• Title/Summary/Keyword: 나노-UTM

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Measurement of Tensile and Bending Properties of Nanohoneycomb Structures (나노허니컴 구조물의 인장 및 굽힘 물성 측정)

  • Jeon, Ji-Hoon;Choi, Duk-Hyun;Lee, Pyung-Soo;Lee, Kun-Hong;Park, Hyun-Chul;Hwang, Woon-Bong
    • Composites Research
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    • v.19 no.6
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    • pp.23-31
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    • 2006
  • We measured mechanical properties, including Young's modulus, effective bending modulus and nominal fracture strength of nanohoneycomb structures using an Atomic Force Microscope(AFM) and a Nano-Universal Testing Machine(UTM). Anodic aluminum oxide(AAO) films are well suited as nanohoneycomb structures because of the simple fabrication process, high aspect ratio, self-ordered hexagonal pore structure, and simple control of pore dimensions. Bending tests were carried out for cantilever structures by pressing AFM tips, and the results were compared with three-point bending tests and tensile tests using a Nano-UTM. One side of the AAO films is clogged by harrier layers, and looks like a face material of conventional sandwich structures. Analysis of this layer showed that it did not influence the bending rigidity, and was just a crack tip. The present results can act as a design guideline in applications of nanohoneycomb structures.

Manufacture and Mechanical Properties of Carbon Nanofiber Reinforced Hybrid Composites (탄소나노섬유가 강화된 하이브리드 복합재료의 제조 및 기계적 특성)

  • Chung Sang-Su;Park Ji-Sang;Kim Tae-Wook;Kong Jin-Woo
    • Composites Research
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    • v.18 no.3
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    • pp.1-6
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    • 2005
  • Carbon nanofiber exhibits superior and of ien unique characteristics of mechanical, electrical, chemical and thermal properties. Despite of the excellent properties of carbon nanofiber, the properties of carbon nanofiber filled polymer composites were not increased largely. The reason is that it is still difficult to ensure the uniform dispersion of carbon nanofiber in a polymer matrix. In this study, for improvement of the mechanical properties of composites, carbon nanofiber reinforced hybrid composites was investigated. For the dispersion of carbon nanofiber. solution blending method using ultrasonic was used. Dispersion of carbon nanoifiber was observed by scanning electron microscope (SEH). Mechanical properties were measured by universal testing machine(UTM).

Synthesis and Properties of Environmentally-friendly Aqueous Polyurethane Dispersion/Clay nanocomposites (환경친화적 수분산성 폴리우레탄/Clay 나노복합체의 제조 및 물성에 관한 연구)

  • Dan, Cheol Ho;Kim, Jeong Ho
    • Clean Technology
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    • v.12 no.1
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    • pp.11-18
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    • 2006
  • In this study, aqueous polyurethane dispersion(PUD) was synthesized using polyhexamethylene carbonate glycol (PHMCG) as soft segment, isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as hard segment. Also, polyurethane/clay nanocomposites were prepared by adding pristine montmorillonite (PM) and organically modified clays, C15A and C30B into PUD. The degree of clay dispersion in the nanocomposites was investigated using XRD and the physical and thermal properties were examined through UTM and TGA. These results showed that nanocomposites with C15A gave higher physical and thermal properties than those with C30B or PM. As a result, the properties of nanocomposites were observed to vary depending on the types of clay modifiers and clay contents.

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Synthesis of Polyurethane Nanocomposite Filled Inorganic Particles and Their Properties (무기입자를 충전한 폴리우레탄 나노복합체의 합성 및 물성)

  • Son, Bok-Gi;Hwang, Taek-Sung
    • Polymer(Korea)
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    • v.31 no.5
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    • pp.379-384
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    • 2007
  • The nanocomposites with inorganic nano powder, improved thermal stability, were prepared by urethane polymerization. The structure and surface properties of the nanocomposites were determined by X-ray diffraction and FT-IR, respectively. The thermal stabilities were studied using TGA and DSC. Their morphologies and mechanical properties were observed by SEM and UTM. As a result, the nanocomposites with MMT led to the increase of the silicate layers. The distance between layers of the nanacomposites with MMT was increased by $7.5{\AA}$ and the new peaks at $1038cm^{-1}$ were shown in the presence of the Si-O groups on the silica. The thermal stabilities of the nanocomposites were higher than those of pore polyurethane matrix. The nanocomposites had higher in mechanical properties than the pure polyurethane matrix.

A Study on the Mechanical Properties of Organo-clay Filled NR/MMT Nanocomposites (Organo-Clay를 이용한 NR/MMT 나노복합체의 기계적 물성에 관한 연구)

  • Oh, Woo-Taek;Lee, Eun-Kyoung;Choi, Sei-Young
    • Elastomers and Composites
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    • v.44 no.4
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    • pp.455-465
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    • 2009
  • In this study, Organo-montmorillonite(MMT) was synthesized by intercalation of various amine(Octylamine, Dodecylamine, Dimethyldodecylamine, Octadecylamine) compounds into layered silicate. Natural Rubber(NR)/MMT nanocomposites were prepared by reinforcement of Organo-MMT. X-ray diffraction(XRD) and Scanning electron microscope(SEM) were employed to characterize the layer distance of Organo-MMT and the morphology of the NR/MMT nanocomposites. The structures of the synthesized Organo-MMTs were analyzed by the measurement of FT-IR. Cure characteristics, surface free energy and mechanical properties such as tensile strength, modulus and hardness of NR/MMT nanocomposites were carefully studied by contact angle meter, ODR, UTM, and hardness tester. FT-IR analysis showed a insertion of the alkyl and amine chains into the interlayers of the MMT. It was shown that the cure time of the organo-MMT was more decreased than that of $Na^+$-MMT. Surface free energy and tensile strength of the NR/DDA-MMT nanocomposite were the highest. NR/ODA-MMT nanocomposite was the highest in hardness.

Preparation and Water Vapor Barrier Properties of PET/Nanohybrid PI Films (폴리에스테르/폴리이미드 나노복합필름의 제조 및 수분차단 특성)

  • Han, Seung San;Kim, Yong Seok;Won, Jong Chan;Lee, Jae Heung;Choi, Kil-Yeong
    • Journal of Adhesion and Interface
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    • v.5 no.1
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    • pp.29-35
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    • 2004
  • We have prepared polyster/nanQhybridized polyimide films in the range of 1~9 wt% of organophilic synthetic layered silicate (STN). Firstly, poly(amic acid)/STN nanocomposite solutions were prepared via solution blending method in DMAc or THF/MeOH solution, and then cast on the polyester film followed by imidization reaction, thermal and chemical method repestively. XRD and TEM experiment showed that the STN was fully exfoliated through the polyimide matrix. Surface morphologies of nanohybridized polyimide films were characterized by AFM and thermal, mechanical properties were also confirmed by TGA, DMA and UTM each. And also, the water vapor permeabilities highly depended on the content of STN. The sample from chemical imidization route and THF/MeOH solvent system showed better water vapor barrier properties than thermal one and DMAc system.

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Study on the PVdF Nanofibers and Graphene Oxide Hybrid Membrane (PVdF 나노섬유와 Graphene Oxide 하이브리드막에 관한 연구)

  • Jung, Hyemin;Chen, Weidong;Yang, Woo Seok;Byun, Hongsik
    • Membrane Journal
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    • v.23 no.3
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    • pp.204-210
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    • 2013
  • Recently, many applications with grapheneoxide (GO) have been reported. But GO membrane for water treatment has not been developed. In this study we prepared polyvinylidene difluoride (PVdF) nanofiber/GO hybrid membrane (FG) for the microfiltration application. The PVdF substrate membrane was prepared by using the electrospinning method with a solution of PVdF in N,N-dimethylacetamide (DMAc) and acetone. GO sheets used in this study were prepared by modified Hummer's method. The PVdF/GO hybrid membrane was finally prepared by spraying the GO solution dispersed in ethanol on the PVdF nanofiber. The successfully prepared FG was thoroughly examined by SEM, Raman, contact angle, porometer and UTM, and water-flux was measured with designed cell (Dead-End Cell). From the contact angle results, it was found that the surface of FG membrane was reformed by hydrophilic property and the water permeability was increased about 2.5 times than that of the nascent PVdF membrane, indicating the possible alternative of the commercial MF membrane.

Preparation and Properties of PAA/PHA/Organoclay Nanocomposite (PAA/PHA/Organoclay 나노복합재료의 제조 및 특성)

  • Yoon, Doo-Soo;Choi, Jae-Kon;Jo, Byung-Wook
    • Polymer(Korea)
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    • v.34 no.4
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    • pp.326-332
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    • 2010
  • Nanocomposite films were prepared by blending poly(amic acid)(PAA), poly(o-hydroxyamide)( PHA) and organically modified montmorillonite (OMMT) that has a layered structure. XRD, SEM and TEM were used to study the morphology of PAA/PHA nanocomposites, and DMA, TGA, UTM, LOI and PCFC techniques were used to characterize the mechanical and thermal properties, and flame retardancy of the nanocomposites. TEM images revealed that OMMT layers were well dispersed in the PAA/PHA matrix and showed exfoliation and intercalation behavior. The addition of 3 wt% OMMT to the PAA/PHA blend increased the initial modulus of PAA/ PHA blend to 3.68 GPa that was ca. 48% higher than that of the control PAA/PHA blend. Above 4 wt%, however, both the initial modulus and the tensile strength were found to decrease, which might be due to the aggregation of OMMT in PAA/PHA matrix. When the OMMT content was below 3 wt%, the thermal stability and flame retardancy of the PAA/PHA nanocomposites increased with increasing OMMT content.

Effect of two compatibilizers haying comonomer in polypropylene/clay nanocomposites (Comonomer 도입한 상용화제가 Polypropylene/clay 나노복합재료에 미치는 영향)

  • Nam, Byeong-Uk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.8 no.2
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    • pp.367-371
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    • 2007
  • Nanocomposites prepared by PP(Polypropylene) based compatibilizers modified with GMA(Glycidyl methacrylate) and HEMA(Hydroxyethyl methacrylate) were used to investigate the clay dispersion and mechanical properties of them. XRD patterns showed the improvement of dispersion through clay intercalation according to the compatibilizers and comonomer. GMA modified polypropylene gave the best mechanical properties of the nanocomposite with respect to the balance of Flexural modulus (FM) and Notched izod impact strength(IS). Compatibilizers with comonoer commonly have higher grafting yield and lower melt flow rate than those of comonomer free. And they enhanced the clay dispersion and mechanical properties of nanocomposites. Optimum ratio of monomer to comonomer for nanocomposites having better mechanical properties is about 1 to 1 ratio.

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Poly(ethylene terephthalate) Nanocomposite Fibers with Thermally Stable Organoclays (내열성 유기화 점토를 이용한 폴리(에틸렌 테레프탈레이트) 나노복합체 섬유)

  • Jung, Min-Hye;Chang, Jin-Hae
    • Polymer(Korea)
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    • v.31 no.6
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    • pp.518-525
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    • 2007
  • The thermomechanical properties and morphologies of nanocomposite fibers of poly(ethylene terephthalate)(PET) incorporating thermally stable organoclays are compared. Dodecyltriphenyl-phosphonium-mica($C_{12}PPh-Mica$) and 1-hexadecane benzimidazole-mica ($C_{16}BIMD-Mica$) were used as reinforcing fillers in the fabrication of PET hybrid fibers. Dispersions of organoclays with PET were studied by using the in-situ polymerization method at various organoclay contents to produce nano-scale composites. The thermo-mechanical properties and morphologies of the PET hybrid fibers were determined using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X-ray diffraction (XRD), electron microscopy (SEM and TEM), and a universal tensile machine (UTM). Transmission electron microscopy (TEM) micrographs show that some of the clay layers are dispersed homogeneously within the polymer matrix on the nano-scale, although some clay particles are agglomerated. We also found that the addition of only a small amount of organoclay is enough to improve the thermal stabilities and mechanical properties of the PET nanocomposite fibers. Even polymers with low organoclay content (<5 wt%) were found to exhibit much higher thermo-mechanical values than pure PET fibers.