• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2A
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• pp.249-257
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• 2008

Various methods have been used to reinforce the cementitious material such as mortar and concrete that have weak tensile strength. Major reinforcing method is to mix matrix with fibers which have strong tensile strength. Recently, micro-fiber reinforced mortar has been studied which removes coarse aggregate and uses micro-fiber with small diameter in order to homogenize the matrix properties and maximize the performance of fiber. Performance of micro-fiber reinforced mortar showing multiple cracking behavior is hardly represented only by the flexural toughness. Therefore, This paper reports the cracking behavior as well as mechanical behavior for various mixtures which have different fiber type and mixture proportions to find the proper parameter representing the cracking characteristic. Correlations between flexural toughness and various cracking characteristics such as cracking area, width and number are explored. As a result, it is found that flexural toughness, volume of fiber and number of cracks are suitable for representing the characteristics of micro-fiber reinforced mortar.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.417-420
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• 2002

마이크로 캡슐에 관한 연구는 벽 혹은 내부 물질의 성질, 캡슐화의 방법, 내부 구성물질의 내구성과 안정성 그리고, 확산, 투과, 부식, 용해등에 의한 유출현상등을 중심으로 진행되어 왔으며$^{1.2}$ , 1980년대 후반부터 섬유의 열적 성능을 개선하고자 캡슐화된 상전이 물질을 이용한 연구들이 시작 되었다[3-4]. 본 연구에서는 온도 조절 기능을 가지고 온도 감응형 섬유로의 적용을 위하여 상전이 물질(phase change materials: PCMs)을 함유하는 마이크로 캡슐을 제조하여 그 특성을 분석하고자 하였다. (중략)

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.293-294
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• 2003

견 피브로인은 대표적인 섬유상 단백질의 하나로 생체적합성, 생분해성, 저독성 등의 유용한 특성을 가지므로 생체재료로 상당한 관심과 연구의 대상이 되어왔다. 우리는 최근의 연구에서 견 피브로인을 생사로부터 추출한 다음, 포름산을 용제로 하여 전기방사함으로써 나노섬유를 제조하고 이들의 각화세포에 대한 친화력을 확인한 바 있다. 본 연구에서는 견 피브로인의 구조체를 나노섬유 부직포, 필름, 마이크로 섬유로 구성된 직물 둥의 형태로 하여 그들의 2차 구조를 비교함과 동시에 구조적 특성이 각화세포와의 친화력에 어떠한 영향을 미치는 가를 비교ㆍ검토 하고자 하였다. (중략)

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.263-271
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• 2005

HPFRCC(High Performance Fiber Reinforced Cementitious Composite) is a class of FRCCs(Fiber Reinforced Cementitious Composites) that exhibit multiple cracking. Multiple cracking leads to improvement in properties such as ductility, toughness, fracture energy, strain hardening, strain capacity, and deformation capacity under tension, compression, and bending. These improved properties of HPFRCCs have triggered unique and versatile structural applications, including damage reduction, damage tolerance, energy absorption, crack distribution, deformation compatibility, and delamination resistance. These mechanical properties of HPFRCCs become different from the kinds and shapes of used fiber, and it is known that the effective size of fiber in macro crack is different from that in micro crack. This paper reports an experimental findings on the mechanical properties of HPFRCCs reinforced with the micro fiber(PP50, PVA100 and PVA200) and macro fiber(PVA660, SF500). Uniaxial compressive tests and three point bending tests are carried out in order to compare with the mechanical properties of HPFRCCs reinforced with micro fibers or hybrid fibers such as compressive strength, ultimate bending stress, toughness, deformation capacity and crack pattern under bending, etc.,

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.470-474
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• 2010

In this study, we presents a simple microfluidic approach for generating uniform Poly(ethylene glycol)(PEG) microfiber. Elongated flow pattern of monomer induced by sheath flow of immiscible oil as continuous phase is generated in Y-shape junction and in situ polymerization by UV exposure. For uniform microfiber, we investigate the optimized flow condition and draw phase diagram as function of Ca and Qd. At the region for stable elongated flow pattern, the microfiber generated in microfluidic chip is very uniform and highly reproducible. Importantly, the thickness of microfibers can be easily controlled by flow rate of continuous and disperse phase. We also demonstrate the feasibility for biological application as encapsulating FITC-BSA in PEG microfiber.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.58-58
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• 2011

현 의류 섬유산업의 트렌드는 친환경, 무공해, 인체친화, 고감성, 고급스러움 등을 표현할 수 있는 제품으로의 전환이 이루어지고 있으며, 최근 부드럽고, 편안하고, 모던한 특징 및 내추럴한 느낌을 나타내는 천연섬유에 대한 요구가 더욱 늘어나고 있다. 양모 섬유는 천염섬유 중 많은 비중을 차지하고 있는 단백질 섬유로서, 이를 이용한 다양한 직물과 의류제품은 국내외적으로 유명 브랜드 바이어와 지속적으로 내수와 수출이 이루어지는 대표적 섬유이다. 그러나 양모 소재에 특유의 구조와 형태로 소재간 섬도차로 인해 고급섬유에의 복합시 물리적, 감성적 이질감으로 상품화가 제한되고 있으며, 소비자 및 바이어들은 기존 보다 더욱 부드러운 고급감의 양모소재를 선호하고 있다. 이에 천염섬유 중에서도 세섬도 생산의 한계가 있는 양모섬유에 대해 양모섬유의 끝단을 마이크로 분활화 및 세섬화를 가능하게 함으로서 새로운 고감성 및 고급감을 부여할 수 있을 것이며, 본 연구에서는 산 및 초음파 등의 물리화학적 분할 기술을 적용하여 부분적 피브릴화 세섬화된 양모소재에 대한 염가공 특성을 기존 양모소재와 비교 함으로서 개질 양모소재의 제품화 실용성 여부를 검토하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.875-880
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• 2014

Recently, three-dimensional scaffolds and nanofibers are being developed for bone tissue regeneration. In this study, we fabricated a hybrid scaffold using a nano-micro precision deposition system. The fabrication process involved the application of the solid freeform fabrication (SFF) technology and electrospinning. The hybrid scaffolds were combined using micro scaffolds and nanofibers. The nanofibers were deposited on each layer of the micro scaffolding using the electrospinning process. The micro scaffolds were fabricated using the SFF technology at a temperature of $100^{\circ}C$, pressure of 650 kPa, and scan velocity of 250 mm/s. Nanofiber fabrication was conducted by means of electrospinning using the flow rate, solution concentration, distance from the tip to the collector (TCD), and voltage. The nanofibers were fabricated using a flow rate of 0.1 ml/min, voltage of 5 kV, TCD of 1 mm, and 10 wt% of solution concentration. MG-63 cells were seeded into the hybrid scaffold for the purpose of its evaluation.

• Proceedings of the Korean Fiber Society Conference
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• 2001.04a
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• pp.347-350
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• 2001

• Proceedings of the Korean Fiber Society Conference
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• 1996.04a
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• pp.171-172
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• 1996

• The Optical Journal
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• s.173
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• pp.31-32
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• 2019