Nanomaterials

18 pages, 2559 KiB

Open AccessArticle

Simultaneous Influence of Gradients in Natural Organic Matter and Abiotic Parameters on the Behavior of Silver Nanoparticles in the Transition Zone from Freshwater to Saltwater Environments

by Ivana Čarapar, Lara Jurković, Dijana Pavičić-Hamer, Bojan Hamer and Daniel Mark Lyons

Nanomaterials 2022, 12(2), 296; https://doi.org/10.3390/nano12020296 - 17 Jan 2022

Cited by 10 | Viewed by 2206

Abstract

As nanoparticles have been found to cause a range of harmful impacts in biota, understanding processes and transformations which may stabilize and increase their persistence time in the environment are of great importance. As nanoparticles carried in riverine or wastewaters will eventually reach [...] Read more.

As nanoparticles have been found to cause a range of harmful impacts in biota, understanding processes and transformations which may stabilize and increase their persistence time in the environment are of great importance. As nanoparticles carried in riverine or wastewaters will eventually reach estuaries, understanding their behavior and transport potential in this transition zone from fresh to marine waters is essential, particularly as estuaries are sensitive ecological zones, oftentimes encompassing ornithologically important areas. In this direction, we report on the influence of combined gradients of riverine and marine natural organic matter (NOM) on the temporal stability of biocorona-encapsulated silver nanoparticles in terms of ion release kinetics. In parallel, salinity, pH and oxygen saturation were simultaneously varied to create a model to mimic the complex estuarine environment. While humic acid (HA) and alginate (Alg) disrupted the stabilizing ability of the nanoparticle protein corona to a greater and lesser degree, respectively, they slowed the rate of ion release in freshwater at pH 6.6 and in saltwater at pH 8, respectively, while oxygen saturation was also found to be an important factor. Thus, as the type of NOM changes with pH along a salinity gradient in an estuary, conditions required to increase the persistence time of nanoparticles are serendipitously met, with greater colloidal stability achieved in cases where there is more rapid replacement of HA with Alg. Despite the strong gradients in ionic strength, pH and oxygen saturation, the protein corona was not sufficiently disrupted at the nanoparticle surface to be substituted by NOM indicating the greater adsorption energy of the protein’s hydrophobic domains. Ultimately, it is the specific NOM profile of individual estuaries that may provide the best indicator for predicting the stability and persistence of silver nanoparticles as they transition from fresh to salt water environments. Full article

(This article belongs to the Special Issue Interfacial Phenomena and Nanoparticle Engineering—Spotlight on Early Career Investigators 2021)

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25 pages, 3275 KiB

Open AccessArticle

Performance of TiO₂/UV-LED-Based Processes for Degradation of Pharmaceuticals: Effect of Matrix Composition and Process Variables

by Danilo Bertagna Silva, Gianluigi Buttiglieri, Bruna Babić, Danijela Ašperger and Sandra Babić

Nanomaterials 2022, 12(2), 295; https://doi.org/10.3390/nano12020295 - 17 Jan 2022

Cited by 6 | Viewed by 2742

Abstract

Ultra-violet light-emitting diode (UV-LED)-based processes for water treatment have shown the potential to surpass the hurdles that prevent the adoption of photocatalysis at a large scale due to UV-LEDs’ unique features and design flexibility. In this work, the degradation of five EU Watch [...] Read more.

Ultra-violet light-emitting diode (UV-LED)-based processes for water treatment have shown the potential to surpass the hurdles that prevent the adoption of photocatalysis at a large scale due to UV-LEDs’ unique features and design flexibility. In this work, the degradation of five EU Watch List 2020/1161 pharmaceutical compounds was comprehensively investigated. Initially, the UV-A and UV-C photolytic and photocatalytic degradation of individual compounds and their mixtures were explored. A design of experiments (DoE) approach was used to quantify the effects of numerous variables on the compounds’ degradation rate constant, total organic carbon abatement, and toxicity. The reaction mechanisms of UV-A photocatalysis were investigated by adding different radical scavengers to the mix. The influence of the initial pH was tested and a second DoE helped evaluate the impact of matrix constituents on degradation rates during UV-A photocatalysis. The results showed that each compound had widely different responses to each treatment/scenario, meaning that the optimized design will depend on matrix composition, target pollutant reactivity, and required effluent standards. Each situation should be analyzed individually with care. The levels of the electrical energy per order are still unfeasible for practical applications, but LEDs of lower wavelengths (UV-C) are now approaching UV-A performance levels. Full article

(This article belongs to the Special Issue Recent Advances in Nanomaterials for Removal of New Emerging Pollutants from Water/Wastewater)

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73 pages, 10240 KiB

Open AccessReview

A Comprehensive Review of Graphitic Carbon Nitride (g-C₃N₄)–Metal Oxide-Based Nanocomposites: Potential for Photocatalysis and Sensing

by Amirhossein Alaghmandfard and Khashayar Ghandi

Nanomaterials 2022, 12(2), 294; https://doi.org/10.3390/nano12020294 - 17 Jan 2022

Cited by 189 | Viewed by 19122

Abstract

g-C₃N₄ has drawn lots of attention due to its photocatalytic activity, low-cost and facile synthesis, and interesting layered structure. However, to improve some of the properties of g-C₃N₄, such as photochemical stability, electrical band structure, and [...] Read more.

g-C₃N₄ has drawn lots of attention due to its photocatalytic activity, low-cost and facile synthesis, and interesting layered structure. However, to improve some of the properties of g-C₃N₄, such as photochemical stability, electrical band structure, and to decrease charge recombination rate, and towards effective light-harvesting, g-C₃N₄–metal oxide-based heterojunctions have been introduced. In this review, we initially discussed the preparation, modification, and physical properties of the g-C₃N₄ and then, we discussed the combination of g-C₃N₄ with various metal oxides such as TiO₂, ZnO, FeO, Fe₂O₃, Fe₃O₄, WO₃, SnO, SnO₂, etc. We summarized some of their characteristic properties of these heterojunctions, their optical features, photocatalytic performance, and electrical band edge positions. This review covers recent advances, including applications in water splitting, CO₂ reduction, and photodegradation of organic pollutants, sensors, bacterial disinfection, and supercapacitors. We show that metal oxides can improve the efficiency of the bare g-C₃N₄ to make the composites suitable for a wide range of applications. Finally, this review provides some perspectives, limitations, and challenges in investigation of g-C₃N₄–metal-oxide-based heterojunctions. Full article

(This article belongs to the Special Issue Advances in Nanostructured Semiconductors and Heterojunctions)

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12 pages, 7980 KiB

Open AccessArticle

Effects of Fe, Mn Individual Doping and (Fe, Mn) Co-Doping on Ferromagnetic Properties of Co₂Si Powders

by Jiang Zou, Lifeng Wang, Juan He, Bo Wu and Quan Xie

Nanomaterials 2022, 12(2), 293; https://doi.org/10.3390/nano12020293 - 17 Jan 2022

Cited by 1 | Viewed by 1943

Abstract

Magnetic materials are crucial energy materials that are widely used in day-to-day life. Therefore, the development and study of high-performance magnetic materials are of great significance. In this study, the magnetic materials Co

_{66.6}

Si

_{33.4}

, Co

_{60.6}

X

_{6}

Si

_{33.4}

[...] Read more.

Magnetic materials are crucial energy materials that are widely used in day-to-day life. Therefore, the development and study of high-performance magnetic materials are of great significance. In this study, the magnetic materials Co

_{66.6}

Si

_{33.4}

, Co

_{60.6}

X

_{6}

Si

_{33.4}

(X = Fe, Mn), and Co

_{60.6}

Fe

_{3}

Mn

_{3}

Si

_{33.4}

were prepared via the ball milling and sintering processes. Their crystal structures, electrical conductivity, and magnetic properties were investigated via the X-ray diffraction analysis and by using a resistivity tester, vibrating sample magnetometer, and vector network analyser. The X-ray diffraction analysis revealed that a single phase of Co

_{66.6}

Si

_{33.4}

and its doped alloy powders were successfully obtained. The electrical conductivities of Mn

_{6}

Co

_{60.6}

Si

_{33.4}

and Fe

_{3}

Mn

_{3}

Co

_{60.6}

Si

_{33.4}

were measured using a resistivity tester. The results indicate that Mn doping and Fe and Mn Co-doping enhanced the electrical conductivity of Co

_{66.6}

Si

_{33.4}

. The magnetic properties of Co

_{66.6}

Si

_{33.4}

were determined using a vibrating sample magnetometer. We observed that the magnetic properties were enhanced after doping. Co

_{60.6}

Fe

_{3}

Mn

_{3}

Si

_{33.4}

exhibited excellent magnetic properties. Further, its permeability was determined using a vector network analyser. At a low frequency, the u’ and u” values of Co

_{60.6}

Fe

_{6}

Si

_{33.4}

and Co

_{60.6}

Fe

_{3}

Mn

_{3}

Si

_{33.4}

were enhanced; whereas, at a high frequency, after doping, the u’ and u” values changed only slightly. This study can be used as a basis for future studies on magnetic functional materials. Full article

(This article belongs to the Special Issue Advances in Ferroelectric Nanoparticles)

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15 pages, 1210 KiB

Open AccessArticle

How to Use Localized Surface Plasmon for Monitoring the Adsorption of Thiol Molecules on Gold Nanoparticles?

by Angeline S. Dileseigres, Yoann Prado and Olivier Pluchery

Nanomaterials 2022, 12(2), 292; https://doi.org/10.3390/nano12020292 - 17 Jan 2022

Cited by 12 | Viewed by 3371

Abstract

The functionalization of spherical gold nanoparticles (AuNPs) in solution with thiol molecules is essential for further developing their applications. AuNPs exhibit a clear localized surface plasmon resonance (LSPR) at 520 nm in water for 20 nm size nanoparticles, which is extremely sensitive to [...] Read more.

The functionalization of spherical gold nanoparticles (AuNPs) in solution with thiol molecules is essential for further developing their applications. AuNPs exhibit a clear localized surface plasmon resonance (LSPR) at 520 nm in water for 20 nm size nanoparticles, which is extremely sensitive to the local surface chemistry. In this study, we revisit the use of UV-visible spectroscopy for monitoring the LSPR peak and investigate the progressive reaction of thiol molecules on 22 nm gold nanoparticles. FTIR spectroscopy and TEM are used for confirming the nature of ligands and the nanoparticle diameter. Two thiols are studied: 11-mercaptoundecanoic acid (MUDA) and 16-mercaptohexadecanoic acid (MHDA). Surface saturation is detected after adding 20 nmol of thiols into 1.3 × 10⁻³ nmol of AuNPs, corresponding approximately to 15,000 molecules per AuNPs (which is equivalent to 10.0 molecules per nm²). Saturation corresponds to an LSPR shift of 2.7 nm and 3.9 nm for MUDA and MHDA, respectively. This LSPR shift is analyzed with an easy-to-use analytical model that accurately predicts the wavelength shift. The case of dodecanehtiol (DDT) where the LSPR shift is 15.6 nm is also quickly commented. An insight into the kinetics of the functionalization is obtained by monitoring the reaction for a low thiol concentration, and the reaction appears to be completed in less than one hour. Full article

(This article belongs to the Special Issue Metallic and Metal Oxide Nanoparticles and Their Applications)

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15 pages, 4105 KiB

Open AccessArticle

Efficient Removal of Cr(VI) by TiO₂ Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

by Yu Song, Xi Lu, Zhibao Liu, Wenfei Liu, Ligang Gai, Xiang Gao and Hongfang Ma

Nanomaterials 2022, 12(2), 291; https://doi.org/10.3390/nano12020291 - 17 Jan 2022

Cited by 19 | Viewed by 2868

Abstract

The low-toxicity treatment of chromium-containing wastewater represents an important way of addressing key environmental problems. In this study, a core-shell structural ZIF-8@TiO₂ photocatalyst was synthesized by a simple one-step hydrothermal method. The obtained composite photocatalyst possessed improved photocatalytic activity compared with TiO [...] Read more.

The low-toxicity treatment of chromium-containing wastewater represents an important way of addressing key environmental problems. In this study, a core-shell structural ZIF-8@TiO₂ photocatalyst was synthesized by a simple one-step hydrothermal method. The obtained composite photocatalyst possessed improved photocatalytic activity compared with TiO₂. The results indicated that the optimized ZIF-8@TiO₂ composite exhibited the highest removal efficiency with 93.1% of Cr(VI) after 120 min under UV-vis irradiation. The removal curves and XPS results indicated that the adsorbed Cr(VI) on the ZIF-8 during the dark process was preferentially reduced. The superior removal efficiency of ZIF-8@TiO₂ is attributed to the combination of both high adsorption of ZIF-8, which attracted Cr(VI) on the composite surface, and the high separation efficiency of photo-induced electron-hole pairs. For the mixture of wastewater that contained methyl orange and Cr(VI), 97.1% of MO and 99.7% of Cr(VI) were removed after 5 min and 60 min light irradiation, respectively. The high removal efficiency of multiple pollutants provides promising applications in the field of Cr(VI) contaminated industrial wastewater treatment. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Nanoscience and Nanotechnology)

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8 pages, 14629 KiB

Open AccessArticle

Enhancement of Terahertz Radiation by Surface Plasmons Based on CdTe Thin Films

by Huiyan Kong, Luyi Huang, Min Li, Ling Zhang and Heping Zeng

Nanomaterials 2022, 12(2), 290; https://doi.org/10.3390/nano12020290 - 17 Jan 2022

Cited by 2 | Viewed by 1962

Abstract

Terahertz (THz) time-domain spectroscopy (TDS) is a powerful tool used to characterize the surface/interface of materials, and semiconductor/metal interfaces can generate THz emission through ultrafast optical excitation, which can be further improved through the optical excitation of surface plasmons. Here, we assembled cadmium [...] Read more.

Terahertz (THz) time-domain spectroscopy (TDS) is a powerful tool used to characterize the surface/interface of materials, and semiconductor/metal interfaces can generate THz emission through ultrafast optical excitation, which can be further improved through the optical excitation of surface plasmons. Here, we assembled cadmium telluride (CdTe) on an AuAg alloy (Au₂₅Ag₇₅, wt.%) substrate and obtained five times stronger THz emission compared with silicon substrate, and found that the enhancement can be tuned by controlling the thickness of the semiconductor materials and plasmonic metal substrates. We believe that our results not only promote the development of THz emission enhancement, but also provide a straightforward way of producing small, thin, and more efficient terahertz photonic devices. Full article

(This article belongs to the Special Issue State-of-the-Art Nanophotonic and Optical Nanomaterials in China)

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9 pages, 2432 KiB

Open AccessArticle

Multi-Channel High-Performance Absorber Based on SiC-Photonic Crystal Heterostructure-SiC Structure

by Jing Han, Jijuan Jiang, Tong Wu, Yang Gao and Yachen Gao

Nanomaterials 2022, 12(2), 289; https://doi.org/10.3390/nano12020289 - 17 Jan 2022

Cited by 9 | Viewed by 1945

Abstract

The multi-channel high-efficiency absorber in the mid-infrared band has broad application prospects. Here, we propose an SiC-photonic crystal (PhC) heterostructure-SiC structure to realize the absorber. The absorption characteristics of the structure are studied theoretically. The results show that the structure can achieve high-efficiency [...] Read more.

The multi-channel high-efficiency absorber in the mid-infrared band has broad application prospects. Here, we propose an SiC-photonic crystal (PhC) heterostructure-SiC structure to realize the absorber. The absorption characteristics of the structure are studied theoretically. The results show that the structure can achieve high-efficiency multi-channel absorption in the mid-infrared range. The absorption peaks come from the coupling of the dual Tamm phonon polariton (TPhP) mode formed at the interface between the two SiC layers and the photonic crystal, and the optical Tamm state (OTS) mode formed in the PhC heterostructure. By adjusting the thickness of the air dielectric layer and the period of the PhC in the heterostructure, the mode coupling intensity can be regulated; thereby, the position and intensity of the absorption peak can be adjusted. In addition, the absorption peaks of TE and TM polarized light can be controlled by changing the incident angle. Adjusting the incident angle can also control the excitation and intensity of the epsilon-near-zero (ENZ) phonon polariton mode produced by TM polarized light. This kind of light absorber may have potential applications in sensors, filters, modulators, switches, thermal radiators, and so on. Full article

(This article belongs to the Section Theory and Simulation of Nanostructures)

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24 pages, 3932 KiB

Open AccessReview

Bacteria-Assisted Transport of Nanomaterials to Improve Drug Delivery in Cancer Therapy

by Carla Jiménez-Jiménez, Víctor M. Moreno and María Vallet-Regí

Nanomaterials 2022, 12(2), 288; https://doi.org/10.3390/nano12020288 - 17 Jan 2022

Cited by 26 | Viewed by 6358

Abstract

Currently, the design of nanomaterials for the treatment of different pathologies is presenting a major impact on biomedical research. Thanks to this, nanoparticles represent a successful strategy for the delivery of high amounts of drugs for the treatment of cancer. Different nanosystems have [...] Read more.

Currently, the design of nanomaterials for the treatment of different pathologies is presenting a major impact on biomedical research. Thanks to this, nanoparticles represent a successful strategy for the delivery of high amounts of drugs for the treatment of cancer. Different nanosystems have been designed to combat this pathology. However, the poor penetration of these nanomaterials into the tumor tissue prevents the drug from entering the inner regions of the tumor. Some bacterial strains have self-propulsion and guiding capacity thanks to their flagella. They also have a preference to accumulate in certain tumor regions due to the presence of different chemo-attractants factors. Bioconjugation reactions allow the binding of nanoparticles in living systems, such as cells or bacteria, in a simple way. Therefore, bacteria are being used as a transport vehicle for nanoparticles, facilitating their penetration and the subsequent release of the drug inside the tumor. This review would summarize the literature on the anchoring methods of diverse nanosystems in bacteria and, interestingly, their advantages and possible applications in cancer therapy. Full article

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12 pages, 3513 KiB

Open AccessArticle

Single Nano-Sized Metal–Organic Framework for Bio-Nanoarchitectonics with In Vivo Fluorescence Imaging and Chemo-Photodynamic Therapy

by Yong-Mei Wang, Ying Xu, Xinxin Zhang, Yifan Cui, Qingquan Liang, Cunshun Liu, Xinan Wang, Shuqi Wu and Rusen Yang

Nanomaterials 2022, 12(2), 287; https://doi.org/10.3390/nano12020287 - 17 Jan 2022

Cited by 15 | Viewed by 2935

Abstract

Theranostics is an emerging technique for cancer treatments due to its safety and high efficiency. However, the stability, efficiency, and convenience of preparation are the main challenges for developing theranostics. Here we describe a one-pot process for biocompatible metal–organic framework (MOF)-based theranostics. The [...] Read more.

Theranostics is an emerging technique for cancer treatments due to its safety and high efficiency. However, the stability, efficiency, and convenience of preparation are the main challenges for developing theranostics. Here we describe a one-pot process for biocompatible metal–organic framework (MOF)-based theranostics. The ligand H₂L designed for the MOF enables both red fluorescence emission and photodynamic therapy (PDT). The frame and regular channel structure of H₂L-MOF empower the theranostics with good drug delivery performance, and the uniform and nano-sized particles facilitate the in vivo imaging/therapy applications. In vivo fluorescence imaging and in vitro chemo-photodynamic therapy were achieved with the MOF without any further modification. Our results reveal an effective strategy to achieve multifunctional theranostics by the synergistic action of the organic ligand, metal node, and channel structure of MOF nanoparticles. Full article

(This article belongs to the Special Issue Synthesis, Characterization and Biomedical Applications of Nanomaterials)

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10 pages, 2313 KiB

Open AccessArticle

The Effect of Silane Coupling Agent on the Texture and Properties of In Situ Synthesized PI/SiO₂ Nanocomposite Film

by Jindong Huang, Hong Chen, Guanglu Zhang, Xiaowei Fan and Juncheng Liu

Nanomaterials 2022, 12(2), 286; https://doi.org/10.3390/nano12020286 - 17 Jan 2022

Cited by 4 | Viewed by 2101

Abstract

PI/SiO₂ composite films have been prepared by using in situ polymerization. The influences of the dosage of silane coupling agent (KH-560) on the structure and performance of PI/SiO₂ composite film have been investigated. The results show that in the components without [...] Read more.

PI/SiO₂ composite films have been prepared by using in situ polymerization. The influences of the dosage of silane coupling agent (KH-560) on the structure and performance of PI/SiO₂ composite film have been investigated. The results show that in the components without KH-560, the addition of SiO₂ decreases the transmittance of the sample. Compared to the same SiO₂ doping amount, the transmittance in the visible light range of the sample using KH-560 is higher than that of the sample without KH-560. After adding KH-560, the tensile strength, the elastic modulus the elongation at break of the sample have largely changed. The thermal stability and the ability to resist ultraviolet radiation of the composite film first increases and then decreases. Furthermore, the optimal dosage of KH-560 is 3%. Moreover, the addition of KH-560 has little effect on the transmittance of the PI/SiO₂ composite films before and after UV irradiation. Full article

(This article belongs to the Special Issue Inorganic Materials in Nanotechnology: Fabrication, Characterization and Application)

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14 pages, 4490 KiB

Open AccessEditor’s ChoiceArticle

Sea Urchin-like Si@MnO₂@rGO as Anodes for High-Performance Lithium-Ion Batteries

by Jiajun Liu, Meng Wang, Qi Wang, Xishan Zhao, Yutong Song, Tianming Zhao and Jing Sun

Nanomaterials 2022, 12(2), 285; https://doi.org/10.3390/nano12020285 - 17 Jan 2022

Cited by 16 | Viewed by 3455

Abstract

Si is a promising material for applications as a high-capacity anode material of lithium-ion batteries. However, volume expansion, poor electrical conductivity, and a short cycle life during the charging/discharging process limit the commercial use. In this paper, new ternary composites of sea urchin-like [...] Read more.

Si is a promising material for applications as a high-capacity anode material of lithium-ion batteries. However, volume expansion, poor electrical conductivity, and a short cycle life during the charging/discharging process limit the commercial use. In this paper, new ternary composites of sea urchin-like Si@MnO₂@reduced graphene oxide (rGO) prepared by a simple, low-cost chemical method are presented. These can effectively reduce the volume change of Si, extend the cycle life, and increase the lithium-ion battery capacity due to the dual protection of MnO₂ and rGO. The sea urchin-like Si@MnO₂@rGO anode shows a discharge specific capacity of 1282.72 mAh g⁻¹ under a test current of 1 A g⁻¹ after 1000 cycles and excellent chemical performance at different current densities. Moreover, the volume expansion of sea urchin-like Si@MnO₂@rGO anode material is ~50% after 150 cycles, which is much less than the volume expansion of Si (300%). This anode material is economical and environmentally friendly and this work made efforts to develop efficient methods to store clean energy and achieve carbon neutrality. Full article

(This article belongs to the Special Issue Nanostructured Electrodes for High-Performance Supercapacitors and Batteries)

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11 pages, 1946 KiB

Open AccessArticle

Movable Layer Device for Rapid Detection of Influenza a H1N1 Virus Using Highly Bright Multi-Quantum Dot-Embedded Particles and Magnetic Beads

by Islam Seder, Ahla Jo, Bong-Hyun Jun and Sung-Jin Kim

Nanomaterials 2022, 12(2), 284; https://doi.org/10.3390/nano12020284 - 17 Jan 2022

Cited by 2 | Viewed by 2193

Abstract

Preventing the rapid spread of viral infectious diseases has become a major concern for global health. In this study, we present a microfluidic platform that performs an immunoassay of viral antigens in a simple, automated, yet highly sensitive manner. The device uses silica [...] Read more.

Preventing the rapid spread of viral infectious diseases has become a major concern for global health. In this study, we present a microfluidic platform that performs an immunoassay of viral antigens in a simple, automated, yet highly sensitive manner. The device uses silica particles embedded with highly bright quantum dots (QD²) and performs the immunoassay with a vertically movable top layer and a rotating bottom layer. Through the motion of the layers and the surface tension in the liquids, reagents move from top chambers to bottom chambers and mix homogeneously. A tip in the top layer with a mobile permanent magnet moves the immune complexes comprising the magnetic beads, virus particles, and QD² between the bottom chambers. In this way, our automated device achieves a highly sensitive magnetic bead-based sandwich immunoassay for the influenza A H1N1 virus within 32.5 min. The detection limit of our method is 5.1 × 10⁻⁴ hemagglutination units, which is 2 × 10³ times more sensitive than that of the conventional hemagglutination method and is comparable to PCR. Our device is useful for the rapid and sensitive detection of infectious diseases in point-of-care applications and resource-limited environments. Full article

(This article belongs to the Special Issue Synthesis and Application of Optical Materials)

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24 pages, 9631 KiB

Open AccessArticle

Curcumin and Silver Doping Enhance the Spinnability and Antibacterial Activity of Melt-Electrospun Polybutylene Succinate Fibers

by Maike-Elisa Ostheller, Abdelrahman M. Abdelgawad, Naveen Kumar Balakrishnan, Ahmed H. Hassanin, Robert Groten and Gunnar Seide

Nanomaterials 2022, 12(2), 283; https://doi.org/10.3390/nano12020283 - 17 Jan 2022

Cited by 12 | Viewed by 2812

Abstract

Melt electrospinning is a polymer processing technology for the manufacture of microfibers and nanofibers. Additives are required to reduce the melt viscosity and increase its conductivity in order to minimize the fiber diameter, and can also impart additional beneficial properties. We investigated the [...] Read more.

Melt electrospinning is a polymer processing technology for the manufacture of microfibers and nanofibers. Additives are required to reduce the melt viscosity and increase its conductivity in order to minimize the fiber diameter, and can also impart additional beneficial properties. We investigated the preparation of polybutylene succinate (PBS) microfibers incorporating different weight percentages of two multifunctional additives (the organic dye curcumin and inorganic silver nanoparticles) using a single-nozzle laboratory-scale device. We determined the influence of these additives on the polymer melt viscosity, electrical conductivity, degradation profile, thermal behavior, fiber diameter, and antibacterial activity. The formation of a Taylor cone followed by continuous fiber deposition was observed for compounds containing up to 3% (w/w) silver nanoparticles and up to 10% (w/w) curcumin, the latter achieving the minimum average fiber diameter of 12.57 µm. Both additives reduced the viscosity and increased the electrical conductivity of the PBS melt, and also retained their specific antibacterial properties when compounded and spun into fibers. This is the first report describing the effect of curcumin and silver nanoparticles on the properties of PBS fibers manufactured using a single-nozzle melt-electrospinning device. Our results provide the basis to develop environmentally benign antibacterial melt-electrospun PBS fibers for biomedical applications. Full article

(This article belongs to the Special Issue Untargeted versus Targeted Antimicrobial Nanomedicines)

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13 pages, 4657 KiB

Open AccessFeature PaperArticle

SnS₂ Nanoparticles and Thin Film for Application as an Adsorbent and Photovoltaic Buffer

by Sreedevi Gedi, Salh Alhammadi, Jihyeon Noh, Vasudeva Reddy Minnam Reddy, Hyeonwook Park, Abdelrahman Mohamed Rabie, Jae-Jin Shim, Dohyung Kang and Woo Kyoung Kim

Nanomaterials 2022, 12(2), 282; https://doi.org/10.3390/nano12020282 - 17 Jan 2022

Cited by 17 | Viewed by 3179

Abstract

Energy consumption and environmental pollution are major issues faced by the world. The present study introduces a single solution using SnS₂ for these two major global problems. SnS₂ nanoparticles and thin films were explored as an adsorbent to remove organic toxic [...] Read more.

Energy consumption and environmental pollution are major issues faced by the world. The present study introduces a single solution using SnS₂ for these two major global problems. SnS₂ nanoparticles and thin films were explored as an adsorbent to remove organic toxic materials (Rhodamine B (RhB)) from water and an alternative to the toxic cadmium sulfide (CdS) buffer for thin-film solar cells, respectively. Primary characterization tools such as X-ray photoelectron spectroscopy (XPS), Raman, X-ray diffraction (XRD), and UV-Vis-NIR spectroscopy were used to analyze the SnS₂ nanoparticles and thin films. At a reaction time of 180 min, 0.4 g/L of SnS₂ nanoparticles showed the highest adsorption capacity of 85% for RhB (10 ppm), indicating that SnS₂ is an appropriate adsorbent. The fabricated Cu(In,Ga)Se₂ (CIGS) device with SnS₂ as a buffer showed a conversion efficiency (~5.1%) close to that (~7.5%) of a device fabricated with the conventional CdS buffer, suggesting that SnS₂ has potential as an alternative buffer. Full article

(This article belongs to the Special Issue Performance of Nanocomposite for Optoelectronic Applications)

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11 pages, 24512 KiB

Open AccessArticle

Nickel-Based Selenides with a Fractal Structure as an Excellent Bifunctional Electrocatalyst for Water Splitting

by Jingxuan He, Ting Qian, Chao Cai, Xia Xiang, Sean Li and Xiaotao Zu

Nanomaterials 2022, 12(2), 281; https://doi.org/10.3390/nano12020281 - 17 Jan 2022

Cited by 34 | Viewed by 3395

Abstract

Nickel-based selenides are believed to be promising non-precious metal electrocatalysts, and have been widely used for both oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Here, we control the aging time to prepare Ni_xSe_y with different fractal structures as [...] Read more.

Nickel-based selenides are believed to be promising non-precious metal electrocatalysts, and have been widely used for both oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). Here, we control the aging time to prepare Ni_xSe_y with different fractal structures as a bifunctional catalyst. An obtained sample with an aging time of 80 min shows outstanding electrocatalytic performance for hydrogen evolution reactions (HER) with an overpotential of 225 mV (η@10 mA/cm²) and for oxygen evolution reactions (OER) with an overpotential of 309 mV (η@50 mA/cm²). Moreover, to further improve catalytic activity, we doped Fe in Ni_xSe_y to obtain the ternary nickel-based selenide, Fe_0.2Ni_0.8Se (FNSs). The HER activity of FNS increased two-fold at 10 mA/cm², and the overpotential of OER decreased to 255 mV at 50 mA/cm². The synthetic strategy and research results of this work have a certain reference value for other low-cost and high-efficiency transition metal catalysts for electrocatalytic water splitting. Full article

(This article belongs to the Topic Catalysis for Sustainable Chemistry and Energy)

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17 pages, 3418 KiB

Open AccessArticle

Contrast Enhanced Ultrasound Molecular Imaging of Spontaneous Chronic Inflammatory Bowel Disease in an Interleukin-2 Receptor α^−/− Transgenic Mouse Model Using Targeted Microbubbles

by Huaijun Wang, Jose G. Vilches-Moure, Thierry Bettinger, Samir Cherkaoui, Amelie Lutz and Ramasamy Paulmurugan

Nanomaterials 2022, 12(2), 280; https://doi.org/10.3390/nano12020280 - 17 Jan 2022

Cited by 3 | Viewed by 2593

Abstract

Inflammatory bowel disease (IBD) is a lifelong inflammatory disorder with relapsing–remission cycles, which is currently diagnosed by clinical symptoms and signs, along with laboratory and imaging findings. However, such clinical findings are not parallel to the disease activity of IBD and are difficult [...] Read more.

Inflammatory bowel disease (IBD) is a lifelong inflammatory disorder with relapsing–remission cycles, which is currently diagnosed by clinical symptoms and signs, along with laboratory and imaging findings. However, such clinical findings are not parallel to the disease activity of IBD and are difficult to use in treatment monitoring. Therefore, non-invasive quantitative imaging tools are required for the multiple follow-up exams of IBD patients in order to monitor the disease activity and determine treatment regimens. In this study, we evaluated a dual P- and E-selectin-targeted microbubble (MB_Selectin) in an interleukin-2 receptor α deficient (IL-2Rα^−/−) spontaneous chronic IBD mouse model for assessing long-term anti-inflammatory effects with ultrasound molecular imaging (USMI). We used IL-2Rα^−/− (male and female on a C57BL/6 genetic background; n = 39) and C57BL/6 wild-type (negative control; n = 6) mice for the study. USMI of the proximal, middle, and distal colon was performed with MB_Selectin using a small animal scanner (Vevo 2100) up to six times in each IL-2Rα^−/− mouse between 6–30 weeks of age. USMI signals were compared between IL-2Rα^−/− vs. wild-type mice, and sexes in three colonic locations. Imaged colon segments were analyzed ex vivo for inflammatory changes on H&E-stained sections and for selectin expression by immunofluorescence staining. We successfully detected spontaneous chronic colitis in IL-2Rα^−/− mice between 6–30 weeks (onset at 6–14 weeks) compared to wild-type mice. Both male and female IL-2Rα^−/− mice were equally (p = 0.996) affected with the disease, and there was no significant (p > 0.05) difference in USMI signals of colitis between the proximal, middle, and distal colon. We observed the fluctuating USMI signals in IL-2Rα^−/− mice between 6–30 weeks, which might suggest a resemblance of the remission-flare pattern of human IBD. The ex vivo H&E and immunostaining further confirmed the inflammatory changes, and the high expression of P- and E-selectin in the colon. The results of this study highlight the IL-2Rα^−/− mice as a chronic colitis model and are suitable for the long-term assessment of treatment response using a dual P- and E-selectin-targeted USMI. Full article

(This article belongs to the Special Issue Nanotechnology-Based Diagnostics)

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10 pages, 2684 KiB

Open AccessArticle

Graphene/Ferroelectric (Ge-Doped HfO₂) Adaptable Transistors Acting as Reconfigurable Logic Gates

by Mircea Dragoman, Adrian Dinescu, Daniela Dragoman, Cătălin Palade, Valentin Şerban Teodorescu and Magdalena Lidia Ciurea

Nanomaterials 2022, 12(2), 279; https://doi.org/10.3390/nano12020279 - 17 Jan 2022

Cited by 6 | Viewed by 2643

Abstract

We present an array of 225 field-effect transistors (FETs), where each of them has a graphene monolayer channel grown on a 3-layer deposited stack of 22 nm control HfO₂/5 nm Ge-HfO₂ intermediate layer/8 nm tunnel HfO₂/p-Si [...] Read more.

We present an array of 225 field-effect transistors (FETs), where each of them has a graphene monolayer channel grown on a 3-layer deposited stack of 22 nm control HfO₂/5 nm Ge-HfO₂ intermediate layer/8 nm tunnel HfO₂/p-Si substrate. The intermediate layer is ferroelectric and acts as a floating gate. All transistors have two top gates, while the p-Si substrate is acting as a back gate. We show that these FETs are acting memtransistors, working as two-input reconfigurable logic gates with memory, the type of the logic gate depending only on the values of the applied gate voltages and the choice of a threshold current. Full article

(This article belongs to the Special Issue Intelligent Nanomaterials and Nanosystems)

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14 pages, 4085 KiB

Open AccessArticle

Manipulation of Skyrmion Motion Dynamics for Logical Device Application Mediated by Inhomogeneous Magnetic Anisotropy

by Jia-Qiang Lin, Ji-Pei Chen, Zhen-Yu Tan, Yuan Chen, Zhi-Feng Chen, Wen-An Li, Xing-Sen Gao and Jun-Ming Liu

Nanomaterials 2022, 12(2), 278; https://doi.org/10.3390/nano12020278 - 16 Jan 2022

Cited by 8 | Viewed by 2940

Abstract

Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by [...] Read more.

Magnetic skyrmions are promising potential information carriers for future spintronic devices owing to their nanoscale size, non-volatility and high mobility. In this work, we demonstrate the controlled manipulation of skyrmion motion and its implementation in a new concept of racetrack logical device by introducing an inhomogeneous perpendicular magnetic anisotropy (PMA) via micromagnetic simulation. Here, the inhomogeneous PMA can be introduced by a capping nano-island that serves as a tunable potential barriers/well which can effectively modulate the size and shape of isolated skyrmion. Using the inhomogeneous PMA in skyrmion-based racetrack enables the manipulation of skyrmion motion behaviors, for instance, blocking, trapping or allowing passing the injected skyrmion. In addition, the skyrmion trapping operation can be further exploited in developing special designed racetrack devices with logic AND and NOT, wherein a set of logic AND operations can be realized via skyrmion–skyrmion repulsion between two skyrmions. These results indicate an effective method for tailoring the skyrmion structures and motion behaviors by using inhomogeneous PMA, which further provide a new pathway to all-electric skyrmion-based memory and logic devices. Full article

(This article belongs to the Special Issue Nano-Magnets and Nano-Magnetisms)

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34 pages, 4309 KiB

Open AccessReview

Biomedical Applications of Metal−Organic Frameworks for Disease Diagnosis and Drug Delivery: A Review

by Miral Al Sharabati, Rana Sabouni and Ghaleb A. Husseini

Nanomaterials 2022, 12(2), 277; https://doi.org/10.3390/nano12020277 - 16 Jan 2022

Cited by 96 | Viewed by 10336

Abstract

Metal−organic frameworks (MOFs) are a novel class of porous hybrid organic−inorganic materials that have attracted increasing attention over the past decade. MOFs can be used in chemical engineering, materials science, and chemistry applications. Recently, these structures have been thoroughly studied as promising platforms [...] Read more.

Metal−organic frameworks (MOFs) are a novel class of porous hybrid organic−inorganic materials that have attracted increasing attention over the past decade. MOFs can be used in chemical engineering, materials science, and chemistry applications. Recently, these structures have been thoroughly studied as promising platforms for biomedical applications. Due to their unique physical and chemical properties, they are regarded as promising candidates for disease diagnosis and drug delivery. Their well-defined structure, high porosity, tunable frameworks, wide range of pore shapes, ultrahigh surface area, relatively low toxicity, and easy chemical functionalization have made them the focus of extensive research. This review highlights the up-to-date progress of MOFs as potential platforms for disease diagnosis and drug delivery for a wide range of diseases such as cancer, diabetes, neurological disorders, and ocular diseases. A brief description of the synthesis methods of MOFs is first presented. Various examples of MOF-based sensors and DDSs are introduced for the different diseases. Finally, the challenges and perspectives are discussed to provide context for the future development of MOFs as efficient platforms for disease diagnosis and drug delivery systems. Full article

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22 pages, 4666 KiB

Open AccessArticle

Impact of Smoluchowski Temperature and Maxwell Velocity Slip Conditions on Axisymmetric Rotated Flow of Hybrid Nanofluid past a Porous Moving Rotating Disk

by Umair Khan, Aurang Zaib, Iskandar Waini, Anuar Ishak, El-Sayed M. Sherif, Wei-Feng Xia and Noor Muhammad

Nanomaterials 2022, 12(2), 276; https://doi.org/10.3390/nano12020276 - 15 Jan 2022

Cited by 28 | Viewed by 2348

Abstract

Colloidal suspensions of regular fluids and nanoparticles are known as nanofluids. They have a variety of applications in the medical field, including cell separation, drug targeting, destruction of tumor tissue, and so on. On the other hand, the dispersion of multiple nanoparticles into [...] Read more.

Colloidal suspensions of regular fluids and nanoparticles are known as nanofluids. They have a variety of applications in the medical field, including cell separation, drug targeting, destruction of tumor tissue, and so on. On the other hand, the dispersion of multiple nanoparticles into a regular fluid is referred to as a hybrid nanofluid. It has a variety of innovative applications such as microfluidics, heat dissipation, dynamic sealing, damping, and so on. Because of these numerous applications of nanofluids in minds, therefore, the objective of the current exploration divulged the axisymmetric radiative flow and heat transfer induced by hybrid nanofluid impinging on a porous stretchable/shrinkable rotating disc. In addition, the impact of Smoluchowski temperature and Maxwell velocity slip boundary conditions are also invoked. The hybrid nanofluid was formed by mixing the copper (Cu) and alumina (Al₂O₃) nanoparticles scattered in the regular (viscous) base fluid (H₂O). Similarity variables are used to procure the similarity equations, and the numerical outcomes are achieved using bvp4c in MATLAB software. According to the findings, double solutions are feasible for stretching

(λ > 0)

and shrinking cases

(λ < 0)

. The heat transfer rate is accelerated as the hybrid nanoparticles increases. The suction parameter enhances the friction factors as well as heat transfer rate. Moreover, the friction factor in the radial direction and heat transfer enrich for the first solution and moderate for the second outcome due to the augmentation

δ_{1}

, while the trend of the friction factor in the radial direction is changed only in the case of stretching for both branches. Full article

(This article belongs to the Special Issue New Research on Heat Transfer with Properties of Nanofluids)

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17 pages, 1123 KiB

Open AccessEditor’s ChoiceReview

Nanodelivery Strategies for Skin Diseases with Barrier Impairment: Focusing on Ceramides and Glucocorticoids

by Cíntia Almeida, Patrícia Filipe, Catarina Rosado and Catarina Pereira-Leite

Nanomaterials 2022, 12(2), 275; https://doi.org/10.3390/nano12020275 - 15 Jan 2022

Cited by 11 | Viewed by 3863

Abstract

The human epidermis has a characteristic lipidic composition in the stratum corneum, where ceramides play a crucial role in the skin barrier homeostasis and in water-holding capacity. Several skin diseases, such as atopic dermatitis and psoriasis, exhibit a dysfunction in the lipid barrier [...] Read more.

The human epidermis has a characteristic lipidic composition in the stratum corneum, where ceramides play a crucial role in the skin barrier homeostasis and in water-holding capacity. Several skin diseases, such as atopic dermatitis and psoriasis, exhibit a dysfunction in the lipid barrier with altered ceramide levels and increased loss of transepidermal water. Glucocorticoids are normally employed in the therapeutical management of these pathologies. However, they have shown a poor safety profile and reduced treatment efficiency. The main objective of this review is to, within the framework of the limitations of the currently available therapeutical approaches, establish the relevance of nanocarriers as a safe and efficient delivery strategy for glucocorticoids and ceramides in the topical treatment of skin disorders with barrier impairment. Full article

(This article belongs to the Special Issue Delivery Systems Based on Innovative Nanomaterials)

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13 pages, 269 KiB

Open AccessArticle

Quantum-Chemical Quasi-Docking for Molecular Dynamics Calculations

by Alexey Sulimov, Danil Kutov, Ivan Ilin and Vladimir Sulimov

Nanomaterials 2022, 12(2), 274; https://doi.org/10.3390/nano12020274 - 15 Jan 2022

Cited by 6 | Viewed by 2026

Abstract

The quantum quasi-docking procedure is used to compare the docking accuracies of two quantum-chemical semiempirical methods, namely, PM6-D3H4X and PM7. Quantum quasi-docking is an approximation to quantum docking. In quantum docking, it is necessary to search directly for the global minimum of the [...] Read more.

The quantum quasi-docking procedure is used to compare the docking accuracies of two quantum-chemical semiempirical methods, namely, PM6-D3H4X and PM7. Quantum quasi-docking is an approximation to quantum docking. In quantum docking, it is necessary to search directly for the global minimum of the energy of the protein-ligand complex calculated by the quantum-chemical method. In quantum quasi-docking, firstly, we look for a wide spectrum of low-energy minima, calculated using the MMFF94 force field, and secondly, we recalculate the energies of all these minima using the quantum-chemical method, and among these recalculated energies we determine the lowest energy and the corresponding ligand position. Both PM6-D3H4X and PM7 are novel methods that describe well-dispersion interactions, hydrogen and halogen bonds. The PM6-D3H4X and PM7 methods are used with the COSMO implicit solvent model as it is implemented in the MOPAC program. The comparison is made for 25 high quality protein-ligand complexes. Firstly, the docking positioning accuracies have been compared, and we demonstrated that PM7+COSMO provides better positioning accuracy than PM6-D3H4X. Secondly, we found that PM7+COSMO demonstrates a much higher correlation between the calculated and measured protein–ligand binding enthalpies than PM6-D3H4X. For future quantum docking PM7+COSMO is preferable, but the COSMO model must be improved. Full article

(This article belongs to the Special Issue Nanomaterials Investigation by Molecular Dynamics Simulation)

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14 pages, 3209 KiB

Open AccessArticle

Sustainable and Printable Nanocellulose-Based Ionogels as Gel Polymer Electrolytes for Supercapacitors

by Rosa M. González-Gil, Mateu Borràs, Aiman Chbani, Tiffany Abitbol, Andreas Fall, Christian Aulin, Christophe Aucher and Sandra Martínez-Crespiera

Nanomaterials 2022, 12(2), 273; https://doi.org/10.3390/nano12020273 - 15 Jan 2022

Cited by 7 | Viewed by 3610

Abstract

A new gel polymer electrolyte (GPE) based supercapacitor with an ionic conductivity up to 0.32–0.94 mS cm⁻² has been synthesized from a mixture of an ionic liquid (IL) with nanocellulose (NC). The new NC-ionogel was prepared by combining the IL 1-ethyl-3-methylimidazolium dimethyl [...] Read more.

A new gel polymer electrolyte (GPE) based supercapacitor with an ionic conductivity up to 0.32–0.94 mS cm⁻² has been synthesized from a mixture of an ionic liquid (IL) with nanocellulose (NC). The new NC-ionogel was prepared by combining the IL 1-ethyl-3-methylimidazolium dimethyl phosphate (EMIMP) with carboxymethylated cellulose nanofibers (CNFc) at different ratios (CNFc ratio from 1 to 4). The addition of CNFc improved the ionogel properties to become easily printable onto the electrode surface. The new GPE based supercapacitor cell showed good electrochemical performance with specific capacitance of 160 F g⁻¹ and an equivalent series resistance (ESR) of 10.2 Ω cm⁻² at a current density of 1 mA cm⁻². The accessibility to the full capacitance of the device is demonstrated after the addition of CNFc in EMIMP compared to the pristine EMIMP (99 F g⁻¹ and 14.7 Ω cm⁻²). Full article

(This article belongs to the Special Issue Multifunctional Nanomaterials for Energy Applications)

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3 pages, 187 KiB

Open AccessEditorial

Nano-Engineering Solutions for Dental Implant Applications

by Karan Gulati

Nanomaterials 2022, 12(2), 272; https://doi.org/10.3390/nano12020272 - 15 Jan 2022

Cited by 3 | Viewed by 1941

Abstract

This Special Issue of Nanomaterials explores the recent advances and trends with respect to nano-engineered strategies towards dental implant applications [...] Full article

(This article belongs to the Special Issue Nano-Engineering Solutions for Dental Implant Applications)

13 pages, 4634 KiB

Open AccessFeature PaperArticle

The Infiltration of Silver Nanoparticles into Porous Silicon for Improving the Performance of Photonic Devices

by Rehab Ramadan and Raúl J. Martín-Palma

Nanomaterials 2022, 12(2), 271; https://doi.org/10.3390/nano12020271 - 15 Jan 2022

Cited by 7 | Viewed by 2396

Abstract

Hybrid nanostructures have a great potential to improve the overall properties of photonic devices. In the present study, silver nanoparticles (AgNPs) were infiltrated into nanostructured porous silicon (PSi) layers, aiming at enhancing the optoelectronic performance of Si-based devices. More specifically, Schottky diodes with [...] Read more.

Hybrid nanostructures have a great potential to improve the overall properties of photonic devices. In the present study, silver nanoparticles (AgNPs) were infiltrated into nanostructured porous silicon (PSi) layers, aiming at enhancing the optoelectronic performance of Si-based devices. More specifically, Schottky diodes with three different configurations were fabricated, using Al/Si/Au as the basic structure. This structure was modified by adding PSi and PSi + AgNPs layers. Their characteristic electrical parameters were accurately determined by fitting the current–voltage curves to the non-ideal diode equation. Furthermore, electrochemical impedance spectroscopy was used to determine the electrical parameters of the diodes in a wide frequency range by fitting the Nyquist plots to the appropriate equivalent circuit model. The experimental results show a remarkable enhancement in electrical conduction after the incorporation of metallic nanoparticles. Moreover, the spectral photoresponse was examined for various devices. An approximately 10-fold increment in photoresponse was observed after the addition of Ag nanoparticles to the porous structures. Full article

(This article belongs to the Special Issue Nanostructures for Photonics and Optoelectronics)

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9 pages, 2365 KiB

Open AccessArticle

Electronic Structure of Monolayer FeSe on Si(001) from First Principles

by Karel Carva, Petru Vlaic and Jan Honolka

Nanomaterials 2022, 12(2), 270; https://doi.org/10.3390/nano12020270 - 14 Jan 2022

Viewed by 2446

Abstract

The huge increase in the superconducting transition temperature of FeSe induced by an interface to SrTiO₃ remains unexplained to date. However, there are numerous indications of the critical importance of specific features of the FeSe band topology in the vicinity of the [...] Read more.

The huge increase in the superconducting transition temperature of FeSe induced by an interface to SrTiO₃ remains unexplained to date. However, there are numerous indications of the critical importance of specific features of the FeSe band topology in the vicinity of the Fermi surface. Here, we explore how the electronic structure of FeSe changes when located on another lattice matched substrate, namely a Si(001) surface, by first-principles calculations based on the density functional theory. We study non-magnetic (NM) and checkerboard anti-ferromagnetic (AFM) magnetic orders in FeSe and determine which interface arrangement is preferred. Our calculations reveal interesting effects of Si proximity on the FeSe band structure. Bands corresponding to hole pockets at the Γ point in NM FeSe are generally pushed down below the Fermi level, except for one band responsible for a small remaining hole pocket. Bands forming electron pockets centered at the M point of the Brillouin zone become less dispersive, and one of them is strongly hybridized with Si. We explain these changes by a redistribution of electrons between different Fe

3 d

orbitals rather than charge transfer to/from Si, and we also notice an associated loss of degeneracy between

d_{x z}

and

d_{y z}

orbitals. Full article

(This article belongs to the Special Issue Progress in Quantum-Computer Calculations)

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17 pages, 5415 KiB

Open AccessArticle

Breakdown Performance and Partial Discharge Development in Transformer Oil-Based Metal Carbide Nanofluids

by Konstantinos N. Koutras, Sokratis N. Tegopoulos, Vasilios P. Charalampakos, Apostolos Kyritsis, Ioannis F. Gonos and Eleftheria C. Pyrgioti

Nanomaterials 2022, 12(2), 269; https://doi.org/10.3390/nano12020269 - 14 Jan 2022

Cited by 33 | Viewed by 3242

Abstract

In this work, the influence of semi-conductive SiC nanoparticles on the AC breakdown voltage and partial discharge development in natural ester oil FR3 is examined. Primarily, the dielectric constant and the electrical conductivity of the nanoparticles are measured following the broadband dielectric spectroscopy [...] Read more.

In this work, the influence of semi-conductive SiC nanoparticles on the AC breakdown voltage and partial discharge development in natural ester oil FR3 is examined. Primarily, the dielectric constant and the electrical conductivity of the nanoparticles are measured following the broadband dielectric spectroscopy technique. The nanoparticles are added into the matrix following the ultrasonication process in three weight percentage ratios in order for their effect to be evaluated as a function of their concentration inside the base oil. The processing of the results reveals that the nanofluid containing SiC nanoparticles at 0.004% w/w demonstrates the highest AC dielectric strength improvement and shows the greatest resistance to the appearance of partial discharge activity. The mechanisms behind the aforementioned results are discussed in detail and confirmed by the broadband dielectric spectroscopy technique, which reveals that this particular nanofluid sample is characterized by lower dielectric constant and electrical conductivity than the one with double the weight percentage ratio. Full article

(This article belongs to the Special Issue New Frontiers in Nanofluids)

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14 pages, 2852 KiB

Open AccessArticle

Antiviral Activities of High Energy E-Beam Induced Copper Nanoparticles against H1N1 Influenza Virus

by Taesung Ha, Thi Tuyet Mai Pham, Mikyung Kim, Yeon-Hee Kim, Ji-Hyun Park, Ji Hae Seo, Kyung-Min Kim and Eunyoung Ha

Nanomaterials 2022, 12(2), 268; https://doi.org/10.3390/nano12020268 - 14 Jan 2022

Cited by 20 | Viewed by 2901

Abstract

The pandemic outbreak of COVID-19 in the year of 2020 that drastically changed everyone’s life has raised the urgent and intense need for the development of more efficacious antiviral material. This study was designed to develop copper nanoparticles (Cu NPs) as an antiviral [...] Read more.

The pandemic outbreak of COVID-19 in the year of 2020 that drastically changed everyone’s life has raised the urgent and intense need for the development of more efficacious antiviral material. This study was designed to develop copper nanoparticles (Cu NPs) as an antiviral agent and to validate the antiviral activities of developed copper NP. The Cu NPs were synthesized using a high energy electron beam, and the characteristic morphologies and antiviral activities of Cu NPs were evaluated. We found that Cu NPs are of spherical shape and uniformly distributed, with a diameter of around 100 nm, as opposed to the irregular shape of commercially available copper microparticles (Cu MPs). An X-ray diffraction analysis showed the presence of Cu and no copper oxide II and I in the Cu NPs. A virus inactivation assay revealed no visible viral DNA after 10- and 30-min treatment of H1N1 virus with the Cu NPs. The infectivity of the Cu NPs-treated H1N1 virus significantly decreased compared with that of the Cu MPs-treated H1N1 virus. The viability of A549 bronchial and Madin-Darby Canine Kidney (MDCK) cells infected with Cu NPs-treated H1N1 was significantly higher than those infected with Cu MPs-treated H1N1 virus. We also found cells infected with Cu NPs-treated H1N1 virus exhibited a markedly decreased presence of virus nucleoprotein (NuP), an influenza virus-specific structural protein, compared with cells infected with Cu MPs-treated H1N1 virus. Taken together, our study shows that Cu NPs are a more effective and efficacious antiviral agent compared with Cu MPs and offer promising opportunities for the prevention of devastatingly infectious diseases. Full article

(This article belongs to the Special Issue Antiviral Nanomaterials in Biomedical and Healthcare Applications)

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13 pages, 4195 KiB

Open AccessArticle

The Golden Fig: A Plasmonic Effect Study of Organic-Based Solar Cells

by Jessica Barichello, Paolo Mariani, Fabio Matteocci, Luigi Vesce, Andrea Reale, Aldo Di Carlo, Maurizio Lanza, Gaetano Di Marco, Stefano Polizzi and Giuseppe Calogero

Nanomaterials 2022, 12(2), 267; https://doi.org/10.3390/nano12020267 - 14 Jan 2022

Cited by 10 | Viewed by 2638

Abstract

An optimization work on dye-sensitized solar cells (DSSCs) based on both artificial and natural dyes was carried out by a fine synthesis work embedding gold nanoparticles in a TiO₂ semiconductor and perfecting the TiO₂ particle sizes of the scattering layer. Noble [...] Read more.

An optimization work on dye-sensitized solar cells (DSSCs) based on both artificial and natural dyes was carried out by a fine synthesis work embedding gold nanoparticles in a TiO₂ semiconductor and perfecting the TiO₂ particle sizes of the scattering layer. Noble metal nanostructures are known for the surface plasmon resonance peculiarity that reveals unique properties and has been implemented in several fields such as sensing, photocatalysis, optical antennas and PV devices. By embedding gold nanoparticles in the mesoporous TiO₂ layer and adding a scattering layer, we were able to boost the power conversion efficiency (PCE) to 10.8%, using an organic ruthenium complex. The same implementation was carried out using a natural dye, betalains, extracted from Sicilian prickly pear. In this case, the conversion efficiency doubled from 1 to 2% (measured at 1 SUN illumination, 100 mW/cm² under solar simulation irradiation). Moreover, we obtained (measured at 0.1 SUN, 10 mW/cm² under blue light LED irradiation) a record efficiency of 15% with the betalain-based dye, paving the way for indoor applications in organic natural devices. Finally, an attempt to scale up the system is shown, and a betalain-based- dye-sensitized solar module (DSSM), with an active area of 43.2 cm² and a PCE of 1.02%, was fabricated for the first time. Full article

(This article belongs to the Special Issue Nanostructured Materials for Organic Solar Cells)

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