• 제목/요약/키워드: carbon nanomaterials

검색결과 171건 처리시간 0.029초

Synthesis of a new class of carbon nanomaterials by solution plasma processing for use as air cathodes in Li-Air batteries

  • Kang, Jun
    • Journal of Advanced Marine Engineering and Technology
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    • 제39권8호
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    • pp.833-837
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    • 2015
  • Li-air batteries have a promising future for because of their high energy density, which could theoretically be equal to that of gasoline. However, substantial Li-air cell performance limitations exist, which are related to the air cathode. The cell discharge products are deposited on the surfaces of the porous carbon materials in the air electrode, which blocks oxygen from diffusing to the reaction sites. Hence, the real capacity of a Li-air battery is determined by the carbon air electrode, especially by the pore volume available for the deposition of the discharged products. In this study, a simple and fast method is reported for the large-scale synthesis of carbon nanoballs (CNBs) consisting of a highly mesoporous structure for Li-air battery cathodes. The CNBs were synthesized by the solution plasma process from benzene solution, without the need for a graphite electrode for carbon growth. The CNBs so formed were then annealed to improve their electrical conductivity. Structural characterization revealed that the CNBs exhibited both an pore structure and high conductivity.

에틸렌 역확산화염을 열원으로 사용하여 촉매금속 기판 상에 합성한 탄소나노튜브와 탄소나노섬유 (Synthesis of Multi-walled Carbon Nanotubes and Nanofibers on a Catalytic Metal Substrate Using an Ethylene Inverse Diffusion Flame as a Heat Source)

  • 이교우;정종수;강경태;황정호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1304-1309
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    • 2004
  • Synthesis of carbon nanotubes and nanofibers on a catalytic metal substrate, using an ethylene fueled inverse diffusion flame, was investigated. Multi-walled carbon nanotubes, with diameters of 20 - 60nm, were formed on the substrate coated with nickel-nitrate in the region of 5 - 6mm from the flame center along the radial direction. The gas temperature for this region was ranging from about 1400 to 900K. Nickel particles originated from the coated nickel-nitrate on the substrate were the major catalyst for the formation of the nanomaterials. HR-TEM and Raman spectrum revealed that synthesized carbon nanotubes had multi-walled structures with some defective graphite layers at walls.

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효과적인 CO2 분리를 위한 혼합 기질 분리막 충진 소재로서의 2차원 나노물질 (Two-Dimensional Nanomaterials Used as Fillers in Mixed-Matrix Membranes for Effective CO2 Separation)

  • ;지호빈;양은태
    • 공업화학
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    • 제35권3호
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    • pp.155-181
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    • 2024
  • 최근, 기존 분리막의 성능을 향상시켜 CO2 분리를 효율적으로 수행하기 위한 중요한 연구가 진행되고 있다. 이는 탄소포집 공정에서의 활용을 확대하는 것을 목표로 하고 있다. 분리막 기술은 비용 및 에너지 효율성, 연속 운전, 작은 공정 크기 등의 장점으로 인해 탄소제로 이슈에 대처하는 유망한 탄소 포집 기술로 부상하고 있다. 연구된 여러 종류의 분리막 중 혼합기질막(mixed-matrix membrane, MMM)이 전반적인 가스 분리 공정의 효율을 향상시킬 수 있는 전통적인 분리막의 대안으로 제안되었다. 2D 나노소재는 쉬운 개질과 기능화, 다른 재료와의 결합 등 특징적인 성질로 인해 다양한 일반적인 2D 나노소재들이 가스 분리를 위한 효율적인 MMMs 제작에 사용되고 있다. 본 논문은 2D 나노소재를 사용한 MMMs 분야의 최근 발전을 검토하였다. 또한, CO2 분리 및 포집을 위한 2D 나노소재 기반 분리막의 현재 도전과 전망을 논의하였다.

진단 및 치료용 나노의약품 (Nanomedicine: An Emerging Modality Based on Nanotechnology for Therapy and Diagnosis)

  • ;박재형;김광명;권익찬
    • 공업화학
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    • 제18권3호
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    • pp.199-204
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    • 2007
  • 나노의약품(Nanomedicine)은 나노기술이 접목된 신기능성 의약품을 의미하며 빠르게 발전하고 있는 신생 분야이다. 아직 상용화된 나노의약품은 많지 않지만 최근 나노기술이 접목된 진단 및 치료제제가 속속 개발되면서 기존 의약품을 대체하는 추세에 있다. 나노의약품 연구는 지난 10여년 동안 미국과 유럽을 중심으로 활발히 진행되었으며, 그 결과로 2000년대에 접어서면서 나노의약품 관련 특허 및 논문의 수가 급속히 증가하고 있다. 본 총설에서는 탄소 나노소재, 고분자 약물전달 시스템, 진단영상 소재 등과 같은 대표적인 나노의약품의 연구개발 동향을 소개하고 있다.

Low Cost, Large Area Nanopatterning via Directed Self-Assembly

  • 김상욱
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.24-25
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    • 2011
  • Molecular self-assembly has several advantages over other nanofabrication methods. Molecular building blocks ensure ultrafine pattern precision, parallel structure formation allows for mass production and a variety of three-dimensional structures are available for fabricating complex structures. Nevertheless, the molecular interaction for self-assembly generally relies on weak forces such as van der Waals force, hydrogen bonding, or hydrophobic interaction. Due to the weak interaction, the structure formation is usually slow and the degree of ordering is low in a self-assembled structure. To promote self-assembly, directed assembly methods employing prepatterned substrates or external fields have been developed and gathered a great deal of technological attention as a next generation nanofabrication process. In this presentation a variety of directed assembly methods for soft nanomaterials including block copolymers, peptides and carbon nanomaterials will be introduced. Block copolymers are representative self-assembling materials extensively utilized in nanofabrication. In contrast to colloid assembly or anodized metal oxides, various shapes of nanostructures, including lines or interconnected networks, can be generated with a precise tunability over their shape and size. Applying prepatterned substrates$^{1,2}$ or introducing thickness modulation$^3$ to block copolymer thin films allowed for the control over the orientational and positional orderings of self-assembled structures. The nanofabrication processes for metals, semiconductors$^4$, carbon nanotubes$^{5,6}$, and graphene$^{6,7}$ templating block copolymer self-assembly will be presented.

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Characterization of nano-structure pyrolytic char for smart and sustainable nanomaterials

  • N. K. Karthikeyan;S. Elavenil
    • Advances in nano research
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    • 제16권1호
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    • pp.53-69
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    • 2024
  • Advancements in the technology of building materials has led to diverse applications of nanomaterials with the aim to monitor concrete structures. While there are myriad instances of the use of nanoparticles in building materials, the production of smart nano cement-composites is often expensive. Thereupon, this research aims to discover a sustainable nanomaterial from tyre waste using the pyrolysis process as part of the green manufacturing circle. Here, Nano Structure Tyre-Char (NSTC) is introduced as a zero-dimension carbon-based nanoparticle. The NSTC particles were characterized using various standard characterization techniques. Several salient results for the NSTC particles were obtained using microscopic and spectroscopic techniques. The size of the particles as well as that of the agglomerates were reduced significantly using the milling process and the results were validated through a scanning electron microscope. The crystallite size and crystallinity were found to be ~35nm and 10.42%, respectively. The direct bandgap value of 5.93eV and good optical conductivity at 786 nm were obtained from the ultra violet visible spectroscopy measurements. The thermal analysis reveals the presence of a substantial amount of carbon, the rate of maximum weight loss, and the two stages of phase transformation. The FT-Raman confirms the presence of carboxyl groups and a ID/IG ratio of 0.83. Water contact angle around 140° on the surface implies the highly hydrophobic nature of the material and its low surface energy. This characteristic process assists to obtain a sustainable nanomaterial from waste tyres, contributing to the development of a smart building material.

In-situ functionalized biomass derived graphite-supported BiFeO3 for eradication of pollutants

  • Deepeka, Deepeka;Paramdeep, Kaur;Jyoti, Jyoti;Sandeep, Bansal;Sonal, Singhal
    • Advances in nano research
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    • 제13권6호
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    • pp.527-543
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    • 2022
  • A novel, green, versatile and magnetically retrievable BiFeO3/CDR (Bismuth ferrite/coriander) nanocomposites were fabricated via simple wet chemical method utilizing in situ functionalized, cheap coriander seed powder (CDR 5%, 10%, 15% and 20 wt%) as a fuel to enhance the efficiency of pristine BiFeO3. A comparative study was performed between BiFeO3/CDR and BiFeO3/CNT (Bismuth ferrite/carbon nanotubes) nanocomposites for the removal of various hazardous pollutants from waste water. The successful synthesis of the fabricated nanomaterials was monitored via FT-IR, Powder XRD, FE-SEM, CV, VSM, CHNS/O and XPS studies. The synthesized nanomaterials were employed for the oxidative degradation of Carbol fuchsin, Reactive black 5, Ciprofloxacin and Doxorubicin; adsorption of a pesticide malathion; and reduction studies for Para-nitrophenol (PNP). The fabricated nanomaterials (BiFeO3/CDR) showcased excellent efficiency and comparable results with (BiFeO3/CNT) for the removal of model pollutants. Moreover, synthesized green heterojunction was also testified for mixture of textile and pharmaceutical waste. Hence CDR can be utilized as a better alternative of CNTs.

Buckling characteristics of multiwalled carbon nanotubes under external pressure

  • Sato, Motohiro;Shima, Hiroyuki
    • Interaction and multiscale mechanics
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    • 제2권2호
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    • pp.209-222
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    • 2009
  • This article describes recent work on mechanics of carbon nanotubes, one of the most fundamental and amazing man-made nanostructures. The noteworthy point is that "nano"-scale mechanics of carbon nanotubes can be well described by the continuum elastic theories for "macro"-scale thin shells. This provides an efficient means to elucidate mechanical deformation effects of carbon nanotubes on their physical and chemical properties, which is significant to develop new-generation nanomaterials based on nanotubes and their composites. Potential applications of the mechanical deformation of nanotubes in nano-electronics and nano-biology are also commented. In addition, theoretical investigations regarding external pressure buckling is carried out here and we have numerically confirmed that larger N (the number of layers) and a smaller D (the innermost diameter) make "corrugation modes" with a larger mode-index k be energetically favored.

Graphene and Carbon Quantum Dots-based Biosensors for Use with Biomaterials

  • Lee, Cheolho;Hong, Sungyeap
    • Journal of information and communication convergence engineering
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    • 제17권1호
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    • pp.49-59
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    • 2019
  • Biosensors, which are analysis devices used to convert biological reactions into electric signals, are made up of a receptor component and a signal transduction part. Graphene quantum dots (GQDs) and carbon quantum dots (CQDs) are new types of carbon nanoparticles that have drawn a significant amount of attention in nanoparticle research. The unique features exhibited by GQDs and CQDs are their excellent fluorescence, biocompatibility, and low cytotoxicity. As a result of these features, carbon nanomaterials have been extensively studied in bioengineering, including biosensing and bioimaging. It is extremely important to find biomaterials that participate in biological processes. Biomaterials have been studied in the development of fluorescence-based detection methods. This review provides an overview of recent advances and new trends in the area of biosensors based on GQDs and CQDs as biosensor platforms for the detection of biomaterials using fluorescence. The sensing methods are classified based on the types of biomaterials, including nucleic acids, vitamins, amino acids, and glucose.