http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Sensitivity of nanoparticles’ stability at the point of zero charge (PZC)
엄하늬,김영훈 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5
Since bare-nanoparticles (NPs) without stabilizers in aqueous phase are stabilized by electrostatic forces, pH control is easily used to influence the surface charge and hence the formation of aggregates or agglomerates. Therefore, herein, the sensitivity of bare-NPs’ stability in aqueous phase was analyzed close to the point of zero charge (PZC) using six model NPs. The results demonstrated that the sensitivity of NPs’ agglomeration/aggregation could be estimated by the diameter ratio (RD) between the primary and secondary particle sizes. Namely, if the primary particle size was almost identical to the hydrodynamic diameter (HDD), the agglomeration proceeded aggressively.
엄하늬,김영훈 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12
With continuing progress of nanotechnologies and various applications of nanoparticles, one needs to develop a quick and fairly standard assessment tool to evaluate cytotoxicity of nanoparticles. However, much cytotoxicity studies on the interpretation of the interaction between nanoparticles and cells are non-mechanistic and time-consuming. Here, we propose a simple screening method for the analysis of the interaction between several AgNPs (5.3 to 64 nm) and fluorescence-dye containing vesicles (12 μm) acting as a biomimetic cellmembrane. Fluorescence-dye containing vesicle was prepared using a fluorescence probe (1,6-diphenyl-1,3,5- hexatryene), which was intercalated into the lipid bilayer due to their hydrophobicity. Zeta potential of all materials except for bare-AgNPs (+32.8 mV) was negative (−26 to −54 mV). The morphological change (i.e., rupture and fusion of vesicle, and release of dye) after mixing of the vesicle and AgNPs was observed by fluorescence microscopy, and fluorescence image were different with coating materials and surface charge of x-AgNPs. In the results, we found that the surface charge of nanoparticles is the key factor for vesicle rupture and fusion. This proposed method might be useful for analyzing the cytotoxicity of nanoparticles with cellmembranes instead of in vitro or in vivo cytotoxicity tests.
엄하늬,김영훈 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.6
It is well-known that silver nanoparticles (AgNPs) with 1–10 nm of diameter attached to the surface of cell membrane were able to penetrate into the cell followed by rupturing of the cell. However, most studies for cytotoxicity used living organisms and were time-consuming. Therefore, in this study, we proposed a model method for fingerprinting of nanotoxicity of AgNPs in mimetic cell membranes using phosphor lipid. The vesicle rupturing mechanism by AgNPs attack was investigated using surface plasmon resonance (SPR) spectroscopy and atomic force microscopy (AFM).
엄하늬 ( Ha Nee Umh ),노진규 ( Jin Kyu Roh ),이병천 ( Byoung Cheun Lee ),박수민 ( Su Min Park ),이종협 ( Jong Heop Yi ),김영훈 ( Young Hun Kim ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.6
Recent rapidly growth in nanotechnolgies is promised novel benefits through the exploitation of their unique industrial and biomedical applications. With increasing utilization of nanomaterials in consumer products, the potential release of nanomaterials into the environment and their impacts on the ecosystem and human health have been the issues of concern, Nanomaterials that was exposed unintentionally in environment might be accumulated in various environmental media, and finally it will be influenced to human and ecosystems. Therefore, it is important to understand the fate and behavior of nanoparticles for understanding effects on environmental media (air, water, and soil phase). Therefore, in this work, we investigated the several cases for environmental exposure of nanomaterials and suggested the direction of further research. In workplace, exposure to air media is dominant, but finally waste and wastewater was moved to the water and soil phase. In addition, we found the existing sewage treatment plant was not suitable to remove completely nanomaterials in wastewater flow. To deeper study, environmental monitoring tool must be developed additionally and we suggested the several analyzing method for aged and pristine physicochemical properties of nanomaterials exposed into environmental media. This review for nanomaterials` exposure to environmental media will be helpful to investigate the envrionmental fate of nanomaterials and define the suitable treatment method for nano-waste.
엄하늬 ( Ha Nee Umh ),노진규 ( Jin Kyu Roh ),박준수 ( Jun Su Park ),곽병규 ( Byoung Kyu Kwak ),이병천 ( Byung Cheon Lee ),최경희 ( Kyung Hee Choi ),이종협 ( Jong Heop Yi ),김영훈 ( Young Hun Kim ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.1
나노기술의 발전과 함께 나노물질을 포함한 소비재가 대중화되고 있다. 그러나 지난 10여년간 조심스럽게 제기되고 있는 나노물질의 잠재적 위해성으로 인해, 나노제품 사용을 불안해하고 있다. 특히 나노제품을 직접 취급하는 생산시설(연구소 및 업체)의 작업자는 직접적인 인체 노출을 초래하게 된다. 따라서 이들에 대한 인체 및 환경 노출 안전관리를 위하여, 직접적인 노출평가가 필요하다. 본 연구에서는 기상 및 액상 반응을 통해 나노물질을 생산하는 두 곳의 업체를 현장 방문하여 나노물질의 주요 노출대상 공정과 노출원을 파악하고 SMPS를 이용한 실시간 현장 모니터링을 실시하였다. 분석 결과, 액상 공정도 기상으로의 나노입자 노출이 심각하게 발생하고 있음을 확인하였다. 가장 문제가 되는 점은 나노물질의 잠재적인 위해성에 관한 인식의 부족으로 제대로 된 방호활동을 못하고 있다는 점이다. 따라서 보다 다양한 나노물질 취급 시설에 대한 환경노출 평가가 필요하고 이를 바탕으로 한 나노물질 취급 안전관리 방법이 제시되어야 한다.
Physicochemical properties between pristine and aged AgNPs for the evaluation of nanotoxicity
최중소,엄하늬,심재훈,신현호,김영훈 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.6
The use of nanomaterials in industrial and commercial applications is growing, and official reports concerning the possible environmental and health effects of nanoparticles are steadily increasing. An understanding of the potential toxicity of nanomaterials is important for creating sustainable and safe nanotechnologies. To test the cytotoxicity of nanomaterials, quantitative and qualitative analyses of raw nanomaterials should be priorities. However, the fundamental properties of raw materials will change compared to those of aged materials in biological media due to the interaction between nanomaterials and media composition. Therefore, the correlation and interdependence between pristine physicochemical properties (PChem) of raw nanomaterials before the toxicity test and aged PChem in biological media were evaluated using modified test guidelines originally suggested by the OECD WPMN (Organization for Economic Cooperation and Development, Working Party on Manufactured Nanomaterials) for peer-reviewed papers concerning silver nanoparticles, during the period of 2005 to 2010. In addition, we investigated whether the suggested analysis tools are applicable to define the PChem of AgNPs with regard to cytotoxicity.
Regeneration of aged-AgNPs via density gradient ultracentrifugal nanoseparation
심재훈,엄하늬,신현호,성화경,이병천,오승연,김영훈,Rengaraj Selvaraj 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5
To reuse aged-silver nanoparticles (AgNPs) and recover the mono-dispersed AgNPs separately, we attempted to recycle the aged-AgNPs with high polydispersity in particle size distribution using the density gradient ultracentrifugation rate (DGUR) separation with five media. Results for the microscopic and spectroscopic showed that Tween series media, which have low density compared to other media, are suitable for the application of DGUR separation for recycling aged-AgNPs. This method might be helpful to regenerate and recycle the precious metal nanoparticles with polydispersity due to long-term storage.
우은석,엄하늬,박대원,임동하 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
In recent years, hydrogen energy is considered as an alternative energy to solve the depletion of fossil fuel. Steam Methane Reforming (SMR) is widely known as cost-effective method for hydrogen production. Ni catalyst with best activity is widely used for SMR reaction. However, It has severe problems such as carbon coking and sintering at high reaction temperature resulting in reducing the SMR performance. In this study, we developed the Ni-La catalyst supported on hierarchically alumina to prevent catalyst deactivation for enhancing durability. The optimum content of La was added in Ni catalyst with best catalytic performance for high hydrogen production. The as-prepared Ni-La showed high mass transfer capacity and minimizing carbon coking and sintering of Ni, resulting in enhancing catalytic activity and durability.