• 한국염색가공학회지
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• 제26권2호
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• pp.71-78
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• 2014

This review paper is a state of the art report of the development of high performance nano-composites with carbon nanotube. We investigate the research and development (R&D) trends of high performance nano-composites with carbon nanotube by analyzing technical trends in research institutes and industry. We report the R&D and technology trends for the properties and applications of fabrication of hybrid composites with aligned carbon nanotubes, multifunctional fiber/carbon nanotube composites. We discuss the specific topics including unidirectional carbon nanotube, carbon nanotube forests, transfer-printing carbon nanotube technology, deposition of carbon nanotube by electrophoresis, vapor grown carbon fiber (VGCF), cup-stacked carbon nanotube, bucky paper and carbon nanotube yarns in this review paper.

• 한국의류학회지
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• 제27권5호
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• pp.554-559
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• 2003

A newly developed contact angle measurement instrument by laser beam projection allows for rapid and direct determination of contact angles. The instrument may have a possibility to characterize newly developed nano-fibers. When the laser beam impinges on an edge of an interface of liquid and solid, projected beam were split across and made two straight lines on a tangent screen. From the result, it could measure the contact angle directly by reading the angle between two split beams. The purpose of this study was to prove reliability and reproducibility of the contact angle measurement instrument by laser beam projection compare to the conventional one by microscope through the comparative experiment and questionnaire. Test samples were selected by consideration of hydrophilic and hydrophobic, such as nylon 6 and polypropylene, respectively. The laser contact angle measurement has accurate, fast and convenient method to measure contact angle, and it can be a unique method to characterize nano-fibers.

• Advances in nano research
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• 제17권3호
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• pp.197-211
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• 2024

This work investigates the thermo-mechanical vibration frequencies of an embedded composite nano-beam restrained with elastic springs at both ends. Composite nanobeam consists of a matrix and short fibers as reinforcement elements placed inside the matrix. An approach based on Fourier sine series and Stokes' transform is adopted to present a general solution that can examine the elastic boundary conditions of the short-fiber-reinforced nanobeam considered with the Halpin-Tsai model. In addition to the elastic medium effect considered by the Winkler model, the size effect is also considered on the basis of nonlocal strain gradient theory. After creating an eigenvalue problem that includes all the mentioned parameters, this problem is solved to examine the effects of fiber and matrix properties, size parameters, Winkler stiffness and temperature change. The numerical results obtained at the end of the study show that increasing the rigidity of the Winkler foundation, the ratio of fiber length to diameter and the ratio of fiber Young's modulus to matrix Young's modulus increase the frequencies. However, thermal loads acting in the positive direction and an increase in the ratio of fiber mass density to matrix mass density lead to a decrease in frequencies. In this study, it is clear from the eigenvalue solution calculating the frequencies of thermally loaded embbeded short-fiber-reinforced nanobeams that changing the stiffness of the deformable springs provides frequency control while keeping the other properties of the nanobeam constant.

• 폴리머
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• 제26권3호
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• pp.360-366
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• 2002

N,N-dimethyl formamide (DMF) 용매에 용해시킨 폴리아크릴로니트릴 용액을 사용하여 전기방사를 통하여 나노섬유를 제조하였다. 전기방사의 공정인자인 집속롤러 속도, 방사거리, 전압이 나노섬유 직경에 미치는 영향을 알아보았다. 방사거리가 5 cm인 경우에는 섬유 표면에서 DMF 용매가 모두 증발되지 못하여 섬유끼리 뭉치는 현상이 발생하여 평균 섬유 직경이 전압이 증가함에 따라 증가하였다. 그러나 방사거리가 9 cm에서는 DMF 용매가 완전히 증발하여 전압이 증가함에 따라 평균 섬유 직경은 감소하였다. 또한 집속롤러 속도가 증가함에 따라 섬유 직경은 감소하였고 가로방향의 부직포 폭은 전압이 감소함에 따라 그리고 방사거리가 증가함에 따라 증가하였다.

• 한국재난정보학회 논문집
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• 제12권4호
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• pp.373-380
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• 2016

본 연구에서는 기존 구조물의 방호 방폭에 대한 보강 방법으로서 프리캐스트 패널의 단층구성 재료에 경량성, 고강도, 내화성능 등을 향상시켜 단층 각각의 개별적인 특수성능과 복합적인 패널 구성물로서 방호 방폭 성능을 극대화 할 수 있는 복합섬유 패널을 제작하기 위해, 아라미드섬유(Aramid Fiber, 이하 AF)와 폴리에스터섬유(Polyester Fiber, 이하 PF)로 혼합된 내피와 외피의 기초물성을 평가하였다. 또한, 내화성능이 우수하고 경량인 Nano size의 복합소재를 이용한 충전재의 압축강도, 휨강도, 인장강도를 평가하여 복합섬유패널의 성능에 대한 기초 연구를 수행하였다.

• 접착 및 계면
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• 제8권3호
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• pp.9-15
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• 2007

표면처리에 따른 Jute 섬유 강화 폴리프로필렌 복합재료의 수화 전 후 계면 물성을 미세역학시험과 동적 접촉각으로 평가하였다. 알칼리 및 실란 커플링제 용액으로 Jute 섬유의 표면을 처리함으로 Jute 섬유와 폴리프로필렌 기지재 사이의 계면전단강도가 증가를 하였으며, 수화 이후 미처리, 알칼리 그리고 실란 커플링제 용액으로 표면처리된 Jute 섬유와 기지재 사이의 계면전단강도는 수분침투에 의해 감소하였다. 실란 커플링제 용액으로 표면처리된 Jute 섬유와 폴리프로필렌 기지재 사이의 계면전단강도는 알칼리 용액 및 미처리의 경우에 비해 높았다. 미처리, 실란 커플링제 및 알칼리 용액 처리된 Jute 섬유의 표면에너지는 동적 접촉각 측정을 통해 계산되어졌다. 수화 이후의 열역학적 접착일은 섬유와 기지재 사이의 물 중간층을 고려하여 계산하였다. 계산되어진 결과를 통해 실란 커플링제 용액으로 표면처리된 Jute 섬유와 폴리프로필렌 계면 사이가 가장 안정한 것으로 나타났다.

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.200-206
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• 2014

PURPOSE. This in vitro study investigated the fracture resistance of endodontically treated premolars restored using silorane-or methacrylate-based composite along with or without fiber or nano-ionomer base. MATERIALS AND METHODS. Ninety-six intact maxillary premolars were randomly divided into eight groups (n = 12). G1 (negative control) was the intact teeth. In Groups 2-8, root canal treatment with mesio-occlusodistal preparation was performed. G2 (positive control) was kept unrestored. The other groups were restored using composite resin as follows: G3, methacrylate-based composite (Z250); G4, methacrylate composite (Z250) with polyethylene fiber; G5 and G6, silorane-based composite (Filtek P90) without and with the fiber, respectively; G7 and G8, methacrylate-and silorane-based composite with nano-ionomer base, respectively. After aging period and thermocycling for 1000 cycles, fracture strength was tested and fracture patterns were inspected. The results were analyzed using ANOVA and Tukey HSD tests (${\alpha}$=0.05). RESULTS. Mean fracture resistance for the eight groups (in Newton) were G1: $1200{\pm}169^a$, G2: $360{\pm}93^b$, G3: $632{\pm}196^c$, G4: $692{\pm}195^c$, G5: $917{\pm}159^d$, G6: $1013{\pm}125^{ad}$, G7: $959{\pm}148^d$, G8: $947{\pm}105^d$ (different superscript letters revealed significant difference among groups). Most of the fractures in all the groups were restorable, except Group 3. CONCLUSION. Silorane-based composite revealed significantly higher strength of the restored premolars compared to that of methacrylate one. Fiber insertion demonstrated no additional effect on the strength of both composite restorations; however, it increased the prevalence of restorable fracture of methacrylate-based composite restored teeth. Using nano-ionomer base under methacrylate-based composite had a positive effect on fracture resistance and pattern. Only fiber-reinforced silorane composite restoration resulted in a strength similar to that of the intact teeth.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.231-232
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• 2007

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.293-294
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• 2007

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.431-432
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• 2007

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