Nanomaterials

13 pages, 1581 KiB

Open AccessArticle

Synthesis and Characterization of Reproducible Linseed Oil-Loaded Silica Nanoparticles with Potential Use as Oxygen Scavengers in Active Packaging

by Juan Felipe Alvarado, Daniel Fernando Rozo, Luis Miguel Chaparro, Jorge Alberto Medina and Felipe Salcedo-Galán

Nanomaterials 2022, 12(18), 3257; https://doi.org/10.3390/nano12183257 - 19 Sep 2022

Cited by 4 | Viewed by 1903

Abstract

Commercially available oxygen scavengers used to prevent lipid autoxidation, microbial growth and enzymatic browning in food products present several issues, which include the usage of metals and their moisture dependence to work properly. We present the synthesis and characterization of a moisture-independent oil-based [...] Read more.

Commercially available oxygen scavengers used to prevent lipid autoxidation, microbial growth and enzymatic browning in food products present several issues, which include the usage of metals and their moisture dependence to work properly. We present the synthesis and characterization of a moisture-independent oil-based oxygen scavenging system comprised of linseed oil and silica nanoparticles. The system was synthesized via sol-gel chemistry and was characterized using morphological analysis (SEM, AFM, TEM, and N₂ adsorption/desorption), oil-loading analysis (TGA), and surface analysis (ζ-potential and ATR-FTIR). Performance of the system was evaluated through headspace measurements and reproducibility of synthetic procedure was verified using six replicates. Nanoparticles showed the desired spherical shape with a diameter of (122.7 ± 42.7 nm) and mesoporosity (pore diameter = 3.66 ± 0.08 nm), with an encapsulation efficiency of 33.9 ± 1.5% and a highly negative ζ-potential (−56.1 ± 1.2 mV) in basic solution. Performance of the system showed a promising high value for oxygen absorption of 25.8 ± 4.5 mL O₂/g of encapsulated oil (8.3 ± 1.5 mL O₂/g of nanocapsules) through a moisture independent mechanism, which suggests that the synthesized system can be used as an oxygen scavenger in dry atmosphere conditions. Full article

(This article belongs to the Special Issue Synthesis and Application of Silicon Dioxide Nanoparticles)

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15 pages, 6688 KiB

Open AccessArticle

On the Critical Heat Flux Assessment of Micro- and Nanoscale Roughened Surfaces

by Uzair Sajjad, Imtiyaz Hussain, Waseem Raza, Muhammad Sultan, Ibrahim M. Alarifi and Chi-Chuan Wang

Nanomaterials 2022, 12(18), 3256; https://doi.org/10.3390/nano12183256 - 19 Sep 2022

Cited by 13 | Viewed by 1598

Abstract

The boiling crisis or critical heat flux (CHF) is a very critical constraint for any heat-flux-controlled boiling system. The existing methods (physical models and empirical correlations) offer a specific interpretation of the boiling phenomenon, as many of these correlations are considerably influenced by [...] Read more.

The boiling crisis or critical heat flux (CHF) is a very critical constraint for any heat-flux-controlled boiling system. The existing methods (physical models and empirical correlations) offer a specific interpretation of the boiling phenomenon, as many of these correlations are considerably influenced by operational variables and surface morphologies. A generalized correlation is virtually unavailable. In this study, more physical mechanisms are incorporated to assess CHF of surfaces with micro- and nano-scale roughness subject to a wide range of operating conditions and working fluids. The CHF data is also correlated by using the Pearson, Kendal, and Spearman correlations to evaluate the association of various surface morphological features and thermophysical properties of the working fluid. Feature engineering is performed to better correlate the inputs with the desired output parameter. The random forest optimization (RF) is used to provide the optimal hyper-parameters to the proposed interpretable correlation and experimental data. Unlike the existing methods, the proposed method is able to incorporate more physical mechanisms and relevant parametric influences, thereby offering a more generalized and accurate prediction of CHF (R² = 0.971, mean squared error = 0.0541, and mean absolute error = 0.185). Full article

(This article belongs to the Special Issue Surface Functionalization on Nanostructured Materials for Multiple Application)

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15 pages, 5072 KiB

Open AccessEditor’s ChoiceArticle

Exciton Manifolds in Highly Ambipolar Doped WS₂

by David Otto Tiede, Nihit Saigal, Hossein Ostovar, Vera Döring, Hendrik Lambers and Ursula Wurstbauer

Nanomaterials 2022, 12(18), 3255; https://doi.org/10.3390/nano12183255 - 19 Sep 2022

Viewed by 1821

Abstract

The disentanglement of single and many particle properties in 2D semiconductors and their dependencies on high carrier concentration is challenging to experimentally study by pure optical means. We establish an electrolyte gated WS

_{2}

monolayer field-effect structure capable of shifting the Fermi level [...] Read more.

The disentanglement of single and many particle properties in 2D semiconductors and their dependencies on high carrier concentration is challenging to experimentally study by pure optical means. We establish an electrolyte gated WS

_{2}

monolayer field-effect structure capable of shifting the Fermi level from the valence into the conduction band that is suitable to optically trace exciton binding as well as the single-particle band gap energies in the weakly doped regime. Combined spectroscopic imaging ellipsometry and photoluminescence spectroscopies spanning large n- and p-type doping with charge carrier densities up to 10

^{14}

cm

^{- 2}

enable to study screening phenomena and doping dependent evolution of the rich exciton manifold whose origin is controversially discussed in literature. We show that the two most prominent emission bands in photoluminescence experiments are due to the recombination of spin-forbidden and momentum-forbidden charge neutral excitons activated by phonons. The observed interband transitions are redshifted and drastically weakened under electron or hole doping. This field-effect platform is not only suitable for studying exciton manifold but is also suitable for combined optical and transport measurements on degenerately doped atomically thin quantum materials at cryogenic temperatures. Full article

(This article belongs to the Special Issue Recent Advances in Optical Spectroscopy of Layered Materials)

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12 pages, 3801 KiB

Open AccessEditor’s ChoiceArticle

Highly Luminescent and Photostable Core/Shell/Shell ZnSeS/Cu:ZnS/ZnS Quantum Dots Prepared via a Mild Aqueous Route

by Salima Mabrouk, Hervé Rinnert, Lavinia Balan, Jordane Jasniewski, Sébastien Blanchard, Ghouti Medjahdi, Rafik Ben Chaabane and Raphaël Schneider

Nanomaterials 2022, 12(18), 3254; https://doi.org/10.3390/nano12183254 - 19 Sep 2022

Viewed by 1565

Abstract

An aqueous-phase synthesis of 3-mercaptopropionic acid (3-MPA)-capped core/shell/shell ZnSeS/Cu:ZnS/ZnS QDs was developed. The influence of the Cu-dopant location on the photoluminescence (PL) emission intensity was investigated, and the results show that the introduction of the Cu dopant in the first ZnS shell leads [...] Read more.

An aqueous-phase synthesis of 3-mercaptopropionic acid (3-MPA)-capped core/shell/shell ZnSeS/Cu:ZnS/ZnS QDs was developed. The influence of the Cu-dopant location on the photoluminescence (PL) emission intensity was investigated, and the results show that the introduction of the Cu dopant in the first ZnS shell leads to QDs exhibiting the highest PL quantum yield (25%). The influence of the Cu-loading in the dots on the PL emission was also studied, and a shift from blue–green to green was observed with the increase of the Cu doping from 1.25 to 7.5%. ZnSeS/Cu:ZnS/ZnS QDs exhibit an average diameter of 2.1 ± 0.3 nm and are stable for weeks in aqueous solution. Moreover, the dots were found to be photostable under the continuous illumination of an Hg–Xe lamp and in the presence of oxygen, indicating their high potential for applications such as sensing or bio-imaging. Full article

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15 pages, 2205 KiB

Open AccessArticle

A Hydrofluoric Acid-Free Green Synthesis of Magnetic M.Ti₂CT_x Nanostructures for the Sequestration of Cesium and Strontium Radionuclide

by Jibran Iqbal, Kashif Rasool, Fares Howari, Yousef Nazzal, Tapati Sarkar and Asif Shahzad

Nanomaterials 2022, 12(18), 3253; https://doi.org/10.3390/nano12183253 - 19 Sep 2022

Cited by 1 | Viewed by 1826

Abstract

MAX phases are the parent materials used for the formation of MXenes, and are generally obtained by etching using the highly corrosive acid HF. To develop a more environmentally friendly approach for the synthesis of MXenes, in this work, titanium aluminum carbide MAX [...] Read more.

MAX phases are the parent materials used for the formation of MXenes, and are generally obtained by etching using the highly corrosive acid HF. To develop a more environmentally friendly approach for the synthesis of MXenes, in this work, titanium aluminum carbide MAX phase (Ti₂AlC) was fabricated and etched using NaOH. Further, magnetic properties were induced during the etching process in a single-step etching process that led to the formation of a magnetic composite. By carefully controlling etching conditions such as etching agent concentration and time, different structures could be produced (denoted as M.Ti₂CT_x). Magnetic nanostructures with unique physico-chemical characteristics, including a large number of binding sites, were utilized to adsorb radionuclide Sr²⁺ and Cs⁺ cations from different matrices, including deionized, tap, and seawater. The produced adsorbents were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The synthesized materials were found to be very stable in the aqueous phase, compared with corrosive acid-etched MXenes, acquiring a distinctive structure with oxygen-containing functional moieties. Sr²⁺ and Cs⁺ removal efficiencies of M.Ti₂CT_x were assessed via conventional batch adsorption experiments. M.Ti₂CT_x-A_III showed the highest adsorption performance among other M.Ti₂CT_x phases, with maximum adsorption capacities of 376.05 and 142.88 mg/g for Sr²⁺ and Cs⁺, respectively, which are among the highest adsorption capacities reported for comparable adsorbents such as graphene oxide and MXenes. Moreover, in seawater, the removal efficiencies for Sr²⁺ and Cs⁺ were greater than 93% and 31%, respectively. Analysis of the removal mechanism validates the electrostatic interactions between M.Ti₂C-A_III and radionuclides. Full article

(This article belongs to the Special Issue Green Synthesis of Nanomaterials for Environmental and Biomedical Applications)

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10 pages, 6271 KiB

Open AccessArticle

High Linearity Synaptic Devices Using Ar Plasma Treatment on HfO₂ Thin Film with Non-Identical Pulse Waveforms

by Ke-Jing Lee, Yu-Chuan Weng, Li-Wen Wang, Hsin-Ni Lin, Parthasarathi Pal, Sheng-Yuan Chu, Darsen Lu and Yeong-Her Wang

Nanomaterials 2022, 12(18), 3252; https://doi.org/10.3390/nano12183252 - 19 Sep 2022

Cited by 2 | Viewed by 1297

Abstract

We enhanced the device uniformity for reliable memory performances by increasing the device surface roughness by exposing the HfO₂ thin film surface to argon (Ar) plasma. The results showed significant improvements in electrical and synaptic properties, including memory window, linearity, pattern recognition [...] Read more.

We enhanced the device uniformity for reliable memory performances by increasing the device surface roughness by exposing the HfO₂ thin film surface to argon (Ar) plasma. The results showed significant improvements in electrical and synaptic properties, including memory window, linearity, pattern recognition accuracy, and synaptic weight modulations. Furthermore, we proposed a non-identical pulse waveform for further improvement in linearity accuracy. From the simulation results, the Ar plasma processing device using the designed waveform as the input signals significantly improved the off-chip training and inference accuracy, achieving 96.3% training accuracy and 97.1% inference accuracy in only 10 training cycles. Full article

(This article belongs to the Special Issue 2D Semiconducting Materials for Device Applications)

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11 pages, 21718 KiB

Open AccessArticle

High-Energy Ball Milling for High Productivity of Nanobiochar from Oil Palm Biomass

by Lawrence Yee Foong Ng, Hidayah Ariffin, Tengku Arisyah Tengku Yasim-Anuar, Mohammed Abdillah Ahmad Farid and Mohd Ali Hassan

Nanomaterials 2022, 12(18), 3251; https://doi.org/10.3390/nano12183251 - 19 Sep 2022

Cited by 9 | Viewed by 2500

Abstract

The current production method of nanobiochar (NBC), an emerging, environmentally friendly nanocarbon material, is tedious and lengthy. Therefore, in this study we aimed to improve the productivity of NBC via high-energy ball milling by manipulating the grinding media and processing time. The particle [...] Read more.

The current production method of nanobiochar (NBC), an emerging, environmentally friendly nanocarbon material, is tedious and lengthy. Therefore, in this study we aimed to improve the productivity of NBC via high-energy ball milling by manipulating the grinding media and processing time. The particle size distribution of the resulting NBC measured using dynamic light scattering showed that grinding media with steel balls of different sizes were more effective at producing NBC than small uniform steel balls, which failed to produce NBC even after 90 min of milling. Average NBC particles of around 95 nm were achieved after only 30 min of ball milling, and the size was further reduced to about 30 nm when the milling was prolonged to 150 min. Further prolonging the milling duration led to agglomeration, which increased the size of the biochar nanoparticles. The thermogravimetric analysis (TGA) data showed that the duration of milling and particle size did not cause noticeable differences in the thermal stability of the NBC. Based on the FTIR analysis, the chemical structure of the NBC was not affected by the ball milling. The results showed that 60 min of high-energy ball milling is sufficient to produce NBC particles of 75 nm, with a large surface area and high thermal stability. This could prove beneficial in a myriad of applications, ranging from agriculture to composite fabrication. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

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21 pages, 4444 KiB

Open AccessArticle

Efficient Removal of Cr(VI) Ions in Petrochemical Wastewater Using Fe₃O₄@Saccharomyces cerevisiae Magnetic Nanocomposite

by Wei Long, Zhilong Chen, Jie Shi and Shilin Yang

Nanomaterials 2022, 12(18), 3250; https://doi.org/10.3390/nano12183250 - 19 Sep 2022

Cited by 3 | Viewed by 1203

Abstract

Saccharomyces cerevisiae (SC) is a widely available biobased source for function material. In this work, a kind of new efficient magnetic composite adsorbent containing Fe₃O₄ and SC was prepared successfully and used for the removal of Cr(VI) ions [...] Read more.

Saccharomyces cerevisiae (SC) is a widely available biobased source for function material. In this work, a kind of new efficient magnetic composite adsorbent containing Fe₃O₄ and SC was prepared successfully and used for the removal of Cr(VI) ions in petrochemical wastewater. The morphology and structure of this magnetic adsorbent were characterized with FT-IR, TG, XRD, VSM, SEM and XPS. The effect of the different factors such as pH, adsorption time, initial Cr(VI) ions concentration and adsorption temperature on the adsorption behavior were investigated. The results showed that 10%-Fe₃O₄@SC exhibited high removal rate, reutilization and large removal capacity. The corresponding removal capacity and removal rate could reach 128.03 mg/g and 96.02% when the pH value was 2, adsorption time was 180 min, and initial Cr(VI) ions concentration were 80 mg/L at 298 K. The kinetics followed the pseudo-first-order, which indicated that the adsorption behavior of 10%-Fe₃O₄@SC for Cr(VI) ions belonged to the physical adsorption and chemical adsorption co-existence. The thermodynamic study showed that the adsorption process was spontaneous and exothermic. It still showed better adsorption performance and reutilization after the fifth adsorption-desorption experiment. The possible mechanism of Cr(VI) ions adsorption onto the 10%-Fe₃O₄@SC magnetic adsorbent has been discussed. Hence, this new adsorbent will be a candidate for industry-level applications in petrochemical wastewater containing Cr(VI) ions. Full article

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21 pages, 5203 KiB

Open AccessArticle

A New Texturing Approach of a Polyimide Shielding Cover for Enhanced Light Propagation in Photovoltaic Devices

by Iuliana Stoica, Raluca Marinica Albu, Camelia Hulubei, Dragos George Astanei, Radu Burlica, Gaber A. M. Mersal, Tarek A. Seaf Elnasr, Andreea Irina Barzic and Ashraf Y. Elnaggar

Nanomaterials 2022, 12(18), 3249; https://doi.org/10.3390/nano12183249 - 19 Sep 2022

Cited by 2 | Viewed by 1525

Abstract

The efficiency of photovoltaics (PVs) is related to cover material properties and light management in upper layers of the device. This article investigates new polyimide (PI) covers for PVs that enable light trapping through their induced surface texture. The latter is attained via [...] Read more.

The efficiency of photovoltaics (PVs) is related to cover material properties and light management in upper layers of the device. This article investigates new polyimide (PI) covers for PVs that enable light trapping through their induced surface texture. The latter is attained via a novel strategy that involves multi-directional rubbing followed by plasma exposure. Atomic force microscopy (AFM) is utilized to clarify the outcome of the proposed light-trapping approach. Since a deep clarification of either random or periodic surface morphology is responsible for the desired light capturing in solar cells, the elaborated texturing procedure generates a balance among both discussed aspects. Multidirectional surface abrasion with sand paper on pre-defined directions of the PI films reveals some relevant modifications regarding both surface morphology and the resulted degree of anisotropy. The illuminance experiments are performed to examine if the created surface texture is suitable for proper light propagation through the studied PI covers. The adhesion among the upper layers of the PV, namely the PI and transparent electrode, is evaluated. The correlation between the results of these analyses helps to identify not only adequate polymer shielding materials, but also to understand the chemical structure response to new design routes for light-trapping, which might significantly contribute to an enhanced conversion efficiency of the PV devices. Full article

(This article belongs to the Special Issue Nano-Photonics and Meta-Nanomaterials)

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36 pages, 7449 KiB

Open AccessReview

Design and Application of Electrochemical Sensors with Metal–Organic Frameworks as the Electrode Materials or Signal Tags

by Yong Chang, Jiaxin Lou, Luyao Yang, Miaomiao Liu, Ning Xia and Lin Liu

Nanomaterials 2022, 12(18), 3248; https://doi.org/10.3390/nano12183248 - 19 Sep 2022

Cited by 13 | Viewed by 2653

Abstract

Metal–organic frameworks (MOFs) with fascinating chemical and physical properties have attracted immense interest from researchers regarding the construction of electrochemical sensors. In this work, we review the most recent advancements of MOF−based electrochemical sensors for the detection of electroactive small molecules and biological [...] Read more.

Metal–organic frameworks (MOFs) with fascinating chemical and physical properties have attracted immense interest from researchers regarding the construction of electrochemical sensors. In this work, we review the most recent advancements of MOF−based electrochemical sensors for the detection of electroactive small molecules and biological macromolecules (e.g., DNA, proteins, and enzymes). The types and functions of MOF−based nanomaterials in terms of the design of electrochemical sensors are also discussed. Furthermore, the limitations and challenges of MOF−based electrochemical sensing devices are explored. This work should be invaluable for the development of MOF−based advanced sensing platforms. Full article

(This article belongs to the Special Issue Nanomaterials and Nanostructures for Biosensors)

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12 pages, 3950 KiB

Open AccessArticle

Ultra-Fast Construction of Novel S-Scheme CuBi₂O₄/CuO Heterojunction for Selectively Photocatalytic CO₂ Conversion to CO

by Weina Shi, Xiu Qiao, Jichao Wang, Miao Zhao, Hongling Ge, Jingjing Ma, Shanqin Liu and Wanqing Zhang

Nanomaterials 2022, 12(18), 3247; https://doi.org/10.3390/nano12183247 - 19 Sep 2022

Cited by 2 | Viewed by 1484

Abstract

Herein, step-scheme (S-scheme) CuBi₂O₄/CuO (CBO/CuO) composite films were successfully synthesized on glass substrates by the ultra-fast spraying-calcination method. The photocatalytic activities of the obtained materials for CO₂ reduction in the presence of H₂O vapor were evaluated [...] Read more.

Herein, step-scheme (S-scheme) CuBi₂O₄/CuO (CBO/CuO) composite films were successfully synthesized on glass substrates by the ultra-fast spraying-calcination method. The photocatalytic activities of the obtained materials for CO₂ reduction in the presence of H₂O vapor were evaluated under visible light irradiation (λ > 400 nm). Benefiting from the construction of S-scheme heterojunction, the CO, CH₄ and O₂ yields of the optimal CBO/CuO composite reached 1599.1, 5.1 and 682.2 μmol/m² after irradiation for 9 h, and the selectivity of the CO product was notably enhanced from below 18.5% to above 98.5% compared with those of the bare samples. In the sixth cycling experiment, the yields of main products decreased by less than 15%, and a high CO selectivity was still kept. The enhanced photocatalytic performance of CO₂ reduction was attributed to the efficient separation of photogenerated charge carriers. Based on the photocatalytic activity, band structure and in situ-XPS results, the S-scheme charge transfer mechanism was conformed. The study provides an insight into the design of S-scheme photocatalysts for selective CO₂ conversion. Full article

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23 pages, 3099 KiB

Open AccessArticle

Carbon Nanostructure/Zeolite Y Composites as Supports for Monometallic and Bimetallic Hydrocracking Catalysts

by Roba Saab, Kyriaki Polychronopoulou, Dalaver H. Anjum, Nikolaos Charisiou, Maria A. Goula, Steven J. Hinder, Mark A. Baker and Andreas Schiffer

Nanomaterials 2022, 12(18), 3246; https://doi.org/10.3390/nano12183246 - 19 Sep 2022

Cited by 2 | Viewed by 1540

Abstract

In this study, we examine the effect of integrating different carbon nanostructures (carbon nanotubes, CNTs, graphene nanoplatelets, GNPs) into Ni- and Ni-W-based bi-functional catalysts for hydrocracking of heptane performed at 400 °C. The effect of varying the SiO₂/Al₂O₃ [...] Read more.

In this study, we examine the effect of integrating different carbon nanostructures (carbon nanotubes, CNTs, graphene nanoplatelets, GNPs) into Ni- and Ni-W-based bi-functional catalysts for hydrocracking of heptane performed at 400 °C. The effect of varying the SiO₂/Al₂O₃ ratio of the zeolite Y support (between 5 and 30) on the heptane conversion is also studied. The results show that the activity, in terms of heptane conversion, followed the order CNT/Ni-ZY5 (92%) > GNP/Ni-ZY5 (89%) > CNT/Ni-W-ZY30 (86%) > GNP/Ni-W-ZY30 (85%) > CNT/Ni-ZY30 (84%) > GNP/Ni-ZY30 (83%). Thus, the CNT-based catalysts exhibited slightly higher heptane conversion as compared to the GNP-based ones. Furthermore, bimetallic (Ni-W) catalysts possessed higher BET surface areas (725 m²/g for CNT/Ni-W-ZY30 and 612 m²/g for CNT/Ni-ZY30) and exhibited enhanced hydrocracking activity as compared to the monometallic (Ni) catalyst with the same zeolite support and type of carbon structure. It was also shown that CNT-based catalysts possessed higher regeneration capability than their GNP-based counterparts due to the slightly higher thermal stability of the CVD-grown CNTs. Full article

(This article belongs to the Section Energy and Catalysis)

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15 pages, 6543 KiB

Open AccessArticle

Molecular Dynamics and Experimental Investigation on the Interfacial Binding Mechanism in the Fe/Cu_1−x-Ni_x Bimetallic Interface

by Guowei Zhang, Mingjie Wang, Huan Yu, Hong Xu and An Wan

Nanomaterials 2022, 12(18), 3245; https://doi.org/10.3390/nano12183245 - 19 Sep 2022

Cited by 2 | Viewed by 1405

Abstract

To systematically investigate the diffusion behavior of Fe/Cu bimetallic materials and the influence of the Ni element on the diffusion and mechanical properties of the Fe/Cu bimetallic interface, the diffusion distance, diffusion coefficient, and strain–stress process based on molecular dynamics (MD) calculations and [...] Read more.

To systematically investigate the diffusion behavior of Fe/Cu bimetallic materials and the influence of the Ni element on the diffusion and mechanical properties of the Fe/Cu bimetallic interface, the diffusion distance, diffusion coefficient, and strain–stress process based on molecular dynamics (MD) calculations and experimental testing were analyzed. All simulation results indicated that the liquid Cu matrix had a higher diffusion coefficient but hardly diffused into the Fe matrix, and the solid Fe matrix had a smaller diffusion coefficient but diffused deep into the Cu matrix at the same temperature. Compared with the initial state, the addition of nickel atoms to the Cu matrix favored the improvement of the diffusion coefficient and the diffusion distance of Fe/Cu bimetallic materials. Moreover, we found that the diffusion distance and the yield strength simultaneously increased and then decreased with the increase in Ni atoms, which is in agreement with the experimental test results. These improvements in the diffusion and mechanical properties were attributed to the enrichment of Ni atoms at the interface, but excessive Ni content resulted in deteriorated properties. Finally, our research described the enhancement mechanism of the addition of nickel atoms to the Fe/Cu bimetallic diffusion system. An analysis of the contributions of the diffusion distance, the diffusion coefficient, and the yield strength revealed that the diffusion properties of nickel atoms play an important role in Fe/Cu bimetallic materials. Full article

(This article belongs to the Special Issue Advances in Computational Materials Science on Functional Interfaces and Surfaces)

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20 pages, 6486 KiB

Open AccessArticle

Multifunctional Zn-Doped ITO Sol–Gel Films Deposited on Different Substrates: Application as CO₂-Sensing Material

by Mariuca Gartner, Mihai Anastasescu, Jose Maria Calderon-Moreno, Madalina Nicolescu, Hermine Stroescu, Cristian Hornoiu, Silviu Preda, Luminita Predoana, Daiana Mitrea, Maria Covei, Valentin-Adrian Maraloiu, Valentin Serban Teodorescu, Carmen Moldovan, Peter Petrik and Maria Zaharescu

Nanomaterials 2022, 12(18), 3244; https://doi.org/10.3390/nano12183244 - 19 Sep 2022

Cited by 6 | Viewed by 1934

Abstract

Undoped and Zn-doped ITO (ITO:Zn) multifunctional thin films were successfully synthesized using the sol–gel and dipping method on three different types of substrates (glass, SiO₂/glass, and Si). The effect of Zn doping on the optoelectronic, microstructural, and gas-sensing properties of the [...] Read more.

Undoped and Zn-doped ITO (ITO:Zn) multifunctional thin films were successfully synthesized using the sol–gel and dipping method on three different types of substrates (glass, SiO₂/glass, and Si). The effect of Zn doping on the optoelectronic, microstructural, and gas-sensing properties of the films was investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), spectroscopic ellipsometry (SE), Raman spectroscopy, Hall effect measurements (HE), and gas testing. The results showed that the optical constants, the transmission, and the carrier numbers were correlated with the substrate type and with the microstructure and the thickness of the films. The Raman study showed the formation of ITO films and the incorporation of Zn in the doped film (ITO:Zn), which was confirmed by EDX analysis. The potential use of the multifunctional sol–gel ITO and ITO:Zn thin films was proven for TCO applications or gas-sensing experiments toward CO₂. The Nyquist plots and equivalent circuit for fitting the experimental data were provided. The best electrical response of the sensor in CO₂ atmosphere was found at 150 °C, with activation energy of around 0.31 eV. Full article

(This article belongs to the Special Issue Surface Functionalization on Nanostructured Materials for Multiple Application)

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10 pages, 2252 KiB

Open AccessArticle

Ultralow-Thermal-Budget-Driven IWO-Based Thin-Film Transistors and Application Explorations

by Shanshan Jiang, Gang He, Wenhao Wang, Minmin Zhu, Zhengquan Chen, Qian Gao and Yanmei Liu

Nanomaterials 2022, 12(18), 3243; https://doi.org/10.3390/nano12183243 - 19 Sep 2022

Viewed by 1681

Abstract

Exploiting multifunctional thin film transistors (TFTs) by low-temperature manufacturing strategy is a crucial step toward flexible electronics. Herein, a multifunctional indium–tungsten-oxide (IWO)-based TFT, gated by solid-state chitosan electrolyte membrane, is fabricated on paper substrate at room temperature. The chitosan exhibits a high specific [...] Read more.

Exploiting multifunctional thin film transistors (TFTs) by low-temperature manufacturing strategy is a crucial step toward flexible electronics. Herein, a multifunctional indium–tungsten-oxide (IWO)-based TFT, gated by solid-state chitosan electrolyte membrane, is fabricated on paper substrate at room temperature. The chitosan exhibits a high specific electric-double-layer capacitance of 2.0 µF cm⁻² due to the existence of mobile protons. The IWO-based TFT possesses excellent electrical properties, including a low threshold voltage of 0.2 V, larger current switching ratio of 1.3 × 10⁶, high field effect mobility of 15.0 cm² V⁻¹s⁻¹, and small subthreshold swing of 117 mV/decade, respectively. Multifunctional operations including inverter, Schmitt triggers, and NAND gate are successfully demonstrated. As an example of information processing, the essential signal transmission functions of biological synapses also be emulated in the fabricated IWO-based TFTs. The experimental results indicate that such flexible IWO-based TFTs on low-cost and biodegradable paper provide the new-concept building blocks for flexible electronics. Full article

(This article belongs to the Special Issue Nanoscale Thin Film Transistors and Application Exploration)

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9 pages, 3141 KiB

Open AccessArticle

Atomistic Simulation of the Ion-Assisted Deposition of Silicon Dioxide Thin Films

by F. V. Grigoriev, V. B. Sulimov and A. V. Tikhonravov

Nanomaterials 2022, 12(18), 3242; https://doi.org/10.3390/nano12183242 - 19 Sep 2022

Cited by 4 | Viewed by 1475

Abstract

A systematic study of the most significant parameters of the ion-assisted deposited silicon dioxide films is carried out using the classical molecular dynamics method. The energy of the deposited silicon and oxygen atoms corresponds to the thermal evaporation of the target; the energy [...] Read more.

A systematic study of the most significant parameters of the ion-assisted deposited silicon dioxide films is carried out using the classical molecular dynamics method. The energy of the deposited silicon and oxygen atoms corresponds to the thermal evaporation of the target; the energy of the assisting oxygen ions is 100 eV. It is found that an increase in the flow of assisting ions to approximately 10% of the flow of deposited atoms leads to an increase in density and refractive index by 0.5 g/cm³ and 0.1, respectively. A further increase in the flux of assisting ions slightly affects the film density and density profile. The concentration of point defects, which affect the optical properties of the films, and stressed structural rings with two or three silicon atoms noticeably decrease with an increase in the flux of assisting ions. The film growth rate somewhat decreases with an increase in the assisting ions flux. The dependence of the surface roughness on the assisting ions flux is investigated. The anisotropy of the deposited films, due to the difference in the directions of motion of the deposited atoms and assisting ions, is estimated using the effective medium approach. Full article

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

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16 pages, 5247 KiB

Open AccessArticle

High-Efficiency Utilization of Waste Tobacco Stems to Synthesize Novel Biomass-Based Carbon Dots for Precise Detection of Tetracycline Antibiotic Residues

by Hui Yang, Yunlong Wei, Xiufang Yan, Chao Nie, Zhenchun Sun, Likai Hao and Xiankun Su

Nanomaterials 2022, 12(18), 3241; https://doi.org/10.3390/nano12183241 - 18 Sep 2022

Cited by 5 | Viewed by 1899

Abstract

Recycling waste biomass into valuable products (e.g., nanomaterials) is of considerable theoretical and practical significance to achieve future sustainable development. Here, we propose a one-pot hydrothermal synthesis route to convert waste tobacco stems into biomass-based N, S-codoped carbon dots (C−dots) with the assistance [...] Read more.

Recycling waste biomass into valuable products (e.g., nanomaterials) is of considerable theoretical and practical significance to achieve future sustainable development. Here, we propose a one-pot hydrothermal synthesis route to convert waste tobacco stems into biomass-based N, S-codoped carbon dots (C−dots) with the assistance of carbon black. Unlike most of the previously reported luminescent C−dots, these biomass-based C−dots showed a satisfactory stability, as well as an excitation-independent fluorescence emission at ~520 nm. Furthermore, they demonstrated a pH-dependent fluorescence emission ability, offering a scaffold to design pH-responsive assays. Moreover, these as-synthesized biomass-based C−dots exhibited a fluorescence response ability toward tetracycline antibiotics (TCs, e.g., TC, CTC, and OTC) through the inner filter effect (IFE), thereby allowing for the establishment a smart analytical platform to sensitively and selectively monitor residual TCs in real environmental water samples. In this study, we explored the conversion of waste tobacco stems into sustainable biomass-based C−dots to develop simple, efficient, label-free, reliable, low-cost, and eco-friendly analytical platforms for environmental pollution traceability analysis, which might provide a novel insight to resolve the ecological and environmental issues derived from waste tobacco stems. Full article

(This article belongs to the Topic Advanced Nanomaterials for Sensing Applications)

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14 pages, 7765 KiB

Open AccessArticle

High-Throughput Predictions of the Stabilities of Multi-Type Long-Period Stacking Ordered Structures in High-Performance Mg Alloys

by Touwen Fan, Zhipeng Wang, Yuanyuan Tian, Yu Liu and Pingying Tang

Nanomaterials 2022, 12(18), 3240; https://doi.org/10.3390/nano12183240 - 18 Sep 2022

Cited by 1 | Viewed by 1286

Abstract

The effects of 44 types of elements on the stabilities of I1-constitute multi-type long-period stacking-ordered (LPSO) structures in Mg alloys, such as 4H, 6H, 8H, 9R, 12H, 15R, and 16H phases, are systematically investigated by first-principle high-performance calculations. The intrinsic stacking-fault energies (ISFEs) [...] Read more.

The effects of 44 types of elements on the stabilities of I1-constitute multi-type long-period stacking-ordered (LPSO) structures in Mg alloys, such as 4H, 6H, 8H, 9R, 12H, 15R, and 16H phases, are systematically investigated by first-principle high-performance calculations. The intrinsic stacking-fault energies (ISFEs) and their increments are calculated along with the formation enthalpies of solute atoms, and interaction energies between solute atoms and LPSO structures. The results suggest that the 15R phase is the easiest to form and stabilize among these LPSO structures, and 44 types of solute atoms have different segregation characteristics in these LPSO structures. A high temperature inhibits structural stabilizations of the LPSO phases, and these alloying elements, such as elements (Sb, Te, and Cs) for 4H; elements (S, Fe, Sb, and Te) for 6H, 8H, 9R, 15R, and 16H; and elements (S, Sb, and Te) for 12H, can effectively promote the stability of LPSO structures at high temperatures. S and Fe atoms are the most likely to promote the stabilities of the 16H structure with regard to other LPSO phases, but the Fe atom tends to inhibit the stabilities of 4H and 12H structures. This work can offer valuable references to further study and develop high-performance Mg alloys with multi-type LPSO structures. Full article

(This article belongs to the Special Issue Structural and Functional Nanocrystalline (NC) Materials)

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13 pages, 2918 KiB

Open AccessArticle

Anisotropy Engineering of ZnO Nanoporous Frameworks: A Lattice Dynamics Simulation

by Na Sa, Sue-Sin Chong, Hui-Qiong Wang and Jin-Cheng Zheng

Nanomaterials 2022, 12(18), 3239; https://doi.org/10.3390/nano12183239 - 18 Sep 2022

Cited by 3 | Viewed by 1528

Abstract

The anisotropy engineering of nanoporous zinc oxide (ZnO) frameworks has been performed by lattice dynamics simulation. A series of zinc oxide (ZnO) nanoporous framework structures was designed by creating nanopores with different sizes and shapes. We examined the size effects of varying several [...] Read more.

The anisotropy engineering of nanoporous zinc oxide (ZnO) frameworks has been performed by lattice dynamics simulation. A series of zinc oxide (ZnO) nanoporous framework structures was designed by creating nanopores with different sizes and shapes. We examined the size effects of varying several features of the nanoporous framework (namely, the removal of layers of atoms, surface-area-to-volume ratio, coordination number, porosity, and density) on its mechanical properties (including bulk modulus, Young’s modulus, elastic constant, and Poisson ratio) with both lattice dynamics simulations. We also found that the anisotropy of nanoporous framework can be drastically tuned by changing the shape of nanopores. The maximum anisotropy (defined by Y_max/Y_min) of the Young’s modulus value increases from 1.2 for bulk ZnO to 2.5 for hexagon-prism-shaped ZnO nanoporous framework structures, with a density of 2.72 g/cm³, and, even more remarkably, to 89.8 for a diamond-prism-shape at a density of 1.72 g/cm³. Our findings suggest a new route for desirable anisotropy and mechanical property engineering with nanoporous frameworks by editing the shapes of the nanopores for the desired anisotropy. Full article

(This article belongs to the Special Issue Processing, Surfaces and Interfaces of Nanomaterials)

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10 pages, 3348 KiB

Open AccessArticle

Resonant Lasing Emission in Undoped and Mg-Doped Gallium Nitride Thin Films on Interfacial Periodic Patterned Sapphire Substrates

by Long Xu, Yuehan Cao, Tianwei Song and Caixia Xu

Nanomaterials 2022, 12(18), 3238; https://doi.org/10.3390/nano12183238 - 18 Sep 2022

Viewed by 1448

Abstract

In this work, low-threshold resonant lasing emission was investigated in undoped and Mg-doped GaN thin films on interfacial designed sapphire substrates. The scattering cross-section of the periodic resonant structure was evaluated by using the finite difference time domain (FDTD) method and was found [...] Read more.

In this work, low-threshold resonant lasing emission was investigated in undoped and Mg-doped GaN thin films on interfacial designed sapphire substrates. The scattering cross-section of the periodic resonant structure was evaluated by using the finite difference time domain (FDTD) method and was found to be beneficial for reducing the threshold and enhancing the resonant lasing emission within the periodic structures. Compared with undoped and Si-doped GaN thin films, p-type Mg-doped GaN thin films demonstrated a better lasing emission performance. The lasing energy level system and defect densities played vital roles in the lasing emission. This work is beneficial to the realization of multifunctional applications in optoelectronic devices. Full article

(This article belongs to the Special Issue Functional Nanostructured Systems for Nanophotonics, Plasmonics and Metamaterials)

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19 pages, 9995 KiB

Open AccessArticle

Plasma-Modified PI Substrate for Highly Reliable Laser-Sintered Copper Films Using Cu₂O Nanoparticles

by Wei-Han Cheng, Ming-Tsang Lee, Kiyokazu Yasuda and Jenn-Ming Song

Nanomaterials 2022, 12(18), 3237; https://doi.org/10.3390/nano12183237 - 18 Sep 2022

Cited by 3 | Viewed by 1461

Abstract

Plasma modification of polyimide (PI) substrates upon which electrical circuits are fabricated by the laser sintering of cuprous oxide nanoparticle pastes was investigated systematically in this study. Surface properties of the PI substrate were investigated by carrying out atomic force microscopy (AFM) and [...] Read more.

Plasma modification of polyimide (PI) substrates upon which electrical circuits are fabricated by the laser sintering of cuprous oxide nanoparticle pastes was investigated systematically in this study. Surface properties of the PI substrate were investigated by carrying out atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS), and contact angle measurements. Experimental results show that surface characteristics of PI substrates, including surface energy, surface roughness, and surface binding significantly affected the mechanical reliability of the sintered copper structure. Among the plasma gases tested (air, O₂, Ar-5%H₂, and N₂-30%H₂), O₂ plasma caused the roughest PI surface as well as the most C=O and C–OH surface binding resulting in an increased polar component of the surface energy. The combination of all those factors caused superior bending fatigue resistance. Full article

(This article belongs to the Special Issue Low-Dimensional Nanomaterials and Their Applications)

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10 pages, 2400 KiB

Open AccessArticle

Bio-Fabrication of Bio-Inspired Silica Nanomaterials from Orange Peels in Combating Oxidative Stress

by Mosleh Mohammad Abomughaid

Nanomaterials 2022, 12(18), 3236; https://doi.org/10.3390/nano12183236 - 18 Sep 2022

Cited by 5 | Viewed by 1515

Abstract

Silica nanoparticles were synthesized using the aqueous extract of orange peels by the green chemistry approach and simple method. The physicochemical properties such as optical and chemical banding of as-synthesized silica nanoparticles were analyzed with UV–visible spectroscopy and Fourier transform infrared spectroscopy. Scanning [...] Read more.

Silica nanoparticles were synthesized using the aqueous extract of orange peels by the green chemistry approach and simple method. The physicochemical properties such as optical and chemical banding of as-synthesized silica nanoparticles were analyzed with UV–visible spectroscopy and Fourier transform infrared spectroscopy. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis and X-ray diffraction analysis were employed to confirm the shape, size and elemental purities of the silica nanoparticles. The thermal stability and mass loss of the silica nanoparticles was examined using thermogravimetric analysis and zeta potential analysis. The surface plasmon resonance band of the silica nanoparticle was obtained in the wavelength of 292 nm. Silica nanoparticles with a spherical and amorphous nature and an average size of 20 nm were produced and confirmed by X-ray diffraction and Scanning Electron Microscopy. The zeta potential of the silica nanoparticles was −25.00 mV. The strong and broad bands were located at 457, 642 and 796 cm⁻¹ in the Fourier transform infrared spectra of the silica nanoparticles, associated with the Si–O bond. All the results of the present investigation confirmed and proved that the green synthesized silica nanoparticles were highly stable, pure and spherical in nature. In addition, the antioxidant activity of the green synthesized orange peel extract mediated by the silica nanoparticles was investigated with a DPPH assay. The antioxidant assay revealed that the synthesized silica nanoparticles had good antioxidant activity. In the future, green synthesized silica nanoparticles may be used for the production of nano-medicine. Full article

(This article belongs to the Special Issue Nanotoxicology and Environmental Safety)

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14 pages, 2264 KiB

Open AccessArticle

Synergistic Enhanced Thermal Conductivity and Crack Resistance of Reactor Epoxy Insulation with Boron Nitride Nanosheets and Multiwalled Carbon Nanotubes

by Jun Yang, Zhijie Chen, Longyi Liang, Zhiwen Guan and Junwen Ren

Nanomaterials 2022, 12(18), 3235; https://doi.org/10.3390/nano12183235 - 18 Sep 2022

Cited by 5 | Viewed by 1651

Abstract

Epoxy composites with high thermal conductivity, excellent dielectric, and mechanical properties are very promising for solving epoxy cracking faults in reactors and for extending their service life. In this work, we report on epoxy composites enhanced by ternary fillers of boron nitride nanosheets [...] Read more.

Epoxy composites with high thermal conductivity, excellent dielectric, and mechanical properties are very promising for solving epoxy cracking faults in reactors and for extending their service life. In this work, we report on epoxy composites enhanced by ternary fillers of boron nitride nanosheets (BNNSs), multiwalled carbon nanotubes (MWCNTs), and silica (SiO₂) nanoparticles. The obtained BNNSs/MWCNTs/SiO₂/epoxy composites exhibit a high thermal conductivity of 0.9327 W m⁻¹ K⁻¹, which is more than 4-fold higher than that of pure epoxy. In addition, the resultant composites present an improved mechanical strength (from 2.7% of epoxy to 3.47% of composites), low dielectric constant (4.6), and low dielectric loss (0.02). It is believed that the integration of multifunctional properties into epoxy composites provides guidance for optimizing the design of high-performance materials. Full article

(This article belongs to the Special Issue High-K, Low Loss Polymer Nanocomposites for Energy Storage Applications)

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13 pages, 3161 KiB

Open AccessArticle

Architecting Nanostructured Co-BTC@GO Composites for Supercapacitor Electrode Application

by Tianen Chen, Allen Yang, Wei Zhang, Jinhui Nie, Tingting Wang, Jianchao Gong, Yuanhao Wang and Yaxiong Ji

Nanomaterials 2022, 12(18), 3234; https://doi.org/10.3390/nano12183234 - 18 Sep 2022

Cited by 5 | Viewed by 2314

Abstract

Herein, we present an innovative graphene oxide (GO)-induced strategy for synthesizing GO-based metal-organic-framework composites (Co-BTC@GO) for high-performance supercapacitors. 1,3,5-Benzene tricarboxylic acid (BTC) is used as an inexpensive organic ligand for the synthesis of composites. An optimal GO dosage was ascertained by the combined [...] Read more.

Herein, we present an innovative graphene oxide (GO)-induced strategy for synthesizing GO-based metal-organic-framework composites (Co-BTC@GO) for high-performance supercapacitors. 1,3,5-Benzene tricarboxylic acid (BTC) is used as an inexpensive organic ligand for the synthesis of composites. An optimal GO dosage was ascertained by the combined analysis of morphology characterization and electrochemical measurement. The 3D Co-BTC@GO composites display a microsphere morphology similar to that of Co-BTC, indicating the framework effect of Co-BTC on GO dispersion. The Co-BTC@GO composites own a stable interface between the electrolyte and electrodes, as well as a better charge transfer path than pristine GO and Co-BTC. A study was conducted to determine the synergistic effects and electrochemical behavior of GO content on Co-BTC. The highest energy storage performance was achieved for Co-BTC@GO 2 (GO dosage is 0.02 g). The maximum specific capacitance was 1144 F/g at 1 A/g, with an excellent rate capability. After 2000 cycles, Co-BTC@GO 2 maintains outstanding life stability of 88.1%. It is expected that this material will throw light on the development of supercapacitor electrodes that hold good electrochemical properties. Full article

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22 pages, 7907 KiB

Open AccessReview

Evolution Application of Two-Dimensional MoS₂-Based Field-Effect Transistors

by Chunlan Wang, Yongle Song and Hao Huang

Nanomaterials 2022, 12(18), 3233; https://doi.org/10.3390/nano12183233 - 18 Sep 2022

Cited by 7 | Viewed by 4917

Abstract

High-performance and low-power field-effect transistors (FETs) are the basis of integrated circuit fields, which undoubtedly require researchers to find better film channel layer materials and improve device structure technology. MoS₂ has recently shown a special two-dimensional (2D) structure and superior photoelectric performance, [...] Read more.

High-performance and low-power field-effect transistors (FETs) are the basis of integrated circuit fields, which undoubtedly require researchers to find better film channel layer materials and improve device structure technology. MoS₂ has recently shown a special two-dimensional (2D) structure and superior photoelectric performance, and it has shown new potential for next-generation electronics. However, the natural atomic layer thickness and large specific surface area of MoS₂ make the contact interface and dielectric interface have a great influence on the performance of MoS₂ FET. Thus, we focus on its main performance improvement strategies, including optimizing the contact behavior, regulating the conductive channel, and rationalizing the dielectric layer. On this basis, we summarize the applications of 2D MoS₂ FETs in key and emerging fields, specifically involving logic, RF circuits, optoelectronic devices, biosensors, piezoelectric devices, and synaptic transistors. As a whole, we discuss the state-of-the-art, key merits, and limitations of each of these 2D MoS₂-based FET systems, and prospects in the future. Full article

(This article belongs to the Special Issue Advanced Nanocomposites for Photonics and Optoelectronics and Mechanics)

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12 pages, 3454 KiB

Open AccessEditor’s ChoiceArticle

Synthesis of Mesoporous Silica Adsorbent Modified with Mercapto–Amine Groups for Selective Adsorption of Cu²⁺ Ion from Aqueous Solution

by Sagar M. Mane, Chaitany Jayprakash Raorane and Jae Cheol Shin

Nanomaterials 2022, 12(18), 3232; https://doi.org/10.3390/nano12183232 - 18 Sep 2022

Cited by 3 | Viewed by 1584

Abstract

In a sol–gel co-condensation, a mesoporous silica hybrid integrated with (3-mercaptopropyl)trimethoxysilane (TMPSH) was prepared and then reacted with allylamine via a post-surface functionalization approach. Approximately 15 mol% of TMSPSH was introduced into the mesoporous silica pore walls along with tetraethyl orthosilicate. The mercapto [...] Read more.

In a sol–gel co-condensation, a mesoporous silica hybrid integrated with (3-mercaptopropyl)trimethoxysilane (TMPSH) was prepared and then reacted with allylamine via a post-surface functionalization approach. Approximately 15 mol% of TMSPSH was introduced into the mesoporous silica pore walls along with tetraethyl orthosilicate. The mercapto ligands in the prepared mesoporous silica pore walls were then reacted with allylamine (AM) to form the mercapto–amine-modified mesoporous silica adsorbent (MSH@MA). The MSH@MA NPs demonstrate highly selective adsorption of copper (Cu²⁺) ions (~190 mg/g) with a fast equilibrium adsorption time (30 min). The prepared adsorbent shows at least a five times more efficient recyclable stability. The MSH@MA NPs adsorbent is useful for selective adsorption of Cu²⁺ ions. Full article

(This article belongs to the Special Issue Advanced Nanomaterials for Environmental Remediation)

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22 pages, 7431 KiB

Open AccessArticle

Magneto-Tactile Sensor Based on a Commercial Polyurethane Sponge

by Ioan Bica, Gabriela-Eugenia Iacobescu and Larisa-Marina-Elisabeth Chirigiu

Nanomaterials 2022, 12(18), 3231; https://doi.org/10.3390/nano12183231 - 18 Sep 2022

Cited by 2 | Viewed by 1487

Abstract

In this paper, we present the procedure for fabricating a new magneto-tactile sensor (MTS) based on a low-cost commercial polyurethane sponge, including the experimental test configuration, the experimental process, and a description of the mechanisms that lead to obtaining the MTS and its [...] Read more.

In this paper, we present the procedure for fabricating a new magneto-tactile sensor (MTS) based on a low-cost commercial polyurethane sponge, including the experimental test configuration, the experimental process, and a description of the mechanisms that lead to obtaining the MTS and its characteristics. It is shown that by using a polyurethane sponge, microparticles of carbonyl iron, ethanol, and copper foil with electroconductive adhesive, we can obtain a high-performance and low-cost MTS. With the experimental assembly described in this paper, the variation in time of the electrical capacity of the MTS was measured in the presence of a deforming force field, a magnetic field, and a magnetic field superimposed over a deformation field. It is shown that, by using an external magnetic field, the sensitivity of the MTS can be increased. Using the magnetic dipole model and linear elasticity approximation, the qualitative mechanisms leading to the reported results are described in detail. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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11 pages, 3132 KiB

Open AccessArticle

Fabrication and Characterization of Visible to Near-Infrared Photodetector Based on Multilayer Graphene/Mg₂Si/Si Heterojunction

by Hong Yu, Rui Deng, Zhangjie Mo, Shentong Ji and Quan Xie

Nanomaterials 2022, 12(18), 3230; https://doi.org/10.3390/nano12183230 - 17 Sep 2022

Cited by 2 | Viewed by 1680

Abstract

In this investigation, p–Mg₂Si/n–Si heterojunction photodetector (PD) is fabricated by magnetron sputtering and low vacuum annealing in the absence of argon or nitrogen atmosphere. Multilayer Graphene (MLG)/Mg₂Si/Si heterojunction PD is first fabricated by transferring MLG to Mg₂Si/Si [...] Read more.

In this investigation, p–Mg₂Si/n–Si heterojunction photodetector (PD) is fabricated by magnetron sputtering and low vacuum annealing in the absence of argon or nitrogen atmosphere. Multilayer Graphene (MLG)/Mg₂Si/Si heterojunction PD is first fabricated by transferring MLG to Mg₂Si/Si heterojunction substrate using the suspended self-help transfer MLG method. After characterizing the phase composition, morphology and detection properties of Mg₂Si/Si and MLG/Mg₂Si/Si heterojunction PDs, the successful fabrication of the Mg₂Si/Si and MLG/Mg₂Si/Si heterojunction PDs are confirmed and some detection capabilities are realized. Compared with the Mg₂Si/Si heterojunction PD, the light absorption and the ability to effectively separate and transfer photogenerated carriers of MLG/Mg₂Si/Si heterojunction PD are improved. The responsivity, external quantum efficiency (EQE), noise equivalent power (NEP), detectivity (D*), on/off ratio and other detection properties are enhanced. The peak responsivity and EQE of the MLG/Mg₂Si/Si heterojunction PD are 23.7 mA/W and 2.75%, respectively, which are better than the previous 1–10 mA/W and 2.3%. The results illustrate that the fabrication technology of introducing MLG to regulate the detection properties of the Mg₂Si/Si heterojunction PD is feasible. In addition, this study reveals the potential of MLG to enhance the detection properties of optoelectronic devices, broadens the application prospect of the Mg₂Si/Si-based heterojunction PDs and provides a direction for the regulation of optoelectronic devices. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

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16 pages, 2481 KiB

Open AccessArticle

pH-Driven Intracellular Nano-to-Molecular Disassembly of Heterometallic [Au₂L₂]{Re₆Q₈} Colloids (L = PNNP Ligand; Q = S²⁻ or Se²⁻)

by Bulat Faizullin, Irina Dayanova, Igor Strelnik, Kirill Kholin, Irek Nizameev, Aidar Gubaidullin, Alexandra Voloshina, Tatiana Gerasimova, Ilya Kashnik, Konstantin Brylev, Guzel Sibgatullina, Dmitry Samigullin, Konstantin Petrov, Elvira Musina, Andrey Karasik and Asiya Mustafina

Nanomaterials 2022, 12(18), 3229; https://doi.org/10.3390/nano12183229 - 17 Sep 2022

Cited by 5 | Viewed by 1414

Abstract

The present work introduces a simple, electrostatically driven approach to engineered nanomaterial built from the highly cytotoxic [Au₂L₂]²⁺ complex (Au₂, L = 1,5-bis(p-tolyl)−3,7-bis(pyridine-2-yl)−1,5-diaza-3,7-diphosphacyclooctane (PNNP) ligand) and the pH-sensitive red-emitting [{Re₆Q₈}(OH)₆] [...] Read more.

The present work introduces a simple, electrostatically driven approach to engineered nanomaterial built from the highly cytotoxic [Au₂L₂]²⁺ complex (Au₂, L = 1,5-bis(p-tolyl)−3,7-bis(pyridine-2-yl)−1,5-diaza-3,7-diphosphacyclooctane (PNNP) ligand) and the pH-sensitive red-emitting [{Re₆Q₈}(OH)₆]⁴⁻ (Re₆-Q, Q = S²⁻ or Se²⁻) cluster units. The protonation/deprotonation of the Re₆-Q unit is a prerequisite for the pH-triggered assembly of Au₂ and Re₆-Q into Au₂Re₆-Q colloids, exhibiting disassembly in acidic (pH = 4.5) conditions modeling a lysosomal environment. The counter-ion effect of polyethylenimine causes the release of Re₆-Q units from the colloids, while the binding with lysozyme restricts their protonation in acidified conditions. The enhanced luminescence response of Re₆-S on the disassembly of Au₂Re₆-S colloids in the lysosomal environment allows us to determine their high lysosomal localization extent through the colocalization assay, while the low luminescence of Re₆-Se units in the same conditions allows us to reveal the rapture of the lysosomal membrane through the use of the Acridine Orange assay. The lysosomal pathway of the colloids, followed by their endo/lysosomal escape, correlates with their cytotoxicity being on the same level as that of Au₂ complexes, but the contribution of the apoptotic pathway differentiates the cytotoxic effect of the colloids from that of the Au₂ complex arisen from the necrotic processes. Full article

(This article belongs to the Special Issue Functional Nanocomposite Material Based on Metal Atom Clusters)

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19 pages, 3301 KiB

Open AccessReview

Mechanical Properties and Deformation Behavior of Superhard Lightweight Nanocrystalline Ceramics

by Byeongyun Jeong, Simanta Lahkar, Qi An and Kolan Madhav Reddy

Nanomaterials 2022, 12(18), 3228; https://doi.org/10.3390/nano12183228 - 16 Sep 2022

Cited by 5 | Viewed by 1872

Abstract

Lightweight polycrystalline ceramics possess promising physical, chemical, and mechanical properties, which can be used in a variety of important structural applications. However, these ceramics with coarse-grained structures are brittle and have low fracture toughness due to their rigid covalent bonding (more often consisting [...] Read more.

Lightweight polycrystalline ceramics possess promising physical, chemical, and mechanical properties, which can be used in a variety of important structural applications. However, these ceramics with coarse-grained structures are brittle and have low fracture toughness due to their rigid covalent bonding (more often consisting of high-angle grain boundaries) that can cause catastrophic failures. Nanocrystalline ceramics with soft interface phases or disordered structures at grain boundaries have been demonstrated to enhance their mechanical properties, such as strength, toughness, and ductility, significantly. In this review, the underlying deformation mechanisms that are contributing to the enhanced mechanical properties of superhard nanocrystalline ceramics, particularly in boron carbide and silicon carbide, are elucidated using state-of-the-art transmission electron microscopy and first-principles simulations. The observations on these superhard ceramics revealed that grain boundary sliding induced amorphization can effectively accommodate local deformation, leading to an outstanding combination of mechanical properties. Full article

(This article belongs to the Special Issue Superhard Materials with Nanostructures)

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