also be regressed as a power-law and effect of grinding aids on particle size distribution and on grinding efficiency defined as the increase of specific surface area per the specific grinding consumed energy was investigated. In this study it can be concluded that the grinding energy efficiency using grinding aids was improved about 13.1% than no aids experiment. And the effect of grinding aids on grinding rate constant K was investigated. Also the relationship between grinding rate constant K and experimental conditions including the effect of grinding aids was examined and it is confirm that the grinding rate can be improved in the degree of the maximum of 25.6% compared with without grinding aids.

학회참관기 : "일본분체공학회 가을학술대회(日本粉體工學會 2014年度 秋期硏究發表會)" 참가 및 "국제분체공업전 동경 2014(POWTEX TOKYO 2014)" 참관기

최희규 한국화학공학회 2015 NICE Vol.33 No.1

분쇄공정에서 변화된 입자크기 및 형상특성의 평가방법에 관한 새로운 제언

최희규,이재현,최준우 한국입자에어로졸학회 2013 Particle and Aerosol Research Vol.9 No.1

New evaluation method for the particle size and morphology via change of ground particle during a grinding process was investigated. The grinding experiments were carried by a planetary ball mill. The relationship between the particle outline of the scanning electron microscopy photograph and measurement line, the measurement contact number was evaluated. The value of contact number decreased with the increase in the particle size of the ground sample, and varied with the experimental conditions. The value of contact number, which is related to the particle size of the raw sample, changed at the various experimental conditions.

Application of grinding kinetics analysis of inorganic powders by a stirred ball mill

최희규,Woong Lee,Seongsoo Kim,황진연 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6

The need for ultra fine particles has been increasing in the preparation field of raw powders such as fine ceramics and high functional products. A series of wet grinding experiments were carried out on inorganic powders such as calcite, pyrophyllite and talc by a stirred ball mill. The grinding rate constant K’ in the equation of grinding kinetics was examined based on the grinding kinetics analysis as the same type of function of a previous paper on a vertical type planetary ball mill. The experimental particle size distribution of the ground products was obtained in various grinding conditions. The grinding rate constants K and K' were expressed by empirical equation involving experimental conditions by a stirred ball mill. The empirical equation on the grinding rate constant was expressed in terms of a function involving the ball diameter of grinding balls, the median diameter of feed material, and Bond’s work index of material, in the experimental conditions. The values of empirical constants C1 and C2 were 21.13 and 0.0109 on K, while C1 and C2 were 120.99 and 0.0192 on K', respectively. And the particle size distribution of ground products of each test material for a given grinding time was found to be expressing the selection function (the specific rate of breakage) which was obtained from the grinding kinetics analysis. In this study, the grinding rate change on calcite and pyrophyllite was similar at the same experimental operation condition. However, in the case of talc, it was observed that the grinding rate was not increased compared with other samples.

초고속 유성형 매체 분쇄기를 이용한 건식분쇄공정에서 Al/CNTs 복합재 제조를 위한 알루미늄분말의 분쇄거동

최희규,이재현,김성수,최경필,배대형,이승백,이웅,Choi, Heekyu,Lee, Jehyun,Kim, Seongsoo,Choi, Gyungpil,Bae, Daehyung,Lee, Sungbak,Lee, Woong 한국재료학회 2013 한국재료학회지 Vol.23 No.2

The study of grinding behavior characteristics on aluminum powders and carbon nano tubes (CNTs) has recently gained scientific interest due to their useful effect in enhancing advanced nano materials and components, which significantly improves the property of new mechatronics integrated materials and components. We performed a series of dry grinding experiments using a planetary ball mill to systematically investigate the grinding behavior during Al/CNTs nano composite fabrication. This study focused on a comparative study of the various experimental conditions at several variations of rotation speeds, grinding time and with and without CNTs. The results were monitored for the particle size distribution, median diameter, crystal structure from XRD pattern and particle morphology at a given grinding time. It was observed that pure aluminum powders agglomerated with low rotation speed and completely enhanced powder agglomeration. However, Al/CNTs composites were achieved at maximum experiment conditions (350 rpm, 60 min.) of this study by a mechanical alloy process for Al/CNTs mixed powders because the grinding behavior of Al/CNTs composite powder was affected by addition of CNTs. Indeed, the powder morphology and crystal size of the composite powders changed more by an increase of grinding time and rotation speed.