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  • Title/Summary/Keyword: nanocomposite materials

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Electrospinning Fabrication of Poly(vinyl alcohol)/Pullulan/TiO2 Nanofibers (전기방사를 이용한 Poly(vinyl alcohol)/Pullulan/TiO2 나노부직포의 제조)

  • Yang, Seong Baek;Choi, Woo Seok;Hyun, Jae Min;Shin, Jae Cheon;Choi, Jin Hyun;Yeum, Jeong Hyun
    • Textile Coloration and Finishing
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    • v.26 no.3
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    • pp.195-200
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    • 2014
  • Poly(vinyl alcohol)(PVA)/pullulan/titanium dioxide(TiO2) composite nanofibers were produced at different TiO2 concentrations(1 and 3 wt.%) using the electrospinning method. The parameters of electrospinning including polymer contents, voltage and tip-to-collector distance(TCD) were optimized for fabrication process. The study showed that the best condition to make PVA/pullulan nanofiber and effect of TiO2 nanoparticles. The PVA/pullulan/TiO2 nanofibers were characterized by scanning electron microscope(SEM), transmission electron microscope(TEM), Thermogravimetric analysis (TGA) and X-ray diffraction(XRD).

Improving Gas Barrier Property of Polymer Based Nanocomposites Using Layer by Layer Deposition Method for Hydrogen Tank Liner

  • Lee, Suyeon;Han, Hye Seong;Seong, Dong Gi
    • Composites Research
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    • v.35 no.3
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    • pp.121-126
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    • 2022
  • Owing to advantages of polymeric materials for hydrogen tank liner like light-weight property and high specific strength, polymer based composites have gained much attention. Despite of many benefits, polymeric materials for fuel cell tank cause problems which is critical to applications as low gas barrier property, and poor processability when adding fillers. For these reasons, improving gas barrier property of polymer composites is required to study for expanding application fields. This work presents impermeable polymer nanocomposites by introducing thin barrier coating using layer by layer (LBL) deposition method. Also, bi-layered and quad-layered nanocomposites were fabricated and compared for identifying relationship between deposition step and gas barrier property. Reduction in gas permeability was observed without interrupting mechanical property and processability. It is discussed that proper coating conditions were suggested when different coating materials and deposition steps were applied. We investigated morphology, gas barrier property and mechanical properties of fabricated nanocomposites by FE-SEM, Oxygen permeation analyzer, UTM, respectively. In addition, we revealed the mechanism of barrier performance of LBL coating using materials which have high aspect ratio.

Capacitance Enhancement and Evaluation of Gold-Deposited Carbon Nanotube Film Ion-Selective Electrode (금 입자 증착된 탄소나노튜브의 커패시턴스 증가 및 박막형 이온 선택성 전극으로서의 특성 평가)

  • Do Youn Kim;Hanbyeol Son;Hyo-Ryoung Lim
    • Journal of Powder Materials
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    • v.30 no.4
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    • pp.310-317
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    • 2023
  • Small-film-type ion sensors are garnering considerable interest in the fields of wearable healthcare and home-based monitoring systems. The performance of these sensors primarily relies on electrode capacitance, often employing nanocomposite materials composed of nano- and sub-micrometer particles. Traditional techniques for enhancing capacitance involve the creation of nanoparticles on film electrodes, which require cost-intensive and complex chemical synthesis processes, followed by additional coating optimization. In this study, we introduce a simple one-step electrochemical method for fabricating gold nanoparticles on a carbon nanotube (Au NP-CNT) electrode surface through cyclic voltammetry deposition. Furthermore, we assess the improvement in capacitance by distinguishing between the electrical double-layer capacitance and diffusion-controlled capacitance, thereby clarifying the principles underpinning the material design. The Au NP-CNT electrode maintains its stability and sensitivity for up to 50 d, signifying its potential for advanced ion sensing. Additionally, integration with a mobile wireless data system highlights the versatility of the sensor for health applications.

Nanostructured Bulk Ceramics (Part IV. Polymer Precursor Derived Nanoceramics)

  • Han, Young-Hwan;Mukherjee, Amiya K.
    • Journal of the Korean Ceramic Society
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    • v.47 no.3
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    • pp.205-209
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    • 2010
  • In the last (fourth) section, the discussion will entail a silicon-nitride/silicon-carbide nanocomposite, produced by pyrolysis of liquid polymer precursors, demonstrating one of the lowest creep rates reported so far in ceramics at the comparable temperature of 1400C. This was first achieved by avoiding the oxynitride glass phase at the intergrain boundaries. One important factor in the processing of these nanocomposites was the use of the electrical field assisted sintering method.

Synthesis and Characteristics of Organo-Layered Silicate as an Filler of Polymeric Nanocomposites from deltaNa2Si2O5 (deltaNa2Si2O5 로부터 고분자 나노복합 소재용 유기 층상 실리케이트 합성 및 특성)

  • 김윤섭;고형신
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.226-226
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    • 2003
  • 일반적으로, 고분자 매트릭스에 층상 점토광물이 분산되어 얻어지는 복합재료는 세가지 형태를 이룬다. 첫째 통상의 복합재료는 고분자 매트릭스 내에 점토입자가 고루게 분산된 상태를 말하며, 둘째 점토 층 사이에 고분자 모노머나 올리고머가 일부분 삽입된 삽입형 복합재료(intercalated composite)이며, 셋째 점토 층 사이에 삽입된 모노머나 올리고머의 경화 또는 중합반응을 통해 점토내의 한층 한층 균일하게 매트릭스 내에 분산된 박리형 나노복합소재(exfoliated nanocomposite) 이다. 이들 복합재료들 중 박리형 나노복합소재는 적은 양의 점토가 단위 층으로 고분자 매트릭스에 완전히 분산되어 다양한 물성의 향상이 기대되는 재료이다. 따라서 최근 고분자의 기계적 강도, 팽윤 저항성 그리고 차폐특성 둥 전반적인 물성을 향상시키는 방법으로 층상 점토광물의 층 사이에 다양한 유기물을 삽입하여 층간거리를 확장시킨 유기 점토광물을 제조하고 이를 고분자 소재에 첨가하여 박리형 나노복합소재를 제조하는 방법이 많은 연구가 수행되고 있다.

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Synthesis of TiO2Fe2O3 Magnetic Photocatalyst Nanocomposite Powder (자성 광촉매용 TiO2Fe2O3나노복합분말의 합성)

  • 이창우;김순길;이재성
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.103-103
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    • 2003
  • 대기나 물에 용해된 여러 가지 유해한 유기물을 분해하기 위한 방안으로서 다양한 광촉매 재료를 이용하려는 시도가 진행되고 있다. 하지만 광촉매 반응은, 현탁액 내에서 submicrometer 크기를 갖는 반도체재료에서 발생하므로 처리된 폐수로부터 촉매를 제거해야 하는 정제공정 (downstream process)이 필요하며, 이는 경제적인 측면에서 큰 경비를 요구하게 된다. 이를 해결 하기 위하여, 가장 우수한 광촉매 재료로 평가받는 TiO2를 glass beads, sands, silica gel등의 물질에 고정시키거나, TiO2를 자성 입자에 코팅시킨 형태인, 자성 광촉매입자를 응용하려는 연구가 최근 활발하게 진행되고 있다. 따라서 본 연구에서는 광촉매의 고정화와 재활용 효율을 향상시키기 위하여 TiO2 나노입자를 y-Fe2O3 나노입자의 표면에 코팅하여 나노입자의 큰 비표면적을 활용하고 미세구조를 제어하여 입자간의 고정특성과 자기적 특성의 제어기술을 확립하고자 하였다.

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Preparation of Nylon 6/ Clay Nanocomposites by Reactive Extrusion

  • Soonho Lim;Park, Jung-Hoon;Kim, Woo-Nyeon;Lee, Sang-Soo;Kim, Junkyung
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.16-20
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    • 2003
  • As the preliminary works for the preparation of exfoliated nanocomposites by reactive extrusion (REX) the modified anionic polymerization proceeded in a flask using an ε-caprolactam, catalyst, initiator, and clay. Polymerization methods were classified with a variation of the clay adding time. Intercalations mechanism of clay layers was investigated by measuring the WAXD peaks of clay with polymerization. In the preparation of nanocomposites, the molecular weight of nylon 6 was affected by the clay content. From the mechanical property measurement, improved properties were obtained in comparison to the neat nylon 6, and these properties were also affected by the molecular weight.

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Titanium Dioxide Nanoparticles filled Sulfonated Poly(ether ether ketone) Proton Conducting Nanocomposites Membranes for Fuel Cell

  • Kalappa, Prashantha;Hong, Chang-Eui;Kim, Sung-Kwan;Lee, Joong-Hee
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.87-90
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    • 2005
  • This paper presents an evaluation of the effect of titanium dioxide nanoparticles in sulfonated poly(ether ether ketone) (SPEEK) with sulfonation degree of 57%. A series of inorganic-organic hybrid membranes were prepared with a systematic variation of titanium dioxide nanoparticles content. Their water uptake, methanol permeability and proton conductivity as a function of temperature were investigated. The results obtained show that the inorganic oxide network decreases the proton conductivity and water swelling. It is also found that increase in inorganic oxide content leads to decrease of methanol permeability. In terms of morphology, membranes are homogeneous and exhibit a good adhesion between inorganic domains and the polymer matrix. The properties of the composite membranes are compared with standard nafion membrane.

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Current Research on Conducting Polymer-Carbon Nanocomposites for Bioengineering Applications

  • Lee, Seunghyeon;Lee, Sang Kyu;Jang, Daseul;Shim, Bong Sup
    • Elastomers and Composites
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    • v.52 no.1
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    • pp.69-80
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    • 2017
  • Conducting polymers and carbon nanomaterials offer a wide range of applications because of their unique soft conducting properties. Specifically, these conducting polymer-carbon nanocomposites have recently been utilized in bioengineering applications, partly because of their improved biocompatibility compared to conventional conducting materials such as metals and ceramics. Based on the assumption that these composites offer an important application potential as functional materials for biomedical devices or even as biomaterials, this review surveys the recent research trends on conducting polymers-carbon nanocomposites, focusing on bioengineering applications such as polyaniline (PANI), poly(3,4-ethylenedioxythiophene) or PEDOT, polypyrrole (Ppy), and carbon nanotubes and graphene.

Ultrafine Grained Bulk Al Matrix Carbon Nanotube Composites Processed by High Pressure Torsion (고압비틀림 성형 공정에 의한 Al 기지 CNT 복합재료의 초미세결정 벌크화)

  • Joo,, S.H.;Kim, H.S.
    • Transactions of Materials Processing
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    • v.19 no.7
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    • pp.423-428
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    • 2010
  • Carbon nanotubes(CNTs) are expected to be ideal reinforcements of metal matrix composite materials used in aircraft and sports industries due to their high strength and low density. In this study, a high pressure torsion(HPT) process at an elevated temperature(473K) was employed to achieve both powder consolidation and grain refinement of aluminummatrix nanocomposites reinforced by 5vol% CNTs. CNT/Al nanocomposite powders were fabricated using a novel molecular-level mixing process to enhance the interface bonding between the CNTs and metal matrix before the HPT process. The HPT processed disks were composed of mostly equilibrium grain boundaries. The CNT-reinforced ultrafine grained microstructural features resulted in high strength and good ductility.