• Title/Summary/Keyword: nano fiber

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The Development of High Performance Nano-composites with Carbon Nanotube (카본나노튜브를 이용한 고성능 나노복합재료의 개발 동향)

  • Lee, Min-Kyung;Bae, Soo Bin;Park, Jong Kyoo;Lee, Seung Geol
    • Textile Coloration and Finishing
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    • v.26 no.2
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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.

Feasibility Study of Laser Contact Angle Measurement for Nano-fiber Characterization (나노섬유의 특성분석을 위한 레이저 접촉각 측정기의 효율성 연구)

  • 신경인;안선훈;김성훈
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.5
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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.

On the thermo-mechanical vibration of an embedded short-fiber-reinforced nanobeam

  • Murat Akpinar;Busra Uzun;Mustafa Ozgur Yayli
    • Advances in nano research
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    • v.17 no.3
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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.

The Effect of Processing Parameters on the Diameter of Electrospun Polyacrylonitrile(PAN) Nano Fibers (전기방사한 폴리아크릴니트로 나노섬유의 직경에 미치는 공정인자의 영향)

  • 강영식;김학용;류영준;이덕래;박수진
    • Polymer(Korea)
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    • v.26 no.3
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    • pp.360-366
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    • 2002
  • The electrospinning of polyacrylonitrile dissolved in N,N-dimethyl formamide (DMF) successfully produced nano-scale fibers. The processing parameters such as charged voltage, velocity of collected roller, and tip-to-collector distance (TCD) , affected the ultimate fiber size. At TCD of 5 cm, the average tiber diameter increased with increasing charged voltage because of the more aggregation between fibers due to the remaining DMF solvent on the fiber surface. But, at TCD of 9 cm, the average fiber diameter decreased as the charged voltage was increased because of complete evaporation of DMF. Also, the fiber diameter decreased with increasing the velocity of collected roller. Cross direction width (CWD) of nonwoven mat increased with decreasing the charged voltage and with increasing TCD.

A Study on Material Properties of Composite Panel for Impact·Blast Resistance (방호·방폭 보강용 복합패널의 재료특성에 관한 연구)

  • Kim, Woonhak;Kang, Seokwon
    • Journal of the Society of Disaster Information
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    • v.12 no.4
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    • pp.373-380
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    • 2016
  • In order to develop composite fiber panels that can maximize the protection and blast resistance of the existing structures by improving lightweight, high-strength and fireproof performances of the single layer material of precast panels, the basic properties of the inner and outer covers that are mixed with aramid fibers (AF) and polyester fibers (PF) were evaluated in this study. Also, a basic study was performed on the performance of composite fiber panels by testing Nano-sized composite materials that are lightweight and excellent in fire resistance for their compressive strength, bending strength and tensile strength.

Interfacial Evaluation of Surface Treated Jute Fiber/Polypropylene Composites Before and After Hydration Using Micromechanical Test (미세역학적 시험법을 이용한 표면처리된 Jute 섬유 강화 폴리프로필렌 복합재료의 수화 전·후 계면물성 평가)

  • Kim, Pyung-Gee;Jang, Jung-Hoon;Park, Joung-Man;Hwang, Byung-Sun
    • Journal of Adhesion and Interface
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    • v.8 no.3
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    • pp.9-15
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    • 2007
  • The interfacial evaluation of surface modified Jute fiber/polypropylene (PP) composites before and after hydration was investigated using micromechanical test and dynamic contact angle measurement. The IFSS of alkaline and silane-treated Jute fiber/PP composites increased, whereas after hydration, the IFSS of the untreated, alkaline- and silane-treated Jute fibers/PP composites decreased due to swelled fibrils by water infiltration. The interfacial adhesion of silane treated fiber/PP composites was higher than alkaline-treated or the untreated cases. The surface energies of Jute fiber treated under various conditions were obtained using dynamic contact angle measurement. Especially after hydration, the thermodynamic work of adhesion was calculated by considering water interlayer, which indicated the stability of IFSS between silane treated Jute fiber and PP matrix showing better than others.

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Fracture resistance of endodontically treated maxillary premolars restored by silorane-based composite with or without fiber or nano-ionomer

  • Shafiei, Fereshteh;Tavangar, Maryam Sadat;Ghahramani, Yasamin;Fattah, Zahra
    • The Journal of Advanced Prosthodontics
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    • v.6 no.3
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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.