Academic literature on the topic 'Nanostructures and nanocomposites'
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Journal articles on the topic "Nanostructures and nanocomposites"
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Sen, Dipanjan, and Markus J. Buehler. "Shock Loading of Bone-Inspired Metallic Nanocomposites." Solid State Phenomena 139 (April 2008): 11–22. http://dx.doi.org/10.4028/www.scientific.net/ssp.139.11.
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Nanostructured composites inspired by structural biomaterials such as bone and nacre form intriguing design templates for biomimetic materials. Here we use large scale molecular dynamics to study the shock response of nanocomposites with similar nanoscopic structural features as bone, to determine whether bioinspired nanostructures provide an improved shock mitigating performance. The utilization of these nanostructures is motivated by the toughness of bone under tensile load, which is far greater than its constituent phases and greater than most synthetic materials. To facilitate the computational experiments, we develop a modified version of an Embedded Atom Method (EAM) alloy multi-body interatomic potential to model the mechanical and physical properties of dissimilar phases of the biomimetic bone nanostructure. We find that the geometric arrangement and the specific length scales of design elements at nanoscale does not have a significant effect on shock dissipation, in contrast to the case of tensile loading where the nanostructural length scales strongly influence the mechanical properties. We find that interfacial sliding between the composite’s constituents is a major source of plasticity under shock loading. Based on this finding, we conclude that controlling the interfacial strength can be used to design a material with larger shock absorption. These observations provide valuable insight towards improving the design of nanostructures in shock-absorbing applications, and suggest that by tuning the interfacial properties in the nanocomposite may provide a path to design materials with enhanced shock absorbing capability.
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Seal, S., S. C. Kuiry, P. Georgieva, and A. Agarwal. "Manufacturing Nanocomposite Parts: Present Status and Future Challenges." MRS Bulletin 29, no. 1 (2004): 16–21. http://dx.doi.org/10.1557/mrs2004.11.
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AbstractThe promises of nanotechnology are mostly based upon the ability to produce nanostructured materials with novel properties. Nanocomposites are defined here as a class of materials that contain at least one phase with constituents in the nanometer domain. This article describes the present state of knowledge of the fabrication of nanocomposite materials, with special emphasis on plasma forming of bulk parts. Future challenges facing the development of methods for consolidating nanocomposites with retained nanostructures are also highlighted.
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Chang, Sujie, Xiaomin Wang, Qiaoling Hu, et al. "Self-Assembled Nanocomposites and Nanostructures for Environmental and Energy Applications." Crystals 12, no. 2 (2022): 274. http://dx.doi.org/10.3390/cryst12020274.
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Self-assembled nanocomposites are attracting considerable attention owing to their controllable architectures and self-assembly processes, as well as the increase in worldwide environmental effects and energy needs. Further understanding of the self-assembly procedure for improving environmental and energy applications would advance the design and manufacture of nanomaterials for various applications. These materials can be grouped into major categories for various application fields, including powder photocatalysts, membrane photocatalysts, and thin-film thermoelectric nanomaterials. These self-assembled nanomaterials can be used for environmental and energy applications, such as wastewater purification, hydrogen production by water splitting, energy storage, and energy harvesting. In this review, a brief introduction to the definitions and classifications of self-assembled nanocomposites is provided. We aim to provide a summary of the recent research related to self-assembled nanocomposites and nanostructures used for environmental and energy applications. Moreover, typical examples and discussions are aimed at demonstrating the advantages of self-assembled nanostructures. At the end of each section, the structural properties and the application of the nanocomposite or nanostructure are summarized. Finally, we provide perspectives for future research on the design and fabrication of self-assembled nanocomposites and nanostructures.
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Sharma, Deepali, B. S. Kaith, and Jaspreet Rajput. "Single Step In Situ Synthesis and Optical Properties of Polyaniline/ZnO Nanocomposites." Scientific World Journal 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/904513.
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Polyaniline/ZnO nanocomposites were prepared by in situ oxidative polymerization of aniline monomer in the presence of different weight percentages of ZnO nanostructures. The steric stabilizer added to prevent the agglomeration of nanostructures in the polymer matrix was found to affect the final properties of the nanocomposite. ZnO nanostructures of various morphologies and sizes were prepared in the absence and presence of sodium lauryl sulphate (SLS) surfactant under different reaction conditions like in the presence of microwave radiation (microwave oven), under pressure (autoclave), under vacuum (vacuum oven), and at room temperature (ambient condition). The conductivity of these synthesized nanocomposites was evaluated using two-probe method and the effect of concentration of ZnO nanostructures on conductivity was observed. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV-visible (UV-VIS) spectroscopy techniques were used to characterize nanocomposites. The optical energy band gap of the nanocomposites was calculated from absorption spectra and ranged between 1.5 and 3.21 eV. The reported values depicted the blue shift in nanocomposites as compared to the band gap energies of synthesized ZnO nanostructures. The present work focuses on the one-step synthesis and potential use of PANI/ZnO nanocomposite in molecular electronics as well as in optical devices.
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Bang, Amruta, and Parag Adhyapak. "Synthesis of Au nanospheres, Au/PVDF nanocomposites and their breath sensing properties." Journal of ISAS 2, no. 2 (2023): 51–62. http://dx.doi.org/10.59143/isas.jisas.2.2.qdai6853.
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Herein, we report, a simple breath sensor based on Au/PVDF nanocomposites. Au nanostructures have been synthesized by using a simple seed mediated growth method. The synthesized Au nanostructures exhibited uniform spherical morphology with average diameter ~20 nm, confirmed by FESEM analysis. The synthesized nanostructures were further used to form nanocomposites with Polyvinylidene Fluoride (PVDF). The synthesized Au nanospheres as well as Au nanospheres/PVDF nanocomposites were tested for breath analysis. The nanocomposite materials were found to sense breath and uniform breathing patterns were generated. During breathing over sensor, voltage gets generated. The maximum voltage obtained was around 280 mV in breathing cycle.
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Aït Hocine, Nourredine, Pascal Médéric, and Hanaya Hassan. "Influence of mixing energy on the solid-state behavior and clay fraction threshold of PA12/C30B® nanocomposites." Journal of Polymer Engineering 39, no. 6 (2019): 565–72. http://dx.doi.org/10.1515/polyeng-2018-0307.
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Abstract This study focuses on the influence of mixing energy on the solid-state behavior and clay fraction threshold of nanocomposites. Thus, three polyamide12/clay (PA12/C30B®) nanocomposites exhibiting different nanostructures were prepared from three sets of processing conditions. Then, thermal and dynamical viscoelastic properties of these nanocomposites were analyzed, in relationship with the material nanostructure and processing conditions. For the first time, the solid-state properties of the nanocomposites revealed the existence of a critical specific mixing mechanical energy. Below this critical value, an increase of mechanical energy refines the structure, improving some end-use properties of the nanocomposite. Above this value, a high mixing energy supply is necessary in order to significantly modify the structure. They also highlighted that the clay fraction threshold, which is commonly attributed to the formation of a three-dimensional percolated network, decreases with increasing specific mixing energy, less significantly when this energy is superior to its critical value.
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Kikuchi, Masanori, and M. Tanaka. "Synthesis of Bone-Like Hydroxyapatite/Collagen Nano-Composites by Soft-Nanotechnology." Advances in Science and Technology 49 (October 2006): 1–8. http://dx.doi.org/10.4028/www.scientific.net/ast.49.1.
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Soft-nanotechnologies are based upon the synthesis technologies of nanomaterials and construction technologies of nanostructures by life forms. They are expected as new preparation methods for biomaterials that could be recognized as regular extracellular matrices (ECM) in our body by cells. We applied the soft-nanotechnology to synthesis of artificial bones made of HAp and collagen with bone-like nanostructure and examined their physical and biological properties. The nanocomposite obtained indicates bone-like nanostructure. Computer simulation and FT-IR suggested that the self-organization of HAp and collagen is based on chemical interaction between calcium ions on HAp surface and carboxy groups on collagen. After implantation in rats and dogs, the nanocomposites are resorbed by osteoclasts followed by osteogenesis; therefore, the nanocomposites are recognized as bone in the living body. Resorption rate can be controlled by crosslinkage. We also prepared sponge-like elastic porous body by gel-lyophilization technique using additional small amount of collagen solution. Bone tissue reactions of it are the same as the nanocomposites as prepared. The nanocomposites are now in clinical research in Japan to be commercialized in near future by Pentax Co.
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Navyatha, Bankuru, and Seema Nara. "Gold nanotheranostics: future emblem of cancer nanomedicine." Nanobiomedicine 8 (January 2021): 184954352110539. http://dx.doi.org/10.1177/18495435211053945.
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Cancer nanotheranostics aims at providing alternative approaches to traditional cancer diagnostics and therapies. In this context, plasmonic nanostructures especially gold nanostructures are intensely explored due to their tunable shape, size and surface plasmon resonance (SPR), better photothermal therapy (PTT) and photodynamic therapy (PDT) ability, effective contrast enhancing ability in Magnetic Resonance imaging (MRI) and Computed Tomography (CT) scan. Despite rapid breakthroughs in gold nanostructures based theranostics of cancer, the translation of gold nanostructures from bench side to human applications is still questionable. The major obstacles that have been facing by nanotheranostics are specific targeting, poor resolution and photoinstability during PTT etc. In this regard, various encouraging studies have been carried out recently to overcome few of these obstacles. Use of gold nanocomposites also overcomes the limitations of gold nanostructure probes and emerged as good nanotheranostic probe. Hence, the present article discusses the advances in gold nanostructures based cancer theranostics and mainly emphasizes on the importance of gold nanocomposites which have been designed to decipher the past questions and limitations of in vivo gold nanotheranostics.
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Marković, Darka, Andrea Zille, Ana Isabel Ribeiro, et al. "Antibacterial Bio-Nanocomposite Textile Material Produced from Natural Resources." Nanomaterials 12, no. 15 (2022): 2539. http://dx.doi.org/10.3390/nano12152539.
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Growing demand for sustainable and green technologies has turned industries and research toward the more efficient utilization of natural and renewable resources. In an effort to tackle this issue, we developed an antibacterial textile nanocomposite material based on cotton and peat fibers with immobilized Cu-based nanostructures. In order to overcome poor wettability and affinity for Cu2+-ions, the substrate was activated by corona discharge and coated with the biopolymer chitosan before the in situ synthesis of nanostructures. Field emission scanning electron microscopy (FESEM) images show that the application of gallic or ascorbic acid as green reducing agents resulted in the formation of Cu-based nanosheets and mostly spherical nanoparticles, respectively. X-ray photoelectron spectroscopy (XPS) analysis revealed that the formed nanostructures consisted of Cu2O and CuO. A higher-concentration precursor solution led to higher copper content in the nanocomposites, independent of the reducing agent and chitosan deacetylation degree. Most of the synthesized nanocomposites provided maximum reduction of the bacteria Escherichia coli and Staphylococcus aureus. A combined modification using chitosan with a higher deacetylation degree, a 1 mM solution of CuSO4 solution, and gallic acid resulted in an optimal textile nanocomposite with strong antibacterial activity and moderate Cu2+-ion release in physiological solutions. Finally, the Cu-based nanostructures partially suppressed the biodegradation of the textile nanocomposite in soil.
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Vysikaylo, P. I. "Quantum Size Effects Arising from Nanocomposites Physical Doping with Nanostructures Having High Electron Affinit." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 3 (96) (June 2021): 150–75. http://dx.doi.org/10.18698/1812-3368-2021-3-150-175.
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This article considers main problems in application of nanostructured materials in high technologies. Theoretical development and experimental verification of methods for creating and studying the properties of physically doped materials with spatially inhomogeneous structure on micro and nanometer scale are proposed. Results of studying 11 quantum size effects exposed to nanocomposites physical doping with nanostructures with high electron affinity are presented. Theoretical and available experimental data were compared in regard to creation of nanostructured materials, including those with increased strength and wear resistance, inhomogeneous at the nanoscale and physically doped with nanostructures, i.e., quantum traps for free electrons. Solving these problems makes it possible to create new nanostructured materials, investigate their varying physical properties, design, manufacture and operate devices and instruments with new technical and functional capabilities, including those used in the nuclear industry. Nanocrystalline structures, as well as composite multiphase materials and coatings properties could be controlled by changing concentrations of the free carbon nanostructures there. It was found out that carbon nanostructures in the composite material significantly improve impact strength, microhardness, luminescence characteristics, temperature resistance and conductivity up to 10 orders of magnitude, and expand the range of such components’ possible applications in comparison with pure materials, for example, copper, aluminum, transition metal carbides, luminophores, semiconductors (thermoelectric) and silicone (siloxane, polysiloxane, organosilicon) compounds
Dissertations / Theses on the topic "Nanostructures and nanocomposites"
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Kulkarni, Dhaval Deepak. "Interface properties of carbon nanostructures and nanocomposite materials." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49092.
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Two different interfaces were the focus of study: 1) the interface between disordered amorphous carbon and inorganic materials (metal nanostructures and silicon), and 2) the interface between partially ordered graphene (graphene oxide) and synthetic polymer matrix. Specifically, the uniqueness of this study can be summarized through the following novel findings, fabrication processes, and characterization techniques:
• A simple and efficient process for faster, greener, less-expensive, and highly localized transformation of amorphous carbon nanostructures into graphitic nanostructures using low temperature heat and light treatments was developed for the fabrication of low-resistance interfaces between carbon nanomaterials and inorganic metal surfaces.
• A new protocol for high resolution mapping the charge distribution and electronic properties of nanoscale chemically heterogeneous domains on non-homogeneous surfaces such as graphene oxide was established.
• High strength laminated mechanical nanocomposites based on high interfacial stress transfer between polymer matrices and large area, flat, and non-wrinkled graphene oxide sheets were suggested and demonstrated.
• Scanning Thermal Twist Microscopy – a thermal microscopy based technique was developed and demonstrated for characterizing the thermal properties of homogeneous and heterogeneous interfaces with nanoscale spatial resolution and high thermal sensitivity unachievable using traditional techniques.
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Mahanta, Nayandeep Kumar. "Thermal Transport in Isolated Carbon Nanostructures and Associated Nanocomposites." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1334602932.
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Venkatachalapathy, Viswanathan. "PLASMA PROCESSING FOR RETENTION OF NANOSTRUCTURES." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4197.
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Plasma spray processing is a technique that is used extensively in thermal barrier coatings on gas and steam turbine components, biomedical implants and automotive components. Many processing parameters are involved to achieve a coating with certain functionality. The coating could be required to function as thermal barrier, wear resistant, corrosion resistant or a high temperature oxidation resistant coating. Various parameters, such as, nozzle and electrode design, powder feeding system, spray distances, substrate temperature and roughness, plasma gas flow rates and others can greatly alter the coating quality and resulting performance. Feedstock (powder or solution precursor) composition and morphology are some of the important variables, which can affect the high end coating applications. The amount of heat a plasma plume has to offer to the particles being processed as a coating depends primarily on the dissociation of the atoms of gaseous mixtures being used to create the plasma and the residence time required for the particle to stay in the flame. The parameters that are conducive for nanostructured retention could be found out if the residence time of the particles in the flame and the available heat in the plume for various gas combinations could be predicted. If the feedstock is a liquid precursor instead of a powder feedstock, the heat that has to be offered by the plasma could be increased by suitable gas combination to achieve a good quality coating. Very little information is available with regard to the selection of process parameters and processing of nano materials feedstock to develop nanostructured coatings using plasma spray. In this study, it has been demonstrated that nano ceramics or ceramic composites either in the form of coatings or bulk free form near net components could be processed using DC plasma spray. For powder feedstock, analytical heat transfer calculations could predict the particle states for a given set of parameters by way of heat input from the plasma to the particles. The parameter selection is rendered easier by means of such calculations. Alumina nano ceramic particles are processed as a coating. During Spray drying, a process of consolidation of nano alumina particles to spherical agglomerates, parameter optimization for complete removal of moisture has been achieved. The parameters are tested for alumina nanoparticles with a plasma torch for the veracity of calculations. The amount of heat transfer from the surface of the agglomerates to the core has been quantified as a function of velocity of particles. Since preparation of nanostructured feedstock for plasma spray is expensive and cumbersome, alternative solution precursor route for direct pyrolysis of precursor to coating has been studied in case of nanocrystalline rare earth oxides. Thus, it has also been shown by this research that nanostructured coatings could be either from a powder feedstock or a solution precursor feedstock. MoSi2-Si3N4, Ni-Al2O3, W-HfC nano ceramic composite systems have been processed as a bulk free form nanocomposite with 60-70% retained nanostructures. The importance of selection of substrates, roughness and the substrate temperature for development of free form bulk components has been highlighted. The improvement in mechanical and high temperature properties associated with having such nanostructured coatings or bulk nanocomposites are revealed. These nanostructured coatings are known for their low thermal conductivity, high wear resistance and can be potentially used as steam and gas turbines coatings for improved thermal efficiency. In summary, bulk nanocomposite through plasma spray processing is a viable alternative to conventional processes such as sintering, HIP for high fracture toughness and hardness applications.<br>Ph.D.<br>Department of Mechanical, Materials and Aerospace Engineering;<br>Engineering and Computer Science<br>Materials Science & Engr PhD
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Behler, Kristopher Gogotsi IU G. "Chemically modified carbon nanostructures for electrospun thin film polymer-nanocomposites /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2920.
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Kim, Kwang-Hyon. "Ultrafast nonlinear optical processes in metal-dielectric nanocomposites and nanostructures." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2012. http://dx.doi.org/10.18452/16495.
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Diese Arbeit ist der theoretische Untersuchung nichtlinearer optischer Prozesse in metall-dielektrischen Medien gewidmet, wobei Möglichkeiten zur Ausnutzung der erhöhten nichtlinearen Koeffizienten und der Feldüberhöhung durch metallische Nanoteilchen untersucht wurden. Die wichtigsten Ergebnisse beziehen sich auf eine Untersuchung der zeitabhängigen sättigbaren Absorption in Gläsern, die mit metallischen Nanoteilchen dotiert sind, ihrer physikalischen Ursache sowie verschiedener Anwendungen in der nichtlinearen Optik. Zur Untersuchung der Zeitabhängigkeit der nichtlinearen Rückwirkung wird unter Verwendung des semi-klassischen Zwei-Temperatur-Modells eine zeitabhängige Gleichung für die nichtlineare dielektrische Funktion der Metalle hergeleitet. Die Ergebnisse zeigen, dass solche Gläser, sich als sehr effiziente sättigbare Absorber im Spektralbereich vom sichtbaren bis nahen IR eignen. Für kurzwellige Laser im blau/violetten Spektralbereich wird die Dynamik der Modenkopplung in Festkörper- und Halbleiter-Scheibenlaser untersucht. Weiterhin wird ein neuer Mechanismus für die Realisierung von langsamem Licht vorgeschlagen und im Detail untersucht, der in solchen dotierten Gläsern in einem Pump-Probe Regime infolge der sättigbaren Absorption in der Nähe der Plasmonresonanz realisierbar ist. Weiterhin untersuchten wir die Möglichkeit einer Femtosekunden Plasmon Impulserzeugung durch Modenkopplung eines Oberflächen Plasmonlasers mit einem Bragg Resonator, der aus einer dünnen Schicht aus Silber sowie einem sättigbaren Absorbers und einem Verstärker besteht. Im letzten Teil der Arbeit werden Ergebnisse zur Erzeugung hoher Harmonischer in Edelgasen in der Nähe einer metallischen fraktalen rauen Oberfläche untersucht. Die Berechnungen zeigen eine Reduzierung der geforderten Intensität um drei Größenordnungen und eine um zwei Größenordnungen erhöhte Effizienz gegenüber der bisher experimentell realisierten HHG in der Nähe von metallischen "bow-tie"Nanostrukturen.<br>This work reports results of a theoretical study of nonlinear optical processes in metal-dielectric nanocomposites used for the increase of the nonlinear coefficients and for plasmonic field enhancement. The main results include the study of the transient saturable nonlinearity in dielectric composites doped with metal nanoparticles, its physical mechanism as well its applications in nonlinear optics. For the study of the transient response, a time-depending equation for the dielectric function of the nanocomposite using the semi-classical two-temperature model is derived. By using this approach, we study the transient nonlinear characteristics of these materials in comparison with preceding experimental measurements. The results show that these materials behave as efficient saturable absorbers for passive mode-locking of lasers in the spectral range from the visible to near IR. We present results for the modelocked dynamics in short-wavelength solid-state and semiconductor disk lasers; in this spectral range other efficient saturable absorbers do not exist. We suggest a new mechanism for the realization of slow light phenomenon by using glasses doped with metal nanoparticles in a pump-probe regime near the plasmonic resonance. Furthermore, we study femtosecond plasmon generation by mode-locked surface plasmon polariton lasers with Bragg reflectors and metal-gain-absorber layered structures. In the final part of the thesis, we present results for high-order harmonic generation near a metallic fractal rough surface. The results show a possible reduction of the pump intensities by three orders of magnitudes and two orders of magnitudes higher efficiency compared with preceding experimental results by using bow-tie nanostructures.
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Khanadeev, V. A., B. N. Khlebtsov, G. S. Terentyuk, et al. "Mesoporous Silica and Composite Nanostructures for Theranostics." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35481.
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We discus methods for fabrication of silica and composite nanoparticles, which can be used in various biomedical applications. The most promising types of such nanostructures are hollow silica nanosheres, sil-ica coated plasmon-resonant nanoparticles (gold nanorods and gold-silver nanocages) and nanorattles. Mesoporous silica shell can be doped by desirable targeting molecules. Here we present the results of for-mation of nanocomposites composed of gold nanorods and double-layer silica shell. The secondary mesopo-rous silica shell is doped with a photosensitizer (hematoporphyrine in our case). We demonstate some of promising theranostics applications of these nanocomposites for bioimaging and in vivo therapy of tumors.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35481
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Abdelaaziz, Muftah Ali. "Synthesis of nanocomposites with nano-TiO2 particles and their applications as dental materials." Thesis, Cape Peninsula University of Technology, 2012. http://hdl.handle.net/20.500.11838/1534.
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Thesis submitted in fulfilment of the requirements for the degree
Magister of Technology: Dental Technology
In the Faculty of Health and Wellness Sciences
At the Cape Peninsula University of Technology, 2012<br>A study of the modification of dental nanocomposites with nanosized fillers is presented. The incorporation of TiO2 (titania) nanoparticles, via a silane chemical bond, to a standard dental acrylic resin matrix was explored to determine whether there was an increase in the wear resistance, flexural strength and surface hardness properties of the dental nanocomposites. The principal aim of this study was to synthesize dental nanocomposites with different sizes, treated, nano-TiO2 fillers in urethane dimethacrylate (UDMA) for potential application in posterior restoration and to evaluate their mechanical properties.
Treatment of the nano-TiO2 particles was carried out with a silane coupling agent, 3-(methacryloyloxy)propyltrimethoxysilane (MPTMS), to improve bonding between the nano-TiO2 particles and acrylic matrix (UDMA), and reduce agglomeration of the nano-TiO2. Characterisation of products was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). TEM results were used to compare the particle size distributions of untreated TiO2 and treated TiO2 under various experimental conditions in an ethanol solvent, while SEM images showed the adhesion between the matrix (UDMA) and the nano-TiO2. FTIR was used to show the qualitative composition of untreated TiO2 and treated TiO2.
Eighteen groups of experimental dental nanocomposites were evaluated. Each group contained different average particle sizes of nano-TiO2 (filler): 5 nm, 21 nm and 80 nm. Each particle size category was treated with three different concentrations of the silane, (MPTMS): 2.5, 10 and 30 wt %. Samples were prepared by mixing the monomer resin matrix of UDMA and nano-TiO2 particles. For comparison, a commercially available dental resin was reinforced with untreated and treated nano-TiO2 particle sizes 5, 21 and 80 nm.
Wear resistance, flexural strength and surface hardness of TiO2 nanocomposites treated with 2.5 wt % MPTMS were significantly higher compared to those treated with 10 and 30 wt% MPTMS. The nanocomposites with 5 nm TiO2 had higher wear loss, lower flexural strength and lower surface hardness values compared to those with 21 nm and 80 nm TiO2. Statistical analysis showed that the effect of the concentrations of MPTMS on wear resistance and surface hardness of specimens was significant (p<0.001), which is less than 0.05, while the effect of the concentration of MPTMS on flexural strength was statistically not significant, (p=0.02). Control composites reinforced with treated 80 nm TiO2 particles had much better mechanical properties than any of the other specimens. It was concluded that the most available commercial product for dental restorations could be improved by the addition of nano-TiO2 with relatively large particle size.
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Kana, Jean Bosco Kana. "Towards stimuli-responsive functional nanocomposites : smart tunable plasmonic nanostructures Au-VO2." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_8032_1299494958.
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<p>The fascinating optical properties of metallic nanostructures, dominated by collective oscillations of free electrons known as plasmons, open new opportunities for the development of devices fabrication based on noble metal nanoparticle composite materials. This thesis demonstrates a low-cost and versatile technique to produce stimuli-responsive ultrafast plasmonic nanostructures with reversible tunable optical properties. Albeit challenging, further control using thermal external stimuli to tune the local environment of gold nanoparticles embedded in VO2 host matrix would be ideal for the design of responsive functional nanocomposites. We prepared Au-VO2 nanocomposite thin films by the inverted cylindrical reactive magnetron sputtering (ICMS) known as hollow cathode magnetron sputtering for the first time and report the reversible tuning of surface plasmon resonance of Au nanoparticles by only adjusting the external temperature stimuli. The structural, morphological, interfacial analysis and optical properties of the optimized nanostructures have been studied. ICMS has been attracting much attention for its enclosed geometry and its ability to deposit on large area, uniform coating of smart nanocomposites at high deposition rate. Before achieving the aforementioned goals, a systematic study and optimization process of VO2 host matrix has been done by studying the influence of deposition parameters on the structural, morphological and optical switching properties of VO2 thin films. A reversible thermal tunability of the optical/dielectric constants of VO2 thin films by spectroscopic ellipsometry has been intensively also studied in order to bring more insights about the shift of the plasmon of gold nanoparticles imbedded in VO2 host matrix.</p>
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Xu, Chen. "Alumina based nanocomposites by precipitation." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2bc4b631-6b5e-4536-b842-63c591df2832.
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This project addressed two main problems pertaining to Al<sub>2</sub>O<sub>3</sub>-FeAl2O4 nanocomposites developed via solid state precipitation: the mechanisms for precipitation in ceramic solid solution via reduction reaction, and the mechanisms for the improved mechanical properties and wear resistance of the developed Al2O3-FeAl2O4 nanocomposites. A model was proposed for precipitation in ceramic solid solutions via reduction reactions (the PRCS model). The thermodynamics of reduction reactions during aging treatments under various atmospheres were calculated and discussed relative to the second phase precipitate formation. Attempts were made to measure the corresponding diffusion kinetics using a new theory developed here based on volume fraction profiles of second phase particles in the aged samples. It was found that the measured apparent oxygen vacancy diffusivities conform well to the oxygen vacancy grain boundary diffusion coefficients reported in the literature, and the measured apparent matrix diffusivity conforms well to the Fe3+ ion matrix diffusion coefficients reported in literature. Based on the thermodynamics calculations, diffusion kinetics and some essential mechanisms that were discussed, the PRCS model was proposed. This has two aspects: macroscopic and microscopic. The macroscopic aspect of PRCS model was mainly used to explain the general aspects of microstructure and the distribution of intergranualar second phase particles. The microscopic aspect of the PRCS model was mainly used to explain the precipitation of intragranualar nanoparticles. The mechanical properties, thermal residual stress and wear resistance of selected Al2O3-FeAl2O4 nanocomposites were measured. The results revealed that the Al2O3-FeAl2O4 possessed improved fracture toughness (by around 46%), flexural strength (by around 30%) and abrasive wear resistance (by a factor of around 5) with respect to monolithic alumina. Several mechanisms were proposed to explain the improvements in both mechanical properties and wear resistance. Compressive residual stress was found in the surface layer of Al2O3-FeAl2O4 nanocomposites due to the thermal expansion coefficient mismatch between surface layer and bulk parts. Such residual stress was also interpreted as the main reason for the improvements in both mechanical properties and wear resistance.
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Koh, Pei Yoong. "Deposition and assembly of magnesium hydroxide nanostructures on zeolite 4A surfaces." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37159.
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A deposition - precipitation method was developed to produce magnesium hydroxide / zeolite 4A (Mg(OH)₂ - Z4A) nanocomposites at mild conditions and the effect of processing variables such as precursor concentration, type of base added, and synthesis time on the composition, size, and morphology of the nanocomposite were studied. It was determined that the precursor concentration, basicity, and synthesis time had a significant effect on the composition, size, and morphology of the deposited magnesium hydroxide (Mg(OH)₂) nanostructures. The properties of the Mg(OH)₂ - Z4A such as surface area, pore volume and composition were characterized. Mg(OH)₂ - Z4A samples and bare zeolite 4A were dispersed in Ultem® polymer to form a mixed matrix membrane. The thermal and mechanical properties of the resulting films were investigated. It was found that the addition of rigid bare zeolites into the polymer decreased the mechanical properties of the polymer composite. However, some of these adverse effects were mitigated in the polymer composite loaded with Mg(OH)₂ - Z4A samples. Isotherms for the adsorption of Mg(OH)₂ petals on zeolite 4A were measured in order to determine the optimum conditions for the formation of magnesium hydroxide / zeolite 4A nanocomposites at ambient conditions. The loading of the Mg(OH)₂ can be determined from the adsorption isotherms and it was also found that the adsorption of Mg(OH)₂ on zeolite A occurs via 3 mechanisms: ion exchange, surface adsorption of Mg²⁺ ions, and surface precipitation of Mg(OH)₂. Without the addition of ammonium hydroxide, the predominant processes are ion exchange and surface adsorption of Mg²⁺ ions. In the presence of ammonium hydroxide, Mg(OH)₂ crystals are precipitated on the surface of zeolite 4A at moderate Mg²⁺ ions concentration and the loading of Mg(OH)₂ was found to increase with increasing Mg²⁺ ions concentration. A detailed examination of the interactions between Mg(OH)₂ and functional groups on the zeolite surface was conducted. Solid-state 29Si, 27Al, and 1H NMR spectra were coupled with FTIR measurements, pH and adsorption studies, and thermogravimetric analyses to determine the interactions of Mg(OH)₂ with surface functional groups and to characterize structural changes in the resulting zeolite after Mg(OH)₂ deposition. It was discovered that acid - base interactions between the weakly basic Mg(OH)₂ and the acidic bridging hydroxyl protons on zeolite surface represent the dominant mechanism for the growth of Mg(OH)₂ nanostructures on the zeolite surface.
Books on the topic "Nanostructures and nanocomposites"
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Fesenko, Olena, and Leonid Yatsenko, eds. Nanocomposites, Nanostructures, and Their Applications. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17759-1.
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Thomas, Sabu. Rubber nanocomposites: Preparation, properties, and applications. Wiley, 2010.
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J, Pinnavaia Thomas, and Beall G. W, eds. Polymer-clay nanocomposites. Wiley, 2000.
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Misra, Devesh K. Polymer nanocomposites. Minerals, Metals and Materials Society, 2006.
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Adregno, Michael A. Nanocomposites, nanoparticles, and nanotubes. Nova Science Publishers, 2011.
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R, Arshady, and Guyot Alain, eds. Dendrimers, assemblies, nanocomposites. Citus Books, 2002.
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H, Mancini Lorenzo, and Esposito Christian L, eds. Nanocomposites: Preparation, properties, and performance. Nova Science Publishers, 2008.
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Luigi, Nicolais, and Carotenuto Gianfranco, eds. Metal-polymer nanocomposites. Wiley-Interscience, 2005.
Find full textBook chapters on the topic "Nanostructures and nanocomposites"
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Ji, S., H. Gui, G. Guan, M. Zhou, Q. Guo, and M. Y. J. Tan. "Designing Waterborne Protective Coatings Through Manipulating the Nanostructure of Acrylic-Based Nanocomposites." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_14.
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AbstractWaterborne coatings with intended functionalities have been designed by manipulating acrylic-based nanocomposites with different nanostructures. Taking advantage of the favorable structure of acrylic copolymers, three waterborne coatings with various desired properties were created through molecular engineering either by copolymerizing with other components or through nanocomposite formation. This approach was demonstrated by synthesizing acrylic-based waterborne coatings with three different nanostructures, namely homogeneous, worm-like, and spherical-like nanostructures. The properties of coating samples prepared by this new approach and by traditional physical blending were compared experimentally, which revealed that the incorporation of 3-methacryloxypropyltrimethoxysilane (MPS)-modified nanoparticle TiO2 in an acrylic base enabled the formation of a nanocomposite with nanoparticles uniformly distributed in the acrylic base. The coating film with this acrylic-TiO2 nanocomposite showed significantly better UV absorption performance than the coating made by physical blending. The copolymerization of acrylic copolymers with an organic polymer (alkyd) created a worm-like nanostructure of acrylic–alkyd composite that allowed uniform distribution of the acrylic–alkyd nanocomposite in a more closely packed dense coating film, leading to enhanced barrier property and significantly improved corrosion resistance as confirmed by electrochemical impedance spectroscopy and salt spray tests. The copolymerization of acrylic monomers with an inorganic polymer (polydimethylsiloxane [PDMS]) led to a spherical-like nanostructure of acrylic–PDMS composite film. The formation of this nanostructure arose from the migration of PDMS segments, and a PDMS-rich phase formed on the film’s surface, which resulted in a coating film with PDMS functionalities such as low dirt-picking behavior. Overall, these three cases demonstrated that acrylic copolymer are an excellent base for developing various nanocomposite waterborne coatings with different functionalities through copolymerization and that the nanocomposites with different nanostructures have a significant influence on the coatings’ performance.
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Caseri, W. R. "IN SITUSYNTHESIS OF POLYMER-EMBEDDED NANOSTRUCTURES." In Nanocomposites. John Wiley & Sons, Inc, 2013. http://dx.doi.org/10.1002/9781118742655.ch2.
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Krolow, M. Z., C. A. Hartwig, G. C. Link, et al. "Synthesis and Characterisation of Carbon Nanocomposites." In Carbon Nanostructures. Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31960-0_2.
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Garg, Bhaskar, Tanuja Bisht, and K. R. Justin Thomas. "Magnetic Graphene Nanocomposites for Multifunctional Applications." In Complex Magnetic Nanostructures. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-52087-2_9.
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Tong, Xin, G. Zhang, Jai Prakash, and Shuhui Sun. "3D Graphene and Its Nanocomposites: From Synthesis to Multifunctional Applications." In Carbon Nanostructures. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-32-9057-0_15.
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Yasri, Sora, and Viroj Wiwanitkit. "Application of Chitosan Nanostructures Embedded Composite Materials in Cancer Therapy." In Chitosan Nanocomposites. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-19-9646-7_13.
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Marshall, Jean E., Yan Y. Huang, and Eugene M. Terentjev. "CHAPTER 11. Polymer Nanocomposites: Conductivity, Deformations and Photoactuation." In Responsive Photonic Nanostructures. Royal Society of Chemistry, 2013. http://dx.doi.org/10.1039/9781849737760-00292.
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Tsakalakos, T., R. L. Lehman, T. N. Nosker, et al. "Applications of Functional Nanocomposites." In Nanostructures: Synthesis, Functional Properties and Applications. Springer Netherlands, 2003. http://dx.doi.org/10.1007/978-94-007-1019-1_40.
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Barakat, Nasser A. M., and Muzafar A. Kanjwal. "Influences of Morphology and Doping on the Photoactivity of TiO2 Nanostructures." In Structural Nanocomposites. Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-40322-4_5.
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Mohan, Rajneesh, and Jaromir Hubalek. "Hybrid Oxide Nanostructures as Photocatalysts." In Oxide Thin Films, Multilayers, and Nanocomposites. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14478-8_13.
Full textConference papers on the topic "Nanostructures and nanocomposites"
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Malakooti, Mohammad H., Florian Julé, and Henry A. Sodano. "Energy Harvesting Performance of Printed Barium Titanate Nanocomposites." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8093.
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Development of nanostructured devices for sensing, energy storage, actuating, and energy harvesting has attracted many researchers. The most common type of functional nanostructures is piezoelectric nanomaterials. Regardless of numerous studies in this area, there is a need for rapid fabrication of nanostructured devices, or simply functional nanocomposites. Here we present a simple, scalable fabrication technique for additive manufacturing of nanocomposite energy harvesting devices composed of barium titanate nanowires. Details on hydrothermal synthesis of barium titanate (BaTiO3) nanowires and printable inks, manufacturing process, and energy harvesting performance of the printed devices are presented here. The experimental results suggest that additive manufacturing of functional nanocomposites allows controlling the microstructures and enhancing device performance.
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MORA, ANGEL, CARLOS MEDINA, and FRANCIS AVILÉS. "A COMPUTATIONAL MODEL FOR THE PIEZORESISTIVE RESPONSE OF HYBRID CARBON NANOSTRUCTURED NETWORKS." In Thirty-sixth Technical Conference. Destech Publications, Inc., 2021. http://dx.doi.org/10.12783/asc36/35860.
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Carbon nanotubes (CNTs) and graphenic sheets (GSs) are commonly used fillers for polymer nanocomposites. These nanocomposites can be used as selfsensing materials (strain and damage sensors) due to their piezoresistive response. CNT/GS hybrid fillers could be used to tune the nanocomposite’s piezoresistive response. The piezoresistive response of polymers filled with hybrid carbon nanofillers is a novel topic being studied recently experimentally, and very few computational works are available. Thus, a computational model is developed to study the piezoresistive response of polymers filled with CNT/GS hybrid fillers, reproducing geometries and conditions similar to those used in experiments. This computational model generates a network of three dimensional (3D) representations of carbon nanostructures inside a cube, which represents the polymer matrix. The network of nanostructures is turned into a network of resistors to obtain the electrical conductivity of the cube, and thus the polymer nanocomposite. Mechanical strain is applied via coupling with a finite element software. To reduce computational time, embedded elements are used in the finite element simulations. Capabilities and limitations of the proposed computational model are explored.
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Chen, Chenggang. "Factors Influencing the Morphology Development of Epoxy Nanocomposites." In ASME 2006 Multifunctional Nanocomposites International Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/mn2006-17083.
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Polymer nanocomposites draw great interest due to their unique nanostructures and improved properties [1–2]. Epoxy is a widely-used thermosetting material. The research on the epoxy layered-silicate epoxy nanocomposite has exploded in the last decade [3–9]. The morphology of nanocomposites is the key to making high-performance nanocomposites. In this presentation, the factors influencing the morphology development behavior of epoxy nanocomposites will be discussed. The factors to be investigated include organoclay, epoxide, and curing agent. In this study, the aliphatic diamine (Jeffamines) with different molecular weights and aromatic diamine were selected as the curing agents, S30B (quaternary onium-montmorillonite) and SC18 (primary oniummont-morillonite) as the organoclays, and Epon 862 and Epon 828 as epoxides. In situ small-angle x-ray scattering (SAXS) was utilized to study the morphology development of the epoxy nanocomposite.
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Yang, Ronggui, Gang Chen, and Mildred S. Dresselhaus. "Thermal Conductivity of Core-Shell Nanostructures: From Nanowires to Nanocomposites." In ASME 2005 Summer Heat Transfer Conference collocated with the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems. ASMEDC, 2005. http://dx.doi.org/10.1115/ht2005-72198.
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Core-shell heterostructures could potentially become the building blocks of nanotechnology for electronic and optoelectronic applications. The increased surface or interface area will decrease the thermal conductivity of such nanostructures and impose challenges for the thermal management such devices. In the mean time, the decreased thermal conductivity might benefit the thermoelectric conversion efficiency. In this paper, a generic model is established to study phonon transport in core-shell nanowire structures in the longitudinal direction using the phonon Boltzmann equation. The model can be used to simulate a variety of nanostructures, including nanowires and nanocomposites by changing some of the input parameters. We first report the dependence of the thermal conductivity on the surface conditions and the core-shell geometry for silicon core - germanium shell and tubular silicon nanowires. When the scattering at the outer shell surface in the generic model is assumed to be totally specular, the core-shell nanostructure resembles a simulation unit cell of periodic two-dimensional (2-D) nanocomposites. Thermal conductivity of nanowire composites and cylindrical nanoporous material in longitudinal direction is thus predicted as a function of the size of the nanowires and nanopores, and the volumetric fraction of the constituent materials. Results of this study can be used to direct the development of high efficiency thermoelectric materials.
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Tomar, Vikas, and Min Zhou. "Strength Analyses of FE2O3+Al Nanocomposites Using Classical Molecular Dynamics." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79282.
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Classical molecular dynamics (CMD) simulation is an important technique for analyzing custom-designed nanostructured materials and nano-sized systems such as nanowires and nanobelts. This research focuses on analyzing the strength of Fe2O3+Al energetic nanocomposites using CMD. A generic potential form is used to describe the behavior of the Fe+Al+Fe2O3+Al2O3 system. The potential is able to describe bulk single crystal behavior of Fe, Al, Fe2O3, Al2O3 as well as interfacial transitions among them. The nanostructures analyzed include polycrystalline Aluminum, Fe2O3 as well as their composites with two different volume fractions (0.6/0.4 and 04/0.6). The polycrystalline structures are generated using voronoi tessellation. Quasi-static strength analyses are carried out using a massively parallel CMD code for both tension and compression. The analyses reveal that reverse Hall-Petch (H-P) effect is operative for polycrystalline Al under both tension and compression. However, for polycrystalline Fe2O3 reverse H-P effect is operative under tension only. Compression still shows direct H-P effect. This effect transcends into the strength of both composites at all grain sizes. In addition, we also observe tension-compression strength asymmetry in the all polycrystalline systems. This framework offers an important tool for nanoscale design of advanced nanocomposite materials.
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Lee, Soo-Hyun, ChaeWon Mun, and Sung-Gyu Park. "Active Nanoscale Engineering of 3D Plasmonic Hotspots for SERS-based Optical Sensing Applications." In Applied Industrial Spectroscopy. Optica Publishing Group, 2023. http://dx.doi.org/10.1364/ais.2023.jw2a.5.
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Ultrasensitive optical sensing platform through electrosynthesis of plasmonic-molecule nanocomposites is proposed. Bottom-up growth of metal nanostructures in presence of molecules intensifies light–matter interactions by full utilization of metal-molecule intimacy across entire 3D architecture of nanocomposites.
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Kostic, Milivoje M. "Critical Issues and Application Potentials in Nanofluids Research." In ASME 2006 Multifunctional Nanocomposites International Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/mn2006-17036.
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Development of many industrial and new technologies is limited by existing thermal management, and need for high-performance cooling. Nanofluids, stable colloidal mixtures of nanoparticles (including nanofibers and functional nanocomposites) in common fluids, have a potential to meet these and many other challenges. Colloidal nano-mixtures with functionally-stable and active-like nanostructures that may self-adjust to the process conditions, require systematic surface-chemistry study and enhancements (coatings with functional layers, surfactants, etc), in addition to investigation of thermo-physical characteristics and phenomena. A comprehensive, systematic and interdisciplinary experimental research program is necessary to study, understand and resolve critical issues in nanofluids research to date. The research must focus on both synthesis and a careful exploration of thermo-physical characteristics. Development of new-hybrid, drag-reducing nanofluids may lead to enhanced flow and heat transfer characteristics. The nanoparticles in these fluids yield increased heat-transfer while the long-chain polymers are expected to enhance flow properties, including active and functional interactions with nanoparticles, thus providing potential for many applications yet to be developed and optimized.
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Nakarmi, Sushan, and V. U. Unnikrishnan. "Thermal Transport Properties and Interface Effects of Carbon Nanostructures." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-72475.
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The variations in thermal conductivity of nanocomposites are found to depend not only the intrinsic properties of the fiber and matrix phases but also on the interfacial resistance of the reinforcing phase. As we go down the length scales, the interfacial thermal resistance due to size of the nanoparticle becomes significant. In order to address the effect of size (length and diameter) of nanotube on the thermal transport property of nanotube composites, thermal conductivity of different nanotube samples varying in length and diameter will be estimated first using molecular dynamic (MD) simulations with AIREBO potentials. This will be carried out using the ‘Heat-Bath’ method - non-equilibrium molecular dynamics (NEMD) approach. In the heat bath method, constant amount of heat is added to and removed from the hot and cold regions and the resulting temperature gradient is measured and the thermal conductivity is calculated using the Fourier Law. This will be followed by the study of interfacial thermal resistance of these nanostructures. These intrinsic properties are then used with continuum based mathematical formulations to study the effect of size of the nanoparticle on the overall thermal conductivity of the nanocomposite.
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Lee, Hohyun, Daryoosh Vashaee, Xiaowei Wang, et al. "Thermoelectric Transport in Silicon Germanium Nanocomposite." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67436.
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Direct energy conversion between heat and electrical energy based on thermoelectric effects is attractive for potential applications in waste heat recovery and environmentally-friendly refrigeration. The energy conversion efficiency depends on the dimensionless figure of merit of thermoelectric materials, ZT, which is proportional to the electrical conductivity, the square of the Seebeck coefficient, and the inverse of the thermal conductivity. Currently, the low ZT values of available materials restrict the applications of this technology. However, significant enhancements in ZT were recently reported in nanostructured materials such as superlattices mainly due to their low thermal conductivities. According to recent studies, the reduced thermal conductivity of nanostructures is attributed to the large number of interfaces at which phonons are scattered. Based on this idea, nanocomposites are expected to have a lower thermal conductivity than their bulk counterparts with low fabrication cost just by mixing nano sized particles. In this work, we will discuss mechanisms of thermoelectric transport via modeling and provide experimental evidence on the enhancement of thermoelectric figure of merit in SiGe-based nanocomposites.
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Samvedi, Vikas, and Vikas Tomar. "Role of Interface Thermal Boundary Resistance, Straining, and Morphology in Thermal Conductivity of a Set of Si-Ge Superlattices and Biomimetic Si-Ge Nanocomposites." In ASME 2011 Pacific Rim Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Systems. ASMEDC, 2011. http://dx.doi.org/10.1115/ipack2011-52284.
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Nanoscale engineered materials with tailored thermal properties are desirable for applications such as highly efficient thermoelectric, microelectronic and optoelectronic devices. It has been shown earlier that by judiciously varying interface thermal boundary resistance (TBR) thermal conductivity in nanostructures could be controlled. Two types of nanostructures that have gained significant attention owing to the presence of TBR are superlattices and nanocomposites. A systematic comparison of thermal behavior of superlattices and nanocomposites considering their characteristic structural factors such as periodicity and period length for superlattices, and morphology for nanocomposites, under different extents of straining at a range of temperatures remains to be performed. In this presented work, such analyses are performed for a set of Si-Ge superlattices and Si-Ge biomimetic nanocomposites using non-equilibrium molecular dynamics (NEMD) simulations at three different temperatures (400 K, 600 K, and 800 K) and at strain levels varying between −10% and 10%. The analysis of interface TBR contradicts the usual notion that each interface contributes equally to the heat transfer resistance in a layered structure. The dependence of thermal conductivity of superlattice on the direction of heat flow gives it a characteristic somewhat similar to a thermal diode as found in this study. The comparison of thermal behavior of superlattices and nanocomposites indicate that the nanoscale morphology differences between the superlattices and the nanocomposites lead to a striking contrast in the phonon spectral density, interfacial thermal boundary resistance, and thermal conductivity. Both compressive and tensile strains are observed to be important factors in tailoring the thermal conductivity of the analyzed superlattices, whereas have very insignificant influence on the thermal conductivity of the analyzed nanocomposites.
Reports on the topic "Nanostructures and nanocomposites"
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Seliverstova, Evgeniya, Timur Serikov, Aigyl Sadykova, and Niyazbek Ibrayev. Effect of Ag/TiO2 core/shell nanostructures on the photocatalytic activity of the TiO2/rGO nanocomposite material. Peeref, 2023. http://dx.doi.org/10.54985/peeref.2307p5991014.
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