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1
Hu, Zeyi, Wenliang Liu e Caihe Fan. "Micro-Nanostructure Formation Mechanism of High-Mg Al Alloy". Nanoscience and Nanotechnology Letters 11, n. 10 (1 ottobre 2019): 1338–48. http://dx.doi.org/10.1166/nnl.2019.3016.
Testo completoAbstract (sommario):
Micro-nanostructured materials have superior mechanical properties compared with coarse-grained materials. Severe plastic deformation (SPD) can effectively refine grains, resulting in the formation of typical micro-nanostructures. Fine grains improve alloy strength and toughness. This review summarizes the application of several typical SPD methods for high-Mg Al alloy. The effects of different SPD methods on the microstructure evolution, micro-nanostructure formation mechanism, and mechanical properties of the high-Mg Al alloy are analyzed in sequence. Finally, the development and future of the high-Mg Al alloy micro/nanostructure regulation are described.
2
Afshar, Elham N., Georgi Xosrovashvili, Rasoul Rouhi e Nima E. Gorji. "Review on the application of nanostructure materials in solar cells". Modern Physics Letters B 29, n. 21 (10 agosto 2015): 1550118. http://dx.doi.org/10.1142/s0217984915501183.
Testo completoAbstract (sommario):
In recent years, nanostructure materials have opened a promising route to future of the renewable sources, especially in the solar cells. This paper considers the advantages of nanostructure materials in improving the performance and stability of the solar cell structures. These structures have been employed for various performance/energy conversion enhancement strategies. Here, we have investigated four types of nanostructures applied in solar cells, where all of them are named as quantum solar cells. We have also discussed recent development of quantum dot nanoparticles and carbon nanotubes enabling quantum solar cells to be competitive with the conventional solar cells. Furthermore, the advantages, disadvantages and industrializing challenges of nanostructured solar cells have been investigated.
3
Gupta, Vinod Kumar, Njud S. Alharbie, Shilpi Agarwal e Vladimir A. Grachev. "New Emerging One Dimensional Nanostructure Materials for Gas Sensing Application: A Mini Review". Current Analytical Chemistry 15, n. 2 (19 febbraio 2019): 131–35. http://dx.doi.org/10.2174/1573411014666180319151407.
Testo completoAbstract (sommario):
Background: Nanomaterials have numerous potential applications in many areas such as electronics, optoelectronics, catalysis and composite materials. Particularly, one dimensional (1D) nanomaterials such as nanobelts, nanorods, and nanotubes can be used as either functional materials or building blocks for hierarchical nanostructures. 1D nanostructure plays a very important role in sensor technology. Objective: In the current review, our efforts are directed toward recent review on the use of 1D nanostructure materials which are used in the literature for developing high-performance gas sensors with fast response, quick recovery time and low detection limit. This mini review also focuses on the methods of synthesis of 1D nanostructural sensor array, sensing mechanisms and its application in sensing of different types of toxic gases which are fatal for human mankind. Particular emphasis is given to the relation between the nanostructure and sensor properties in an attempt to address structure-property correlations. Finally, some future research perspectives and new challenges that the field of 1D nanostructure sensors will have to address are also discussed.
4
Yang, Ming, Xiaohua Chen, Zidong Wang, Yuzhi Zhu, Shiwei Pan, Kaixuan Chen, Yanlin Wang e Jiaqi Zheng. "Zero→Two-Dimensional Metal Nanostructures: An Overview on Methods of Preparation, Characterization, Properties, and Applications". Nanomaterials 11, n. 8 (23 luglio 2021): 1895. http://dx.doi.org/10.3390/nano11081895.
Testo completoAbstract (sommario):
Metal nanostructured materials, with many excellent and unique physical and mechanical properties compared to macroscopic bulk materials, have been widely used in the fields of electronics, bioimaging, sensing, photonics, biomimetic biology, information, and energy storage. It is worthy of noting that most of these applications require the use of nanostructured metals with specific controlled properties, which are significantly dependent on a series of physical parameters of its characteristic size, geometry, composition, and structure. Therefore, research on low-cost preparation of metal nanostructures and controlling of their characteristic sizes and geometric shapes are the keys to their development in different application fields. The preparation methods, physical and chemical properties, and application progress of metallic nanostructures are reviewed, and the methods for characterizing metal nanostructures are summarized. Finally, the future development of metallic nanostructure materials is explored.
5
Chen, Huige, Run Shi e Tierui Zhang. "Nanostructured Photothermal Materials for Environmental and Catalytic Applications". Molecules 26, n. 24 (13 dicembre 2021): 7552. http://dx.doi.org/10.3390/molecules26247552.
Testo completoAbstract (sommario):
Solar energy is a green and sustainable clean energy source. Its rational use can alleviate the energy crisis and environmental pollution. Directly converting solar energy into heat energy is the most efficient method among all solar conversion strategies. Recently, various environmental and energy applications based on nanostructured photothermal materials stimulated the re-examination of the interfacial solar energy conversion process. The design of photothermal nanomaterials is demonstrated to be critical to promote the solar-to-heat energy conversion and the following physical and chemical processes. This review introduces the latest photothermal nanomaterials and their nanostructure modulation strategies for environmental (seawater evaporation) and catalytic (C1 conversion) applications. We present the research progress of photothermal seawater evaporation based on two-dimensional and three-dimensional porous materials. Then, we describe the progress of photothermal catalysis based on layered double hydroxide derived nanostructures, hydroxylated indium oxide nanostructures, and metal plasmonic nanostructures. Finally, we present our insights concerning the future development of this field.
6
Han, Yang, e Zhien Zhang. "Nanostructured Membrane Materials for CO2 Capture: A Critical Review". Journal of Nanoscience and Nanotechnology 19, n. 6 (1 giugno 2019): 3173–79. http://dx.doi.org/10.1166/jnn.2019.16584.
Testo completoAbstract (sommario):
To mitigate carbon emission from the combustion of fossil fuels, membrane is advantageous due to the fact that membrane is a thin interphase acting as a selective barrier separating two phases. This thinness, typically in the range of 100 nm to a few micrometers, provides an almost natural platform to implement functional nanostructures. In this review, the recent progress in nanostructured membrane materials for CO2 capture will be discussed, including applications in flue gas decarbonizing (CO2/N2 separation) and syngas purification (CO2/H2 separation). In addition, the fundamentals of membrane technologies are also introduced. The reviewed nanostructure formation is confined to solid state materials, including polymer with intrinsic microporosity, carbon-based membranes, zeolite, and metal organic framework.
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Paul, Sourav, Md Arafat Rahman, Sazzad Bin Sharif, Jin-Hyuk Kim, Safina-E.-Tahura Siddiqui e Md Abu Mowazzem Hossain. "TiO2 as an Anode of High-Performance Lithium-Ion Batteries: A Comprehensive Review towards Practical Application". Nanomaterials 12, n. 12 (13 giugno 2022): 2034. http://dx.doi.org/10.3390/nano12122034.
Testo completoAbstract (sommario):
Lithium-ion batteries (LIBs) are undeniably the most promising system for storing electric energy for both portable and stationary devices. A wide range of materials for anodes is being investigated to mitigate the issues with conventional graphite anodes. Among them, TiO2 has attracted extensive focus as an anode candidate due to its green technology, low volume fluctuations (<4%), safety, and durability. In this review, the fabrication of different TiO2 nanostructures along with their electrochemical performance are presented. Different nanostructured TiO2 materials including 0D, 1D, 2D, and 3D are thoroughly discussed as well. More precisely, the breakthroughs and recent developments in different anodic oxidation processes have been explored to identify in detail the effects of anodization parameters on nanostructure morphology. Clear guidelines on the interconnected nature of electrochemical behaviors, nanostructure morphology, and tunable anodic constraints are provided in this review.
8
Cho, Seong J., Se Yeong Seok, Jin Young Kim, Geunbae Lim e Hoon Lim. "One-Step Fabrication of Hierarchically Structured Silicon Surfaces and Modification of Their Morphologies Using Sacrificial Layers". Journal of Nanomaterials 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/289256.
Testo completoAbstract (sommario):
Fabrication of one-dimensional nanostructures is a key issue for optical devices, fluidic devices, and solar cells because of their unique functionalities such as antireflection and superhydrophobicity. Here, we report a novel one-step process to fabricate patternable hierarchical structures consisting of microstructures and one-dimensional nanostructures using a sacrificial layer. The layer plays a role as not only a micromask for producing microstructures but also as a nanomask for nanostructures according to the etching time. Using this method, we fabricated patterned hierarchical structures, with the ability to control the shape and density of the nanostructure. The various architectures provided unique functionalities. For example, our sacrificial-layer etching method allowed nanostructures denser than what would be attainable with conventional processes to form. The dense nanostructure resulted in a very low reflectance of the silicon surface (less than 1%). The nanostructured surface and hierarchically structured surface also exhibited excellent antiwetting properties, with a high contact angle (>165°) and low sliding angle (<1°). We believe that our fabrication approach will provide new insight into functional surfaces, such as those used for antiwetting and antireflection surface applications.
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Pauly, Alain, Sahal Saad Ali, Christelle Varenne, Jérôme Brunet, Eduard Llobet e Amadou L. Ndiaye. "Phthalocyanines and Porphyrins/Polyaniline Composites (PANI/CuPctBu and PANI/TPPH2) as Sensing Materials for Ammonia Detection". Polymers 14, n. 5 (24 febbraio 2022): 891. http://dx.doi.org/10.3390/polym14050891.
Testo completoAbstract (sommario):
We combined a conducting polymer, polyaniline (PANI), with an organic semiconducting macrocyclic (MCs) material. The macrocycles are the phthalocyanines and porphyrins used to tune the electrical properties of the PANI, which benefits from their ability to enhance sensor response. For this, we proceeded by a simple ultrasonically assisted reaction involving the two components, i.e., the PANI matrix and the MCs, to achieve the synthesis of the composite nanostructure PANI/MCs. The composite nanostructure has been characterized and deposited on interdigitated electrodes (IDEs) to construct resistive sensor devices. The isolated nanostructured composites present good electrical properties dominated by PANI electronic conductivity, and the characterization reveals that both components are present in the nanostructure. The experimental results obtained under gas exposures show that the composite nanostructures can be used as a sensing material with enhanced sensing properties. The sensing performance under different conditions, such as ambient humidity, and the sensor’s operating temperature are also investigated. Sensing behavior in deficient humidity levels and their response at different temperatures revealed unusual behaviors that help to understand the sensing mechanism. Gas sensors based on PANI/MCs demonstrate significant stability over time, but this stability is highly reduced after experiments in lower humidity conditions and at high temperatures.
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Erb, Denise J., Kai Schlage e Ralf Röhlsberger. "Uniform metal nanostructures with long-range order via three-step hierarchical self-assembly". Science Advances 1, n. 10 (novembre 2015): e1500751. http://dx.doi.org/10.1126/sciadv.1500751.
Testo completoAbstract (sommario):
Large-scale nanopatterning is a major issue in nanoscience and nanotechnology, but conventional top-down approaches are challenging because of instrumentation and process complexity while often lacking the desired spatial resolution. We present a hierarchical bottom-up nanopatterning routine using exclusively self-assembly processes: By combining crystal surface reconstruction, microphase separation of copolymers, and selective metal diffusion, we produce monodisperse metal nanostructures in highly regular arrays covering areas of square centimeters. In situ grazing incidence small-angle x-ray scattering during Fe nanostructure formation evidences an outstanding structural order in the self-assembling system and hints at the possibility of sculpting nanostructures using external process parameters. Thus, we demonstrate that bottom-up nanopatterning is a competitive alternative to top-down routines, achieving comparable pattern regularity, feature size, and patterned areas with considerably reduced effort. Intriguing assets of the proposed fabrication approach include the option for in situ investigations during pattern formation, the possibility of customizing the nanostructure morphology, the capacity to pattern arbitrarily large areas with ultrahigh structure densities unachievable by top-down approaches, and the potential to address the nanostructures individually. Numerous applications of self-assembled nanostructure patterns can be envisioned, for example, in high-density magnetic data storage, in functional nanostructured materials for photonics or catalysis, or in surface plasmon resonance–based sensing.
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Salvat-Pujol, Francesc, Harald O. Jeschke e Roser Valentí. "Simulation of electron transport during electron-beam-induced deposition of nanostructures". Beilstein Journal of Nanotechnology 4 (22 novembre 2013): 781–92. http://dx.doi.org/10.3762/bjnano.4.89.
Testo completoAbstract (sommario):
We present a numerical investigation of energy and charge distributions during electron-beam-induced growth of tungsten nanostructures on SiO2 substrates by using a Monte Carlo simulation of the electron transport. This study gives a quantitative insight into the deposition of energy and charge in the substrate and in the already existing metallic nanostructures in the presence of the electron beam. We analyze electron trajectories, inelastic mean free paths, and the distribution of backscattered electrons in different compositions and at different depths of the deposit. We find that, while in the early stages of the nanostructure growth a significant fraction of electron trajectories still interacts with the substrate, when the nanostructure becomes thicker the transport takes place almost exclusively in the nanostructure. In particular, a larger deposit density leads to enhanced electron backscattering. This work shows how mesoscopic radiation-transport techniques can contribute to a model that addresses the multi-scale nature of the electron-beam-induced deposition (EBID) process. Furthermore, similar simulations can help to understand the role that is played by backscattered electrons and emitted secondary electrons in the change of structural properties of nanostructured materials during post-growth electron-beam treatments.
12
Stolbovsky, Alexey V., e Elena Farafontova. "Statistical Analysis of Histograms of Grain Size Distribution in Nanostructured Materials Processed by Severe Plastic Deformation". Solid State Phenomena 284 (ottobre 2018): 431–35. http://dx.doi.org/10.4028/www.scientific.net/ssp.284.431.
Testo completoAbstract (sommario):
Analysis of histograms of grain size distribution of materials nanostructured by severe plastic deformation has been carried out using statistical analysis methods. It has been established that in materials with quite homogeneous nanostructure, the fitting of histograms of grain size distribution by using a logarithmic standard distribution is not accurate enough. It is proposed to compensate for the observed imprecision by including into the model the additional component – normal distribution. It is shown that this approach is applicable to nanostructured materials with both the deformation-origin nanostructure and the grain structure formed during annealing.
13
Tatsuoka, Hirokazu, Wen Li, Er Chao Meng, Daisuke Ishikawa e Kaito Nakane. "Syntheses and Structural Control of Silicide, Oxide and Metallic Nano-Structured Materials". Solid State Phenomena 213 (marzo 2014): 35–41. http://dx.doi.org/10.4028/www.scientific.net/ssp.213.35.
Testo completoAbstract (sommario):
The structural control and morphological modification of a series of silicide, oxide and Ag metal nanostructures have been further discussed with reviews of nanostructure syntheses, such as CrSi2 nanowire bundles dendrites, MoSi2 nanosheets, α-Fe2O3 nanowires nanobelts, CuO/Cu2O nanowire axial heterostructures, ZrO2/SiOx and CrSi2/SiOx core/shell nanowires. In addition, the syntheses of Ag three-dimensional dendrites, two-dimensional dendrites, two-dimensional fractal structures, particles and nanowires also were discussed. Moreover, the structural and morphological properties of the nanostructures were examined. The structural control and morphological modifications of the nanostructures have been successfully demonstrated by the appropriate thermal treatments with specific starting materials. A large volume of silicide nanowire bundles, large area of oxide nanowire arrays and large area Ag nanostructure coatings were successfully fabricated.
14
Maciulis, Vincentas, Almira Ramanaviciene e Ieva Plikusiene. "Recent Advances in Synthesis and Application of Metal Oxide Nanostructures in Chemical Sensors and Biosensors". Nanomaterials 12, n. 24 (10 dicembre 2022): 4413. http://dx.doi.org/10.3390/nano12244413.
Testo completoAbstract (sommario):
Nanostructured materials formed from metal oxides offer a number of advantages, such as large surface area, improved mechanical and other physical properties, as well as adjustable electronic properties that are important in the development and application of chemical sensors and biosensor design. Nanostructures are classified using the dimensions of the nanostructure itself and their components. In this review, various types of nanostructures classified as 0D, 1D, 2D, and 3D that were successfully applied in chemical sensors and biosensors, and formed from metal oxides using different synthesis methods, are discussed. In particular, significant attention is paid to detailed analysis and future prospects of the synthesis methods of metal oxide nanostructures and their integration in chemical sensors and biosensor design.
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Nocua, José E., Fabrice Piazza, Brad R. Weiner e Gerardo Morell. "High-Yield Synthesis of Stoichiometric Boron Nitride Nanostructures". Journal of Nanomaterials 2009 (2009): 1–6. http://dx.doi.org/10.1155/2009/429360.
Testo completoAbstract (sommario):
Boron nitride (BN) nanostructures are structural analogues of carbon nanostructures but have completely different bonding character and structural defects. They are chemically inert, electrically insulating, and potentially important in mechanical applications that include the strengthening of light structural materials. These applications require the reliable production of bulk amounts of pure BN nanostructures in order to be able to reinforce large quantities of structural materials, hence the need for the development of high-yield synthesis methods of pure BN nanostructures. Using borazine (B3N3H6) as chemical precursor and the hot-filament chemical vapor deposition (HFCVD) technique, pure BN nanostructures with cross-sectional sizes ranging between 20 and 50 nm were obtained, including nanoparticles and nanofibers. Their crystalline structure was characterized by (XRD), their morphology and nanostructure was examined by (SEM) and (TEM), while their chemical composition was studied by (EDS), (FTIR), (EELS), and (XPS). Taken altogether, the results indicate that all the material obtained is stoichiometric nanostructured BN with hexagonal and rhombohedral crystalline structure.
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Zhang, Shiying, Huizhao Zhuang, Chengshan Xue e Baoli Li. "Effect of Annealing on Morphology and Photoluminescence of β-Ga2O3 Nanostructures". Journal of Nanoscience and Nanotechnology 8, n. 7 (1 luglio 2008): 3454–57. http://dx.doi.org/10.1166/jnn.2008.138.
Testo completoAbstract (sommario):
A novel method was applied to prepare one-dimensional β-Ga2O3 nanostructure films. In this method, β-Ga2O3 nanostructures have been successfully synthesized on Si(111) substrates through annealing sputtered Ga2O3/Mo films for differernt time under flowing ammonia. The as-synthesized β-Ga2O3 nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results show that the formed nanostructures are single-crystalline Ga2O3 with monoclinic structure. The annealing time of the samples has an evident influence on the morphology and optical property of the nanostructured β-Ga2O3 synthesized. The representative photoluminescence spectrum at room temperature exhibits a strong and broad emission band centered at 411.5 nm and a relatively weak emission peak located at 437.6 nm. The growth mechanism of the β-Ga2O3 nanostructured materials is also discussed briefly.
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Fecht, H. J. "Nanostructure formation and thermal stability of nanophase materials prepared by mechanical means". International Journal of Materials Research 94, n. 10 (1 ottobre 2003): 1134–42. http://dx.doi.org/10.1515/ijmr-2003-0205.
Testo completoAbstract (sommario):
Abstract Mechanical attrition, mechanical alloying and other methods of extreme plastic deformation (high pressure torsion, equal channel angular pressing) have been developed as versatile alternatives to other physical and chemical processing routes in preparing nanophase materials. Here several examples are discussed including the deformation-induced nanophase formation in powder particles, in thin-foil sandwich structures and at the surface of alloys exposed to friction-induced wear, leading to the formation of nanocrystals and, in some cases, amorphous nanostructures. This opens exciting perspectives in preparing nanostructured materials with a number of different interface types in terms of structure (crystalline/crystalline, crystalline/amorphous) as well as atomic bond (metal/metal, metal/semiconductor, metal/ ceramic etc.). It is expected that the study of nanostructure formation by mechanical means in the future not only opens new processing routes for a variety of advanced nanophase materials but also improves the understanding of technologically relevant deformation processes on a nanoscopic level.
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Sen, Dipanjan, e Markus J. Buehler. "Shock Loading of Bone-Inspired Metallic Nanocomposites". Solid State Phenomena 139 (aprile 2008): 11–22. http://dx.doi.org/10.4028/www.scientific.net/ssp.139.11.
Testo completoAbstract (sommario):
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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Kalita, Dhiman, Jiten Kumar Deuri, Puspanjali Sahu e Unnikrishnan Manju. "Plasmonic nanostructure integrated two-dimensional materials for optoelectronic devices". Journal of Physics D: Applied Physics 55, n. 24 (17 febbraio 2022): 243001. http://dx.doi.org/10.1088/1361-6463/ac5191.
Testo completoAbstract (sommario):
Abstract Last decade has seen an explosion in the exploration of two-dimensional materials for optoelectronic applications owing to their novel optical and electronic properties. However, these materials, in general, are poor light absorbers with restricted spectral responsivity which limits their efficiency. Integration of these two-dimensional materials with each other and with plasmonic metal nanostructures enhances their light absorption efficiency and also influence the electronic properties. This review highlights the optical and electronic properties of two-dimensional materials integrated with other plasmonic two- dimensional materials or with plasmonic metal nanostructures. In addition, an overview of the optoelectronic properties of plasmonic nanostructure integrated two-dimensional heterostructures is also presented.
20
Yoon, Sang-Hyeok, e Kyo-Seon Kim. "Preparation of 1-D Nanostructured Tungsten Oxide Thin Film on Wire Mesh by Flame Vapor Deposition Process". Journal of Nanoscience and Nanotechnology 20, n. 7 (1 luglio 2020): 4517–20. http://dx.doi.org/10.1166/jnn.2020.17552.
Testo completoAbstract (sommario):
Flame vapor deposition (FVD) process can be used to prepare the tungsten oxide thin film which has photocatalytic activity at visible light. The FVD process is fast and economical to prepare thin film on substrate comparing to other processes. Various nanostructured thin films could be easily prepared by controlling several process parameters in FVD. One-dimensional (1-D) nanostructures with high surface area also can be prepared reproducibly. The tungsten wire precursor was oxidized and vaporized in flame to be deposited onto the substrate. The nanostructure shapes can be adjusted by controlling nucleation and growth rates of tungsten oxide vapor on substrate. In this study, nanostructured tungsten oxide thin film was fabricated on stainless steel mesh by FVD process changing the process variables of FVD. We found that proper selection of suitable process conditions in FVD was quite important for the 1-D nanostructure growth on stainless steel wire mesh with high surface area, which is quite important for photocatalytic application.
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Franco, Alfredo, Jorge A. García-Macedo, I. G. Marino e P. P. Lottici. "Photoinduced Birefringence in Nanostructured SiO2:DR1 Sol–Gel Films". Journal of Nanoscience and Nanotechnology 8, n. 12 (1 dicembre 2008): 6576–83. http://dx.doi.org/10.1166/jnn.2008.18428.
Testo completoAbstract (sommario):
Pump-probe photoinduced birefringence measurements were carried out in amorphous and in nanostructured sol–gel films with Disperse Red 1 (DR1) azochromophores embedded in a SiO2 matrix. X-ray diffraction (XRD) patterns determine the long-range nanostructure order of the films, exhibiting a lamellar nanostructure, with two different d-spacings, due to the presence during the sol–gel process of the Sodium Dodecyl Sulfate (SDS) or of the Cetyltrimethylammonium Bromide (CTAB) ionic surfactants. The photoinduced birefringence measurements were performed on fresh and on heat treated films as a function of the pumping time. The measurements give us information about the effect of the nanostructures on the azochromophores orientation dynamics. As a result, for the same azochromophores concentration, annealed nanostructured films exhibited the largest azochromophore mobilities but by the other side, amorphous films had the largest signal intensities. Besides, we established a phenomenological model for the analysis of the azochromophores orientation in the films as a function of the pumping time.
22
Jakubinek, Michael B., Champika J. Samarasekera e Mary Anne White. "Elephant ivory: A low thermal conductivity, high strength nanocomposite". Journal of Materials Research 21, n. 1 (1 gennaio 2006): 287–92. http://dx.doi.org/10.1557/jmr.2006.0029.
Testo completoAbstract (sommario):
There has been much recent interest in heat transport in nanostructures, and alsoin the structure, properties, and growth of biological materials. Here we present measurements of thermal properties of a nanostructured biomineral, ivory. The room-temperature thermal conductivity of ivory is anomalously low in comparison with its constituent components. Low-temperature (2–300 K) measurements ofthermal conductivity and heat capacity reveal a glass-like temperature dependenceof the thermal conductivity and phonon mean free path, consistent with increased phonon-boundary scattering associated with nanostructure. These results suggest that biomineral-like nanocomposite structures could be useful in the design of novel high-strength materials for low thermal conductivity applications.
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Chen, Hongjun, e Lianzhou Wang. "Nanostructure sensitization of transition metal oxides for visible-light photocatalysis". Beilstein Journal of Nanotechnology 5 (23 maggio 2014): 696–710. http://dx.doi.org/10.3762/bjnano.5.82.
Testo completoAbstract (sommario):
To better utilize the sunlight for efficient solar energy conversion, the research on visible-light active photocatalysts has recently attracted a lot of interest. The photosensitization of transition metal oxides is a promising approach for achieving effective visible-light photocatalysis. This review article primarily discusses the recent progress in the realm of a variety of nanostructured photosensitizers such as quantum dots, plasmonic metal nanostructures, and carbon nanostructures for coupling with wide-bandgap transition metal oxides to design better visible-light active photocatalysts. The underlying mechanisms of the composite photocatalysts, e.g., the light-induced charge separation and the subsequent visible-light photocatalytic reaction processes in environmental remediation and solar fuel generation fields, are also introduced. A brief outlook on the nanostructure photosensitization is also given.
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Jana, Malay, Anjan Sil e Subrata Ray. "Influence of Melting of Transition Metal Oxides on the Morphology of Carbon Nanostructures". Advanced Materials Research 585 (novembre 2012): 159–63. http://dx.doi.org/10.4028/www.scientific.net/amr.585.159.
Testo completoAbstract (sommario):
Different types of carbon nanostructure materials have been grown on nano-sized transition metal oxide based catalyst particles by catalytic chemical vapour deposition. The present investigation reveals an important role of melting or surface melting of oxide catalysts for the growth of carbon nanostructure materials. In the reducing environment prevailing during the growth of nanostructures, oxide catalysts are reduced to metals, which may act as a template for the growth of carbon nanostructure materials. Flow rate of acetylene gas is crucial in catalyzing the growth, as high flow rate of acetylene may cover the catalyst particles with a layer of decomposed carbon, rendering the particles incapable of playing the role of catalyst. The size of the catalyst and the extent of melting, determined primarily by the extent of doping, are important in deciding whether the conditions are favourable for the growth of multi walled carbon nanotube, nanofiber or other nanostructures. Smaller particle size and low doping level favour the growth of multi walled carbon nanotube while growth of nanofiber is commonly observed with larger particles and higher doping level. The size (i.e. diameter) of the nanostructures growing around the catalyst is proportional to the particle size of the catalyst.
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Ji, Xiu Jie, Bin Wang, Chao Liu, Bo Wen Cheng, Jun Song, Dong Xia Ma, Guo Feng Zhang, Bo Wei Li, Zhi Xiong Yang e Zhi Yong Fang. "Surfactant-Templated Synthesis and Magnetic Properties of Ordered Nanostructured Fe3O4". Advanced Materials Research 427 (gennaio 2012): 169–72. http://dx.doi.org/10.4028/www.scientific.net/amr.427.169.
Testo completoAbstract (sommario):
Surfactant-templated synthesis of ordered nanostructured materials attracts more and more attention. In this paper, ordered nanostructured Fe3O4powder was synthesized via a facile reflux method in ethanol-water media using sodium dodecyl sulphonate (SDS, C12H25SO3Na) as template. XRD and VSM were used to characterize the ordered nanostructure, inorganic phase and magnetic properties. Results show that Fe3O4powder is of an ordered nanostructure of 7.6 nm which was detected by SAXRD and the inorganic phase is composed of cubic Fe3O4nanocrystals. VSM analysis shows that the ordered nanostructured Fe3O4exhibits a two-phase structure and a soft magnetic property with a saturation magnetization of 40emu/g.
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LI, WEN, DAISUKE ISHIKAWA e HIROKAZU TATSUOKA. "SYNTHESES OF NANOSTRUCTURE BUNDLES BASED ON SEMICONDUCTING METAL SILICIDES". Functional Materials Letters 06, n. 05 (ottobre 2013): 1340011. http://dx.doi.org/10.1142/s1793604713400110.
Testo completoAbstract (sommario):
A variety of nanostructure bundles and arrays based on semiconducting metal silicides have been synthesized using abundant and non-toxic starting materials. Three types of fabrication techniques of the nanostructure bundles or arrays, including direct growth, template synthesis using natural nanostructured materials and template synthesis using artificially fabricated nanostructured materials are demonstrated. CrSi 2 nanowire bundles were directly grown by the exposure of Si substrates to CrCl 2 vapor at atmospheric pressure. A hexagonal MoSi 2 nanosheet, Mg 2 Si / MgO composite nanowire and Mg 2 Si nanowire bundles and MnSi 1.7 nanowire array were synthesized using a MoS 2 layered material, a SiO x nanofiber bundle, a Si nanowire array, and a Si nanowire array as the templates, respectively. Additionally, the fabrication phenomenon and structural properties of the nanostructured semiconducting metal silicides were investigated. These reactions provided the low-cost and controllable synthetic techniques to synthesize large scale and one-dimensional semiconducting metal silicides for thermoelectric applications.
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YANG, CHENG, SEUNG-HEON RYU, YEONG-DAE LIM e WON JONG YOO. "SELF-ASSEMBLY OF Si NANOSTRUCTURES IN SF6/O2 PLASMA". Nano 03, n. 03 (giugno 2008): 169–73. http://dx.doi.org/10.1142/s179329200800099x.
Testo completoAbstract (sommario):
Self-assembled Si nanostructure arrays were formed in an inductively coupled plasma (ICP) reactor using SF 6/ O 2 plasma at noncryogenic temperature. It was possible to form nanopillar arrays of a mean diameter of ~100 nm and a mean height up to 4.77 μm over areas >100 cm2. The self-assembly of the nanostructures was studied as a function of time, bias RF-power, and O 2/ SF 6 ratio. It was found that the nanostructure arrays could be formed only when O 2/ SF 6 was in the range of 0.8 to 2.5. Two types of the self-assembled nanostructure arrays were formed at the different bias RF-power ranges: one was nanohole arrays and the other was nanopillar arrays. The hole-type nanostructure was formed when the bias power was low at ~10 W, while the pillar-type nanostructure was formed when the bias power increased to 30 W. It was also found that, the height of the nanostructure arrays increased with the onset of an etching time of 40 s, but it decreased after excessively long etching time as the nanostructure arrays could no longer sustain themselves. The correlation between the formation of nanostructures and plasma properties was investigated using OES, XPS, AFM, and SEM analyses. According to the analyses, sidewall passivation layers which were formed by the reaction of Si with F and O radicals generated from the SF 6/ O 2 plasma were responsible for giving rise to various nanostructure arrays.
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Chen, Yusi, Yangsen Kang, Jieyang Jia, Yijie Huo, Muyu Xue, Zheng Lyu, Dong Liang, Li Zhao e James S. Harris. "Nanostructured Dielectric Layer for Ultrathin Crystalline Silicon Solar Cells". International Journal of Photoenergy 2017 (2017): 1–6. http://dx.doi.org/10.1155/2017/7153640.
Testo completoAbstract (sommario):
Nanostructures have been widely used in solar cells due to their extraordinary photon management properties. However, due to poor pn junction quality and high surface recombination velocity, typical nanostructured solar cells are not efficient compared with the traditional commercial solar cells. Here, we demonstrate a new approach to design, simulate, and fabricate whole-wafer nanostructures on dielectric layer on thin c-Si for solar cell light trapping. The optical simulation results show that the periodic nanostructure arrays on dielectric materials could suppress the reflection loss over a wide spectral range. In addition, by applying the nanostructured dielectric layer on 40 μm thin c-Si, the reflection loss is suppressed to below 5% over a wide spectra and angular range. Moreover, a c-Si solar cell with 2.9 μm ultrathin absorber layer demonstrates 32% improvement in short circuit current and 44% relative improvement in energy conversion efficiency. Our results suggest that nanostructured dielectric layer has the potential to significantly improve solar cell performance and avoid typical problems of defects and surface recombination for nanostructured solar cells, thus providing a new pathway towards realizing high-efficiency and low-cost c-Si solar cells.
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WANG, BAOMIN, TONGCHUAN GAO e PAUL W. LEU. "COMPUTATIONAL SIMULATIONS OF NANOSTRUCTURED SOLAR CELLS". Nano LIFE 02, n. 02 (giugno 2012): 1230007. http://dx.doi.org/10.1142/s1793984411000517.
Testo completoAbstract (sommario):
Simulation methods are vital to the development of next-generation solar cells such as plasmonic, organic, nanophotonic, and semiconductor nanostructure solar cells. Simulations are predictive of material properties such that they may be used to rapidly screen new materials and understand the physical mechanisms of enhanced performance. They can be used to guide experiments or to help understand results obtained in experiments. In this paper, we review simulation methods for modeling the classical optical and electronic transport properties of nanostructured solar cells. We discuss different techniques for light trapping with an emphasis on silicon nanostructures and silicon thin films integrated with nanophotonics and plasmonics.
30
Yin, Xiaowei, Fengli Liu, Wentao Qiu, Can Liu, Heyuan Guan e Huihui Lu. "Electric Field Sensor Based on High Q Fano Resonance of Nano-Patterned Electro-Optic Materials". Photonics 9, n. 6 (17 giugno 2022): 431. http://dx.doi.org/10.3390/photonics9060431.
Testo completoAbstract (sommario):
This paper presents theoretical studies of Fano resonance based electric-field (E-field) sensors. E-field sensor based on two electro-optical (EO) materials i.e., barium titanate (BaTiO3, BTO) nanoparticles and relaxor ferroelectric material Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) combined with nanostructure are studied. As for the BTO based E-field sensor, a configuration of filling the BTO nanoparticles into a nano-patterned thin film silicon is proposed. The achieved resonance quality factor (Q) is 11,855 and a resonance induced electric field enhancement factor is of around 105. As for the design of PMN-PT based E-field sensor, a configuration by combining two square lattice air holes in PMN-PT thin film but with one offsetting hole left is chosen. The achieved resonance Q is of 9,273 and an electric field enhancement factor is of around 96. The resonance wavelength shift sensitivity of PMN-PT nanostructured can reach up to 4.768 pm/(V/m), while the BTO based nanostructure has a sensitivity of 0.1213 pm/(V/m). If a spectrum analyzer with 0.1 pm resolution is considered, then the minimum detection of the electric field Emin is 20 mV/m and 0.82 V/m for PMN-PT and BTO based nanostructures, respectively. The nano-patterned E-field sensor studied here are all dielectric, it has therefore the advantage of large measurement bandwidth, high measurement fidelity, high spatial resolution and high sensitivity.
31
Mendes, Rafael, Paweł Wróbel, Alicja Bachmatiuk, Jingyu Sun, Thomas Gemming, Zhongfan Liu e Mark Rümmeli. "Carbon Nanostructures as a Multi-Functional Platform for Sensing Applications". Chemosensors 6, n. 4 (5 dicembre 2018): 60. http://dx.doi.org/10.3390/chemosensors6040060.
Testo completoAbstract (sommario):
The various forms of carbon nanostructures are providing extraordinary new opportunities that can revolutionize the way gas sensors, electrochemical sensors and biosensors are engineered. The great potential of carbon nanostructures as a sensing platform is exciting due to their unique electrical and chemical properties, highly scalable, biocompatible and particularly interesting due to the almost infinite possibility of functionalization with a wide variety of inorganic nanostructured materials and biomolecules. This opens a whole new pallet of specificity into sensors that can be extremely sensitive, durable and that can be incorporated into the ongoing new generation of wearable technology. Within this context, carbon-based nanostructures are amongst the most promising structures to be incorporated in a multi-functional platform for sensing. The present review discusses the various 1D, 2D and 3D carbon nanostructure forms incorporated into different sensor types as well as the novel functionalization approaches that allow such multi-functionality.
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Schernthaner, Michaela, Gerd Leitinger, Heimo Wolinski, Sepp D. Kohlwein, Bettina Reisinger, Ruxandra-A. Barb, Wolfgang F. Graier, Johannes Heitz e Klaus Groschner. "Enhanced Ca2+Entry and Tyrosine Phosphorylation Mediate Nanostructure-Induced Endothelial Proliferation". Journal of Nanomaterials 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/251063.
Testo completoAbstract (sommario):
Nanostructured substrates have been recognized to initiate transcriptional programs promoting cell proliferation. Specificallyβ-catenin has been identified as transcriptional regulator, activated by adhesion to nanostructures. We set out to identify processes responsible for nanostructure-induced endothelialβ-catenin signaling. Transmission electron microscopy (TEM) of cell contacts to differently sized polyethylene terephthalate (PET) surface structures (ripples with 250 to 300 nm and walls with 1.5 µm periodicity) revealed different patterns of cell-substrate interactions. Cell adhesion to ripples occurred exclusively on ripple peaks, while cells were attached to walls continuously. The Src kinase inhibitor PP2 was active only in cells grown on ripples, while the Abl inhibitors dasatinib and imatinib suppressedβ-catenin translocation on both structures. Moreover, Gd3+sensitive Ca2+entry was observed in response to mechanical stimulation or Ca2+store depletion exclusively in cells grown on ripples. Both PP2 and Gd3+suppressedβ-catenin nuclear translocation along with proliferation in cells grown on ripples but not on walls. Our results suggest that adhesion of endothelial cells to ripple structured PET induces highly specific, interface topology-dependent changes in cellular signalling, characterized by promotion of Gd3+-sensitive Ca2+entry and Src/Abl activation. We propose that these signaling events are crucially involved in nanostructure-induced promotion of cell proliferation.
33
Fan, Jiakang. "The realization of a broadband light absorber via the synergistic effect of graphene and silicon nanostructures". Journal of Physics: Conference Series 2285, n. 1 (1 giugno 2022): 012001. http://dx.doi.org/10.1088/1742-6596/2285/1/012001.
Testo completoAbstract (sommario):
Abstract Due to the increasing demand for clean energy, it becomes more and more necessary to find out more efficient ways to generate clean energy. Because of this, the light conversion efficiency of different materials has been largely studied. The purpose of the study is to investigate how the silicon pyramidal nanostructures and graphene layer affect the light-absorbing performance of materials and achieve a broadband light absorber. Simulations of four experimental groups, including both with nanostructure and graphene, with nanostructure and without graphene, without nanostructure and with graphene, both without nanostructure and graphene, are done to obtain and compare the data through the method of finite difference time domain (FDTD). By analyzing the simulation results, it is found that the silicon pyramidal structures can improve the light absorption within the range of visible light. Moreover, the presence of graphene layers can improve the light absorption within the range of near-infrared to infrared light. The number of layers can also have effects on light absorption.
34
Jang, Hyun-Ik, Hae-Su Yoon, Tae-Ik Lee, Sangmin Lee, Taek-Soo Kim, Jaesool Shim e Jae Hong Park. "Creation of Curved Nanostructures Using Soft-Materials-Derived Lithography". Nanomaterials 10, n. 12 (3 dicembre 2020): 2414. http://dx.doi.org/10.3390/nano10122414.
Testo completoAbstract (sommario):
In this study, curved nanostructures, which are difficult to obtain, were created on an Si substrate through the bonding, swelling, and breaking processes of the polymer and silicone substrate. This method can be utilized to obtain convex nanostructures over large areas. The method is simpler than typical semiconductor processing with photolithography or compared to wet- or vacuum-based dry etching processes. The polymer bonding, swelling (or no swelling), and breaking processes that are performed in this process were theoretically analyzed through a numerical analysis of permeability and modeling. Through this process, we designed a convex nanostructure that can be produced experimentally in an accurate manner.
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Bechelany, Mikhael, Sebastien Balme e Philippe Miele. "Atomic layer deposition of biobased nanostructured interfaces for energy, environmental and health applications". Pure and Applied Chemistry 87, n. 8 (1 agosto 2015): 751–58. http://dx.doi.org/10.1515/pac-2015-0102.
Testo completoAbstract (sommario):
AbstractThe most fundamental phenomena in the immobilising of biomolecules on the nanostructured materials for energy, environmental and health applications are the control of interfaces between the nanostructures/nanopores and the immobilized biomaterials. Thus, the throughput of all those biobased nanostructured materials and devices can be improved or controlled by the enhanced geometric area of the nanostructured interfaces if an efficient immobilization of the biomolecules is warranted. In this respect, an accurate control of the geometry (size, porosity, etc.) and interfaces is primordial to finding the delicate balance between large/control interface areas and good immobilization conditions. Here, we will show how the atomic layer deposition (ALD) can be used as a tool for the creation of controlled nanostructured interfaces in which the geometry can be tuned accurately and the dependence of the physical-chemical properties on the geometric parameters can be studied systematically in order to immobilize biomolecules. We will show mainly examples of how these methods can be used to create single nanopores for mass spectroscopy and DNA sequencing, and membrane for gas separation and water treatment in which the performance varies with the nanostructure morphologies/interfaces and the immobilization conditions.
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Su, Jian-Qing, Tracy W. Nelson e Colin J. Sterling. "A new route to bulk nanocrystalline materials". Journal of Materials Research 18, n. 8 (agosto 2003): 1757–60. http://dx.doi.org/10.1557/jmr.2003.0243.
Testo completoAbstract (sommario):
Despite their interesting properties, nanostructured materials have found limited use as a result of the cost of preparation and the difficulty in scaling up. Herein, the authors report a technique, friction stir processing (FSP), to refine grain sizes to a nanoscale. Nanocrystalline 7075 Al with an average grain size of 100 nm was successfully obtained using FSP. It may be possible to further control the microstructure of the processed material by changing the processing parameters and the cooling rate. In principle, by applying multiple overlapping passes, it should be possible to produce any desired size thin sheet to nanostructure using this technique. We expect that the FSP technique may pave the way to large-scale structural applications of nanostructured metals and alloys.
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Barra, Ana, Cláudia Nunes, Eduardo Ruiz-Hitzky e Paula Ferreira. "Green Carbon Nanostructures for Functional Composite Materials". International Journal of Molecular Sciences 23, n. 3 (6 febbraio 2022): 1848. http://dx.doi.org/10.3390/ijms23031848.
Testo completoAbstract (sommario):
Carbon nanostructures are widely used as fillers to tailor the mechanical, thermal, barrier, and electrical properties of polymeric matrices employed for a wide range of applications. Reduced graphene oxide (rGO), a carbon nanostructure from the graphene derivatives family, has been incorporated in composite materials due to its remarkable electrical conductivity, mechanical strength capacity, and low cost. Graphene oxide (GO) is typically synthesized by the improved Hummers’ method and then chemically reduced to obtain rGO. However, the chemical reduction commonly uses toxic reducing agents, such as hydrazine, being environmentally unfriendly and limiting the final application of composites. Therefore, green chemical reducing agents and synthesis methods of carbon nanostructures should be employed. This paper reviews the state of the art regarding the green chemical reduction of graphene oxide reported in the last 3 years. Moreover, alternative graphitic nanostructures, such as carbons derived from biomass and carbon nanostructures supported on clays, are pointed as eco-friendly and sustainable carbonaceous additives to engineering polymer properties in composites. Finally, the application of these carbon nanostructures in polymer composites is briefly overviewed.
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Liu, Yi, e David J. Sellmyer. "Selected Reflection Imaging of Nanostructured Materials". Microscopy and Microanalysis 4, S2 (luglio 1998): 752–53. http://dx.doi.org/10.1017/s1431927600023886.
Testo completoAbstract (sommario):
Nanostructured materials are finding increasing applications. In characterizing the nanostructured materials, we have developed a technique using a conventional TEM to characterize the nanostructure. The technique is named selected reflection imaging and could be used for measuring the grain size, measuring the volume fraction of a second phase in a dual phase material, measuring the texture and identifying the crystal structure in multiphase materials.The technique is evolved from dark field imaging which is known to generate strong contrast. In conventional materials with a grain size larger than 1 μm, selected area diffraction pattern is from a single crystal. Dark field image could be formed by allowing one of the diffracted beam to go through the objective aperture. In nanostructured materials, however, the diffraction pattern becomes a ring pattern. Ordinary dark field image could be formed by allowing one of the spot in the ring to go through the aperture. However, only a limited number of grains are differentiated from the rest.
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Soares, Sofia F., Tiago Fernandes, Ana L. Daniel-da-Silva e Tito Trindade. "The controlled synthesis of complex hollow nanostructures and prospective applications". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, n. 2224 (aprile 2019): 20180677. http://dx.doi.org/10.1098/rspa.2018.0677.
Testo completoAbstract (sommario):
Functionality in nanoengineered materials has been usually explored on structural and chemical compositional aspects of matter that exist in such solid materials. It is well known that the absence of solid matter is also relevant and the existence of voids confined in the nanostructure of certain particles is no exception. Indeed, over the past decades, there has been great interest in exploring hollow nanostructured materials that besides the properties recognized in the dense particles also provide empty spaces, in the sense of condensed matter absence, as an additional functionality to be explored. As such, the chemical synthesis of hollow nanostructures has been driven not only for tailoring the size and shape of particles with well-defined chemical composition, but also to achieve control on the type of hollowness that characterize such materials. This review describes the state of the art on late developments concerning the chemical synthesis of hollow nanostructures, providing a number of examples of materials obtained by distinct strategies. It will be apparent by reading this progress report that the absence of solid matter determines the functionality of hollow nanomaterials for several technological applications.
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Suárez-Franco, José Luis, Manuel García-Hipólito, Miguel Ángel Surárez-Rosales, José Arturo Fernández-Pedrero, Octavio Álvarez-Fregoso, Julio Alberto Juárez-Islas e Marco Antonio Álvarez-Pérez. "Effects of Surface Morphology ofZnAl2O4Ceramic Materials on Osteoblastic Cells Responses". Journal of Nanomaterials 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/361249.
Testo completoAbstract (sommario):
Ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. The purpose of this study was to investigate the effect of surface morphology of nanostructure thin films of ZnAl2O4prepared by spray pyrolysis and bulk pellets of polycrystalline ZnAl2O4prepared by chemical coprecipitation reaction on thein vitrocell adhesion, viability, and cell-material interactions of osteoblastic cells. Our result showed that cell attachment was significantly enhanced from 60 to 80% on the ZnAl2O4nanostructured material surface when compared with bulk ceramic surfaces. Moreover, our results showed that the balance of morphological properties of the thin film nanostructure ceramic improves cell-material interaction with enhanced spreading and filopodia with multiple cellular extensions on the surface of the ceramic and enhancing cell viability/proliferation in comparison with bulk ceramic surfaces used as control. Altogether, these results suggest that zinc aluminate nanostructured materials have a great potential to be used in dental implant and bone substitute applications.
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Wang, S. L., H. W. Zhu, W. H. Tang e P. G. Li. "Propeller-Shaped ZnO Nanostructures Obtained by Chemical Vapor Deposition: Photoluminescence and Photocatalytic Properties". Journal of Nanomaterials 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/594290.
Testo completoAbstract (sommario):
Propeller-shaped and flower-shaped ZnO nanostructures on Si substrates were prepared by a one-step chemical vapor deposition technique. The propeller-shaped ZnO nanostructure consists of a set of axial nanorod (50 nm in tip, 80 nm in root and 1 μm in length), surrounded by radial-oriented nanoribbons (20–30 nm in thickness and 1.5 μm in length). The morphology of flower-shaped ZnO nanostructure is similar to that of propeller-shaped ZnO, except the shape of leaves. These nanorods leaves (30 nm in diameter and 1–1.5 μm in length) are aligned in a radial way and pointed toward a common center. The flower-shaped ZnO nanostructures show sharper and stronger UV emission at 378 nm than the propeller-shaped ZnO, indicating a better crystal quality and fewer structural defects in flower-shaped ZnO. In comparison with flower-shaped ZnO nanostructures, the propeller-shaped ZnO nanostructures exhibited a higher photocatalytic property for the photocatalytic degradation of Rhodamine B under UV-light illumination.
42
Li, Fan, Jiang Li, Baijun Dong, Fei Wang, Chunhai Fan e Xiaolei Zuo. "DNA nanotechnology-empowered nanoscopic imaging of biomolecules". Chemical Society Reviews 50, n. 9 (2021): 5650–67. http://dx.doi.org/10.1039/d0cs01281e.
Testo completoAbstract (sommario):
DNA nanotechnology has led to the rise of DNA nanostructures, which possess programmable shapes and are capable of organizing different functional molecules and materials. A variety of DNA nanostructure-based imaging probes have been developed.
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Breus, A., S. Abashin, I. Lukashov e O. Serdiuk. "Anodic growth of copper oxide nanostructures in glow discharge". Archives of Materials Science and Engineering 114, n. 1 (1 marzo 2022): 24–33. http://dx.doi.org/10.5604/01.3001.0015.9850.
Testo completoAbstract (sommario):
Purpose: Application of plasma glow discharge to copper oxide nanostructure growth is studied. The simplicity of the proposed technique may be beneficial for the development of new plasma reactors for large-scale production of diverse metal oxide nanostructures. Design/methodology/approach: Copper sample was placed on anode of a setup designed to ignite plasma glow discharge. The proposed approach allows eliminating the negative effects of ion bombardment, like sputtering and generation of defects on a surface of the growing nanostructures, but preserves the advantages of thermal growth. The growth process was explained in terms of thermal processes interaction occurring on a surface of the anode with the glow discharge plasma. Findings: Plasma treatment resulted in generation of reach and diverse nanostructures that was confirmed by SEM images. Nanowire-like, flower-like, anemone-like nanostructures and nanodisks composed into the nanoassemblies are observed; the nanostructures are associated with microbabbles on CuO layer. These findings allow concluding about the possible implementation of the proposed method in industry. Research limitations/implications: The main limitation is conditioned by the lack of heat supplied to the anode, and absence of independent control of the heat and ion fluxes; thus, the additional heater should be installed under the anode in order to expand the nomenclature of the nanospecies in the future studies. Practical implications: High-productivity plasma process in copper oxide nanostructures synthesis was confirmed in this research. It may be applied for field emitter and supercapacitor manufacturing. Originality/value: Oxide nanostructure synthesis is conducted by use of a simple and well-known glow discharge technique in order to expand the production yield and diversity of nanostructure obtained in the processes of thermal growth.
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Jang, Jae Min, Sung Hak Yi, Seung Kyu Choi, Jeong A. Kim e Woo Gwang Jung. "Synthesis of ZnO Flower-Like Nanostructures on GaN Epitaxial Layer by Hydrothermal Process". Solid State Phenomena 124-126 (giugno 2007): 555–58. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.555.
Testo completoAbstract (sommario):
3D type flower-like ZnO nanostructure is fabricated on GaN epitaxial layer by hydrothermal synthesis. The formation of ZnO nanostructures is controlled dominantly by pH of the aqueous solution. The microstructure of flower-like ZnO nanostructure was examined by FE-SEM, XRD and FE-TEM. It is found that the shape of ZnO nanostructures are likely flower and chestnut bur shapes. FE-TEM and XRD analysis shows that ZnO nanostructures are single crystalline. Some discussion is made on the mechanism of ZnO growth in solutions with different pH.
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Liu, Xiaoyan, Shaotong Feng, Caihua Wang, Dayun Yan, Lei Chen e Bao Wang. "Wettability Improvement in Oil–Water Separation by Nano-Pillar ZnO Texturing". Nanomaterials 12, n. 5 (22 febbraio 2022): 740. http://dx.doi.org/10.3390/nano12050740.
Testo completoAbstract (sommario):
The nanostructure-based surface texturing can be used to improve the materials wettability. Regarding oil–water separation, designing a surface with special wettability is as an important approach to improve the separation efficiency. Herein, a ZnO nanostructure was prepared by a two-step process for sol–gel process and crystal growth from the liquid phase to achieve both a superhydrophobicity in oil and a superoleophobic property in water. It is found that the filter material with nanostructures presented an excellent wettability. ZnO-coated stainless-steel metal fiber felt had a static underwater oil contact angle of 151.4° ± 0.8° and an underoil water contact angle of 152.7° ± 0.6°. Furthermore, to achieve water/oil separation, the emulsified impurities in both water-in-oil and oil-in-water emulsion were effectively intercepted. Our filter materials with a small pore (~5 μm diameter) could separate diverse water-in-oil and oil-in-water emulsions with a high efficiency (>98%). Finally, the efficacy of filtering quantity on separation performance was also investigated. Our preliminary results showed that the filtration flux decreased with the collection of emulsified impurities. However, the filtration flux could restore after cleaning and drying, suggesting the recyclable nature of our method. Our nanostructured filter material is a promising candidate for both water-in-oil and oil-in-water separation in industry.
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Arevalo, Benyl John A., Jocelyn P. Doronio, Dionesio C. Pondoc e Juvy J. Monserate. "Facile Synthesis and Characterization of Sea Urchin ZnO Nanostructures via Sol-Gel Method". Key Engineering Materials 913 (18 marzo 2022): 99–105. http://dx.doi.org/10.4028/p-juibvf.
Testo completoAbstract (sommario):
Sea urchin zinc oxide (SU-ZnO) nanostructures were successfully synthesized using the sol-gel method and characterized by various analytical techniques. The present work reports a facile and straightforward route for synthesizing sea urchin ZnO nanostructures consisted of self-assembled ZnO nanorods with sharp tips yielding the sea urchin-like shape. The SU-ZnO nanostructures were characterized using Scanning electron microscopy and Energy dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared (FTIR) spectroscopy, particle size analysis (dynamic light scattering technique), and ultraviolet-visible (UV-vis) spectroscopy. The result of energy dispersive X-ray spectroscopy shows that the SU-ZnO nanostructure contains 77.30% zinc and 22.70% oxygen content. Scanning electron microscopy shows that the synthesized ZnO exhibits a sea urchin-like structure with a homogeneous and consistent size. FTIR spectroscopy confirmed the structural features and functional groups that are present in ZnO nanostructures. The particle size analysis shows that the synthesized SU-ZnO nanostructures have an average particle size of 812.62 ± 55.92 nm. The growth of SU-ZnO nanostructure was also investigated by recording the UV-Vis absorption spectra at different reaction times.
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Ngiam, Michelle, Luong TH Nguyen, Susan Liao, Casey K. Chan e Seeram Ramakrishna. "Biomimetic Nanostructured Materials — Potential Regulators for Osteogenesis?" Annals of the Academy of Medicine, Singapore 40, n. 5 (15 maggio 2011): 213–22. http://dx.doi.org/10.47102/annals-acadmedsg.v40n5p213.
Testo completoAbstract (sommario):
Nanostructured materials are gaining new impetus owing to the advancements in material fabrication techniques and their unique properties (their nanosize, high surface area-to-volume ratio, and high porosity). Such nanostructured materials mimic the subtleties of extracellular matrix (ECM) proteins, creating artificial microenvironments which resemble the native niches in the body. On the other hand, the isolation of mesenchymal stem cells (MSCs) from various tissue sources has resulted in the interest to study the multiple differentiation lineages for various therapeutic treatments. In this review, our focus is tailored towards the potential of biomimetic nanostructured materials as osteoinductive scaffolds for bone regeneration to differentiate MSCs towards osteoblastic cell types without the presence of soluble factors. In addition to mimicking the nanostructure of native bone, the supplement of collagen and hydroxyapatite which mimic the main components of the ECM also brings significant advantages to these materials. Key words: Biomaterials, Biomimetic, Bone, Hydroxyapatites, Nanomaterials, Stem cells, Tissue engineering
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Pu, Pengpeng, e Tijun Chen. "Nanostructured Metals with an Excellent Synergy of Strength and Ductility: A Review". Materials 15, n. 19 (23 settembre 2022): 6617. http://dx.doi.org/10.3390/ma15196617.
Testo completoAbstract (sommario):
Nanocrystalline metals developed based on fine grain strengthening always have an excellent strength, but are accompanied by a drop in ductility. In the past 20 years, substantial efforts have been dedicated to design new microstructures and develop the corresponding processing technologies in order to solve this problem. In this article, the novel nanostructures designed for simultaneously achieving high strength and high ductility developed in recent years, including bimodal grain size distribution nanostructure, nanotwinned structure, hierarchical nanotwinned structure, gradient nanostructure, and supra-nano-dual-phase nanostructure, are reviewed. Based on a comprehensive understanding of the simultaneously strengthening and toughening mechanisms, the microstructures and corresponding processing techniques are mainly discussed, and the related prospects that may be emphasized in the future are proposed.
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He, Minghao, Mingzhao Li e Zeyu Sun. "The Development of Si Anode Materials by Nanotechnology for Lithium-ion Battery". E3S Web of Conferences 308 (2021): 01007. http://dx.doi.org/10.1051/e3sconf/202130801007.
Testo completoAbstract (sommario):
Nowadays, lithium-ion batteries (LIBs) are applied in many fields for their high energy density, low cost, and long cycle life, highly appreciated in a commercial application. Anode materials, a vital factor contributing to high specific capacity, have caught great attention in next-generation LIBs development. Silicon (Si) has been generally considered one of the best substitutes for the commercial carbon-based anodes of lithium-ion batteries due to its extremely high theoretical capacity, excellent charge-discharge performance, and low cost compared with other anode materials. In this review, various silicon-based materials, including nanostructured silicon and silicon composite materials, are summarized, and both advantages and challenges are analyzed. The article emphasizes the remarkable electrochemical characteristics and significant improvement of battery performance by applying nanostructure and silicon composites conjugates. Besides, the challenges and outlook on the nanostructure design of Si and silicon composites are presented.
50
Gamal, Mohammed, Ishac Kandas, Hussein Badran, Ali Hajjiah, Mufasila Muhammed e Nader Shehata. "Decay Rates of Plasmonic Elliptical Nanostructures via Effective Medium Theory". Nanomaterials 11, n. 8 (27 luglio 2021): 1928. http://dx.doi.org/10.3390/nano11081928.
Testo completoAbstract (sommario):
This paper investigates the spontaneous decay rate of elliptical plasmonic nanostructures. The refractive index was analyzed using the effective medium theory (EMT). Then, the polarizability, spontaneous radiative, non-radiative decay rate, and electric field enhancement factor were characterized for the targeted elliptical nanostructures at different aspect ratios. All of the optical analyses were analyzed at different distances between the excited fluorescent coupled atom and the plasmonic nanostructure (down to 100 nm). This work is promising in selecting the optimum elliptical nanostructure according to the required decay rates for optical conversion efficiency control in energy harvesting for solar cells and optical sensing applications.