• 제목/요약/키워드: nanocomposite materials

검색결과 538건 처리시간 0.024초

Review on fabrication of graphitic carbon nitride based efficient nanocomposites for photodegradation of aqueous phase organic pollutants

  • Sudhaik, Anita;Raizada, Pankaj;Shandilya, Pooja;Jeong, Dae-Yong;Lim, Ji-Ho;Singh, Pardeep
    • Journal of Industrial and Engineering Chemistry
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    • 제67권
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    • pp.28-51
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    • 2018
  • Graphitic carbon nitride ($g-C_3N_4$) as a fascinating visible light active semiconductor photocatalyst has medium band gap, non-toxic nature, stable chemical structure and high thermal stability. Recently, intensive researches are focused on photocatalytic activity of $g-C_3N_4$ for wastewater treatment. This review demonstrates latest progress in fabrication of graphitic carbon nitride $C_3N_4$ incorporated nanocomposite to explore photocatalytic ability for water purification. The $g-C_3N_4$-based nanocomposites were categorized as $g-C_3N_4$ metal-free nanocomposite, noble metals/$g-C_3N_4$ heterojunction, non-metal doped $g-C_3N_4$, transition and post transition metal based $g-C_3N_4$ nanocomposite. Apart from fabrication methods, we emphasized on elaborating the mechanism of activity enhancement during photocatalytic process.

On the measurement of the transient dynamics of the nanocomposites reinforced concrete systems as the main part of bridge construction

  • Shuzhen Chen;Hou Chang-ze;Gongxing Yan;M. Atif
    • Structural Engineering and Mechanics
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    • 제90권4호
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    • pp.417-428
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    • 2024
  • Nanocomposite-reinforced concrete systems have gained increasing attention in bridge construction due to their enhanced mechanical properties and durability. Understanding the transient dynamics of these advanced materials is crucial for ensuring the structural integrity and performance of bridge infrastructure under dynamic loading conditions. This paper presents a comprehensive study of the measurement techniques employed for assessing the transient dynamics of nanocompositereinforced concrete systems in bridge construction applications. A numerical method, including modal analysis are discussed in detail, highlighting their advantages, limitations, and applications. Additionally, recent advancements in sensor technologies, data acquisition systems, and signal processing techniques for capturing and analyzing transient responses are explored. The paper also addresses challenges and opportunities in the measurement of transient dynamics, such as the characterization of nanocomposite-reinforced concrete materials, the development of accurate numerical models, and the integration of advanced sensing technologies into bridge monitoring systems. Through a critical review of existing literature and case studies, this paper aims to provide insights into best practices and future directions for the measurement of transient dynamics in nanocompositereinforced concrete systems, ultimately contributing to the design, construction, and maintenance of resilient and sustainable bridge infrastructure.

Sustainable construction material using nanosilica and multi-walled carbon nanotubes in cement concrete

  • Breetha Yesudhas Jayakumari;Elangovan Nattanmai Swaminathan;Pachaivannan Partheeban
    • Advances in nano research
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    • 제16권5호
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    • pp.459-472
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    • 2024
  • Nanotechnology is a popular field in the construction industry due to its multiple functions. It mitigates CO2 emissions and enhances the desirable properties of concrete by replacing small amounts of cement with supplements. This study assess the sustainability impact of using two different nanoparticles partially replacing the cement with 0.3%, 0.6%, 1.0% of nano silica (NS) and 0.03%, 0.045%, 0.06% of Multi-Walled Carbon Nanotubes (MWCNT) in the green concrete mix developement. Nano-sized fragments at the atomic scale tends to modify the properties of concrete. Concrete may increase its strength, durability by adding nanocomposite materials, which will decrease the amount of nano and micropores in structural parts. The strength of the structural elements can be greatly improved and allowing them to withstand higher loads and resist deformation. It improved durability properties by 64.8% in water absorption, 56.4% in acid attack, 78.1% in sulphate attack, and 53.4% in chloride attack. There was an improvement in compressive strength of 37% and split tensile strength of 90%. SEM, FTIR, and XRD investigations have used to look at the microstructural characteristics of nanoconcrete dictated the microstructure characteristics may be made more consistent and dense by adding nanocomposite materials.

마이크로광조형에서 고 세장비 구조물 집적화 가공을 위한 UV 경화성 수지의 물성 개선 (Improvement of Mechanical Properties of UV-curable Resin for High-aspect Ratio Microstructures Fabricated in Microstereolithography)

  • 이수도;최재원;박인백;하창식;이석희
    • 한국정밀공학회지
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    • 제24권12호
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    • pp.119-127
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    • 2007
  • Recently, microstructures fabricated using microstereolithography technology have been used in the biological, medical and mechanical fields. Microstereolithography can fabricate real 3D microstructures with fine features, although there is presently a limited number of materials available for use in the process. Deformation of the fine features on a fabricated microstructure remains a critical issue for successful part fabrication, and part deformation can occur during rinsing or during fabrication as a result of fluid flow forces that occur during movement of mechanical parts of the system. Deformation can result in failure to fabricate a particular feature by breaking the feature completely, spatial deflection of the feature, or attaching the feature to neighboring microstructures. To improve mechanical strength of fabricated microstructures, a clay nanocomposite can be used. In particular, a high-aspect ratio microstructure can be fabricated without distortion using photocurable liquid resin containing a clay nanocomposite. In this paper, a clay nanocomposite was blended with a photocurable liquid resin to solve the deformation problem that occurs during fabrication and rinsing. An optimal mixture ratio of a clay nanocomposite was found through tensile testing and the minimal allowable distance between microstructures was found through fabrication experimentation. Finally, using these results, high-aspect ratio microstructures were fabricated using a clay nanocomposite resin without distortion.

Influence of Ni Addition on Mechanical and Magnetic Properties of Yttria-Stabilized Tetragonal Zirconia

  • Kondo, H.;Sekino, T.;Choa, Y.H.;Kusunose, T.;Nakayama, T.;Niihara, K.
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 2000년도 Proceedings of 2000 International Nano Crystals/Ceramics Forum and International Symposium on Intermaterials
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    • pp.243-248
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    • 2000
  • Effect of NiO addition on microstructure, stability of tetragonal phase and mechanical properties was investigated. (Y, Ni)-TZP solid solution was obtained by pressureless sintering. The fracture toughness was increased by solid solution of NiO. Neither reaction phase nor glassy phase was observed at the grain boundaries. From these results, it was determined that solid solution of NiO was destabilized tetragonal phase of Y-TZP. Y-TZP/Ni nanocomposite that contained nano-sized Ni particles was also fabricated by internal reduction method. Some evaluations and discussions were carried out for both (Y, Ni)-TZP solid solution and Y-TZP/Ni nanocomposite.

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Size dependent effect on deflection and buckling analyses of porous nanocomposite plate based on nonlocal strain gradient theory

  • Khazaei, Pegah;Mohammadimehr, Mehdi
    • Structural Engineering and Mechanics
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    • 제76권1호
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    • pp.27-56
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    • 2020
  • In this paper, the deflection and buckling analyses of porous nano-composite piezoelectric plate reinforced by carbon nanotube (CNT) are studied. The equations of equilibrium using energy method are derived from principle of minimum total potential energy. In the research, the non-local strain gradient theory is employed to consider size dependent effect for porous nanocomposite piezoelectric plate. The effects of material length scale parameter, Eringen's nonlocal parameter, porosity coefficient and aspect ratio on the deflection and critical buckling load are investigated. The results indicate that the effect of porosity coefficient on the increase of the deflection and critical buckling load is greatly higher than the other parameters effect, and size effect including nonlocal parameter and the material length scale parameter have a lower effect on the deflection increase with respect to the porosity coefficient, respectively and vice versa for critical buckling load. Porous nanocomposites are used in various engineering fields such as aerospace, medical industries and water refinery.

Microstructural Wear Mechanism of $Al_2O_3-5$ vol% SiC nanocomposite and $Si_3N_4$Ceramics

  • Riu, Doh-Hyung;Kim, Yoon-Ho;Lee, Soo-Wohn;Koichi Niihara
    • 한국분말재료학회지
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    • 제8권3호
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    • pp.179-185
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    • 2001
  • Through the observation of wear scar of two ceramic materials, microstructural wear mechanisms was investigated. As for the $Al_2O_3$-5 vol% SiC nanocomposite, the grain boundary fracture was suppressed by the presence of SiC nano-particles. The intragranular SiC particles have inhibited the extension of plastic deformation through the whole grain. Part of plastic deformation was accommodated around SiC particles, which made a cavity at the interface between SiC and matrix alumina. On the other hand, gas-pressure sintered silicon nitride showed extensive grain boundary fracture due to the thermal fatigue. The lamination of wear scar was initiated by the dissolution of grain boundary phase. These two extreme cases showed the importance of microstructures in wear behavior.

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