• Polymer(Korea)
• /
• v.31 no.3
• /
• pp.215-220
• /
• 2007

The control of the surface energy by electrohydrodynamic force provides electrospraying with various potential advantages such as simple particle size control, mono-dispersity, high recovery, and mild processing conditions. The advantages are quite helpful to improve the stability of protein drug and control its release. Herein, the nano-encapsulation of protein drugs using electrospraying was investigated. Albumin as a model protein was processed using uniaxial and co-axial electrospraying, and chitosan, polycaporlactone (PCL), and poly (ethylene glycol) (PEG) were used as encapsulation materials. The major processing parameters such as the conductivity of spraying liquids, flow rate, the distance of electrical potential gradient, etc were measured to obtain the maximum efficiency. In the chitosan systems, mean particles size decreases as flow rate and the distance between nozzle and the collecting part decreases. In the uniaxial technique of the PCL systems, mean particles size decreases as flow rate decreases. In the coaxial technique of the PCL systems, it was found that the particles size gets larger under the application of the higher ratio of inner-to-outer liquid flow rates. The primary particles formed out of an electrospraying nozzle showed narrow particle size distribution, but once they arrived to the collecting part, aggregation behavior was observed obviously. Efficient nano-encapsulation of albumin with PCL, PEG, and chitosan was conveniently achieved using electrospraying at above 12 kV.

• Polymer(Korea)
• /
• v.35 no.3
• /
• pp.254-259
• /
• 2011

In electrospraying of polymer solutions, metal sample collectors are often ineffective in fully removing solvent from sprayed particles and recovering redispersable sprayed particles. Herein, a novel electro spraying system, where sprayed particles were dispersed into laminar flow of dispersant (coagulation liquid), was designed for the nano-encapsulation of protein drugs. Chitosan and polyacrylic acid were used as the encapsulation materials. Aggregation of particles could be prevented by using this new electrospraying system, and unimodal size distribution was observed at an applied voltage between 4~16 kV and a low flow rate. The effects of the applied voltage on mean particle size were not significant on the other hand.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.179.1-179.1
• /
• 2005

• Plant Journal
• /
• v.16 no.1
• /
• pp.34-37
• /
• 2020

The need to improve the performance of the dust collector by increasing the fine dust pollution in Korea is eminent. In this study, electrostatic spray wet electrostatic precipitator is used to remove Particulate Matter (PM). In order to enter the Cone-jet mode, which is the most stable spray mode among the various modes of electrostatic spraying, an appropriate voltage-flow condition must be satisfied, and a voltage-flow interval enabling this can be expressed as Stability Island. The voltage at which the conduit mode starts in the Stability Island section is referred to as the electrostatic spray minimum voltage (Onset Voltage). However, the conventional electrostatic spray is uses a very low flowrate, at most few millilitres per minute. The use of much higher flowrates has introduced different patterns of electrospray modes. In this study, the different spray modes will be studied in detail.

• Polymer(Korea)
• /
• v.33 no.4
• /
• pp.353-357
• /
• 2009

Spray drying is an effective and stable process, which has been widely used to produce pharmaceutical powders. In the traditional spray drying process, it was not quite easy to control the aggregation and the size of particles. Particularly, the preparation of polymeric particles was relatively hard compared to the preparation of food and pharmaceutical ingredients, typically organic materials of small molecular weights. In this study, modification of a conventional spray dryer was tried to use electrical charge and co-axial nozzles to prepare polymeric particles. Poly(ethylene glycol) and poly (D,L-lactide-co-glycolide) were used as the inner polymeric materials, and lactose as the outer shell materials. The results showed that electrohydrodynamic spray-dried particles had a relatively uniform size and particle morphology, and the aggregation of particles could be suppressed compared to the conventional spray-dried particles. The electrohydrodynamic spray-dried powders consisted of spherical particles of $2{\sim}5{\mu}m$ diameters.

• Proceedings of the KIEE Conference
• /
• 2008.10c
• /
• pp.26-28
• /
• 2008

전기기기 제품, 부품의 부식을 검증하기 위해서 염수, 아황산가스, 암모니아 가스 등을 이용한다. 염수시험은 입수를 액체 분무형태로 생성하며, 시편이 부식되도록 일정한 양을 분무하고 시험조 내에 균일한 분포를 갖도록 조정할 필요가 있다 본 논문은 연수분무 시험장치의 주요 인자를 바탕으로 실험계획법을 적용하여 시험용액의 분포가 균질하도록 최적의 조건을 찾는 방법을 제시하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05b
• /
• pp.47-53
• /
• 2003

자발착화연소법과 분무열분해법을 동시에 적용한 초음파분무연소법을 이용하여 40~50nm 크기를 갖는 결정성 ZnO 분말을 합성하였다. 또한 바리스터로의 응용을 위해 Bi, Sb, Co, Mn을 초기출발원료인 Zn-nitrate에 첨가하여 복합조성의 ZnO계 바리스터 분말을 합성하였다. 합성된 바리스터의 분말을 성형 및 소결하여 전기적 특성을 관찰한 결과 Co를 첨가한 분말보다 Mn을 첨가한 분말에서 우수한 전기적 특성을 나타내었다.

• Journal of ILASS-Korea
• /
• v.11 no.3
• /
• pp.131-139
• /
• 2006

An experimental study was performed to investigate the liquid breakup and atomization characteristics in electrohydrodynamic atomization according to the changing of experimental parameters such as nozzle size, fluid flow, and electrical intensity. An original electrohydrodynamic atomizer equipment was designed and manufactured for the analysis of spray visualization and the exploration of relationship between applied power and the behavior of liquid atomization. The image processing technique by using the back-illumination method was applied to visualize the distilled liquid breakup process and to examine the variation of the droplet size distribution. The results show that the spray modes of electrohydrodynamic atomization are closelyconnected by the strength of the electric stresses at the surface of the liquid film and the kinetic energy of the liquid jet leaving the needle tip.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.25 no.3
• /
• pp.23-46
• /
• 1999

LC/MS는 HPLC의 분리능과 질량분석기의 화합물의 확인 능력을 결합시킨 기기이다. 여기서 사용되는 이온화 방법은 GCJMS에서 사용되어지는 전자이온화법(electron ionization, EI)이나, 화학이온화법(chemical ionization, CI)은 부적당하기 때문에 최근 개발되어진 연성 이온화법의 대표적인 고속원자폭격식(Fast atom bombardment, FAB)이나 전기분무이온화식 (electrospray ionization, ESI) 등이 사용되고 있다. 이중 전기분무이온화법은 고속원자폭격법에서 사용되는 매트릭스를 사용하지 않기 때문에 매트릭스 이온의 부재로 인한 낮은 바탕 신호, 오래 지속되면서 안정된 초기 이온 전류, 샘플링의 용이성, HPLC와의 더 좋은 호환성 등의 장점을 제공한다. 이러한 전기분무이온화 방법은 극성이 매우 크거나 휘발성이 낮은 물질로 보통의 EI나 CI 이온화 방법으로 분석이 어려운 물질들을 분석할 수 있다. 또한 열에 불안정하거나 분자의 분자량이 다른 단백질 등의 분석도 가능하다. 이러한 LC/ESI/MS 방법을 이용하여 열에 불안정하고 극성이면서 분자량이 커서 GC/MS 펄의 분석이 어려운 기능성 화장품 원료로 주목받고 있고 생체에 존재하는 지질 성분으로 알려진 레시틴과 세라마이드의 분석이 가능함을 소개하고 분리와 동시에 그 분자량과 구조에 대한 정보를 빠르게 얻을 수 있음을 소개하였다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.115-115
• /
• 2011

최근 유기물을 사용한 유기 태양 전지의 주된 제작 방식은 유기물질을 유기용매에 녹여 사용 하는 스핀코팅 방식이다. 스핀코팅은 박막 형성이 쉽고 대량생산이 용이하다는 장점이 있지만, 표면분석의 측면에서 보면 박막이 한번에 형성되기 때문에 전극 위에 유기물질이 박막을 형성하는 순간의 계면을 측정하기 어렵다. 그에 반해 진공전기분무 방식은 진공에서 얇은 박막에서부터 점차적으로 두께를 늘려가며 증착 할 수 있고 또한 증착이 진공에서 이루어져서 불순물을 최소화 할 수 있기 때문에 표면분석의 측면에서 용이하다. 특히 본 실험에서는 유기 태양전지에서 벌크 이질접합(bulk heterojunction)을 만드는데 널리 쓰이는 물질인 Poly(3-hexythiophene) (P3HT)과 (PCBM)을 toluene에 녹인 후(0.2 mg/ml), 4-5 kV 사이의 전압을 인가하여, 고전압을 걸어 준 뒤 $5{\times}10^{-6}$ torr의 조건에서 분무하여 Indium Tin Oxide (ITO) 위에 박막의 두께를 늘려가며 증착시켰다. 이렇게 ITO 위에 만들어진 P3HT와 PCBM의 박막을 Photoemission spectroscopic (PES)을 이용하여 따른 화학적 구조와 전자구조를 분석하였고, 또한 동일한 농도의 용액으로 스핀코팅 방법을 이용하여 만든 시료와 앞서 언급한 조건의 진공전기분무 방법을 이용하여 만든 시료 사이의 표면거칠기와 morphology는 Atomic Force Microscopy(AFM)을 이용하여 비교 분석하였다.