Latent and thermal energy storage enhancement of silver nanowires-nitrate molten salt for concentrated solar power

>Magister Scientiae - MScPhase change material (PCM) through latent heat of molten salt, is a convincing way for thermal energy storage in CSP applications due to its high volume density. Molten salt, with (60% NaNO3 and 40% KNO3) has been used extensively for energy storage however; the low thermal conductivity and specific heat have limited its large implementation in solar applications. For that, molten salt with the additive of silver nanowires (AgNWs) was synthesized and characterized. This research project aims to investigate the thermophysical properties enhancement of nanosalt (Mixture of molten salt and silver nanowires). The results obtained showed that by simply adjusting the temperature, Silver nanowires with high aspect ratio have been synthesized through the enhanced PVP polyol process method. SEM results revealed a network of silver nanowires and TEM results confirmed the presence of silver nanowires with an average diameter of 129 nm and 16 μm in length

Recent Progress in Nanostructured Zinc Oxide Grown on Fabric for Wearable Thermoelectric Power Generator with UV Shielding

Traditional materials for thermoelectric such as bismuth telluride have been studied and utilized commercially for the last half century, but recent advancements in materials selection are one of the principal function of the active thermoelectric device as it determines the reliability of the fabrication regarding technical and economic aspects. Recently, many researcher’s efforts have been made to utilize oxide nanomaterials for wearable thermoelectric power generator (WTPG) applications which may provide environmental stable, mechanical flexibility, and light weight with low cost of manufacturing. In precise, fabric containing oxide metals have shown great promise as P−/N-type materials with improved transport and UV shielding properties. On the other hand, we have focused on ZnO nanostructures as a high-efficiency WTPG material because they are non-toxic to skin, inexpensive and easy to obtain and possess attractive electronic properties, which means that they are available for clothing with low-cost fabrication. To our observation, we are chaptering about the thermoelectric properties of ZnO and their composite nanostructures coated cotton fabric via the solvothermal method for the first time

Polymer/Fullerene Nanocomposite for Optoelectronics—Moving toward Green Technology

Optoelectronic devices have been developed using the polymer/fullerene nanocomposite, as focused in this review. The polymer/fullerene nanocomposite shows significant structural, electronics, optical, and useful physical properties in optoelectronics. Non-conducting and conducting polymeric nanocomposites have been applied in optoelectronics, such as light-emitting diodes, solar cells, and sensors. Inclusion of fullerene has further broadened the methodological application of the polymer/fullerene nanocomposite. The polymeric matrices and fullerene may have covalent or physical interactions for charge or electron transportation and superior optical features. Green systems have also been explored in optoelectronic devices; however, due to limited efforts, further design innovations are desirable in green optoelectronics. Nevertheless, the advantages and challenges of the green polymer/fullerene nanocomposite in optoelectronic devices yet need to be explored

Effect of Wrapped Carbon Nanotubes on Optical Properties, Morphology, and Thermal Stability of Electrospun Poly(vinyl alcohol) Composite Nanofibers

Electrospinning was used to elaborate poly(vinyl alcohol) (PVA) nanofibers in the presence of embedded multiwall carbon nanotubes (MWCNTs) in surfactant and polymer. MWCNTs were dispersed in aqueous solution using both sodium dodecyl sulfate (SDS) as surfactant and Poly(vinyl pyrrolidone) (PVP). Changing the surfactant and polymer concentration reveals that the maximum dispersion achievable is corresponding to the mass ratios MWCNTs : SDS—1 : 5 and MWCNTs : SDS : PVP—1 : 5 : 0.6 in the presence of the PVP. After the optimization of the dispersion process, the SEM image of the PVA/PVP/SDS/MWCNTs electrospun fibers presents high stability of the fibers with diameter around 224 nm. Infrared spectroscopy and thermal gravimetric analysis elucidate the type of interaction between the PVA and the coated carbon nanotube. The presence of PVP wrapped carbon nanotubes reduced slightly the onset of the degradation temperature of the electrospun nanofibers

The International Research and Educational Programs of Clark Atlanta University's Center for Functional Nanoscale Materials

Atlanta Conference on Science and Innovation Policy 2009This presentation was part of the session : Science and Innovation WorkforceThis material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. ©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE

Ion Beams for Space Applications

This chapter uses an active space mission as well as current and ongoing research work to showcase the role of ion beams in the advancement of space science and technology. It uses the mission objectives of the ZACUBE-2 space mission developed at the Cape Peninsula University of Technology in Cape Town, South Africa, to predict the space environment it will encounter when in orbit. These predictions are then used to show how ion beam parameters for single event effect testing are selected, and how trade-offs are made to achieve a cost effective use of beam time. An experiment is detailed, showcasing the role of ion beams in the investigation of the shielding capabilities of coatings obtained from the pulsed laser ablation of W2B5/B4C for solar panel applications in space. The results of this experiment show that indeed this is a potential shield capable of reducing solar panel degradation due to low energy protons. By using ZACUBE-2 and coatings made from W2B5/B4C, this chapter takes a practical and current approach to demonstrate the central role played by ion beams in advancing space technology. More importantly, it eases the conversation between the satellite and the ion beam communities

Structural and magnetic properties of E-Fe_{1-x}Co_xSi thin films deposited via pulsed laser deposition

We report pulsed laser deposition synthesis and characterization of polycrystalline Fe1-xCox Si thin films on Si (111). X-ray diffraction, transmission electron, and atomic force microscopies reveal films to be dense, very smooth, and single phase with a cubic B20 crystal structure. Ferromagnetism with significant magnetic hysteresis is found for all films including nominally pure FeSi films in contrast to the very weak paramagnetism of bulk FeSi. For Fe1-xCoxSi this signifies a change from helimagnetism in bulk, to ferromagnetism in thin films. These ferromagnetic thin films are promising as a magnetic-silicide/silicon system for polarized current production, manipulation, and detection.Comment: 12 pages, 4 figures accepted in the Applied Physics Letter

Photoluminescence Quenching and Structure of Nanocomposite Based on Graphene Oxide Layers Decorated with Nanostructured Porphyrin

Nanocomposites based on few-layers graphene oxide (FGO) decorated with porphyrin nanorods (PN) were synthesized and the interfacial interaction between these two components was investigated by using scanning electron microscopy (SEM), photoluminescence spectroscopy, resonant Raman scattering and Fourier transform infrared (FT-IR) techniques. SEM showed good exfoliation of FGO and its successful interaction with the PN. The photoluminescence results showed an important interaction between FGO and PN resulting in a quenching of the photoluminescence of the PN-FGO composite. Resonant Raman with PN aggregates and FT-IR results revealed a π- π intermolecular interaction confirming the energy/charge transfer. Moreover, the investigation of X-ray diffraction confirmed the intercalation of PN in FGO and their disaggregation. The findings presented here are an important contribution to achieving the functionalization of graphene derivative surfaces with PN for various optoelectronic applications and particularly photovoltaic cells

Using nanomaterials as excellent immobilisation layer for biosensor design

The endless development in nanotechnology has introduced new vitality in device fabrication including biosensor design for biomedical applications. With outstanding features like suitable biocompatibility, good electrical and thermal conductivity, wide surface area and catalytic activity, nanomaterials have been considered excellent and promising immobilisation candidates for the development of high-impact biosensors after they emerged. Owing to these reasons, the present review deals with the efficient use of nanomaterials as immobilisation candidates for biosensor fabrication. These include the implementation of carbon nanomaterials—graphene and its derivatives, carbon nanotubes, carbon nanoparticles, carbon nanodots—and MXenes, likewise their synergistic impact when merged with metal oxide nanomaterials. Furthermore, we also discuss the origin of the synthesis of some nanomaterials, the challenges associated with the use of those nanomaterials and the chemistry behind their incorporation with other materials for biosensor design. The last section covers the prospects for the development and application of the highlighted nanomaterials

Structural and magnetic properties of ε -Fe1-x Cox Si thin films deposited via pulsed laser deposition

We report pulsed laser deposition synthesis and characterization of polycrystalline Fe1-x Cox Si thin films on Si (111). X-ray diffraction, transmission electron, and atomic force microscopies reveal films to be dense, very smooth, and single phase with a cubic B20 crystal structure. Ferromagnetism with significant magnetic hysteresis is found for all films including nominally pure FeSi films in contrast to the very weak paramagnetism of bulk FeSi. For Fe1-x Cox Si this signifies a change from helimagnetism in bulk, to ferromagnetism in thin films. These ferromagnetic thin films are promising as a magnetic-silicide/silicon system for polarized current production, manipulation, and detection. © 2009 American Institute of Physics