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1
Saha, Sourav, et J. Fraser Stoddart. « Photo-driven molecular devices ». Chem. Soc. Rev. 36, no 1 (2007) : 77–92. http://dx.doi.org/10.1039/b607187b.
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You, Liwen. « Integrated Photo - rechargeable Batteries : Photoactive Nanomaterials and Opportunities ». E3S Web of Conferences 375 (2023) : 02010. http://dx.doi.org/10.1051/e3sconf/202337502010.
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The demand for fossil fuels has been increasing over the last few decades but will one day be depleted and researchers are now using biomass to alleviate the fuel crisis. This paper concentrates on a range of current devices with intrinsic solar energy collection, conversion and storage properties, different classes of cells as well as their areas of application and recent research advances. Nanomaterials, meanwhile, are key to making significant progress in the study of photovoltaic electrodes for solar rechargeable batteries, and this paper describes seven currently commonly used semiconductor and nanomaterials. This not only alleviates the severe environmental pollution and greenhouse effect caused by fossil fuels, but also makes a significant contribution to the sustainability of human existence.
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Bouzin, Margaux, Amirbahador Zeynali, Mario Marini, Laura Sironi, Riccardo Scodellaro, Laura D’Alfonso, Maddalena Collini et Giuseppe Chirico. « Multiphoton Laser Fabrication of Hybrid Photo-Activable Biomaterials ». Sensors 21, no 17 (1 septembre 2021) : 5891. http://dx.doi.org/10.3390/s21175891.
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The possibility to shape stimulus-responsive optical polymers, especially hydrogels, by means of laser 3D printing and ablation is fostering a new concept of “smart” micro-devices that can be used for imaging, thermal stimulation, energy transducing and sensing. The composition of these polymeric blends is an essential parameter to tune their properties as actuators and/or sensing platforms and to determine the elasto-mechanical characteristics of the printed hydrogel. In light of the increasing demand for micro-devices for nanomedicine and personalized medicine, interest is growing in the combination of composite and hybrid photo-responsive materials and digital micro-/nano-manufacturing. Existing works have exploited multiphoton laser photo-polymerization to obtain fine 3D microstructures in hydrogels in an additive manufacturing approach or exploited laser ablation of preformed hydrogels to carve 3D cavities. Less often, the two approaches have been combined and active nanomaterials have been embedded in the microstructures. The aim of this review is to give a short overview of the most recent and prominent results in the field of multiphoton laser direct writing of biocompatible hydrogels that embed active nanomaterials not interfering with the writing process and endowing the biocompatible microstructures with physically or chemically activable features such as photothermal activity, chemical swelling and chemical sensing.
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Zheng, Shuo, Walter W. Duley, Peng Peng et Norman Zhou. « Laser modification of Au–CuO–Au structures for improved electrical and electro-optical properties ». Nanotechnology 33, no 24 (25 mars 2022) : 245205. http://dx.doi.org/10.1088/1361-6528/ac5b52.
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Abstract CuO nanomaterials are one of the metal-oxides that received extensive investigations in recent years due to their versatility for applications in high-performance nano-devices. Tailoring the device performance through the engineering of properties in the CuO nanomaterials thus attracted lots of effort. In this paper, we show that nanosecond (ns) laser irradiation is effective in improving the electrical and optoelectrical properties in the copper oxide nanowires (CuO NWs). We find that ns laser irradiation can achieve joining between CuO NWs and interdigital gold electrodes. Meanwhile, the concentration and type of point defects in CuO can be controlled by ns laser irradiation as well. An increase in the concentration of defect centers, together with a reduction in the potential energy barrier at the Au/CuO interfaces due to laser irradiation increases electrical conductivity and enhances photo-conductivity. We demonstrate that the enhanced electrical and photo-conductivity achieved through ns laser irradiation can be beneficial for applications such as resistive switching and photo-detection.
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Comparelli, Roberto. « Special Issue : Application of Photoactive Nanomaterials in Degradation of Pollutants ». Materials 12, no 15 (2 août 2019) : 2459. http://dx.doi.org/10.3390/ma12152459.
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Photoactive nanomaterials are receiving increasing attention due to their potential application to light-driven degradation of water and gas-phase pollutants. However, to exploit the strong potential of photoactive materials and access their properties require a fine tuning of their size/shape dependent chemical-physical properties and on the ability to integrate them in photo-reactors or to deposit them on large surfaces. Therefore, the synthetic approach, as well as post-synthesis manipulation could strongly affect the final photocatalytic properties of nanomaterials. The potential application of photoactive nanomaterials in the environmental field includes the abatement of organic pollutant in water, water disinfection, and abatement of gas-phase pollutants in outdoor and indoor applications.
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Nikić, Marta, Aleksandar Opančar, Florian Hartmann, Ludovico Migliaccio, Marie Jakešová, Eric Daniel Głowacki et Vedran Đerek. « Micropyramid structured photo capacitive interfaces ». Nanotechnology 33, no 24 (23 mars 2022) : 245302. http://dx.doi.org/10.1088/1361-6528/ac5927.
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Abstract Optically driven electronic neuromodulation devices are a novel tool in basic research and offer new prospects in medical therapeutic applications. Optimal operation of such devices requires efficient light capture and charge generation, effective electrical communication across the device’s bioelectronic interface, conformal adhesion to the target tissue, and mechanical stability of the device during the lifetime of the implant—all of which can be tuned by spatial structuring of the device. We demonstrate a 3D structured opto-bioelectronic device—an organic electrolytic photocapacitor spatially designed by depositing the active device layers on an inverted micropyramid-shaped substrate. Ultrathin, transparent, and flexible micropyramid-shaped foil was fabricated by chemical vapour deposition of parylene C on silicon moulds containing arrays of inverted micropyramids, followed by a peel-off procedure. The capacitive current delivered by the devices showed a strong dependency on the underlying spatial structure. The device performance was evaluated by numerical modelling. We propose that the developed numerical model can be used as a basis for the design of future functional 3D design of opto-bioelectronic devices and electrodes.
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Kirner, Simon, Peter Bogdanoff, Bernd Stannowski, Roel van de Krol, Bernd Rech et Rutger Schlatmann. « Architectures for scalable integrated photo driven catalytic devices-A concept study ». International Journal of Hydrogen Energy 41, no 45 (décembre 2016) : 20823–31. http://dx.doi.org/10.1016/j.ijhydene.2016.05.088.
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Zhang, Li-De, et Xiao-Sheng Fang. « Controlled Growth and Characterization Methods of Semiconductor Nanomaterials ». Journal of Nanoscience and Nanotechnology 8, no 1 (1 janvier 2008) : 149–201. http://dx.doi.org/10.1166/jnn.2008.n02.
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One-dimensional (1D) semiconductor nanomaterials attract much attention because they are ideal systems for investigation and studying the relationship between properties and structures and having extensive application future in the high technical field. They are expected to play an important role in fabrication of the next generation nanocircuits, nanotools, nanowires lasers, photon tunneling devices, near-field photo-waveguide devices, etc. This article described controlled growth, characterization of structures and morphologies and properties of 1D semiconductor nanomaterials based on our previous works. This article is organized into two parts: The first part is complicated nanostructures of semiconductors, which includes coaxial nanocables, heterostructure nanowires and nanowires with metal–semiconductor junction behavior, hierarchical structures, doping of the nanowires and nanobelts, porous materials and periodically twined nanowires and asymmetrical polytypic nanobelts. The second part contains semiconductor nanoarrays based on anodic alumina membrane (AAM) templates. Finally, we propose that further investigation of the influence of nanomaterial morphologies on properties and how to design the morphology of nanostructures to meet the property requirements of nanodevices are our future research directions in this field.
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Saleh, Hosam M., et Amal I. Hassan. « Synthesis and Characterization of Nanomaterials for Application in Cost-Effective Electrochemical Devices ». Sustainability 15, no 14 (11 juillet 2023) : 10891. http://dx.doi.org/10.3390/su151410891.
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Nanomaterials have gained significant attention as a remarkable class of materials due to their unique properties and the fact that they encompass a wide range of samples with at least one dimension ranging from 1 to 100 nm. The deliberate design of nanoparticles enables the achievement of extremely large surface areas. In the field of cost-effective electrochemical devices for energy storage and conversion applications, nanomaterials have emerged as a key area of research. Their exceptional physical and chemical properties have led to extensive investigations aimed at improving the performance and cost-effectiveness of electrochemical devices, including batteries, supercapacitors, and fuel cells. The continuous development and enhancement of these high-performance materials are driven by the demand for enhanced productivity, connectivity, and sustainability at a reduced cost. This review focuses on the electrochemical performance of electrodes, energy storage, and electrochemical sensors (ES) based on nanotechnology. It discusses the application of nanotechnology in electrochemistry for water purification and the fate of substances in water, while also introducing green nanotechnology and cost-effective, high-fidelity product creation through electrochemical methods. The study emphasizes the synthesis of novel nanomaterials, such as metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and MXenes, with applications in electrochemical devices. Furthermore, it explores the integration of nanostructures with electrochemical systems in economically significant and future applications, along with the challenges faced by nanotechnology-based industries. The paper also explores the interplay between nanomaterials and biosensors, which play a vital role in electrochemical devices. Overall, this review provides a comprehensive overview of the significance of nanomaterials in the development of cost-effective electrochemical devices for energy storage and conversion. It highlights the need for further research in this rapidly evolving field and serves as a valuable resource for researchers and engineers interested in the latest advancements in nanomaterials for electrochemical devices.
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Grabowski, Przemysław, Jakub Haberko et Piotr Wasylczyk. « Photo-Mechanical Response Dynamics of Liquid Crystal Elastomer Linear Actuators ». Materials 13, no 13 (30 juin 2020) : 2933. http://dx.doi.org/10.3390/ma13132933.
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With continuous miniaturization of many technologies, robotics seems to be lagging behind. While the semiconductor technologies operate confidently at the nanometer scale and micro-mechanics of simple structures (MEMS) in micrometers, autonomous devices are struggling to break the centimeter barrier and have hardly colonized smaller scales. One way towards miniaturization of robots involves remotely powered, light-driven soft mechanisms based on photo-responsive materials, such as liquid crystal elastomers (LCEs). While several simple devices have been demonstrated with contracting, bending, twisting, or other, more complex LCE actuators, only their simple behavior in response to light has been studied. Here we characterize the photo-mechanical response of a linear light-driven LCE actuator by measuring its response to laser beams with varying power, pulse duration, pulse energy, and the energy spatial distribution. Light absorption decrease in the actuator over time is also measured. These results are at the foundation of further development of soft, light-driven miniature mechanisms and micro-robots.
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Liu, Yuan, Yun Ji et Ya Yang. « Growth, Properties and Applications of Bi0.5Na0.5TiO3 Ferroelectric Nanomaterials ». Nanomaterials 11, no 7 (30 juin 2021) : 1724. http://dx.doi.org/10.3390/nano11071724.
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The emerging demands for miniaturization of electronics has driven the research into various nanomaterials. Lead-free Bi0.5Na0.5TiO3 (BNT) ferroelectric nanomaterials have drawn great interest owing to their superiorities of large remanent polarization, high pyroelectric and piezoelectric coefficients, unique photovoltaic performance and excellent dielectric properties. As attractive multifunctional ferroelectrics, BNT nanomaterials are widely utilized in various fields, such as energy harvest, energy storage, catalysis as well as sensing. The growing desire for precisely controlling the properties of BNT nanomaterials has led to significant advancements in material design and preparation approaches. BNT ferroelectric nanomaterials exhibit significant potential in fabrication of electronic devices and degradation of waste water, which pushes forward the advancement of the Internet of things and sustainable human development. This article presents an overview of research progresses of BNT ferroelectric nanomaterials, including growth, properties and applications. In addition, future prospects are discussed.
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Garbovskiy, Yuriy. « Ion-Generating and Ion-Capturing Nanomaterials in Liquid Crystals ». Proceedings 2, no 14 (21 mai 2018) : 1122. http://dx.doi.org/10.3390/iecc_2018-05257.
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The majority of tunable liquid crystal devices are driven by electric fields. The performance of such devices can be altered by the presence of small amounts of ions in liquid crystals. Therefore, the understanding of possible sources of ions in liquid crystal materials is very critical to a broad range of existing and future applications employing liquid crystals. Recently, nanomaterials in liquid crystals have emerged as a hot research topic, promising for its implementation in the design of wearable and tunable liquid crystal devices. An analysis of published results revealed that nanodopants in liquid crystals can act as either ion-capturing agents or ion-generating objects. In this presentation, a recently developed model of contaminated nanomaterials is analyzed. Nanoparticle-enabled ion capturing and ion generation regimes in liquid crystals are discussed within the framework of the proposed model. This model is in very good agreement with existing experimental results. Practical implications and future research directions are also discussed.
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Sial, Atif, Afzal Ahmed Dar, Yifan Li et Chuanyi Wang. « Plasmon-Induced Semiconductor-Based Photo-Thermal Catalysis : Fundamentals, Critical Aspects, Design, and Applications ». Photochem 2, no 4 (2 octobre 2022) : 810–30. http://dx.doi.org/10.3390/photochem2040052.
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Photo-thermal catalysis is among the most effective alternative pathways used to perform chemical reactions under solar irradiation. The synergistic contributions of heat and light during photo-thermal catalytic processes can effectively improve reaction efficiency and alter design selectivity, even under operational instability. The present review focuses on the recent advances in photo-thermal-driven chemical reactions, basic physics behind the localized surface plasmon resonance (LSPR) formation and enhancement, pathways of charge carrier generation and transfer between plasmonic nanostructures and photo-thermal conversion, critical aspects influencing photo-thermal catalytic performance, tailored symmetry, and morphology engineering used to design efficient photo-thermal catalytic systems. By highlighting the multifield coupling benefits of plasmonic nanomaterials and semiconductor oxides, we summarized and discussed several recently developed photo-thermal catalysts and their catalytic performance in energy production (CO2 conversion and H2 dissociation), environmental protection (VOCs and dyes degradation), and organic compound synthesis (Olefins). Finally, the difficulties and future endeavors related to the design and engineering of photo-thermal catalysts were pointed out to draw the attention of researchers to this sustainable technology used for maximum solar energy utilization.
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Xiong, Yihuang, Weinan Chen, Wenbo Guo, Hua Wei et Ismaila Dabo. « Data-driven analysis of the electronic-structure factors controlling the work functions of perovskite oxides ». Physical Chemistry Chemical Physics 23, no 11 (2021) : 6880–87. http://dx.doi.org/10.1039/d0cp05595f.
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Tuning the work functions of materials is critical to the performance of microelectronic and (photo)electrochemical devices. We validate data-driven models to predict the work functions of cubic perovskites from simple electronic descriptors.
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Shin, Jihyun, et Hocheon Yoo. « Photogating Effect-Driven Photodetectors and Their Emerging Applications ». Nanomaterials 13, no 5 (26 février 2023) : 882. http://dx.doi.org/10.3390/nano13050882.
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Rather than generating a photocurrent through photo-excited carriers by the photoelectric effect, the photogating effect enables us to detect sub-bandgap rays. The photogating effect is caused by trapped photo-induced charges that modulate the potential energy of the semiconductor/dielectric interface, where these trapped charges contribute an additional electrical gating-field, resulting in a shift in the threshold voltage. This approach clearly separates the drain current in dark versus bright exposures. In this review, we discuss the photogating effect-driven photodetectors with respect to emerging optoelectrical materials, device structures, and mechanisms. Representative examples that reported the photogating effect-based sub-bandgap photodetection are revisited. Furthermore, emerging applications using these photogating effects are highlighted. The potential and challenging aspects of next-generation photodetector devices are presented with an emphasis on the photogating effect.
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Darus, Libertus, Takuya Sadakane, Pablo Ledezma, Seiya Tsujimura, Isioma Osadebe, Dónal Leech, Lo Gorton et Stefano Freguia. « Redox-Polymers Enable Uninterrupted Day/Night Photo-Driven Electricity Generation in Biophotovoltaic Devices ». Journal of The Electrochemical Society 164, no 3 (6 décembre 2016) : H3037—H3040. http://dx.doi.org/10.1149/2.0091703jes.
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Ninan, Neethu, Nirmal Goswami et Krasimir Vasilev. « The Impact of Engineered Silver Nanomaterials on the Immune System ». Nanomaterials 10, no 5 (18 mai 2020) : 967. http://dx.doi.org/10.3390/nano10050967.
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Over the last decades there has been a tremendous volume of research efforts focused on engineering silver-based (nano)materials. The interest in silver has been mostly driven by the element capacity to kill pathogenic bacteria. In this context, the main area of application has been medical devices that are at significant risk of becoming colonized by bacteria and subsequently infected. However, silver nanomaterials have been incorporated in a number of other commercial products which may or may not benefit from antibacterial protection. The rapid expansion of such products raises important questions about a possible adverse influence on human health. This review focuses on examining currently available literature and summarizing the current state of knowledge of the impact of silver (nano)materials on the immune system. The review also looks at various surface modification strategies used to generate silver-based nanomaterials and the immunomodulatory potential of these materials. It also highlights the immune response triggered by various silver-coated implantable devices and provides guidance and perspective towards engineering silver nanomaterials for modulating immunological consequences.
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Garbovskiy, Yuriy. « Nanoparticle-Enabled Ion Trapping and Ion Generation in Liquid Crystals ». Advances in Condensed Matter Physics 2018 (5 juillet 2018) : 1–8. http://dx.doi.org/10.1155/2018/8914891.
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Nowadays, nanomaterials in liquid crystals and their possible applications in the design of tunable, responsive, and wearable devices are among the most promising research directions. In the majority of cases, all liquid crystal based devices have one thing in common; namely, they are driven by electric fields. This type of device driving can be altered by minor amounts of ions typically present in liquid crystal materials. Therefore, it is very important to understand how nanodopants can affect ions in liquid crystals. In this paper, a recently developed model of contaminated nanoparticles is applied to existing experimental data. The presented analysis unambiguously indicates that, in general, nanomaterials in liquid crystals can behave as a source of ions or as ion traps. Physical factors determining the type of the nanoparticle behaviour and their effects on the concentration of ions in liquid crystals are discussed.
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Kalia, Anu, Kamel A. Abd-Elsalam et Kamil Kuca. « Zinc-Based Nanomaterials for Diagnosis and Management of Plant Diseases : Ecological Safety and Future Prospects ». Journal of Fungi 6, no 4 (13 octobre 2020) : 222. http://dx.doi.org/10.3390/jof6040222.
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A facet of nanorenaissance in plant pathology hailed the research on the development and application of nanoformulations or nanoproducts for the effective management of phytopathogens deterring the growth and yield of plants and thus the overall crop productivity. Zinc nanomaterials represent a versatile class of nanoproducts and nanoenabled devices as these nanomaterials can be synthesized in quantum amounts through economically affordable processes/approaches. Further, these nanomaterials exhibit potential targeted antimicrobial properties and low to negligible phytotoxicity activities that well-qualify them to be applied directly or in a deviant manner to accomplish significant antibacterial, antimycotic, antiviral, and antitoxigenic activities against diverse phytopathogens causing plant diseases. The photo-catalytic, fluorescent, and electron generating aspects associated with zinc nanomaterials have been utilized for the development of sensor systems (optical and electrochemical biosensors), enabling quick, early, sensitive, and on-field assessment or quantification of the test phytopathogen. However, the proficient use of Zn-derived nanomaterials in the management of plant pathogenic diseases as nanopesticides and on-field sensor system demands that the associated eco- and biosafety concerns should be well discerned and effectively sorted beforehand. Current and possible utilization of zinc-based nanostructures in plant disease diagnosis and management and their safety in the agroecosystem is highlighted.
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Shawkat, Mashiyat Sumaiya, Tanvir Ahmed Chowdhury, Hee-Suk Chung, Shahid Sattar, Tae-Jun Ko, J. Andreas Larsson et Yeonwoong Jung. « Large-area 2D PtTe2/silicon vertical-junction devices with ultrafast and high-sensitivity photodetection and photovoltaic enhancement by integrating water droplets ». Nanoscale 12, no 45 (2020) : 23116–24. http://dx.doi.org/10.1039/d0nr05670g.
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Beranek, Radim. « (Photo)electrochemical Methods for the Determination of the Band Edge Positions of TiO2-Based Nanomaterials ». Advances in Physical Chemistry 2011 (9 février 2011) : 1–20. http://dx.doi.org/10.1155/2011/786759.
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TiO2-based nanomaterials play currently a major role in the development of novel photochemical systems and devices. One of the key parameters determining the photoactivity of TiO2-based materials is the position of the band edges. Although its knowledge is an important prerequisite for understanding and optimizing the performance of photochemical systems, it has been often rather neglected in recent research, particularly in the field of heterogeneous photocatalysis. This paper provides a concise account of main methods for the determination of the position of the band edges, particularly those suitable for measurements on nanostructured materials. In the first part, a survey of key photophysical and photochemical concepts necessary for understanding the energetics at the semiconductor/solution interface is provided. This is followed by a detailed discussion of several electrochemical, photoelectrochemical, and spectroelectrochemical methods that can be applied for the determination of band edge positions in compact and nanocrystalline thin films, as well as in nanocrystalline powders.
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Vermaas, David A., Mark Sassenburg et Wilson A. Smith. « Photo-assisted water splitting with bipolar membrane induced pH gradients for practical solar fuel devices ». Journal of Materials Chemistry A 3, no 38 (2015) : 19556–62. http://dx.doi.org/10.1039/c5ta06315a.
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Yadav, Anshul, et Niraj Sinha. « Nanomaterial-based gas sensors : A review on experimental and theoretical studies ». Materials Express 12, no 1 (1 janvier 2022) : 1–33. http://dx.doi.org/10.1166/mex.2022.2121.
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Gas sensors play an essential role in various fields such as public safety, environmental monitoring, medical engineering, food monitoring, pharmaceutical industries and clinical diagnostic, to name a few. The need for miniaturized sensors possessing high sensitivity, time response, selectivity, reproducibility, durability, and low cost has driven the discovery of nanomaterials-based gas sensing devices due to their inherent properties such as chemical/physical gas adsorption capabilities and high surface-to-volume ratio. Studies in the literature highlight the development of gas sensors using novel nanomaterials to detect toxic gases. The gas molecules are sensed by the nanomaterial due to adsorption of the gas on the sensor surface, which leads to conductivity change in the nanomaterial. However, the sensing mechanism is quite complicated. Computational studies help the researchers elucidate the physical understanding behind such a complicated mechanism and aid in developing tailored nanomaterials for gas sensing applications. This review outlines different sensor types and the advantages and disadvantages of each sensor for various applications. Different nanostructure-based gas sensors and recent studies are discussed elaborately. The contributions made by theoretical and experimental studies in studying the gas sensing applications of nanomaterials are also discussed.
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Yeung, Ka-Wai, Yuqing Dong, Ling Chen, Chak-Yin Tang, Wing-Cheung Law, Gary Chi-Pong Tsui et Daniel S. Engstrøm. « Printability of photo-sensitive nanocomposites using two-photon polymerization ». Nanotechnology Reviews 9, no 1 (15 mai 2020) : 418–26. http://dx.doi.org/10.1515/ntrev-2020-0031.
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AbstractTwo-photon polymerization direct laser writing (TPP DLW) is an emerging technology for producing advanced functional devices with complex three-dimensional (3D) micro-structures. Tremendous efforts have been devoted to developing two-photon polymerizable photo-sensitive nanocomposites with tailored properties. Light-induced reconfigurable smart materials such as liquid crystalline elastomers (LCEs) are promising materials. However, due to the difficulties in designing two-photon polymerizable liquid crystal monomer (LCM) nanocomposite photoresists, it is challenging to fabricate true 3D LCE micro-structures. In this paper, we report the preparation of photo-sensitive LCE nanocomposites containing photothermal nanomaterials, including multiwalled carbon nanotubes, graphene oxide and gold nanorods (AuNRs), for TPP DLW. The printability of the LCE nanocomposites is assessed by the fidelity of the micro-structures under different laser writing conditions. DLW of GO/LCM photoresist has shown a vigorous bubble formation. This may be due to the excessive heat generation upon rapid energy absorption of 780 nm laser energy. Compared to pure LCM photoresists, AuNR/LCM photoresists have a lower laser intensity threshold and higher critical laser scanning speed, due to the high absorption of AuNRs at 780 nm, which enhanced the photo-sensitivity of the photoresist. Therefore, a shorter printing time can be achieved for the AuNR/LCM photoresist.
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Homaeigohar, Shahin, Qiqi Liu et Danial Kordbacheh. « Biomedical Applications of Antiviral Nanohybrid Materials Relating to the COVID-19 Pandemic and Other Viral Crises ». Polymers 13, no 16 (23 août 2021) : 2833. http://dx.doi.org/10.3390/polym13162833.
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The COVID-19 pandemic has driven a global research to uncover novel, effective therapeutical and diagnosis approaches. In addition, control of spread of infection has been targeted through development of preventive tools and measures. In this regard, nanomaterials, particularly, those combining two or even several constituting materials possessing dissimilar physicochemical (or even biological) properties, i.e., nanohybrid materials play a significant role. Nanoparticulate nanohybrids have gained a widespread reputation for prevention of viral crises, thanks to their promising antimicrobial properties as well as their potential to act as a carrier for vaccines. On the other hand, they can perform well as a photo-driven killer for viruses when they release reactive oxygen species (ROS) or photothermally damage the virus membrane. The nanofibers can also play a crucial protective role when integrated into face masks and personal protective equipment, particularly as hybridized with antiviral nanoparticles. In this draft, we review the antiviral nanohybrids that could potentially be applied to control, diagnose, and treat the consequences of COVID-19 pandemic. Considering the short age of this health problem, trivially the relevant technologies are not that many and are handful. Therefore, still progressing, older technologies with antiviral potential are also included and discussed. To conclude, nanohybrid nanomaterials with their high engineering potential and ability to inactivate pathogens including viruses will contribute decisively to the future of nanomedicine tackling the current and future pandemics.
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Frontiera, Renee. « (Invited) Ultrafast Reducing Power of a Plasmonic Photocatalyst ». ECS Meeting Abstracts MA2022-02, no 48 (9 octobre 2022) : 1825. http://dx.doi.org/10.1149/ma2022-02481825mtgabs.
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Plasmonic nanomaterials are promising catalysts for selective, green, and efficient photo-driven processes, however currently the mechanisms involved in plasmon-driven catalysis are under debate. Contributions from processes such as vibrational and electronic energy transfer, electron transfer, or electromagnetic field enhancement could all lead to modified potential energy landscapes in the plasmon-molecule system. We have developed ultrafast and electrochemical surface-enhanced Raman spectroscopic (SERS) techniques to probe the contribution of these processes on the nanometer length scale and femtosecond timescale. This talk will highlight the use of these approaches in quantifying the rate, yield, and lifetime of plasmon-to-molecule charge transfer. We monitor changes in the vibrational spectra of adsorbed molecular species following plasmon excitation with picosecond time resolution, and quantify how many molecules are reduced and how quickly they undergo back electron transfer. Overall, these methods allow for quantification of the ultrafast reducing power of a plasmonic surface, and suggest routes for optimizing plasmonic systems for efficient and selective photochemistry.
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Cengiz, Busra, Tugce Nihal Gevrek, Laura Chambre et Amitav Sanyal. « Self-Assembly of Cyclodextrin-Coated Nanoparticles:Fabrication of Functional Nanostructures for Sensing and Delivery ». Molecules 28, no 3 (20 janvier 2023) : 1076. http://dx.doi.org/10.3390/molecules28031076.
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In recent years, the bottom-up approach has emerged as a powerful tool in the fabrication of functional nanomaterials through the self-assembly of nanoscale building blocks. The cues embedded at the molecular level provide a handle to control and direct the assembly of nano-objects to construct higher-order structures. Molecular recognition among the building blocks can assist their precise positioning in a predetermined manner to yield nano- and microstructures that may be difficult to obtain otherwise. A well-orchestrated combination of top-down fabrication and directed self-assembly-based bottom-up approach enables the realization of functional nanomaterial-based devices. Among the various available molecular recognition-based “host–guest” combinations, cyclodextrin-mediated interactions possess an attractive attribute that the interaction is driven in aqueous environments, such as in biological systems. Over the past decade, cyclodextrin-based specific host–guest interactions have been exploited to design and construct structural and functional nanomaterials based on cyclodextrin-coated metal nanoparticles. The focus of this review is to highlight recent advances in the self-assembly of cyclodextrin-coated metal nanoparticles driven by the specific host–guest interaction.
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Ferrando, Giulio, Matteo Gardella, Matteo Barelli, Debasree Chowdhury, Pham Duy Long, Nguyen Si Hieu, Maria Caterina Giordano et Francesco Buatier de Mongeot. « Plasmonic and 2D-TMD nanoarrays for large-scale photon harvesting and enhanced molecular photo-bleaching ». EPJ Web of Conferences 266 (2022) : 09003. http://dx.doi.org/10.1051/epjconf/202226609003.
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The urgent environmental and energy challenges require novel solutions for efficient light harvesting and conversion in new-generation ultra-thin devices. Plasmonic nanoantennas and flat optics nanogratings can promote light matter interaction at the nanoscale being very attractive for ultra-thin photonics and sensing applications. In this work we developed two light trapping solutions based on large-scale nanomaterials. The first system is a large-scale (cm2) plasmonic metasurface based on self-organized gold nanostripes. The second is based on the periodic re-shaping of ultra-thin semiconducting MoS2 layers forming large-area flat-optics nanogratings. Under this condition Rayleigh Anomalies can be resonantly excited thus promoting in-plane light confinement and photon absorption into the few-layers material. To demonstrate the impact of these nanopatterned systems in photon harvesting we probed their efficiency into a prototypal photochemical reaction: the photo-bleaching of Methylene Blue (MB). We demonstrate the resonant enhancement of the photo-bleaching of these polluting dye molecules promoted either by the localized plasmon resonance in Au nanostripes or by the Rayleigh Anomaly in flat-optics MoS2 nanogratings. We investigate this effect through a quantitative analysis of the solution photodissociation induced by a monochromatic light. These results show the strong potential of flat-optics templates for light-harvesting and energy conversion in ultra-thin photonic devices.
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Bikramaditya, Bibhuti, Rakesh Kumar Singh, Nishant Kumar et Pushpendra Kumar Verma. « Studies on Structural, optical and Magnetic properties of Yttrium Aluminum Bromate (YAB) Nanomaterials, prepared at high annealing temperature ». Journal of Physics : Conference Series 2070, no 1 (1 novembre 2021) : 012067. http://dx.doi.org/10.1088/1742-6596/2070/1/012067.
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Abstract In this research, we present structural, photo-luminescence and magnetic properties of the Yttrium Aluminum Borate (YAB) nanomaterial, synthesized by low-cost Sol-gel method in high temperature range. X-ray diffraction (XRD) analysis, shows that crystal structure of YAB is of nanometric size ranging between 38 nm to 47 nm for the annealing temperature above 900°C. Photoluminescence property shows that YAB gives intense Blue light emission in the visible region. High-temperature annealing was found to increase the grain size and enhance the blue luminescence. Vibrating Sample Magnetometer (VSM) shows that coercivity increases while Magnetization and retentivity decreases for YAB nanomaterials for the temperature above 900 degree Celsius. Prepared YAB materials may be useful for LED or related devices.
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Haq, Sharmin, Tasnuva Ashrafee, Mahmuda Begum, Tasmia Sharmin, Nirban Bhowmick et Zahid Hasan Mahmood. « Room Temperature Synthesis and Characterization of Au Nanoparticles ». Advanced Materials Research 159 (décembre 2010) : 303–6. http://dx.doi.org/10.4028/www.scientific.net/amr.159.303.
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The new emergent properties of nanoparticles include quantam size effect, nonlinear optical properties and thus the nanomaterials have extensive applications in microelectronic, bacteriostatic and catalytic or magnetic recording materials. Nanoparticles find potential applications in DNA detection and photo detection. Gold nano particles (AuNPs) are useful in nanoscale devices and systems due to its resistance to oxidation. In this paper a cost effective, versatile and simple one step room temperature synthesis of highly stable and freestanding Au quantum dots capped by TTAB (Tetradecyltrimethyl Amonium Bromide) in the range of 10-90 nm is reported. Ultraviolet- visible spectroscopy (UV-VIS), Fourier transformation infrared spectroscopy (FT-IR) was carried out to characterize these samples. Scanning Electron Microscopy (SEM) confirms the AuNPs sizes of about 80 and 88 nm.
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Goda, Kazuya, Maya Omori et Kohki Takatoh. « Optical switching in guest–host liquid crystal devices driven by photo- and thermal isomerisation of azobenzene ». Liquid Crystals 45, no 4 (14 août 2017) : 485–90. http://dx.doi.org/10.1080/02678292.2017.1355987.
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Moorthy, Vijai M., Joseph D. Rathnasami et Viranjay M. Srivastava. « Design Optimization and Characterization with Fabrication of Nanomaterials-Based Photo Diode Cell for Subretinal Implant Application ». Nanomaterials 13, no 5 (4 mars 2023) : 934. http://dx.doi.org/10.3390/nano13050934.
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An ultrathin nano photodiode array fabricated in a flexible substrate can be an ideal therapeutic replacement for degenerated photoreceptor cells damaged by Age-related Macula Degeneration (AMD) and Retinitis Pigmentosa (RP), such as retinal infections. Silicon-based photodiode arrays have been attempted as artificial retinas. Considering the difficulties caused by hard silicon subretinal implants, researchers have diverted their attention towards organic photovoltaic cells-based subretinal implants. Indium-Tin Oxide (ITO) has been a favorite choice as an anode electrode. A mix of poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyleste (P3HT: PCBM) has been utilized as an active layer in such nanomaterial-based subretinal implants. Though encouraging results have been obtained during the trial of such retinal implants, the need to replace ITO with a suitable transparent conductive electrode will be a suitable substitute. Further, conjugated polymers have been used as active layers in such photodiodes and have shown delamination in the retinal space over time despite their biocompatibility. This research attempted to fabricate and characterize Bulk Hetero Junction (BHJ) based Nano Photo Diode (NPD) utilizing Graphene–polyethylene terephthalate (G–PET)/semiconducting Single-Wall Carbon Nano Tubes (s-SWCNT): fullerene (C60) blend/aluminium (Al) structure to determine the issues in the development of subretinal prosthesis. An effective design approach adopted in this analysis has resulted in developing an NPD with an Efficiency of 10.1% in a non-ITO-driven NPD structure. Additionally, the results show that the efficiency can be further improved by increasing active layer thickness.
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Lee, Sher, et Chi-Jung Chang. « Recent Developments about Conductive Polymer Based Composite Photocatalysts ». Polymers 11, no 2 (24 janvier 2019) : 206. http://dx.doi.org/10.3390/polym11020206.
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Conductive polymers have been widely investigated in various applications. Several conductive polymers, such as polyaniline (PANI), polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT)), and polythiophene (PTh) have been loaded with various semiconductor nanomaterials to prepare the composite photocatalysts. However, a critical review of conductive polymer-based composite photocatalysts has not been available yet. Therefore, in this review, we summarized the applications of conductive polymers in the preparation of composite photocatalysts for photocatalytic degradation of hazardous chemicals, antibacterial, and photocatalytic hydrogen production. Various materials were systematically surveyed to illustrate their preparation methods, morphologies, and photocatalytic performances. The synergic effect between conductive polymers and semiconductor nanomaterials were observed for a lot of composite photocatalysts. The band structures of the composite photocatalysts can be analyzed to explain the mechanism of their enhanced photocatalytic activity. The incorporation of conductive polymers can result in significantly improved visible-light driven photocatalytic activity by enhancing the separation of photoexcited charge carriers, extending the light absorption range, increasing the adsorption of reactants, inhibiting photo-corrosion, and reducing the formation of large aggregates. This review provides a systematic concept about how conductive polymers can improve the performance of composite photocatalysts.
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Samson, Kerr D. G., Eleonore C. L. Bolle, Mariah Sarwat, Tim R. Dargaville et Ferry P. W. Melchels. « Elastic Bioresorbable Polymeric Capsules for Osmosis-Driven Delayed Burst Delivery of Vaccines ». Pharmaceutics 13, no 3 (23 mars 2021) : 434. http://dx.doi.org/10.3390/pharmaceutics13030434.
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Single-administration vaccine delivery systems are intended to improve the efficiency and efficacy of immunisation programs in both human and veterinary medicine. In this work, an osmotically triggered delayed delivery device was developed that was able to release a payload after a delay of approximately 21 days, in a consistent and reproducible manner. The device was constructed out of a flexible poly(ε-caprolactone) photo-cured network fabricated into a hollow tubular shape, which expelled approximately 10% of its total payload within 2 days after bursting. Characterisation of the factors that control the delay of release demonstrated that it was advantageous to adjust material permeability and device wall thickness over manipulation of the osmogent concentration in order to maintain reproducibility in burst delay times. The photo-cured poly(ε-caprolactone) network was shown to be fully degradable in vitro, and there was no evidence of cytotoxicity after 11 days of direct contact with primary dermal fibroblasts. This study provides strong evidence to support further development of flexible biomaterials with the aim of continuing improvement of the device burst characteristics in order to provide the greatest chance of the devices succeeding with in vivo vaccine booster delivery.
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ZHANG, YUEGANG. « CARBON NANOTUBE BASED NONVOLATILE MEMORY DEVICES ». International Journal of High Speed Electronics and Systems 16, no 04 (décembre 2006) : 959–75. http://dx.doi.org/10.1142/s0129156406004107.
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The technology progress and increasing high density demand have driven the nonvolatile memory devices into nanometer scale region. There is an urgent need of new materials to address the high programming voltage and current leakage problems in the current flash memory devices. As one of the most important nanomaterials with excellent mechanical and electronic properties, carbon nanotube has been explored for various nonvolatile memory applications. While earlier proposals of "bucky shuttle" memories and nanoelectromechanical memories remain as concepts due to fabrication difficulty, recent studies have experimentally demonstrated various prototypes of nonvolatile memory cells based on nanotube field-effect-transistor and discrete charge storage bits, which include nano-floating gate memory cells using metal nanocrystals, oxide-nitride-oxide memory stack, and more simpler trap-in-oxide memory devices. Despite of the very limited research results, distinct advantages of high charging efficiency at low operation voltage has been demonstrated. Single-electron charging effect has been observed in the nanotube memory device with quantum dot floating gates. The good memory performance even with primitive memory cells is attributed to the excellent electrostatic coupling of the unique one-dimensional nanotube channel with the floating gate and the control gate, which gives extraordinary charge sensibility and high current injection efficiency. Further improvement is expected on the retention time at room temperature and programming speed if the most advanced fabrication technology were used to make the nanotube based memory cells.
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Han, Aiguo, Mei Li, Shengbo Zhang, Xinli Zhu, Jinyu Han, Qingfeng Ge et Hua Wang. « Ti3+ Defective SnS2/TiO2 Heterojunction Photocatalyst for Visible-Light Driven Reduction of CO2 to CO with High Selectivity ». Catalysts 9, no 11 (6 novembre 2019) : 927. http://dx.doi.org/10.3390/catal9110927.
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In recent years, defective TiO2-based composite nanomaterials have received much attention in the field of photocatalysis. In this work, TiB2 was used as a precursor to successfully prepare Ti3+ defective TiO2 (TiO2-B) with a truncated bipyramidal structure by a one-step method. Then, the SnS2 nanosheets were assembled onto the as-prepared TiO2-B through simple hydrothermal reaction. TiO2-B exhibits strong visible light absorption properties, but the recombination rate of the photo-generated electron-hole pair was high and does not exhibit ideal photocatalytic performance. Upon introducing SnS2, the heterojunction catalyst SnS2-Ti3+ defective TiO2 (SnS2/TiO2-B) not only possesses the strong light absorption from UV to visible light region, the lowest photo-generated charge recombination rate but also achieves a more negative conduction band potential than the reduction potential of CO2 to CO, and thereby, exhibits the significantly enhanced selectivity and yield of CO in photocatalytic CO2 reduction. Notably, SnS2/TiO2-B produces CO at a rate of 58 µmol·h−1·g−1 with CO selectivity of 96.3% under visible light irradiation, which is 2 and 19 times greater than those of alone TiO2-B and SnS2, respectively. Finally, a plausible photocatalytic mechanism on SnS2/TiO2-B was proposed that the electron transfer between TiO2 and SnS2 follows the Z-scheme mode. Our results present an effective way to gain highly efficient TiO2 based photocatalysts for CO2 reduction by combining different modification methods of TiO2 and make full use of the synergistic effects.
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Dishari, Shudipto K. « (Invited) Novel Nature-Inspired Concepts to Design Ionomeric Nanomaterials for Energy Conversion and Storage Devices ». ECS Meeting Abstracts MA2022-01, no 38 (7 juillet 2022) : 1707. http://dx.doi.org/10.1149/ma2022-01381707mtgabs.
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Ion-conducting polymers (ionomers) are an integral part of renewable energy-driven technologies. Proton exchange membrane fuel cells (PEMFCs) have already been incorporated into low-duty vehicles and are now being adopted in heavy-duty vehicles. Therefore, we need more durable and efficient fuel cell materials than ever. A major technical challenge of PEMFCs is the ion transport limitation at the ionomer-catalyst interface which negatively impacts the efficiency of the cells. The current state-of-the-art fuel cell ionomers (both fluorocarbon- and hydrocarbon-based) conduct protons efficiently in bulk, several tens of micron thick, free-standing membranes, but poorly in sub-micron thick films. This needs attention as sub-micron thick ionomer layers are used as catalyst binders on electrodes of PEMFCs and other energy conversion and storage devices. However, the nanoscale behavior of these existing ionomers within complex hydration environment is not well-understood yet. More importantly, ionomers are rarely designed to improve the thin film ion conduction properties. To address and overcome these issues, we do not only design innovative nanoscale materials characterization techniques to explore the distribution of ion conduction environment across ionomer films/membrane, but also design novel classes of ionomers inspired by natural living systems to facilitate ion conduction in thin films. We experimentally measure the ion conductivity, morphology, and mechanical properties, and combine them with computational studies to elevate our understanding of ion conduction mechanism within 10-200 nm thick films of these newly designed ionomers. The results suggest the great promise of these new classes of ionomers as efficiently ion-transporting catalyst binders for fuel cells, electrolyzers, and batteries.
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Kumar, Sandeep, et Sunil Kumar. « Ultrafast light-induced THz switching in exchange-biased Fe/Pt spintronic heterostructure ». Applied Physics Letters 120, no 20 (16 mai 2022) : 202403. http://dx.doi.org/10.1063/5.0091934.
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The ultrafast optical control of magnetization in spintronic structures enables one to access to the high-speed information processing, approaching the realm of terahertz (THz). Femtosecond visible/near-infrared laser-driven ferromagnetic/nonmagnetic metallic spintronic heterostructures-based THz emitters combine the aspects from the ultrafast photo-induced dynamics and spin-charge inter-conversion mechanisms through the generation of THz electromagnetic pulses. In this Letter, we demonstrate photoexcitation density-dependent induced exchange-bias tunability and THz switching in an annealed Fe/Pt thin-film heterostructure, which otherwise is a widely used conventional spintronic THz emitter. By combining the exchange-bias effect along with THz emission, the photo-induced THz switching is observed without any applied magnetic field. These results pave the way for an all-optical ultrafast mechanism to exchange-bias tuning in spintronic devices for high-density storage, read/write magnetic memory applications.
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Wu, Qiaoyun, Yunzhe Zhang, Qian Yang, Ning Yuan et Wei Zhang. « Review of Electrochemical DNA Biosensors for Detecting Food Borne Pathogens ». Sensors 19, no 22 (12 novembre 2019) : 4916. http://dx.doi.org/10.3390/s19224916.
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The vital importance of rapid and accurate detection of food borne pathogens has driven the development of biosensor to prevent food borne illness outbreaks. Electrochemical DNA biosensors offer such merits as rapid response, high sensitivity, low cost, and ease of use. This review covers the following three aspects: food borne pathogens and conventional detection methods, the design and fabrication of electrochemical DNA biosensors and several techniques for improving sensitivity of biosensors. We highlight the main bioreceptors and immobilizing methods on sensing interface, electrochemical techniques, electrochemical indicators, nanotechnology, and nucleic acid-based amplification. Finally, in view of the existing shortcomings of electrochemical DNA biosensors in the field of food borne pathogen detection, we also predict and prospect future research focuses from the following five aspects: specific bioreceptors (improving specificity), nanomaterials (enhancing sensitivity), microfluidic chip technology (realizing automate operation), paper-based biosensors (reducing detection cost), and smartphones or other mobile devices (simplifying signal reading devices).
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Kallambadi Sadashivappa, Prashanth, Revathi Venkatachalam, Ramyakrishna Pothu, Rajender Boddula, Prasun Banerjee, Ramachandra Naik, Ahmed Bahgat Radwan et Noora Al-Qahtani. « Progressive Review of Functional Nanomaterials-Based Polymer Nanocomposites for Efficient EMI Shielding ». Journal of Composites Science 7, no 2 (13 février 2023) : 77. http://dx.doi.org/10.3390/jcs7020077.
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Nanomaterials have assumed an imperative part in the advancement of human evolution and are more intertwined in our thinking and application. Contrary to the conventional micron-filled composites, the unique nanofillers often modify the properties of the polymer matrix at the same time, bestowing new functionality because of their chemical composition and their nano dimensions. The unprecedented technological revolution is driving people to adapt to miniaturized electronic gadgets. The sources of electromagnetic fields are ubiquitous in a tech-driven society. The COVID-19 pandemic has escalated the proliferation of electromagnetic interference as the world embraced remote working and content delivery over mobile communication devices. While EMI shielding is performed using the combination of reflection, absorption, and electrical and magnetic properties, under certain considerations, the dominant nature of any one of the properties may be required. The miniaturization of electronic gadgets coupled with wireless technologies is driving us to search for alternate lightweight EMI shielding materials with improved functionalities relative to conventional metals. Polymer nanocomposites have emerged as functional materials with versatile properties for EMI shielding. This paper reviews nanomaterials-based polymer nanocomposites for EMI shielding applications.
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Chew, Xiong Yeu, Guang Ya Zhou et Fook Siong Chau. « Novel Doubly Nano-Scale Perturbative Resonance Control of a Free-Suspending Photonic Crystal Structure ». Applied Mechanics and Materials 83 (juillet 2011) : 147–50. http://dx.doi.org/10.4028/www.scientific.net/amm.83.147.
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The impact of developing nanophotonic components have proven to be a promising research on the future optical integrated circuit complementing the current scaling of semiconductors for faster board-board, chip-chip interconnect speeds. Essentially photonic crystals (PhC) symbolize an emerging class of periodic nanomaterials that offers flexibilities in achieving novel devices. Based on the investigations of the high-Q resonance mode energy distributions, we optimized the nanoscale tip for optimal perturbative effect with low loss resonance control in the optical near field regime. In this study to achieve larger spectral resonance, we proposed using a novel doubly nanoscale perturbative tip to achieve optimal accurate photonic crystal resonance control. Such method may be driven by a nano-electromechanical (NEMS) system that may be fabricated with monolithic approaches.
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Lin, Yin-Pai, Boris Polyakov, Edgars Butanovs, Aleksandr A. Popov, Maksim Sokolov, Dmitry Bocharov et Sergei Piskunov. « Excited States Calculations of MoS2@ZnO and WS2@ZnO Two-Dimensional Nanocomposites for Water-Splitting Applications ». Energies 15, no 1 (27 décembre 2021) : 150. http://dx.doi.org/10.3390/en15010150.
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Transition metal dichalcogenide (TMD) MoS2 and WS2 monolayers (MLs) deposited atop of crystalline zinc oxide (ZnO) and graphene-like ZnO (g-ZnO) substrates have been investigated by means of density functional theory (DFT) using PBE and GLLBSC exchange-correlation functionals. In this work, the electronic structure and optical properties of studied hybrid nanomaterials are described in view of the influence of ZnO substrates thickness on the MoS2@ZnO and WS2@ZnO two-dimensional (2D) nanocomposites. The thicker ZnO substrate not only triggers the decrease of the imaginary part of dielectric function relatively to more thinner g-ZnO but also results in the less accumulated charge density in the vicinity of the Mo and W atoms at the conduction band minimum. Based on the results of our calculations, we predict that MoS2 and WS2 monolayers placed at g-ZnO substrate yield essential enhancement of the photoabsorption in the visible region of solar spectra and, thus, can be used as a promising catalyst for photo-driven water splitting applications.
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Kim, Junhee, Sanghoon Jung, Han-Jung Kim, Yoonkap Kim, Chanyong Lee, Soo Min Kim, Donghwan Kim et Yongseok Jun. « SiNW/C@Pt Arrays for High-Efficiency Counter Electrodes in Dye-Sensitized Solar Cells ». Energies 13, no 1 (27 décembre 2019) : 139. http://dx.doi.org/10.3390/en13010139.
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Modern energy needs and the pressing issue of environmental sustainability have driven many research groups to focus on energy-generation devices made from novel nanomaterials. We have prepared platinum nanoparticle-decorated silicon nanowire/carbon core–shell nanomaterials (SiNW/C@Pt). The processing steps are relatively simple, including wet chemical etching to form the silicon nanowires (SiNWs), chemical vapor deposition to form the carbon shell, and drop-casting and thermal treatment to embed platinum nanoparticles (Pt NPs). This nanomaterial was then tested as the counter electrode (CE) in dye-sensitized solar cells (DSSCs). SiNW/C@Pt shows potential as a good electrocatalyst based on material characterization data from Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectroscopy shows that the surface reactivity of the SiNW/C is increased by the decoration of Pt NPs. These data also show that the carbon shell included both graphitic (sp 2 hybridization) and defective (sp 3 hybridization) phases of carbon. We achieved the minimum charge-transfer resistance of 0.025 Ω · cm 2 and the maximum efficiency of 9.46% with a symmetric dummy cell and DSSC device fabricated from the SiNW/C@Pt CEs, respectively.
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Makgopa, Katlego, et Mpho Sofnee Ratsoma. « Structural Elucidation of Nitrogen-Doped Reduced Graphene Oxide/Hausmannite Manganese Oxide Nanocomposite for Supercapacitor Applications ». ECS Meeting Abstracts MA2022-02, no 1 (9 octobre 2022) : 71. http://dx.doi.org/10.1149/ma2022-02171mtgabs.
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The increasing consumption of fossils fuel accompanied by related carbon emissions and complex set of issues associated with the generation and use of electricity has raised an urgent need for reliable, renewable and sustainable energy alternatives [1]. Nanotechnology and the production of nanostructured materials has driven the rapid growth in the research of carbon nanomaterials as energy storage materials for supercapacitor (SCs) applications. Among several carbon nanomaterials explored for SCs, graphene has shown to be the leading carbon nanomaterial, due to its intriguing properties such as highly tunable surface area, outstanding electrical conductivity, good chemical stability and excellent mechanical behavior [2]. Due to challenges in the bulk synthesis of graphene, reduced graphene oxide (rGO) has been opted as the preferred choice for the development of SC devices. Transition metal oxides also gained much interest in various research industries as materials for SCs applications. Among transition metal oxides, manganese oxide, MnxOy, appeared to be the promising electrode material due to its interesting properties such as cost effectiveness, high theoretical specific capacitance, high theoretical surface area (≥ 1370 m2 g-1), and excellent electrochemical reversibility. However, the poor conductivity of manganese oxide restricts its progress in SC applications [2, 3]. Therefore, great attention has been devoted to the improvement of the electronic properties of manganese oxides-based electrode materials by decorating them on highly conductive carbon-based nanomaterials. Although intensive study has been done on carbon nanomaterials integrated with MnxOy for pseudocapacitors, there is still less literature on the use of Mn3O4 nanoparticles decorated on carbon materials for application in SCs This work presents a hydrothermal synthesis of the nitrogen-doped reduced graphene oxide/hausmannite manganese oxide (N-rGO/Mn3O4) nanohybrid which showed a great electrochemical performance such as high specific capacitance of 345 F g-1 and a maximum of specific energy of 12.0 Wh kg-1 (current density: 0.1 A g−1), and a maximum specific power of 22.5 kW kg-1 (current density: 10.0 A g−1) in a symmetric configuration. The nanohybrid further showed excellent supercapacitor performance in an asymmetric configuration, with the maximum specific energy and power reaching 34.6 Wh kg−1 (0.1 A g−1) and 14.01 kW kg−1 (10.0 A g−1) respectively. The results obtained affirm the use of N-rGO/Mn3O4 as a potential electrode material for high energy and power supercapacitor devices that can be commercially competitive to that of rechargeable batteries. References [1] P. Simon, Y. Gogotsi, Materials for electrochemical capacitors., Nat. Mater. 7 (2008) 845 [2] K. Xie, B. Wei, Nanomaterials for stretchable energy storage and conversion devices, Nanosci. Technol. (2016) 159 [3] K. Makgopa, K. Raju, P.M. Ejikeme, K.I. Ozoemena, High-performance Mn3O4/onion-like carbon (OLC) nanohybrid pseudocapacitor: Unravelling the intrinsic properties of OLC against other carbon supports, Carbon 117 (2017) 20
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Xu, Ruitong, Jun Pan, Bo Wu, Yangguang Li, Hong-En Wang et Ting Zhu. « Fabrication of Zn-Cu-Ni Ternary Oxides in Nanoarrays for Photo-Enhanced Pseudocapacitive Charge Storage ». Nanomaterials 12, no 14 (18 juillet 2022) : 2457. http://dx.doi.org/10.3390/nano12142457.
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To meet the increasing demands of energy consumption, sustainable energy sources such as solar energy should be better employed to promote electrochemical energy storage. Herein, we fabricated a bifunctional photoelectrode composed of copper foam (CF)-supported zinc-nickel-copper ternary oxides in nanoarrays (CF@ZnCuNiOx NAs) to promote photo-enhanced pseudocapacitive charge storage. The as-fabricated CF@ZnCuNiOx NAs have shown both photosensitive and pseudocapacitive characteristics, demonstrating a synergistic effect on efficient solar energy harvest and conversion. As a result, a high areal specific capacitance of 2741 mF cm−2 (namely 418 μAh cm−2) under light illumination can be calculated at 5 mA cm−2, which delivered photo-enhancement of 38.3% compared to that obtained without light. In addition, the photoelectric and photothermal effects of the light energy on pseudocapacitive charge storage have been preliminarily studied and compared. This work may provide some evidence on the different mechanisms of photoelectric/thermal conversion for developing solar-driven energy storage devices.
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Anwar, Asima, Muhammad Asif Yousuf, Bashir Tahir, Muhammad Shahid, Muhammad Imran, Muhammad Azhar Khan, Muhammad Sher et Muhammad Farooq Warsi. « New Er3+-substituted NiFe2O4 Nanoparticles and their Nano-heterostructures with Graphene for Visible Light-Driven Photo-catalysis and other Potential Applications ». Current Nanoscience 15, no 3 (19 février 2019) : 267–78. http://dx.doi.org/10.2174/1573413714666180911101337.
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Background: Spinel ferrites have great scientific and technological significance because of their easy manufacturing, low cost and outstanding electrical and magnetic properties. Nickel ferrite nanoparticles are ferromagnetic material with an inverse spinel structure. They show remarkable magnetic properties and hence have a wide range of applications in magnetic storage devices, microwave devices, gas sensors, telecommunication, drug delivery, catalysis and magnetic resonance imaging. Objective: The aim and objective of this research article is to study the relative effect of NiErxFe2-xO4 nanoparticles and their composites with reduced graphene oxide (rGO) for the photocatalytic degradation reaction and other physical parameters. Method: Rare earth Er3+ substituted NiErxFe2-xO4 nanoparticles were synthesized via the facile wet chemical route. Six different compositions of NiErxFe2-xO4 with varied Er3+ contents such as (x) = 0.00, 0.005, 0.01, 0.015, 0.02 and 0.025 were selected for evaluation of the effect of Er3+ on various parameters of NiFe2O4 nanoparticles. Reduced graphene oxide (rGO) was prepared by Hummer’s method and was characterized by UV-Visible spectroscopy, X-ray powder diffraction and Raman spectroscopy. Nano-heterostructures of NiErxFe2-xO4 with rGO were prepared by the ultra-sonication method. Results: X-ray powder diffraction (XRD) confirmed the spinel cubic structure of all the compositions of NiErx- Fe2-xO4 nanoparticles. The photocatalytic degradation rate of methylene blue and congo red under visible light irradiation was found faster in the presence of NiErxFe2-xO4-rGO nanocomposites as compared to bare nanoparticles. It was also investigated that as the Er3+ contents were increased in NiErxFe2-xO4 nanoparticles, the dielectric parameters were largely affected. The room temperature DC-resistivity measurements showed that the Er3+ contents in NiFe2O4 are responsible for the increased electrical resistivity of ferrite particles. The electrochemical impedance spectroscopic (EIS) analysis of NiErxFe2-xO4 nanoparticles and NiErxFe2-xO4-rGO nanocomposites revealed that the ferrite particles possess low conductance as compared to the corresponding composites with graphene. Conclusion: The data obtained from all these characterization techniques suggested the potential applications of the NiErxFe2-xO4 nanoparticles and NiErxFe2-xO4-rGO nanocomposites for visible light driven photo-catalysis and high-frequency devices fabrication.
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Marzolf, Daniel R., Aidan M. McKenzie, Matthew C. O’Malley, Nina S. Ponomarenko, Coleman M. Swaim, Tyler J. Brittain, Natalie L. Simmons et al. « Mimicking Natural Photosynthesis : Designing Ultrafast Photosensitized Electron Transfer into Multiheme Cytochrome Protein Nanowires ». Nanomaterials 10, no 11 (28 octobre 2020) : 2143. http://dx.doi.org/10.3390/nano10112143.
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Efficient nanomaterials for artificial photosynthesis require fast and robust unidirectional electron transfer (ET) from photosensitizers through charge-separation and accumulation units to redox-active catalytic sites. We explored the ultrafast time-scale limits of photo-induced charge transfer between a Ru(II)tris(bipyridine) derivative photosensitizer and PpcA, a 3-heme c-type cytochrome serving as a nanoscale biological wire. Four covalent attachment sites (K28C, K29C, K52C, and G53C) were engineered in PpcA enabling site-specific covalent labeling with expected donor-acceptor (DA) distances of 4–8 Å. X-ray scattering results demonstrated that mutations and chemical labeling did not disrupt the structure of the proteins. Time-resolved spectroscopy revealed three orders of magnitude difference in charge transfer rates for the systems with otherwise similar DA distances and the same number of covalent bonds separating donors and acceptors. All-atom molecular dynamics simulations provided additional insight into the structure-function requirements for ultrafast charge transfer and the requirement of van der Waals contact between aromatic atoms of photosensitizers and hemes in order to observe sub-nanosecond ET. This work demonstrates opportunities to utilize multi-heme c-cytochromes as frameworks for designing ultrafast light-driven ET into charge-accumulating biohybrid model systems, and ultimately for mimicking the photosynthetic paradigm of efficiently coupling ultrafast, light-driven electron transfer chemistry to multi-step catalysis within small, experimentally versatile photosynthetic biohybrid assemblies.
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Subirada, Francesc, Roberto Paoli, Jessica Sierra-Agudelo, Anna Lagunas, Romen Rodriguez-Trujillo et Josep Samitier. « Development of a Custom-Made 3D Printing Protocol with Commercial Resins for Manufacturing Microfluidic Devices ». Polymers 14, no 14 (21 juillet 2022) : 2955. http://dx.doi.org/10.3390/polym14142955.
Texte intégralRésumé :
The combination of microfluidics and photo-polymerization techniques such as stereolithography (SLA) has emerged as a new field which has a lot of potential to influence in such important areas as biological analysis, and chemical detection among others. However, the integration between them is still at an early stage of development. In this article, after analyzing the resolution of a custom SLA 3D printer with commercial resins, microfluidic devices were manufactured using three different approaches. First, printing a mold with the objective of creating a Polydimethylsiloxane (PDMS) replica with the microfluidic channels; secondly, open channels have been printed and then assembled with a flat cover of the same resin material. Finally, a closed microfluidic device has also been produced in a single process of printing. Important results for 3D printing with commercial resins have been achieved by only printing one layer on top of the channel. All microfluidic devices have been tested successfully for pressure-driven fluid flow.
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Litchman, Michelle L., Heather R. Walker, Caroline Fitzgerald, Mariana Gomez Hoyos, Dana Lewis et Perry M. Gee. « Patient-Driven Diabetes Technologies : Sentiment and Personas of the #WeAreNotWaiting and #OpenAPS Movements ». Journal of Diabetes Science and Technology 14, no 6 (4 juillet 2020) : 990–99. http://dx.doi.org/10.1177/1932296820932928.
Texte intégralRésumé :
Background: Patients with diabetes have developed innovative do-it-yourself (DIY) methods for adapting existing medical devices to better fit individual needs. Method: A multiple method study used Symplur Analytics to analyze aggregated Twitter data of #WeAreNotWaiting and #OpenAPS tweets between 2014 and 2017 to examine DIY patient-led innovation. Conversation sentiment was examined between diabetes stakeholders to determine changes over time. Two hundred of the most shared photos were analyzed to understand visual representations of DIY patient-led innovations. Finally, discourse analysis was used to identify the personas who engage in DIY patient-led diabetes technologies activities and conversations on Twitter. Results: A total of 7886 participants who generated 46 578 tweets were included. Sentiment analysis showed that 82%-85% of interactions around DIY patient-led innovation was positive among patient/caregiver and physician groups. Through photo analysis, five content themes emerged: (1) disseminating media and conference coverage, (2) showcasing devices, (3) celebrating connections, (4) providing instructions, and (5) celebrating accomplishments. Six personas emerged across the overlapping userbase: (1) fearless leaders, (2) loopers living it up, (3) parents on a mission, (4) the tech titans, (5) movement supporters, and (6) healthcare provider advocates. Personas had varying goals and behaviors within the community. Conclusions: #WeAreNotWaiting and #OpenAPS on Twitter reveal a fast-moving patient-led movement focused on DIY patient innovation that is further mobilized by an expanding and diverse userbase. Further research is indicated to bring technology savvy persons with diabetes into conversation with healthcare providers and researchers alike.
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Bendicho, Carlos, Isela Lavilla, Francisco Pena-Pereira, Inmaculada de la Calle et Vanesa Romero. « Nanomaterial-Integrated Cellulose Platforms for Optical Sensing of Trace Metals and Anionic Species in the Environment ». Sensors 21, no 2 (16 janvier 2021) : 604. http://dx.doi.org/10.3390/s21020604.
Texte intégralRésumé :
The development of disposable sensors that can be easily adapted to every analytical problem is currently a hot topic that is revolutionizing many areas of science and technology. The need for decentralized analytical measurements at real time is increasing for solving problems in areas such as environment pollution, medical diagnostic, food quality assurance, etc., requiring fast action. Despite some current limitations of these devices, such as insufficient detection capability at (ultra)trace level and risk of interferent effects due to matrix, they allow low-cost analysis, portability, low sample consumption, and fast response. In the last years, development of paper-based analytical devices has undergone a dramatic increase for on-site detection of toxic metal ions and other pollutants. Along with the great availability of cellulose substrates, the immobilization of receptors providing enhanced recognition ability, such as a variety of nanomaterials, has driven the design of novel sensing approaches. This review is aimed at describing and discussing the different possibilities arisen with the use of different nanoreceptors (e.g., plasmonic nanoparticles, quantum dots, carbon-based fluorescent nanoparticles, etc.) immobilized onto cellulose-based substrates for trace element detection, their advantages and shortcomings.