Coatings

10 pages, 3500 KiB

Open AccessArticle

Memory Properties of Zr-Doped ZrO₂ MOS-like Capacitor

by Catalin Palade, Adrian Slav, Ionel Stavarache, Valentin Adrian Maraloiu, Catalin Negrila and Magdalena Lidia Ciurea

Coatings 2022, 12(9), 1369; https://doi.org/10.3390/coatings12091369 - 19 Sep 2022

Cited by 6 | Viewed by 2177

Abstract

The high-k-based MOS-like capacitors are a promising approach for the domain of non-volatile memory devices, which currently is limited by SiO₂ technology and cannot face the rapid downsizing of the electronic device trend. In this paper, we prepare MOS-like trilayer memory structures [...] Read more.

The high-k-based MOS-like capacitors are a promising approach for the domain of non-volatile memory devices, which currently is limited by SiO₂ technology and cannot face the rapid downsizing of the electronic device trend. In this paper, we prepare MOS-like trilayer memory structures based on high-k ZrO₂ by magnetron sputtering, with a 5% and a 10% concentrations of Zr in the Zr–ZrO₂ floating gate layer. For crystallization of the memory structure, rapid thermal annealing at different temperatures between 500 °C and 700 °C was performed. Additionally, Al electrodes were deposited in a top-down configuration. High-resolution transmission electron microscopy reveals that ZrO₂ has a polycrystalline–columnar crystallization and a tetragonal crystalline structure, which was confirmed by X-ray diffraction measurements. It is shown that the tetragonal phase is stabilized during the crystallization by the fast diffusion of oxygen atoms. The capacitance–voltage characteristics show that the widest memory window (ΔV = 2.23 V) was obtained for samples with 10% Zr annealed at 700 °C for 4 min. The charge retention characteristics show a capacitance decrease of 36% after 10 years. Full article

(This article belongs to the Special Issue Advances of Nanoparticles and Thin Films)

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9 pages, 2391 KiB

Open AccessArticle

Approach to the Modification of Carbon-Based Composite Conductive Ink for Silicone Keypads

by Yujie Zheng, Xiutao Yang, Qianyan Zhao, Yaning Hao, Yucheng Yang, Juehan Sun, Junqiang Tang, Hongguo Zhang and Guanggen Zeng

Coatings 2022, 12(9), 1368; https://doi.org/10.3390/coatings12091368 - 19 Sep 2022

Viewed by 1815

Abstract

Carbon-based composite conductive ink (3CI) has some challenges to its properties. Here, combined with the application of 3CI on silicon keypads, a series of studies on the electrical, mechanical and thermal performance of 3CI has been conducted by adding specific concentrations of silver [...] Read more.

Carbon-based composite conductive ink (3CI) has some challenges to its properties. Here, combined with the application of 3CI on silicon keypads, a series of studies on the electrical, mechanical and thermal performance of 3CI has been conducted by adding specific concentrations of silver powder, silica powder and SiO₂@Ag core-shell particles. The properties of the modified 3CI were characterized by using the four-point probe tester, scanning electron microscope, Rockwell hardness tester, cross-cut tester and laser thermal conductivity analyzer. The experimental results revealed that by adding silver powder with a particle size of 20 microns equivalent to 12% by weight of the 3CI, ink resistance decreased by 76%, from 8.44 kΩ/□ to 2.03 kΩ/□. Meanwhile, adding silica can increase the ink’s tensile strength and thermal diffusivity while improving the adhesion of the 3CI on the silicone rubber. It was worth noting that when the particle size of the SiO₂@Ag core-shell particle was smaller than that of the added silver powder, the resistance of the 3CI was further reduced. Finally, a modified 3CI with the adhesion of 4B, a conductivity of about1 kΩ/□, a hardness of 232 HV0.5, and a thermal diffusivity of 0.217 cm²s⁻¹ was achieved experimentally, which provided an experimental basis for the modified 3CI suitable for silicone keypads. Full article

(This article belongs to the Section Surface Characterization, Deposition and Modification)

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17 pages, 7254 KiB

Open AccessArticle

Increased Electromagnetic Wave Absorption through Controlled Sonication Processing on BaFe_11.2Mg_0.4Al_0.4O₁₉ Nanoparticles

by Erlina Yustanti, Alfian Noviyanto, Laila Chusnul Chotimah, Muhamad Abdur Rais Saputra, Maulana Randa and Maykel Manawan

Coatings 2022, 12(9), 1367; https://doi.org/10.3390/coatings12091367 - 19 Sep 2022

Cited by 2 | Viewed by 2091

Abstract

Electromagnetic waves show rapid development in electronics, telecommunications, and the military. One of the efforts to overcome the effects of electromagnetic interference is by developing microwave-absorbing materials. Barium hexaferrite is the best candidate for development as an absorber material. Microwave absorption in barium [...] Read more.

Electromagnetic waves show rapid development in electronics, telecommunications, and the military. One of the efforts to overcome the effects of electromagnetic interference is by developing microwave-absorbing materials. Barium hexaferrite is the best candidate for development as an absorber material. Microwave absorption in barium hexaferrite can be increased through Mg-Al doping and reducing the particle size. This study aimed to analyze sonication parameters to reduce the particle size by combining destruction methods using mechanical alloying followed by high-power ultrasonic irradiation. Barium hexaferrite was synthesized through mechanical alloying by mixing stoichiometric BaCO₃, Fe₂O₃, Al₂O₃, and MgO (Sigma-Aldrich p.a 99%) (Mg-Al 0.4%wt). The samples continued the sintering process at 1200 °C for 2 h to grow crystal embryos. The optimal parameters for ultrasonic destruction were using a transducer:reactor diameter ratio of 1:10, a particle density of 5 g/250 mL, and adding a non-ionic surfactant of 0.01% at an amplitude of 55% and a sonication time of 8 h. These methods resulted in the saturation magnetization of 18.50 emu/g and a coercivity of 0.08 Tesla. The reduction in the particle size of BHF doped with Mg-Al was successfully up to 21 nm, resulting in a reflection loss of up to −40.8697 dB at 11.896 GHz (x-band, 8–12 GHz). The BHF nanoparticles doped with Mg-Al effectively absorbed up to 99.99% electromagnetic waves. Full article

(This article belongs to the Section Surface Engineering for Energy Harvesting, Conversion, and Storage)

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15 pages, 2918 KiB

Open AccessArticle

Magnetic Properties of Nanosized Fe and FeCo Systems on Trenched Mo Templates

by Anda Elena Stanciu, Gabriel Schinteie, Andrei Cristian Kuncser, Claudiu Locovei, Lucian Trupina, Nicusor Iacob, Aurel Leca, Bogdana Borca and Victor Kuncser

Coatings 2022, 12(9), 1366; https://doi.org/10.3390/coatings12091366 - 19 Sep 2022

Cited by 6 | Viewed by 2206

Abstract

The manipulation of magnetic anisotropy represents the fundamental prerequisite for the application of magnetic materials. Here we present the vectorial magnetic properties of nanostructured systems and thin films of Fe and FeCo prepared on linearly trenched Mo templates with thermally controlled periodicity. The [...] Read more.

The manipulation of magnetic anisotropy represents the fundamental prerequisite for the application of magnetic materials. Here we present the vectorial magnetic properties of nanostructured systems and thin films of Fe and FeCo prepared on linearly trenched Mo templates with thermally controlled periodicity. The magnetic properties of the nanosystems are engineered by tuning the shape, size, thickness, and composition parameters of the thin films. Thus, we control coercivity, magnetization, orientation of the easy axis of magnetization, and the long-range magnetic order of the system in the function of the temperature. We distinguish magnetic components that emerge from the complex morpho-structural features of the undulating Fe or FeCo nanostructured films on trenched Mo templates: (i) assembly of magnetic nanowires and (ii) assembly of magnetic islands/clusters. Uniaxial anisotropy at room temperature was proven, characterized, and explained in the case of all systems. Our work contributes to the understanding of magnetic properties necessary for possible further applications of linear systems and undulated thin films. Full article

(This article belongs to the Special Issue Advances of Nanoparticles and Thin Films)

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3 pages, 179 KiB

Open AccessEditorial

Special Issue: Advanced Semiconductor Materials and Films: Properties and Applications

by Xia Shen, Qihang Lv and Pengfei Guo

Coatings 2022, 12(9), 1365; https://doi.org/10.3390/coatings12091365 - 19 Sep 2022

Cited by 1 | Viewed by 1508

Abstract

Advanced semiconductor materials and films are building blocks for multifunctional devices and circuits, integrated optoelectronic chips, and high-throughput communications, which have proved basic material platforms for nanoscience and technologies [...] Full article

(This article belongs to the Special Issue Advanced Semiconductor Materials and Films: Properties and Applications)

13 pages, 20607 KiB

Open AccessArticle

Evaluating the Topological Surface Properties of Cu/Cr Thin Films Using 3D Atomic Force Microscopy Topographical Maps

by Mohammad Sadeghi, Amir Zelati, Sahar Rezaee, Carlos Luna, Robert Saraiva Matos, Marcelo Amanajás Pires, Nilson S. Ferreira, Henrique Duarte da Fonseca Filho, Azin Ahmadpourian and Ştefan Ţălu

Coatings 2022, 12(9), 1364; https://doi.org/10.3390/coatings12091364 - 19 Sep 2022

Cited by 8 | Viewed by 2195

Abstract

In the present work, Cu/Cr thin films were deposited on substrates of a different nature (Si, Glass, Bk7, and ITO) through a thermal evaporation deposition method. Non-contact atomic force microscopy (AFM) was used to obtain 3D AFM topographical maps of the surface for [...] Read more.

In the present work, Cu/Cr thin films were deposited on substrates of a different nature (Si, Glass, Bk7, and ITO) through a thermal evaporation deposition method. Non-contact atomic force microscopy (AFM) was used to obtain 3D AFM topographical maps of the surface for the Cu/Cr samples. Various analyses were carried out to obtain crucial parameters for the characterization of the surface features. In particular, Minkowski functionals (including the normalized Minkowski volume, the Minkowski boundary, and the Minkowski connectivity) and studies of the spatial microtexture by fractal and multifractal analyses were carried out. Different roughness parameters (including arithmetical mean height, root mean square height, skewness, kurtosis, fractal dimension, Hurst coefficient, topographical entropy, and fractal lacunarity) were quantified in these analyses for the comparison of the surface morphology of the different samples. All the samples displayed non-Gaussian randomly rough surfaces, indicating the presence of multifractal features. Full article

(This article belongs to the Section Corrosion, Wear and Erosion)

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16 pages, 8021 KiB

Open AccessArticle

Investigations on Microstructures and Properties of (Fe, Cr, W)₇C₃ Carbides by First Principles and Experiments

by Chao Chen, Junfa Wang, Yiyuan Ge and Lili Ma

Coatings 2022, 12(9), 1363; https://doi.org/10.3390/coatings12091363 - 18 Sep 2022

Cited by 1 | Viewed by 1645

Abstract

Tungsten doping is critical for the wear resistance and application of High-Chromium Cast Iron (HCCI). A series of investigations of (Fe, Cr, W)₇C₃ carbides were performed by first principles calculations and experimental analysis. The calculated results showed that with the [...] Read more.

Tungsten doping is critical for the wear resistance and application of High-Chromium Cast Iron (HCCI). A series of investigations of (Fe, Cr, W)₇C₃ carbides were performed by first principles calculations and experimental analysis. The calculated results showed that with the increase in tungsten content in M₇C₃, the equilibrium cell volumes and the density gradually increased, and the formation energy of M₇C₃ carbides gradually decreased. The TEM results showed that the (Fe, Cr, W)₇C₃ carbides were (Fe_3.27Cr_2.99W_0.74) C₃ with a hexagonal structure after adding 2.13 wt % tungsten into laser cladding coatings of High-Chromium Cast Iron with a composition of Fe-26.8 wt % Cr-3.62 wt % C. These results from calculations and in situ nanoindentation show that tungsten doping could improve the ductility and indentation modulus of (Fe, Cr)₇C₃ carbides, and the composition of (Fe, Cr, W)₇C₃ was expected to be a high hardness and softness material. The wear test results showed that the wear resistance of tungsten-bearing HCCI was better than ordinary HCCI. Full article

(This article belongs to the Special Issue Laser Cladding Coatings: Microstructure, Properties, and Applications)

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12 pages, 3137 KiB

Open AccessArticle

Tribological Characteristics of Al359/Si3N4/Eggshell Surface Composite Produced by Friction Stir Processing

by Ashish Kumar Srivastava, Suryank Dwivedi, Ambuj Saxena, Deepak Kumar, Amit Rai Dixit, Gyanendra Kumar Singh, Javed Khan Bhutto and Rajesh Verma

Coatings 2022, 12(9), 1362; https://doi.org/10.3390/coatings12091362 - 18 Sep 2022

Cited by 11 | Viewed by 2286

Abstract

In the present study, the surface composite Al359/Si3N4/Eggshell is prepared by friction stir processing (FSP). The effect of reinforced particle volume fraction on the microstructural and tribological properties of the Al359/Si3N4/Eggshell surface composites was investigated and compared with the friction stir processed (FSPed) [...] Read more.

In the present study, the surface composite Al359/Si3N4/Eggshell is prepared by friction stir processing (FSP). The effect of reinforced particle volume fraction on the microstructural and tribological properties of the Al359/Si3N4/Eggshell surface composites was investigated and compared with the friction stir processed (FSPed) Al359 alloy. The microstructural properties were further investigated by light microscopy, FESEM, and EDS mapping. The tribological properties of the developed composite and FSPed Al359 were investigated using a reciprocating ball-on-plate universal tribometer. The microstructural results showed that defect-free composite surfaces are produced due to improved physical properties, severe plastic deformation, and better grain refinement. Moreover, the mean value of the friction coefficient (µ) for the developed composite and FSPed alloy are 0.36 µ and 0.47 µ, respectively. The obtained results indicated that Si₃N₄/Eggshell is a promising reinforced particle for improving microstructural and tribological performance in journal bearing, rotors, and machinery applications. Full article

(This article belongs to the Special Issue Research Progress of Metals and Alloys by Thermal Layering and Deposition)

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20 pages, 8589 KiB

Open AccessArticle

Effect of the Location of Broken Wires on Prestressed Concrete Cylinder Pipes under Working Pressure

by Zhu Zhang, Tongchun Li, Lanhao Zhao and Huijun Qi

Coatings 2022, 12(9), 1361; https://doi.org/10.3390/coatings12091361 - 18 Sep 2022

Cited by 1 | Viewed by 2193

Abstract

The precise analysis of the overall mechanical performance of prestressed concrete cylinder pipes (PCCPs) with broken wires is a complicated problem. In this article, powerful finite element numerical means are applied to solve this problem. Firstly, the advantages and shortcomings of the current [...] Read more.

The precise analysis of the overall mechanical performance of prestressed concrete cylinder pipes (PCCPs) with broken wires is a complicated problem. In this article, powerful finite element numerical means are applied to solve this problem. Firstly, the advantages and shortcomings of the current prestress simulation methods in the finite element analysis (FEA) literature are discussed, and the initial stress method based on a novel single-spring joint element method to model the pre-stress of wires is proposed. Then, different distributions of broken zones, including random broken distributions, are developed for two typical PCCP pipes with different wire-wrapped layers. The established nonlinear FEA model considers actual service processes such as manufacturing, installation and operation to investigate the mechanical behavior of two typical PCCP pipes with different breakage distribution regions and breakage ratios, and in particular, the overall mechanical behavior of a pipe with random breakage is determined first. To verify the accuracy of the proposed pre-stress simulation method and the established nonlinear finite element model, the overall mechanical response of a pipe before wires broke is compared with the results obtained via the specifications. The computed results under the corresponding breakage assumptions are consistent with the conclusions in the existing literature, providing important guidance for pipeline management and operation. Full article

(This article belongs to the Special Issue Current Research in Cement and Building Materials)

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16 pages, 5300 KiB

Open AccessArticle

Effects of Cu-Ni-Ti Interlayer on Microstructure and Wear Resistance around Gas Tungsten Arc Cladding Copper Matrix Composite Coatings on Steel

by Jihong Li, Longyu Lei, Mingke Du, Zhiqiang Zhang and Min Zhang

Coatings 2022, 12(9), 1360; https://doi.org/10.3390/coatings12091360 - 18 Sep 2022

Viewed by 1756

Abstract

Due to the huge difference in thermophysical properties, it is difficult to obtain a defect-free bonding interface between copper and steel. A Cu-Ni-Ti interlayer was added between a TiC-reinforced copper matrix composite coating and Q235 steel in this study to improve its interfacial [...] Read more.

Due to the huge difference in thermophysical properties, it is difficult to obtain a defect-free bonding interface between copper and steel. A Cu-Ni-Ti interlayer was added between a TiC-reinforced copper matrix composite coating and Q235 steel in this study to improve its interfacial bond. The influence of the interlayer on its microstructure and properties was studied by characterizing microstructure, phase composition, and wear resistance of the composite coatings. Both coatings were found to consist of α-Cu matrix, in situ-generated TiC, and Fe-rich phases. With the addition of the Cu-Ni-Ti interlayer, the high-hardness unmixed zone at the interface was successfully eliminated due to the sufficient mixing of the molten pool. Even more importantly, liquid metal embrittlement cracks were also restrained, resulting from the Fe-rich solid solution band that reduced the contact probability around liquid copper atoms with the steel grain boundaries formed. In addition, the results showed that the microhardness of composite coatings was improved and the wear loss reduced by 4.2% after adding that interlayer, which was related to the combined action of solid solution strengthening, second-phase strengthening and grain-refinement strengthening mechanisms. Full article

(This article belongs to the Section Surface Characterization, Deposition and Modification)

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11 pages, 3444 KiB

Open AccessArticle

Design of a Tester for In Situ Simultaneous Measurement of the Wear of Two Different Film Materials

by Dongai Wang and Meihua Liu

Coatings 2022, 12(9), 1359; https://doi.org/10.3390/coatings12091359 - 18 Sep 2022

Cited by 1 | Viewed by 1664

Abstract

The amount of wear is one of the most important indicators for assessing the wear resistance of materials, controlling product quality and studying the mechanisms of frictional wear of materials. Due to the limitations of the friction and wear test equipment currently in [...] Read more.

The amount of wear is one of the most important indicators for assessing the wear resistance of materials, controlling product quality and studying the mechanisms of frictional wear of materials. Due to the limitations of the friction and wear test equipment currently in use for measuring material wear resistance, it is not possible to accurately compare the wear resistance of two different materials. To solve this problem, this paper proposes a new type of friction and wear tester. With the newly designed friction and wear tester, it is possible to perform friction tests and in situ measurements of wear on two different materials at the same time. This will significantly reduce the measurement errors of currently used friction and wear test equipment that requires adjustment in order to measure the amount of wear; it is particularly suitable for accurately comparing the wear resistance of two different materials. The newly designed friction and wear tester can be used extensively to test and analyse the wear resistance of solid materials such as metals, ceramic materials and engineering plastics. Full article

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11 pages, 2649 KiB

Open AccessArticle

Influence of a Precursor Film with a Copper Gradient on the Properties of a Copper Indium Gallium Selenide Solar Cell

by Yuandong Liu, Yangzheng Li, Junlei Tang, Wenfeng Zhang and Bing Lin

Coatings 2022, 12(9), 1358; https://doi.org/10.3390/coatings12091358 - 17 Sep 2022

Cited by 2 | Viewed by 1704

Abstract

A precursor film with a Cu gradient was prepared in order to improve the quality of the absorber film produced by sputtering CIGS targets when using glass substrates. Two ceramic quaternary targets with different copper content were used for alternatively sputtering to get [...] Read more.

A precursor film with a Cu gradient was prepared in order to improve the quality of the absorber film produced by sputtering CIGS targets when using glass substrates. Two ceramic quaternary targets with different copper content were used for alternatively sputtering to get a bi-layer precursor film with a Cu gradient; meanwhile, the crystallization property and cell performance were studied. This was done in order to study the activities of the Cu element in the precursor layer before and after selenization. The film states of the temperature-rise period and high temperature selenization period were investigated. The appropriate structure of the precursor film was the Cu-rich layer underneath the Cu-poor layer. The Cu–Se phase, which is important for the crystalline property, can be produced in the Cu-rich layer under the heating period. The Cu-poor layer on the top reacts with the Cu-Se compound in the annealing process at a high temperature, and the big grain size of the absorber layer can be obtained due to Cu diffusion promoted by the gradient in the precursor film, as well as better conversion efficiency. This result shows that constructing the precursor film with a Cu gradient by sputtering different quaternary CIGS targets is a very promising fabrication method to obtain high-performance solar-cell devices with a good crystallization property under an annealing temperature of 550 °C and is suitable for further industrialized application. Full article

(This article belongs to the Section Plasma Coatings, Surfaces & Interfaces)

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5 pages, 181 KiB

Open AccessEditorial

Advanced Materials for High Biocompatible Hydrogel System

by Guanlin Li and Zheng Zhao

Coatings 2022, 12(9), 1357; https://doi.org/10.3390/coatings12091357 - 17 Sep 2022

Cited by 5 | Viewed by 1934

Abstract

Hydrogels are gels with water as the dispersion medium and three-dimensional porous polymer networks cross-linked chemically or physically [...] Full article

(This article belongs to the Special Issue Advanced Materials for Highly Biocompatible Hydrogel Systems)

13 pages, 5553 KiB

Open AccessArticle

Experimental Study on Shear Performance of Post-Tensioning Prestressed Concrete Beams with Locally Corroded Steel Strands

by Rihua Yang, Yiming Yang, Peng Liu and Xinzhong Wang

Coatings 2022, 12(9), 1356; https://doi.org/10.3390/coatings12091356 - 17 Sep 2022

Cited by 1 | Viewed by 1855

Abstract

To study the effect of the local corrosion of prestressed steel strands on the shear failure mode and shear bearing capacity of concrete beams, unilateral steel strands in four post-tensioning prestressed concrete (PC) beams are corroded, and the shear test of four PC [...] Read more.

To study the effect of the local corrosion of prestressed steel strands on the shear failure mode and shear bearing capacity of concrete beams, unilateral steel strands in four post-tensioning prestressed concrete (PC) beams are corroded, and the shear test of four PC beams are performed. Moreover, a simplified calculation method for the shear bearing capacity of concrete beams with diagonal steel bars is proposed considering the effect of cross-sectional reduction of steel bars, the degradation of mechanical properties, and the cross-sectional damage of concrete. Results shows that the crack propagation mode and failure mode are unrelated to the corrosion of prestressed steel bars when the shear span ratio of beam is the same. The shear capacity of the beam decreases with the increase of corrosion rate, but the decreasing rate is lower than the increasing rate of the corrosion rate. The growth rate of stirrup stress is much greater than that of load after concrete tension and compression loss cracking, and the yield of stirrup can be used as a sign of the ultimate bearing capacity of the beam. In addition, by comparing the experimental and numerical simulation results, the proposed simplified calculation method for the shear bearing capacity of concrete beams is of high accuracy. Full article

(This article belongs to the Special Issue Current Research in Cement and Building Materials)

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15 pages, 9146 KiB

Open AccessArticle

Fabrication and Characterization of W-Substituted ZnFe₂O₄ for Gas Sensing Applications

by Abdullah M. Al-Enizi, Omar H. Abd-Elkader, Shoyebmohamad F. Shaikh, Mohd Ubaidullah, Mohamed O. Abdelkader and Nasser Y. Mostafa

Coatings 2022, 12(9), 1355; https://doi.org/10.3390/coatings12091355 - 17 Sep 2022

Cited by 8 | Viewed by 2891

Abstract

A sol–gel technique was successfully employed in creating pure and W-substituted zinc ferrite, with nominal compositions of ZnFe_2−2xW_xO₄ (0.0 ≤ x ≤ 0.15). For the purposes of investigating the physical and chemical properties of the generated powders, several [...] Read more.

A sol–gel technique was successfully employed in creating pure and W-substituted zinc ferrite, with nominal compositions of ZnFe_2−2xW_xO₄ (0.0 ≤ x ≤ 0.15). For the purposes of investigating the physical and chemical properties of the generated powders, several analytical techniques were used. In TEM images of all the compositions, mixed-shaped particles (cubic, spherical, and hexagonal) were observed. The crystallite size decreases from 82 nm (x = 0.0) to 32 nm (x = 0.15) with an increase in the W doping contents in the ZnFe₂O₄ lattice. The microstrain increases with increasing W doping content. Furthermore, the surface area of pure ZnFe₂O₄, 0.05 W-ZnFe₂O₄, 0.10 W-ZnFe₂O₄, and 0.15 W-ZnFe₂O₄ NPs were calculated as being 121.5, 129.1, 134.4 and 143.2 m² g⁻¹, respectively, with a mesoporous pore structure for all ferrite samples. The calculated BJH pore size distribution was within the range of 160 to 205 Å. All W-doped ZnFe₂O₄ samples show H-M loops with paramagnetic characteristics. The magnetization (M) directly increases by increasing the applied field (H) without achieving saturation up to 20 kA/m. For comparison, the magnetization at 20 kA/m gradually decreases with increasing W doping content. Among all the synthesized samples, the 0.15 W-ZnFe₂O₄ NPs demonstrated the highest sensitivity towards acetone gas at 350 °C. Full article

(This article belongs to the Section Functional Polymer Coatings and Films)

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15 pages, 6085 KiB

Open AccessArticle

Study of the Machining Process of GFRP Materials by Milling Technology with Coated Tools

by Artur Knap, Štěpánka Dvořáčková and Tomáš Knápek

Coatings 2022, 12(9), 1354; https://doi.org/10.3390/coatings12091354 - 16 Sep 2022

Cited by 6 | Viewed by 1866

Abstract

Glass fibers are often used as reinforcing fibers in reinforced polymers. Composites reinforced with glass fibers (GFRP) stand out with excellent mechanical and physical properties applicable to industrial practice. Machining these composites requires the correct choice of tools and cutting conditions so that [...] Read more.

Glass fibers are often used as reinforcing fibers in reinforced polymers. Composites reinforced with glass fibers (GFRP) stand out with excellent mechanical and physical properties applicable to industrial practice. Machining these composites requires the correct choice of tools and cutting conditions so that the machined surface shows good properties, there is no fiber delamination, thermal stress on the workpiece and the tool, or excessive tool wear. The study was devoted to circumferential milling of fabric-bonded GFRP plates, in which attention was paid to the influence of the abrasive effect of glass fibers on wear and tool life. Attention was also paid to surface roughness after machining, material delamination, and forces during machining were measured. Three end mills of the same diameter with different coatings, number of teeth, and geometry were selected for the study. This choice of tools was intended to achieve various accompanying and subsequent phenomena that were investigated. Milling was performed on a CNC milling center under preselected cutting conditions. The paper summarizes information on fiber delamination and machined laminate damage after milling, tool wear, and surface roughness parameters as a function of tool wear. This paper provides an opportunity for researchers to increase their knowledge of specific aspects of milling GFRP composites, whether with a tool specifically designed for this or not. Full article

(This article belongs to the Special Issue New Cutting Techniques for Improved Machining)

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13 pages, 5221 KiB

Open AccessArticle

Exploration of Key Process Parameters and Properties of 40Cr Steel in Ultrasonic Surface Rolling Process

by Xiaobin Wu, Jun Cheng, Zhilong Xu, Leyang Dai, Qingshan Jiang, Bosheng Su, Li Zhu and Zhenye Zhao

Coatings 2022, 12(9), 1353; https://doi.org/10.3390/coatings12091353 - 16 Sep 2022

Cited by 8 | Viewed by 2337

Abstract

Ultrasonic surface rolling (USRP) is an effective process to improve a workpiece’s fatigue property, in which ultrasonic vibration and static force are applied on the workpiece’s surface. In order to clarify the ultrasonic rolling strengthening mechanism of critical components and optimize the USRP [...] Read more.

Ultrasonic surface rolling (USRP) is an effective process to improve a workpiece’s fatigue property, in which ultrasonic vibration and static force are applied on the workpiece’s surface. In order to clarify the ultrasonic rolling strengthening mechanism of critical components and optimize the USRP parameters, a theoretical model of ultrasonic rolling was established. Based on the stress-strain curve of 40Cr steel, the USRP parameters were formulated. The compressive residual stress field of single point impact was analyzed by finite element simulation, and the simulation results were validated by conducting an experimental research. In addition, the changes in the surface properties of specimens under different USRP parameters were studied experimentally. The results show that with the increase in depth, the compressive residual stress on the external surface increases firstly and then decreases, and the maximum compressive residual stress is −338 MPa. As the amplitude is 12 μm and the frequency is 20 kHz, the static force of 600 N is optimal for the ultrasonic rolling of 40Cr steel. This study could provide a guide for the key parameters’ selection in USRP. Full article

(This article belongs to the Special Issue Recent Advancement in Surface Modification of Metallic and Composite Materials)

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13 pages, 9030 KiB

Open AccessArticle

Analysis of Influence of Insulating Resin Paint Film on Enameled Wire Properties Based on Molecular Simulation

by Zhongli Zhang, Zhensheng Wu, Huiyuan Zhang, Yibin Cheng and Hao Ren

Coatings 2022, 12(9), 1352; https://doi.org/10.3390/coatings12091352 - 16 Sep 2022

Cited by 2 | Viewed by 2094

Abstract

As one of the varieties of magnet wire, the enameled wire has excellent mechanical properties, heat resistance, ageing resistance, dimensional stability and chemical stability. This is one of the keys affecting the development of the electrical industry, especially the development of new motors. [...] Read more.

As one of the varieties of magnet wire, the enameled wire has excellent mechanical properties, heat resistance, ageing resistance, dimensional stability and chemical stability. This is one of the keys affecting the development of the electrical industry, especially the development of new motors. Different varieties of enameled wire insulating varnishes have advantages and disadvantages, in addition to their general properties. In order to improve the service life and reliability of the electrical coil of the motor, it is necessary to select the appropriate enameled wire reasonably according to different purposes. Molecular simulation technology can play a guiding role in the relationship between the molecular structure and properties of resins, help to understand the microscopic mechanism, shorten the experimental period, improve efficiency and save costs. In this paper, based on density functional theory (DFT) and molecular dynamics (MD), the microscopic properties of four insulating resins, polyamide–imide (PAI), polyester (PET), polyesterimide (PEI), and polyimide (PI), were studied. We also studied the influence mechanism of the insulating resin microstructure on the macroscopic properties of enameled wires, including adhesion, insulating properties and flexibility. The calculation results show that the polyester insulating enameled wire paint has good insulation performance and flexibility, the polyamide–imide paint has the best adhesion, and the polyimide insulating paint has very reliable insulation performance and flexibility. The performance research in this paper lays a foundation for the preparation of insulating resin coatings with better comprehensive properties. The performance research in this paper lays a foundation for preparing insulating resin paint with excellent comprehensive performance. Full article

(This article belongs to the Section Functional Polymer Coatings and Films)

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10 pages, 1384 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Gold Nanoparticles Decorated Titanium Oxide Nanotubes with Enhanced Antibacterial Activity Driven by Photocatalytic Memory Effect

by Hongqin Zhu, Ji Tan, Jiajun Qiu, Donghui Wang, Zhe Zhao, Zihan Lu, Gaoshan Huang, Xuanyong Liu and Yongfeng Mei

Coatings 2022, 12(9), 1351; https://doi.org/10.3390/coatings12091351 - 16 Sep 2022

Cited by 11 | Viewed by 2415

Abstract

Titanium and its alloys have been widely used for orthopedic and dental implants. However, implant failures often occur due to the implant-related bacterial infections. Herein, titanium oxide nanotubes (TNTs) with an average diameter of 75 nm were formed by anodizing on the surface [...] Read more.

Titanium and its alloys have been widely used for orthopedic and dental implants. However, implant failures often occur due to the implant-related bacterial infections. Herein, titanium oxide nanotubes (TNTs) with an average diameter of 75 nm were formed by anodizing on the surface of titanium, and subsequently gold (Au) nanoparticles were deposited on TNTs by magnetron sputtering (Au@TNTs). The antibacterial study shows that TNTs surface decorated with Au nanoparticles exhibits the preferable effect in restricting the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) even under dark conditions, and the antibacterial rates reached 84% and 75%, respectively. In addition, the constructed film showed no cytotoxicity. Such a selective bactericidal effect of Au@TNTs samples might be attributed to the photocatalytic memory effect, which provides a new insight in the designing of antibacterial surfaces for biomedical application. Full article

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24 pages, 10511 KiB

Open AccessArticle

Calcium Sulfate in Implantology (Biphasic Calcium Sul-Fate/Hydroxyapatite, BCS/HA, Bond Apatite^®): Review of the Literature and Case Reports

by Aina Torrejon-Moya, Alina Apalimova, Beatriz González-Navarro, Ramiro Zaera-Le Gal, Antonio Marí-Roig and José López-López

Coatings 2022, 12(9), 1350; https://doi.org/10.3390/coatings12091350 - 16 Sep 2022

Cited by 2 | Viewed by 3360

Abstract

Calcium sulfate is used as a synthetic graft material in orthopedics, plastic surgery, oncological surgery, and dentistry, and it has been used in a variety of clinical applications, such as the repair of periodontal defects, the treatment of osteomyelitis, maxillary sinus augmentation, and [...] Read more.

Calcium sulfate is used as a synthetic graft material in orthopedics, plastic surgery, oncological surgery, and dentistry, and it has been used in a variety of clinical applications, such as the repair of periodontal defects, the treatment of osteomyelitis, maxillary sinus augmentation, and as a complement to the placement of dental implants. To carry out this systematic review, a bibliographic search was carried out. The PICO (Patient, Intervention, Comparison, Outcome) question was: Does the use of calcium sulfate as a material in guided bone regeneration in dentistry have better results compared to other bone graft materials? Finally, a case series is presented using the calcium sulfate for different procedures. Currently, the available literature on the use of calcium sulfate as a graft material in implant surgery is scarce, and what is available provides low-quality evidence. That is why more research studies on the subject are necessary to allow more comparisons and meaningful conclusions. After using Bond Apatite^® in our case series, we can conclude that it is a useful and easy-to-handle material in implantology practice, but more controlled studies should be carried out in this regard to assess its long-term efficacy, especially in horizontal and/or vertical regeneration. Full article

(This article belongs to the Special Issue Recent Advances in Coatings of Implant and Dental Biomaterials)

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5 pages, 186 KiB

Open AccessEditorial

Special Issue: Surface Modification of Magnesium, Aluminum Alloys, and Steel

by Aurel Mihail Titu, Bin Miao and Alina Bianca Pop

Coatings 2022, 12(9), 1349; https://doi.org/10.3390/coatings12091349 - 16 Sep 2022

Viewed by 1642

Abstract

The subject of coatings is mainly analyzed in different fields [...] Full article

(This article belongs to the Special Issue Surface Modification of Magnesium, Aluminum Alloys, and Steel)

20 pages, 1947 KiB

Open AccessFeature PaperReview

The Suitability of Photocatalyst Precursor Materials in Geopolymer Coating Applications: A Review

by Liyana Jamaludin, Rafiza Abd Razak, Mohd Mustafa Al Bakri Abdullah, Petrica Vizureanu, Ana Bras, Thanongsak Imjai, Andrei Victor Sandu, Shayfull Zamree Abd Rahim and Heah Cheng Yong

Coatings 2022, 12(9), 1348; https://doi.org/10.3390/coatings12091348 - 16 Sep 2022

Cited by 18 | Viewed by 3034

Abstract

Today, the building and construction sector demands environmentally friendly and sustainable protective coatings using inorganic coating materials for safe, non-hazardous, and great performance. Many researchers have been working on sustainable solutions to protect concrete and metal infrastructures against corrosion and surface deterioration with [...] Read more.

Today, the building and construction sector demands environmentally friendly and sustainable protective coatings using inorganic coating materials for safe, non-hazardous, and great performance. Many researchers have been working on sustainable solutions to protect concrete and metal infrastructures against corrosion and surface deterioration with the intention of introducing green alternatives to conventional coatings. This article presents a review of developments of geopolymer pastes doped with different types of photocatalyst precursors including factors affecting geopolymer properties for enhancing coating with photocatalytic performance. Photodegradation using geopolymer photocatalyst has great potential for resolving harmless substances and removing pollutants when energized with ultraviolet (UV) light. Although geopolymer is a potentially new material with great properties, there has been less research focusing on the development of this coating. This study demonstrated that geopolymer binders are ideal precursor support materials for the synthesis of photocatalytic materials, with a significant potential for optimizing their distinctive properties. Full article

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19 pages, 3087 KiB

Open AccessArticle

Dynamics of Colloidal Mixture of Cu-Al₂O₃/Water in an Inclined Porous Channel Due to Mixed Convection: Significance of Entropy Generation

by Dalia Sabina Cimpean

Coatings 2022, 12(9), 1347; https://doi.org/10.3390/coatings12091347 - 16 Sep 2022

Viewed by 1358

Abstract

The unavailability of energy has become a major challenge to industry in the last years, as an important percentage of the generated energy is dissipated as heat in transport. Since heat transfer processes are irreversible, the role of entropy generation minimization in nanofluid [...] Read more.

The unavailability of energy has become a major challenge to industry in the last years, as an important percentage of the generated energy is dissipated as heat in transport. Since heat transfer processes are irreversible, the role of entropy generation minimization in nanofluid flow and heat transfer cannot be neglected. The present paper was dedicated to the study of entropy generation for the problem of steady mixed-convection flow in a porous inclined channel filled with a hybrid nanofluid (Cu-Al₂O₃/water). A symmetrical uniform heat flux was considered at the walls and a constant flow rate was given through the channel. The mathematical model, consisting of a system of equations with given boundary conditions, was transformed in terms of dimensionless variables and the proposed analytical solution was found to be valid for all the cases of the inclined channel. The solution was validated by comparison with previously published results. The behavior of the velocity and temperature of the hybrid nanofluid were studied together with the entropy generation inside the channel by considering the influence of different important parameters, such as the nanoparticle volume fraction, the mixed-convection parameter and the inclination angle of the channel from horizontal. The results were focused to prevent the dissipation of energy by calculating the maximum thermal advantage at a minimum entropy generation in the system. Full article

(This article belongs to the Section Liquid–Fluid Coatings, Surfaces and Interfaces)

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25 pages, 12043 KiB

Open AccessArticle

Oxide Nanostructured Coating for Power Lines with Anti-Icing Effect

by Andrey Vladimirovcih Blinov, Dmitry Aleksandrovich Kostyukov, Maria Anatolevna Yasnaya, Pavel Aleksandrovich Zvada, Lyudmila Pavlovna Arefeva, Valery Nikolaevich Varavka, Roman Aleksandrovich Zvezdilin, Alexander Aleksandrovich Kravtsov, David Guramievich Maglakelidze, Alexey Borisovich Golik, Alexey Alekseevich Gvozdenko, Natalia Viatcheslavovna Lazareva, Elena Nikolaevna Kushch, Vadim Nikolaevich Goncharov, Maxim Andreevich Kolodkin, Mohammad Ali Shariati and Andrey Ashotovich Nagdalian

Coatings 2022, 12(9), 1346; https://doi.org/10.3390/coatings12091346 - 16 Sep 2022

Cited by 5 | Viewed by 2574

Abstract

This paper presents the results of the development of a technology to obtain a nanostructured coating for the protection of overhead wires and the possibility of their application in the electric power industry. The paper provides an analysis of available data on methods [...] Read more.

This paper presents the results of the development of a technology to obtain a nanostructured coating for the protection of overhead wires and the possibility of their application in the electric power industry. The paper provides an analysis of available data on methods of combating ice in different countries, ways to protect the surface of metals from environmental influences, and new materials used for protection. We studied the possibility of using a protective nanostructured coating to protect overhead wires. A technology for obtaining a protective nanostructured coating based on silicon oxide and methods for applying it to the wire of overhead lines are proposed. The analysis of the elemental composition and surface morphology of overhead line wires with protective coating is carried out by scanning electron microscopy. The influence of the nanostructured coating on the high-frequency signal bandwidth and wire resistance using a PCIe-6351 data acquisition board, equipped with a BNC-2120 terminal module generating a frequency signal were determined using the National Instruments LabVIEW software package. The subject of the study was a 110 kV overhead power line with a protective coating developed in this work. By analyzing the calculation, we obtained the operating requirements of the developed nanostructured coating. As a result, we developed a protective coating satisfying the working conditions and investigated its properties. In the final phase of the experiment, we tested the electrical characteristics of overhead wires with the developed protective coating. Full article

(This article belongs to the Special Issue Protective Composite Coatings: Implementation, Structure, Properties)

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37 pages, 4979 KiB

Open AccessReview

Progress on Current-Carry Friction and Wear: An Overview from Measurements to Mechanism

by Shuaibing Li, Xingzu Yang, Yongqiang Kang, Zongying Li and Hongwei Li

Coatings 2022, 12(9), 1345; https://doi.org/10.3390/coatings12091345 - 15 Sep 2022

Cited by 26 | Viewed by 4179

Abstract

As aerospace, electrified railway, weapon equipment manufacturing, and other fields have leapt forward, the operating environment of current-carrying friction pairs is becoming increasingly severe, and research on the current-carrying friction and wear theory and its vital technologies are progressively in demand. This study [...] Read more.

As aerospace, electrified railway, weapon equipment manufacturing, and other fields have leapt forward, the operating environment of current-carrying friction pairs is becoming increasingly severe, and research on the current-carrying friction and wear theory and its vital technologies are progressively in demand. This study summarizes the relevant research on the current-carrying friction and wear. In this study, the essential characteristics and classification of current-carrying friction and wear are summarized, the effect of working parameters on current-carrying friction and wear performance is clarified, and the generation mechanism, failure mechanism, and factors of current-carrying friction and wear are emphatically investigated. Moreover, the mechanism of arc generation and the effect of environmental conditions and surface facial masks on the friction and wear process are summarized. This paper also introduces the preparation technology of a conductive wear-resistant self-lubricating material, the main factors affecting the conductive wear-resistant property of the coating, and the action mechanism. The simulation and prediction results of the current-carrying friction and wear temperature field and the wear amount are presented. Finally, the problems in the current-carrying friction and wear research are classified, and future research directions in this field are proposed. The future’s critical development and improvement directions are also proposed from the aspects of developing coating quality evaluation equipment, optimizing the coating quality, and studying the coating self-lubricating mechanisms. Full article

(This article belongs to the Special Issue Advances in Dielectric Coatings)

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10 pages, 3675 KiB

Open AccessArticle

A Facile Way to Modify Polyester Fabric to Enhance the Adhesion Behavior to Rubber

by Hongwei He, Pengfeng Wu, Zeguang Yang, Zhihao Shi, Wenwen Yu, Fuyong Liu, Fengbo Zhu, Qiang Zheng, Dezhong Zhang and Shumin Li

Coatings 2022, 12(9), 1344; https://doi.org/10.3390/coatings12091344 - 15 Sep 2022

Cited by 6 | Viewed by 2786

Abstract

Due to the extremely inert surface of polyester (PET) fabric, a toxic and traditional resorcinol-formaldehyde-latex (RFL) dipping solution is always necessary in the rubber composite industry. Unfortunately, other effective methods for fabric surface treatment are in urgent need to improve the poor bonding [...] Read more.

Due to the extremely inert surface of polyester (PET) fabric, a toxic and traditional resorcinol-formaldehyde-latex (RFL) dipping solution is always necessary in the rubber composite industry. Unfortunately, other effective methods for fabric surface treatment are in urgent need to improve the poor bonding interface between the fabric and the rubber matrix. In our study, a facile way to modify PET fabric was developed. Specifically, the fabric was treated by an alkaline solution and a coupling agent with magnetic agitation. Afterwards, the treated fabric/rubber composites were prepared through a co-vulcanization process. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and thermogravimetric analysis (TGA) were used to characterize the surface chemical composition of the modified fabrics. The adhesion behavior was analyzed by the peel test. The results showed that the fabric surface was successfully grafted with a coupling agent, and the peel strength reached 9.8 N/mm after KH550 treatment, which was an increase if 32% compared with that of the original fabric/rubber composite. In addition, the vulcanization rate and interfacial fracture mechanism are also researched. Full article

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16 pages, 5219 KiB

Open AccessArticle

Increasing the Life Span of Tools Applied in Cheese Cutting Machines via Appropriate Micro-Blasting

by Georgios Skordaris, Konstantinos Vogiatzis, Leonidas Kakalis, Ioannis Mirisidis, Vasiliki Paralidou and Soultana Paralidou

Coatings 2022, 12(9), 1343; https://doi.org/10.3390/coatings12091343 - 15 Sep 2022

Viewed by 1707

Abstract

The potential to increase the life span of tools applied in cheese cutting machines is of great importance, considering their cost and the risk of fragmented metallic parts of the tool being inserted into the cheese. Such tools are commonly manufactured using stainless [...] Read more.

The potential to increase the life span of tools applied in cheese cutting machines is of great importance, considering their cost and the risk of fragmented metallic parts of the tool being inserted into the cheese. Such tools are commonly manufactured using stainless steel 405 and are subjected to dynamic loads during their operation, leading to fatigue failure. An efficient method to improve the fatigue properties of such tools is the application of micro-blasting. In this work, for the first time, an experimental–analytical methodology was developed for determining optimum micro-blasting conditions and ascertaining a preventive replacement of the tool before its extensive fracture. This methodology is based on the construction of a pneumatic system for the precise cutting of cheese and simultaneous force measurements. Additionally, the entire cheese-cutting process is simulated by appropriate FEA modeling. According to the attained results, micro-blasting on steel tools significantly improves the resistance against dynamic loads, whilst the number of impacts that a tool can withstand until fatigue fracture is more than three times larger. Via the developed methodology, a preventive replacement of the tool can be conducted, avoiding the risk of a sudden tool failure. The proposed methodology can be applied to different tool geometries and materials. Full article

(This article belongs to the Special Issue 10th Anniversary of Coatings: Invited Papers in "Surface Characterization, Deposition and Modification" Section)

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16 pages, 8656 KiB

Open AccessArticle

Helium Metastable Distributions and Their Effect on the Uniformity of Hydrogenated Amorphous Silicon Depositions in He/SiH₄ Capacitively Coupled Plasmas

by Sanghyun Jo, Suik Kang, Kyungjun Lee and Ho Jun Kim

Coatings 2022, 12(9), 1342; https://doi.org/10.3390/coatings12091342 - 15 Sep 2022

Cited by 1 | Viewed by 2365

Abstract

This study investigates, numerically, the spatial distribution of metastable helium (He*) in He/SiH₄ capacitively coupled plasma (CCP) for the purpose of optimizing plasma density distributions. As a first step, we presented the results of a two-dimensional fluid model of He discharges, followed [...] Read more.

This study investigates, numerically, the spatial distribution of metastable helium (He*) in He/SiH₄ capacitively coupled plasma (CCP) for the purpose of optimizing plasma density distributions. As a first step, we presented the results of a two-dimensional fluid model of He discharges, followed by those of He/SiH₄ discharges to deposit hydrogenated amorphous silicon films, to investigate which factor dominates the coating uniformity. We retained our CCPs in the 300 mm wafer reactor used by the semiconductor industry in the recent past. Selected parameters, such as a sidewall gap (radial distance between the electrode edge and the sidewall), electrical condition of the sidewall, and position of the powered electrode, were considered. In addition, by increasing the gas pressure while varying the sidewall condition, we observed modification of the plasma distributions and, thus, the deposition rate profiles. According to the results, the shift in He* distributions was mainly due to the reduction in the electron mean free path under conditions of gas pressure higher than 100 Pa, as well as local perturbations in the ambipolar electric field due to the finite electrode structure. Small additions of SiH₄ largely changed the He* density profile in the midplane of the discharge due to He* quenching. Furthermore, we found that the wide sidewall gap did not improve deposition uniformity against the expectation. This was because the excitation and ionization rate profiles were enhanced and localized only near the bottom electrode edge. Full article

(This article belongs to the Special Issue New Advances in Plasma Deposition and Its Applications)

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16 pages, 2177 KiB

Open AccessArticle

Graphene Nanoribbon Bending (Nanotubes): Interaction Force between QDs and Graphene

by Sahar Armaghani, Ali Rostami and Peyman Mirtaheri

Coatings 2022, 12(9), 1341; https://doi.org/10.3390/coatings12091341 - 15 Sep 2022

Viewed by 1695

Abstract

Carbon materials in different shapes—such as fullerene molecules (0D), nanotubes and graphene nanoribbons (1D), graphene sheets (2D), and nanodiamonds (3D)—each have distinct electrical and optical properties. All graphene-based nanostructures are expected to exhibit extraordinary electronic, thermal, and mechanical properties. Moreover, they are therefore [...] Read more.

Carbon materials in different shapes—such as fullerene molecules (0D), nanotubes and graphene nanoribbons (1D), graphene sheets (2D), and nanodiamonds (3D)—each have distinct electrical and optical properties. All graphene-based nanostructures are expected to exhibit extraordinary electronic, thermal, and mechanical properties. Moreover, they are therefore promising candidates for a wide range of nanoscience and nanotechnology applications. In this work, we theoretically studied and analyzed how an array of quantum dots affects a charged graphene plate. To that end, the array of quantum dots was embedded on the graphene plate. Then, considering the interaction between QDs and graphene nanoribbons, we transformed the charged plate of a graphene capacitor into a nanotube using the bipolar-induced interaction and the application of an external electromagnetic field. In this work, the dimensions of the graphene plate were 40 nm × 3100 nm. The bending process of a charged graphene plate is controlled by the induced force due to the applied electromagnetic field and the electric field induced by the quantum dots. Finally, using the predetermined frequency and amplitude of the electromagnetic field, the graphene nanoribbon was converted into a graphene nanotube. Since the electrical and optical properties of nanotubes are different from those of graphene plates, this achievement has many practical potential applications in the electro-optical industry. Full article

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11 pages, 3999 KiB

Open AccessArticle

Simulation of Light-Trapping Characteristics of Self-Assembled Nano-Ridges in Ternary Organic Film

by Chang Li, Mingxin Chen, Fen Li, Xiaoxiang Sun, Zhuoliang Yu, Jiayou Tao, Zhijun Zou, Gaohua Liao and Jianjun Zhang

Coatings 2022, 12(9), 1340; https://doi.org/10.3390/coatings12091340 - 15 Sep 2022

Cited by 2 | Viewed by 1763

Abstract

The presence of self-assembled nano-ridged (SANR) structures in PTB7-Th:PC₇₀BM:PC₆₀BM ternary organic blend film with the specific component ratio was experimentally clarified, and the light-trapping effect of the SANR structures was demonstrated. On this basis, the light-trapping characteristics of the [...] Read more.

The presence of self-assembled nano-ridged (SANR) structures in PTB7-Th:PC₇₀BM:PC₆₀BM ternary organic blend film with the specific component ratio was experimentally clarified, and the light-trapping effect of the SANR structures was demonstrated. On this basis, the light-trapping characteristics of the PTB7-Th:PC₇₀BM:PC₆₀BM ternary blend film with the SANR structures were investigated by using the finite-difference time-domain (FDTD) algorithm. The results showed that the SANR structures have a light-trapping effect, which can effectively reduce the transmittance and reflectance of the incident photons at the specific wavelengths and thus exhibit stronger photon absorption, especially for the photons in the wavelength range of 550–650 nm. The light-trapping effect of the SANR structures does not depend on the direction of photon incidence, and the active layer traps the photons incident from both its top and bottom. The dimensional variation of the SANR has a significant effect on the light-trapping characteristics of the active layer, and the effect caused by the height variation is overwhelmingly superior compared with that of the width variation. In addition, the higher the density of the SANR, the more significant the light-trapping effect of the active layer. This work provides a theoretical basis for the further experimental enhancement of the photon absorption capacity of the PTB7-Th:PC₇₀BM:PC₆₀BM active layer with SANR structures. Full article

(This article belongs to the Special Issue Chemical Vapor Deposition (CVD) of Coatings and Films)

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Coatings, Volume 12, Issue 9 (September 2022) – 140 articles

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