• Journal of Plant Biotechnology
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• v.49 no.3
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• pp.257-270
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• 2022

The aim of this work was to prepare a new biodegradable polyhydroxybutyrate (PHB) submicron fiber mat loaded with hypericin-rich Hypericum perforatum raw extract by centrifugal spinning technology, an alternative approach to the traditional method of electrospinning to fabricate nanofibers or microfibers from solutions at high speed and low cost. Hypericins in methanol/acetone extract of H. perforatum were determined by UHPLC-MS/MS and HPLC/PDA. Submicron fiber mats composed of pure PHB or PHB enriched with H. perforatum extract were prepared using a pilot plant demonstrator for the centrifugal spinning technology and characterized by SEM. Singlet oxygen production was quantified by the 1,3-diphenylisobenzofuran (DPIBF) method in hexane. The results proved a significant production of singlet oxygen by the prepared submicron fiber mat. We also found a significant antibacterial activity against the bacterial strain Escherichia coli CCM 5417 by a method in accordance with JIS Z 2801/ISO 22196 standards. The H. perforatum extract-enriched PHB submicron fiber mats showed potential for the development of self-cleaning and antimicrobial air filters.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.259-268
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• 2001

In this study, we have developed a simulation method to predict the initial collection efficiency of a unipolar charged fiber in the electret filters. The particle sizes considered were in the submicron range and thus Brownian motion of particles was also taken into consideration along with electrostatic forces acting on the particles. The simulation results were compared with other investigators experimental data on single fiber efficiency as well as with the calculated results using the existing correlations on single fiber efficiency. It has been shown that simulation results are in good agreement both with the experimental data with those predicted by the correlations.

• Journal of the Korean Applied Science and Technology
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• v.31 no.1
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• pp.59-65
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• 2014

Indoor air quality including metro subway is of recent interests in large cities. Inflow air to the inside of the train and circulating air flow through MVAC of stations contain large amount of iron based fine particles. This paper evaluated the collection of such a dust by magnetic filters as comparing to conventional particle capturing mechanisms such as inertia, direct impaction and diffusion. It was found that filtration velocity, magnetic field intensity, and fiber size were the most important parameters for magnetic filtration. Application of magnetic force obviously enhances the collection efficiency particularly in fine modes smaller than 10 mm. However, its effect was found greater in 2.5 mm than submicron particles.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.376-377
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• 2003

전기방사(electrospinning)는 최근 나노기술의 대두와 함께 서브마이크론(submicron)의 직경을 가지는 섬유를 제조할 수 있는 방법으로 활발한 연구가 진행되고 있는 실정이다[1]. 이러한 전기방사는 고분자 용액이나 용융된 고분자에 고전압을 걸어주어, 모세관 팁과 웹을 받아주는 컬렉터(collector) 사이에 전기장을 형성시켜 섬유를 제조하는 방법이다. 열가소성 폴리우레탄은 우수한 탄성을 갖는 유용한 고분자중의 하나로 섬유나 플라스틱에 널리 사용되고 있다. 특히, 이는 고무에 비하여 탄성률이 높고 내마모성이 강하며 용매에 대한 저항성이 좋은 장점을 지니고 있다[2]. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.465-466
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• 1999

섬유층 여과기(fibrous filter)는 일반적으로 공기여과기(air filter) 라고 불리는 여과기로 fiber의 직경, filter의 두께, 공극률, 하전 여부에 따라 그 용도가 다양하다. 전하를 가진 섬유로 제조한 정전 필터는 장시간 사용시에 일반 섬유층 필터에 비해 작은 압력강하와 높은 집진 효율을 나타내기 때문에 성능과 수명이 증가한다.(중략)

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.271-272
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• 2003

Electrospinning is a novel process for forming fibers with submicron scale diameters through the action of electrical force. In the previous study, we performed study on the ultrafine PVDF nanofiber production in the stable spinning condition. Recently it would be great interest to fabricate IP(inorganic particle) assemblies in nanofibe. since such IP/nanofiber hybrid materials might be used in a nonwoven form as nanowires, medical gauges for bums healing and cell growing, sensors, chemical and gas filteration. (omitted)

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.95-97
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• 2003

전기방사는 submicron 이하 크기의 섬유를 부직포형태인 3차원으로 적층된 웹상으로 얻을 수 있는 방법으로 최근 많은 연구가 되고 있다[1-3]. 전통적인 방사방법인 용융방사와 melt blown 방사 방법으로 제조되는 피치계 탄소섬유는 우수한 방사성을 갖는 프리커서 피치를 이용해야 하고 이러한 방법으로 제조되는 탄소섬유나 활성탄소 섬유는 주로 직경 10-15 um 내외의 것이 대부분이어서 상대적으로 직경이 크기 때문에 굽힘 강도가 낮아 압축가공이 취약하다. (중략)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.105-109
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• 2001

The micro optical parts such as ferrules are required to be manufactured within very small tolerances, as the slight deviation of the tolerance would give very large amount of loss in communication efficiency. For efficient optical communication, outer diameter, fiber diameter, fiber separation and eccentricity are significant parameters to be inspected., Thus we developed an automatic inspection system to evaluate shape parameters of the optical fiber connectors(ferrule) upto submicron accuracy using machine vision. new optical probe of multi fields of views has been developed and the image processing and data analysis algorithms have been complemented in real time basis. The developed system is successfully used in the practical ferrule manufacturing industry, and about 0.1$\mu\textrm{m}$ accuracy can be obtained with very fast inspection time.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.265-266
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• 2003

The first developed engineering plastic and synthetic fiber, Nylon has been widely used because of its excellent properties. Recently, electrospinning has been gradually spotlighted as a different method of producing fibers, in which fibers of submicron can be consistently produced [1,2]. In this work, we have prepared nanofiber non-woven from Nylon 66 of which properties were investigated. The morphological properties of Nylon 66 non-woven was observed by SEM. (omitted)

• Particle and aerosol research
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• v.10 no.2
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• pp.45-51
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• 2014

Fine particle capture is facing a challenge since traditional filtration which relies on the combination of impaction, interception, diffusion has a limited efficiency for fine particle capture particularly in size from 0.1 to $0.5{\mu}m$. This paper reviewed the collection efficiency of above mechanisms, as well as magnetic mechanisms for ferromagnetic particles, and mainly studied the influencing factors of magnetic filtration. Filtration velocity, magnetic field intensity and fiber size were found to be the most important parameters for magnetic filtration.