Nanomaterials

Research

Jump to: Review

15 pages, 4045 KiB

Open AccessArticle

Morphological, Optical, and Electrical Properties of p-Type Nickel Oxide Thin Films by Nonvacuum Deposition

by Chien-Chen Diao, Chun-Yuan Huang, Cheng-Fu Yang and Chia-Ching Wu

Nanomaterials 2020, 10(4), 636; https://doi.org/10.3390/nano10040636 - 29 Mar 2020

Cited by 37 | Viewed by 6094

Abstract

In this study, a p-type 2 at% lithium-doped nickel oxide (abbreviation L2NiO) solution was prepared using Ni(NO₃)₂·6H₂O, and LiNO₃·L2NiO thin films were deposited using an atomizer by spraying the L2NiO solution onto a glass substrate. [...] Read more.

In this study, a p-type 2 at% lithium-doped nickel oxide (abbreviation L2NiO) solution was prepared using Ni(NO₃)₂·6H₂O, and LiNO₃·L2NiO thin films were deposited using an atomizer by spraying the L2NiO solution onto a glass substrate. The sprayed specimen was heated at a low temperature (140 °C) and annealed at different high temperatures and times. This method can reduce the evaporation ratio of the L2NiO solution, affording high-order nucleating points on the substrate. The L2NiO thin films were characterized by X-ray diffraction, scanning electron microscopy, UV–visible spectroscopy, and electrical properties. The figure of merit (FOM) for L2NiO thin films was calculated by Haacke’s formula, and the maximum value was found to be 5.3 × 10⁻⁶ Ω⁻¹. FOM results revealed that the L2NiO thin films annealed at 600 °C for 3 h exhibited satisfactory optical and electrical characteristics for photoelectric device applications. Finally, a transparent heterojunction diode was successfully prepared using the L2NiO/indium tin oxide (ITO) structure. The current–voltage characteristics revealed that the transparent heterojunction diode exhibited rectifying properties, with a turn-on voltage of 1.04 V, a leakage current of 1.09 × 10⁻⁴ A/cm² (at 1.1 V), and an ideality factor of n = 0.46. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

10 pages, 2483 KiB

Open AccessArticle

Vertically Aligned Single-Crystalline CoFe₂O₄ Nanobrush Architectures with High Magnetization and Tailored Magnetic Anisotropy

by Lisha Fan, Xiang Gao, Thomas O. Farmer, Dongkyu Lee, Er-Jia Guo, Sai Mu, Kai Wang, Michael R. Fitzsimmons, Matthew F. Chisholm, Thomas Z. Ward, Gyula Eres and Ho Nyung Lee

Nanomaterials 2020, 10(3), 472; https://doi.org/10.3390/nano10030472 - 5 Mar 2020

Cited by 5 | Viewed by 3597

Abstract

Micrometer-tall vertically aligned single-crystalline CoFe₂O₄ nanobrush architectures with extraordinarily large aspect ratio have been achieved by the precise control of a kinetic and thermodynamic non-equilibrium pulsed laser epitaxy process. Direct observations by scanning transmission electron microscopy reveal that the nanobrush [...] Read more.

Micrometer-tall vertically aligned single-crystalline CoFe₂O₄ nanobrush architectures with extraordinarily large aspect ratio have been achieved by the precise control of a kinetic and thermodynamic non-equilibrium pulsed laser epitaxy process. Direct observations by scanning transmission electron microscopy reveal that the nanobrush crystal is mostly defect-free by nature, and epitaxially connected to the substrate through a continuous 2D interface layer. In contrast, periodic dislocations and lattice defects such as anti-phase boundaries and twin boundaries are frequently observed in the 2D interface layer, suggesting that interface misfit strain relaxation under a non-equilibrium growth condition plays a critical role in the self-assembly of such artificial architectures. Magnetic property measurements have found that the nanobrushes exhibit a saturation magnetization value of 6.16 μB/f.u., which is much higher than the bulk value. The discovery not only enables insights into an effective route for fabricating unconventional high-quality nanostructures, but also demonstrates a novel magnetic architecture with potential applications in nanomagnetic devices. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

15 pages, 3431 KiB

Open AccessArticle

Defect Structure Determination of GaN Films in GaN/AlN/Si Heterostructures by HR-TEM, XRD, and Slow Positrons Experiments

by Vladimir Lucian Ene, Doru Dinescu, Nikolay Djourelov, Iulia Zai, Bogdan Stefan Vasile, Andreea Bianca Serban, Victor Leca and Ecaterina Andronescu

Nanomaterials 2020, 10(2), 197; https://doi.org/10.3390/nano10020197 - 23 Jan 2020

Cited by 15 | Viewed by 5274

Abstract

The present article evaluates, in qualitative and quantitative manners, the characteristics (i.e., thickness of layers, crystal structures, growth orientation, elemental diffusion depths, edge, and screw dislocation densities), within two GaN/AlN/Si heterostructures, that alter their efficiencies as positron moderators. The structure of the GaN [...] Read more.

The present article evaluates, in qualitative and quantitative manners, the characteristics (i.e., thickness of layers, crystal structures, growth orientation, elemental diffusion depths, edge, and screw dislocation densities), within two GaN/AlN/Si heterostructures, that alter their efficiencies as positron moderators. The structure of the GaN film, AlN buffer layer, substrate, and their growth relationships were determined through high-resolution transmission electron microscopy (HR-TEM). Data resulting from high-resolution X-ray diffraction (HR-XRD) was mathematically modeled to extract dislocation densities and correlation lengths in the GaN film. Positron depth profiling was evaluated through an experimental Doppler broadening spectroscopy (DBS) study, in order to quantify the effective positron diffusion length. The differences in values for both edge

(ρ_{d}^{e})

and screw

(ρ_{d}^{s})

dislocation densities, and correlation lengths (L^e, L^s) found in the 690 nm GaN film, were associated with the better effective positron diffusion length (L_eff) of

L_{eff}^{GaN 2}

= 43 ± 6 nm. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

14 pages, 7691 KiB

Open AccessArticle

Strong Biomimetic Immobilization of Pt-Particle Catalyst on ABS Substrate Using Polydopamine and Its Application for Contact-Lens Cleaning with H₂O₂

by Yuji Ohkubo, Tomonori Aoki, Daisuke Kaibara, Satoshi Seino, Osamu Mori, Rie Sasaki, Katsuyoshi Endo and Kazuya Yamamura

Nanomaterials 2020, 10(1), 114; https://doi.org/10.3390/nano10010114 - 7 Jan 2020

Cited by 6 | Viewed by 3571

Abstract

Polydopamine (PDA)—a known adhesive coating material—was used herein to strongly immobilize a Pt-particle catalyst on an acrylonitrile–butadiene–styrene copolymer (ABS) substrate. Previous studies have shown that the poor adhesion between Pt particles and ABS surfaces is a considerable problem, leading to low catalytic durability [...] Read more.

Polydopamine (PDA)—a known adhesive coating material—was used herein to strongly immobilize a Pt-particle catalyst on an acrylonitrile–butadiene–styrene copolymer (ABS) substrate. Previous studies have shown that the poor adhesion between Pt particles and ABS surfaces is a considerable problem, leading to low catalytic durability for H₂O₂ decomposition during contact-lens cleaning. First, the ABS substrate was coated with PDA, and the PDA film was evaluated by X-ray photoelectron spectroscopy. Second, Pt particles were immobilized on the PDA-coated ABS substrate (ABS-PDA) using the electron-beam irradiation reduction method. The Pt particles immobilized on ABS-PDA (Pt/ABS-PDA) were observed using a scanning electron microscope. The Pt-loading weight was measured by inductively coupled plasma atomic emission spectroscopy. Third, the catalytic activity of the Pt/ABS-PDA was evaluated as the residual H₂O₂ concentration after immersing it in a 35,000-ppm H₂O₂ solution (the target value was less than 100 ppm). The catalytic durability was evaluated as the residual H₂O₂ concentration after repeated use. The PDA coating drastically improved both the catalytic activity and durability because of the high Pt-loading weight and strong adhesion among Pt particles, PDA, and the ABS substrate. Plasma treatment prior to PDA coating further improved the catalytic durability. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Graphical abstract

8 pages, 2753 KiB

Open AccessArticle

Ferroelectric Diode Effect with Temperature Stability of Double Perovskite Bi₂NiMnO₆ Thin Films

by Wen-Min Zhong, Qiu-Xiang Liu, Xin-Gui Tang, Yan-Ping Jiang, Wen-Hua Li, Wan-Peng Li and Tie-Dong Cheng

Nanomaterials 2019, 9(12), 1783; https://doi.org/10.3390/nano9121783 - 15 Dec 2019

Cited by 4 | Viewed by 3095

Abstract

Double perovskite Bi₂NiMnO₆ (BNMO) thin films grown on p-Si (100) substrates with LaNiO₃ (LNO) buffer layers were fabricated using chemical solution deposition. The crystal structure, surface topography, surface chemical state, ferroelectric, and current-voltage characteristics of BNMO thin films were [...] Read more.

Double perovskite Bi₂NiMnO₆ (BNMO) thin films grown on p-Si (100) substrates with LaNiO₃ (LNO) buffer layers were fabricated using chemical solution deposition. The crystal structure, surface topography, surface chemical state, ferroelectric, and current-voltage characteristics of BNMO thin films were investigated. The results show that the nanocrystalline BNMO thin films on p-Si substrates without and with LNO buffer layer are monoclinic phase, which have antiferroelectric-like properties. The composition and chemical state of BNMO thin films were characterized by X-ray photoelectron spectroscopy. In the whole electrical property testing process, when the BNMO/p-Si heterojunction changed into a BNMO/LNO/p-Si heterojunction, the diode behavior of a single diode changing into two tail to tail diodes was observed. The conduction mechanism and temperature stability were also discussed. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

12 pages, 3955 KiB

Open AccessArticle

Electrochemical Deposition of Silicon-Carbon Films: A Study on the Nucleation and Growth Mechanism

by Nina K. Plugotarenko, Tatiana N. Myasoedova, Mikhail N. Grigoryev and Tatiana S. Mikhailova

Nanomaterials 2019, 9(12), 1754; https://doi.org/10.3390/nano9121754 - 10 Dec 2019

Cited by 11 | Viewed by 3039

Abstract

Silicon-carbon films have been deposited on silicon and Al₂O₃/Cr-Cu substrates, making use of the electrolysis of methanol/dimethylformamide-hexamethyldisilazane (HMDS) solutions. The electrodeposited films were characterized by Raman spectroscopy and scanning electron microscopy, respectively. Moreover, the nucleation and growth mechanism of [...] Read more.

Silicon-carbon films have been deposited on silicon and Al₂O₃/Cr-Cu substrates, making use of the electrolysis of methanol/dimethylformamide-hexamethyldisilazane (HMDS) solutions. The electrodeposited films were characterized by Raman spectroscopy and scanning electron microscopy, respectively. Moreover, the nucleation and growth mechanism of the films were studied from the experimental current transients. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

22 pages, 26008 KiB

Open AccessArticle

Influence of Sintering Strategy on the Characteristics of Sol-Gel Ba_1−xCe_xTi_1−x/4O₃ Ceramics

by Cătălina A. Stanciu, Ioana Pintilie, Adrian Surdu, Roxana Truşcă, Bogdan S. Vasile, Mihai Eftimie and Adelina C. Ianculescu

Nanomaterials 2019, 9(12), 1675; https://doi.org/10.3390/nano9121675 - 23 Nov 2019

Cited by 2 | Viewed by 3449

Abstract

Single-phase Ce³⁺-doped BaTiO₃ powders described by the nominal formula Ba_1−xCe_xTi_1−x/4O₃ with x = 0.005 and 0.05 were synthesized by the acetate variant of the sol-gel method. The structural parameters, particle [...] Read more.

Single-phase Ce³⁺-doped BaTiO₃ powders described by the nominal formula Ba_1−xCe_xTi_1−x/4O₃ with x = 0.005 and 0.05 were synthesized by the acetate variant of the sol-gel method. The structural parameters, particle size, and morphology are strongly dependent on the Ce³⁺ content. From these powders, dense ceramics were prepared by conventional sintering at 1300 °C for 2 h, as well as by spark plasma sintering at 1050 °C for 2 min. For the conventionally sintered ceramics, the XRD data and the dielectric and hysteresis measurements reveal that at room temperature, the specimen with low cerium content (x = 0.005) was in the ferroelectric state, while the samples with significantly higher Ce³⁺ concentration (x = 0.05) were found to be in the proximity of the ferroelectric–paraelectric phase transition. The sample with low solute content after spark plasma sintering exhibited insulating behavior, with significantly higher values of relative permittivity and dielectric losses over the entire investigated temperature range relative to the conventionally sintered sample of similar composition. The spark-plasma-sintered Ce-BaTiO₃ specimen with high solute content (x = 0.05) showed a fine-grained microstructure and an almost temperature-independent colossal dielectric constant which originated from very high interfacial polarization. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

24 pages, 5600 KiB

Open AccessArticle

Cultivar-Dependent Anticancer and Antibacterial Properties of Silver Nanoparticles Synthesized Using Leaves of Different Olea Europaea Trees

by Valeria De Matteis, Loris Rizzello, Chiara Ingrosso, Eva Liatsi-Douvitsa, Maria Luisa De Giorgi, Giovanni De Matteis and Rosaria Rinaldi

Nanomaterials 2019, 9(11), 1544; https://doi.org/10.3390/nano9111544 - 30 Oct 2019

Cited by 40 | Viewed by 6990

Abstract

The green synthesis of nanoparticles (NPs) is currently under worldwide investigation as an eco-friendly alternative to traditional routes (NPs): the absence of toxic solvents and catalysts make it suitable in the design of promising nanomaterials for nanomedicine applications. In this work, we used [...] Read more.

The green synthesis of nanoparticles (NPs) is currently under worldwide investigation as an eco-friendly alternative to traditional routes (NPs): the absence of toxic solvents and catalysts make it suitable in the design of promising nanomaterials for nanomedicine applications. In this work, we used the extracts collected from leaves of two cultivars (Leccino and Carolea) belonging to the species Olea Europaea, to synthesize silver NPs (AgNPs) in different pH conditions and low temperature. NPs underwent full morphological characterization with the aim to define a suitable protocol to obtain a monodispersed population of AgNPs. Afterwards, to validate the reproducibility of the mentioned synthetic procedure, we moved on to another Mediterranean plant, the Laurus Nobilis. Interestingly, the NPs obtained using the two olive cultivars produced NPs with different shape and size, strictly depending on the cultivar selected and pH. Furthermore, the potential ability to inhibit the growth of two woman cancer cells (breast adenocarcinoma cells, MCF-7 and human cervical epithelioid carcinoma, HeLa) were assessed for these AgNPs, as well as their capability to mitigate the bacteria concentration in samples of contaminated well water. Our results showed that toxicity was stronger when MCF-7 and Hela cells were exposed to AgNPs derived from Carolea obtained at pH 7 presenting irregular shape; on the other hand, greater antibacterial effect was revealed using AgNPs obtained at pH 8 (smaller and monodispersed) on well water, enriched with bacteria and coliforms. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

9 pages, 14458 KiB

Open AccessCommunication

Formation of Nanospikes on AISI 420 Martensitic Stainless Steel under Gallium Ion Bombardment

by Zoran Cenev, Malte Bartenwerfer, Waldemar Klauser, Ville Jokinen, Sergej Fatikow and Quan Zhou

Nanomaterials 2019, 9(10), 1492; https://doi.org/10.3390/nano9101492 - 19 Oct 2019

Viewed by 3346

Abstract

The focused ion beam (FIB) has proven to be an extremely powerful tool for the nanometer-scale machining and patterning of nanostructures. In this work, we experimentally study the behavior of AISI 420 martensitic stainless steel when bombarded by Ga⁺ ions in a [...] Read more.

The focused ion beam (FIB) has proven to be an extremely powerful tool for the nanometer-scale machining and patterning of nanostructures. In this work, we experimentally study the behavior of AISI 420 martensitic stainless steel when bombarded by Ga⁺ ions in a FIB system. The results show the formation of nanometer sized spiky structures. Utilizing the nanospiking effect, we fabricated a single-tip needle with a measured 15.15 nanometer curvature radius and a microneedle with a nanometer sized spiky surface. The nanospikes can be made straight or angled, depending on the incident angle between the sample and the beam. We also show that the nanospiking effect is present in ferritic AISI 430 stainless steel. The weak occurrence of the nanospiking effect in between nano-rough regions (nano-cliffs) was also witnessed for austenitic AISI 316 and martensitic AISI 431 stainless steel samples. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Graphical abstract

16 pages, 13977 KiB

Open AccessArticle

Enhanced Protective Coatings Based on Nanoparticle fullerene C60 for Oil & Gas Pipeline Corrosion Mitigation

by Xingyu Wang, Fujian Tang, Xiaoning Qi, Zhibin Lin, Dante Battocchi and Xi Chen

Nanomaterials 2019, 9(10), 1476; https://doi.org/10.3390/nano9101476 - 17 Oct 2019

Cited by 38 | Viewed by 4696

Abstract

Corrosion accounts for huge maintenance cost in the pipeline community. Promotion of protective coatings used for oil/gas pipeline corrosion control, in terms of high corrosion resistance as well as high damage tolerance, are still in high demand. This study was to explore the [...] Read more.

Corrosion accounts for huge maintenance cost in the pipeline community. Promotion of protective coatings used for oil/gas pipeline corrosion control, in terms of high corrosion resistance as well as high damage tolerance, are still in high demand. This study was to explore the inclusion of nanoparticle fullerene-C60 in protective coatings for oil/gas pipeline corrosion control and mitigation. Fullerene-C60/epoxy nanocomposite coatings were fabricated using a solvent-free dispersion method through high-speed disk (HSD) and ultrasonication. The morphology of fullerene-C60 particles was characterized by transmission electron microscopy (TEM), and dynamic light scattering (DLS). The data analysis indicated that the nanoparticles were effectively dispersed in the matrix. The performance of the nanocomposites was investigated through their mechanical and electrochemical properties, including corrosion potential, tensile strength, strain at failure, adhesion to substrate, and durability performance. Dogbone shaped samples were fabricated to study the tensile properties of the nanocomposites, and improvement of strength, ultimate strain, and Young’s modulus were observed in the C60/epoxy specimens. The results demonstrated that the C60/epoxy composite coatings also had improvements in adhesion strength, suggesting that they could provide high damage tolerance of coatings for engineering applications. Moreover, the electrochemical impedance spectroscopy (EIS) results generated from the accelerated durability test revealed that the developed fullerene-C60 loaded composite coatings exhibited significantly improved corrosion resistance. The nanocomposite with 0.5 and 1.0 wt.% of C60 particles behaved as an intact layer for corrosion protection, even after 200-h salt spray exposure, as compared to the control coating without nanofiller in which severe damage by over 50% reduction was observed. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

21 pages, 11748 KiB

Open AccessArticle

Bi_1−xEu_xFeO₃ Powders: Synthesis, Characterization, Magnetic and Photoluminescence Properties

by Vasile-Adrian Surdu, Roxana Doina Trușcă, Bogdan Ștefan Vasile, Ovidiu Cristian Oprea, Eugenia Tanasă, Lucian Diamandescu, Ecaterina Andronescu and Adelina Carmen Ianculescu

Nanomaterials 2019, 9(10), 1465; https://doi.org/10.3390/nano9101465 - 16 Oct 2019

Cited by 10 | Viewed by 3135

Abstract

Europium substituted bismuth ferrite powders were synthesized by the sol-gel technique. The precursor xerogel was characterized by thermal analysis. Bi_1−xEu_xFeO₃ (x = 0–0.20) powders obtained after thermal treatment of the xerogel at 600 °C for 30 min were [...] Read more.

Europium substituted bismuth ferrite powders were synthesized by the sol-gel technique. The precursor xerogel was characterized by thermal analysis. Bi_1−xEu_xFeO₃ (x = 0–0.20) powders obtained after thermal treatment of the xerogel at 600 °C for 30 min were investigated by X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, and Mössbauer spectroscopy. Magnetic behavior at room temperature was tested using vibrating sample magnetometry. The comparative results showed that europium has a beneficial effect on the stabilization of the perovskite structure and induced a weak ferromagnetism. The particle size decreases after the introduction of Eu³⁺ from 167 nm for x = 0 to 51 nm for x = 0.20. Photoluminescence spectroscopy showed the enhancement of the characteristic emission peaks intensity with the increase of Eu³⁺ concentration. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Graphical abstract

16 pages, 9816 KiB

Open AccessArticle

Novel Nanocomposites Based on Functionalized Magnetic Nanoparticles and Polyacrylamide: Preparation and Complex Characterization

by Eugenia Tanasa, Catalin Zaharia, Ionut-Cristian Radu, Vasile-Adrian Surdu, Bogdan Stefan Vasile, Celina-Maria Damian and Ecaterina Andronescu

Nanomaterials 2019, 9(10), 1384; https://doi.org/10.3390/nano9101384 - 27 Sep 2019

Cited by 25 | Viewed by 3912

Abstract

This paper reports the synthesis and complex characterization of nanocomposite hydrogels based on polyacrylamide and functionalized magnetite nanoparticles. Magnetic nanoparticles were functionalized with double bonds by 3-trimethoxysilyl propyl methacrylate. Nanocomposite hydrogels were prepared by radical polymerization of acrylamide monomer and double bond modified [...] Read more.

This paper reports the synthesis and complex characterization of nanocomposite hydrogels based on polyacrylamide and functionalized magnetite nanoparticles. Magnetic nanoparticles were functionalized with double bonds by 3-trimethoxysilyl propyl methacrylate. Nanocomposite hydrogels were prepared by radical polymerization of acrylamide monomer and double bond modified magnetite nanoparticles. XPS spectra for magnetite and modified magnetite were recorded to evaluate the covalent bonding of silane modifying agent. Swelling measurements in saline solution were performed to evaluate the behavior of these hydrogels having various compositions. Mechanical properties were evaluated by dynamic rheological analysis for elastic modulus and vibrating sample magnetometry was used to investigate the magnetic properties. Morphology, geometrical evaluation (size and shape) of nanostructural characteristics and the crystalline structure of the samples were investigated by SEM, HR-TEM and selected area electron diffraction (SAED). The nanocomposite hydrogels will be further tested for the soft tissue engineering field as repairing scaffolds, due to their mechanical and magnetization behavior that can stimulate tissue regeneration. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

23 pages, 17729 KiB

Open AccessArticle

Photoluminescent Hydroxylapatite: Eu³⁺ Doping Effect on Biological Behaviour

by Ecaterina Andronescu, Daniela Predoi, Ionela Andreea Neacsu, Andrei Viorel Paduraru, Adina Magdalena Musuc, Roxana Trusca, Ovidiu Oprea, Eugenia Tanasa, Otilia Ruxandra Vasile, Adrian Ionut Nicoara, Adrian Vasile Surdu, Florin Iordache, Alexandra Catalina Birca, Simona Liliana Iconaru and Bogdan Stefan Vasile

Nanomaterials 2019, 9(9), 1187; https://doi.org/10.3390/nano9091187 - 22 Aug 2019

Cited by 19 | Viewed by 3865

Abstract

Luminescent europium-doped hydroxylapatite (Eu_XHAp) nanomaterials were successfully obtained by co-precipitation method at low temperature. The morphological, structural and optical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), UV-Vis and [...] Read more.

Luminescent europium-doped hydroxylapatite (Eu_XHAp) nanomaterials were successfully obtained by co-precipitation method at low temperature. The morphological, structural and optical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FT-IR), UV-Vis and photoluminescence (PL) spectroscopy. The cytotoxicity and biocompatibility of Eu_XHAp were also evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)) assay, oxidative stress assessment and fluorescent microscopy. The results reveal that the Eu³⁺ has successfully doped the hexagonal lattice of hydroxylapatite. By enhancing the optical features, these Eu_XHAp materials demonstrated superior efficiency to become fluorescent labelling materials for bioimaging applications. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

7 pages, 1729 KiB

Open AccessCommunication

Stretchable and Low-Haze Ag-Nanowire-Network 2-D Films Embedded into a Cross-linked Polydimethylsiloxane Elastomer

by Ki-Wook Lee, Yong-Hoe Kim, Wen Xuan Du and Jin-Yeol Kim

Nanomaterials 2019, 9(4), 576; https://doi.org/10.3390/nano9040576 - 9 Apr 2019

Cited by 5 | Viewed by 4390

Abstract

We report the fabrication of stretchable transparent electrode films (STEF) using 15-nm-diameter Ag nanowires networks embedded into a cross-linked polydimethylsiloxane elastomer. 15-nm-diameter Ag NWs with a high aspect ratio (˃1000) were synthesized through pressure-induced polyol synthesis in the presence of AgCl particles with [...] Read more.

We report the fabrication of stretchable transparent electrode films (STEF) using 15-nm-diameter Ag nanowires networks embedded into a cross-linked polydimethylsiloxane elastomer. 15-nm-diameter Ag NWs with a high aspect ratio (˃1000) were synthesized through pressure-induced polyol synthesis in the presence of AgCl particles with KBr. These Ag NW network-based STEF exhibited considerably low haze values (<1.5%) with a transparency of 90% despite the low sheet resistance of 20 Ω/sq. The STEF exhibited an outstanding mechanical elasticity of up to 20% and no visible change occurred in the sheet resistance after 100 cycles at a stretching-release test of 20%. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

Review

Jump to: Research

14 pages, 3564 KiB

Open AccessReview

Fly Ash, from Recycling to Potential Raw Material for Mesoporous Silica Synthesis

by Marius Gheorghe Miricioiu and Violeta-Carolina Niculescu

Nanomaterials 2020, 10(3), 474; https://doi.org/10.3390/nano10030474 - 5 Mar 2020

Cited by 69 | Viewed by 7110

Abstract

In order to meet the increasing energy demand and to decrease the dependency on coal, environmentally friendly methods for fly ash utilization are required. In this respect, the priority is to identify the fly ash properties and to consider its potential as raw [...] Read more.

In order to meet the increasing energy demand and to decrease the dependency on coal, environmentally friendly methods for fly ash utilization are required. In this respect, the priority is to identify the fly ash properties and to consider its potential as raw material in the obtaining of high-value materials. The physico-chemical and structural characteristics of the fly ash coming from various worldwide power plants are briefly presented. The fly ash was sampled from power plants where the combustion of lignite and hard coal in pulverized-fuel boilers (PC) and circulating fluidized bed (CFB) boilers was applied. The fly ash has high silica content. Due to this, the fly ash can be considered a potential raw material for the synthesis of nanoporous materials, such as zeolites or mesoporous silica. The samples with the highest content of SiO₂ can be used to obtain mesoporous silica materials, such as MCM-41 or SBA-15. The resulting mesoporous silica can be used for removing/capture of CO₂ from emissions or for wastewater treatment. The synthesis of various porous materials using wastes would allow a high level of recycling for a sustainable society with low environmental impact. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Graphical abstract

18 pages, 1470 KiB

Open AccessReview

Ceramic Composite Materials Obtained by Electron-Beam Physical Vapor Deposition Used as Thermal Barriers in the Aerospace Industry

by Bogdan Stefan Vasile, Alexandra Catalina Birca, Vasile Adrian Surdu, Ionela Andreea Neacsu and Adrian Ionut Nicoară

Nanomaterials 2020, 10(2), 370; https://doi.org/10.3390/nano10020370 - 20 Feb 2020

Cited by 50 | Viewed by 6441

Abstract

This paper is focused on the basic properties of ceramic composite materials used as thermal barrier coatings in the aerospace industry like SiC, ZrC, ZrB₂ etc., and summarizes some principal properties for thermal barrier coatings. Although the aerospace industry is mainly based [...] Read more.

This paper is focused on the basic properties of ceramic composite materials used as thermal barrier coatings in the aerospace industry like SiC, ZrC, ZrB₂ etc., and summarizes some principal properties for thermal barrier coatings. Although the aerospace industry is mainly based on metallic materials, a more attractive approach is represented by ceramic materials that are often more resistant to corrosion, oxidation and wear having at the same time suitable thermal properties. It is known that the space environment presents extreme conditions that challenge aerospace scientists, but simultaneously, presents opportunities to produce materials that behave almost ideally in this environment. Used even today, metal-matrix composites (MMCs) have been developed since the beginning of the space era due to their high specific stiffness and low thermal expansion coefficient. These types of composites possess properties such as high-temperature resistance and high strength, and those potential benefits led to the use of MMCs for supreme space system requirements in the late 1980s. Electron beam physical vapor deposition (EB-PVD) is the technology that helps to obtain the composite materials that ultimately have optimal properties for the space environment, and ceramics that broadly meet the requirements for the space industry can be silicon carbide that has been developed as a standard material very quickly, possessing many advantages. One of the most promising ceramics for ultrahigh temperature applications could be zirconium carbide (ZrC) because of its remarkable properties and the competence to form unwilling oxide scales at high temperatures, but at the same time it is known that no material can have all the ideal properties. Another promising material in coating for components used for ultra-high temperature applications as thermal protection systems is zirconium diboride (ZrB₂), due to its high melting point, high thermal conductivities, and relatively low density. Some composite ceramic materials like carbon–carbon fiber reinforced SiC, SiC-SiC, ZrC-SiC, ZrB₂-SiC, etc., possessing low thermal conductivities have been used as thermal barrier coating (TBC) materials to increase turbine inlet temperatures since the 1960s. With increasing engine efficiency, they can reduce metal surface temperatures and prolong the lifetime of the hot sections of aero-engines and land-based turbines. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

31 pages, 3879 KiB

Open AccessReview

Recent Advances in Magnetite Nanoparticle Functionalization for Nanomedicine

by Roxana Cristina Popescu, Ecaterina Andronescu and Bogdan Stefan Vasile

Nanomaterials 2019, 9(12), 1791; https://doi.org/10.3390/nano9121791 - 16 Dec 2019

Cited by 90 | Viewed by 8521

Abstract

Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe₃O₄) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated [...] Read more.

Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe₃O₄) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated in clinical practice. This article makes a summary of the surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine. Full article

(This article belongs to the Special Issue Synthesis, Processing and Application of Micro and Nanostructured Materials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Synthesis, Processing and Application of Micro and Nanostructured Materials

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (17 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI