Next Issue
Volume 13, October
Previous Issue
Volume 13, August
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.7
3.4
Journals
Coatings
Volume 13
Issue 9
share announcement

Coatings, Volume 13, Issue 9 (September 2023) – 185 articles

Cover Story (view full-size image): The intricacies of the PEO discharge environment have rendered the underlying mechanisms of PEO discharge elusive. In a recent development researchers used the scheme of elemental tracing equipped with plasma emission spectroscopy to analyze the mechanism of the dynamic evolution of PEO discharge. This innovative approach allows for the effective monitoring of particle motion throughout the PEO discharge process, enabling for the capture of dynamic processes during breakdown discharge. Consequently, this research presents a promising strategy for a comprehensive investigation into the mechanisms governing PEO discharge and has significant reference value in this field. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
16 pages, 309 KiB  
Review
Surface Modification of Metallic Nanoparticles for Targeting Drugs
by Abdullah Abdelkawi, Aliyah Slim, Zaineb Zinoune and Yashwant Pathak
Coatings 2023, 13(9), 1660; https://doi.org/10.3390/coatings13091660 - 21 Sep 2023
Cited by 3 | Viewed by 1601
Abstract
This review focuses on the surface modification of metallic nanoparticles for targeted drug delivery. Metallic nanoparticles, owing to their unique size, stability, and payload capacity, have emerged as promising drug carriers. However, their application necessitates surface modification to enable precise targeting. Various strategies, [...] Read more.
This review focuses on the surface modification of metallic nanoparticles for targeted drug delivery. Metallic nanoparticles, owing to their unique size, stability, and payload capacity, have emerged as promising drug carriers. However, their application necessitates surface modification to enable precise targeting. Various strategies, such as polymer coating methods, the use of functional groups, and bio-conjugation with targeting ligands, are explored. The review also discusses the selection of ligands based on target receptors, active and passive targeting approaches, and stimuli-responsive targeting. It further delves into the challenges of translating these strategies to clinical settings, including scalability, toxicity, and regulatory hurdles. The surface modification of metallic nanoparticles is a promising avenue for targeted drug delivery. Various strategies, including polymer coating, functionalization with specific groups, and bioconjugation with targeting ligands, have been explored to enhance the therapeutic potential of these nanoparticles. The challenges in clinical translation, continuous advancements in nanoparticle synthesis, and surface modification techniques offer a positive outlook for the future of targeted metallic nanoparticle systems. Despite the promising potential of metallic nanoparticles in drug delivery, there are several challenges that need to be addressed for their successful clinical translation. These include scalable fabrication and functionalization of nanoparticles, toxicity concerns, and regulatory hurdles. However, continuous advancements in nanoparticle synthesis and surface modification techniques are expected to overcome these challenges in the near future. Full article
(This article belongs to the Special Issue Surface Modification for Improving the Performance of Engineering Components)
16 pages, 6076 KiB  
Article
Effect of Top-Coat Thickness and Interface Fluctuation on the Residual Stress in APS-TBCs
by Weiling Zhao, Zhongchao Hu, Liang Wang, Xintong Wang, Qihao Wu and Runpin Liu
Coatings 2023, 13(9), 1659; https://doi.org/10.3390/coatings13091659 - 21 Sep 2023
Viewed by 803
Abstract
This study focused on the numerical simulation of the distribution of residual stress in yttria-stabilized zirconia (YSZ) coatings prepared with atmospheric plasma spraying (APS). We particularly investigated the stress distribution around the interface between the top coat and bond coat. During thermal spray [...] Read more.
This study focused on the numerical simulation of the distribution of residual stress in yttria-stabilized zirconia (YSZ) coatings prepared with atmospheric plasma spraying (APS). We particularly investigated the stress distribution around the interface between the top coat and bond coat. During thermal spray deposition, droplets and particles deposit on the substrate in a complex manner, causing interface waviness and non-uniform stress distribution. Therefore, residual stress is an important consideration when preparing thermal barrier coatings (TBCs). Residual stresses directly affect the performance of bond coats (BCs) and ceramic top coats (TCs). To accurately evaluate residual stress, we considered interface waviness and the thickness of the ceramic top coat and conducted a detailed analysis of stress distribution. The results show that compressive stress exists at the TC/BC interface, which may be caused by the mismatch in the thermal expansion coefficient between the YSZ top coat and the substrate, potentially leading to coating delamination. Moreover, the residual stress at the TC/BC interface significantly increases with an increasing YSZ thickness. When the top-coat thickness exceeds 300 μm, stress concentration and failure of the coating are likely to occur. Meanwhile, the optimized thermal spray experiment results confirm that the residual stress at the BC/YSZ interface of the thermal barrier coating is tensile stress, with a maximum value of 155 MPa, which is consistent with the finite element calculation results. Furthermore, the failure modes of TBCs with rough interface conditions are discussed in detail. Our research provides important guidance for TBC design and optimizing their performance. Full article
(This article belongs to the Special Issue Recent Advances in the Materials, Preparations, and Properties of Thermal Barrier Coatings)
►▼ Show Figures

Figure 1

12 pages, 2178 KiB  
Article
Bioactive Paper Packaging for Extended Food Shelf Life
by Anamaria Irimia and Carmen-Mihaela Popescu
Coatings 2023, 13(9), 1658; https://doi.org/10.3390/coatings13091658 - 21 Sep 2023
Cited by 2 | Viewed by 1254
Abstract
Food safety and quality are major problems for food producers and industry, governments, and consumers. Conventional plastic-based food packaging is difficult to dispose of and recycle due to its provenience from fossil resources and resistance to biodegradation. Therefore, currently, the trend is to [...] Read more.
Food safety and quality are major problems for food producers and industry, governments, and consumers. Conventional plastic-based food packaging is difficult to dispose of and recycle due to its provenience from fossil resources and resistance to biodegradation. Therefore, currently, the trend is to develop new eco-friendly food packaging that can replace these materials. The limitations of conventional packaging can be solved by developing new active materials with antimicrobial and antioxidant properties, based on cellulose, a natural biodegradable organic compound derived from renewable resources. In this study, new materials with antioxidant and antibacterial activity were obtained by combining a “green” functionalization approach (enzymatic activation) and surface modification using bioactive agents (essential clove oil and cold-pressed grape seed oil). Kraft paper was firstly activated with cellulase, followed by impregnation with the above-mentioned oil solutions, and then its properties were evaluated. The increased values of the O/C ratio for modified Kraft paper indicate an increased polarity due to the presence of phenolic groups. This resulted in an improved hydrophobicity, with the water contact angle increasing from 97° to over 110°. Following different interactions with the functional groups of vegetable oils, the modified Kraft paper exhibited distinct antioxidant and antibacterial properties. However, modified paper with clove essential oil showed higher antioxidant activity (due to the higher content of phenolic compounds), while modified paper with cold-pressed grape seed oil had better antimicrobial activity against Escherichia coli (−), Salmonella enteritidis (−), and Listeria monocytogenes (+) bacterial strains, and was more effective at reducing bacterial growth on fresh beef and fresh curd. The newly obtained bioactive paper provides an effective packaging material that can help control foodborne pathogens in food, thus extending its shelf life and safety. Full article
(This article belongs to the Special Issue Innovations in Active Food Packaging during the Pandemic and into the 'New Normal')
►▼ Show Figures

Figure 1

23 pages, 649 KiB  
Review
Review on Charge Carrier Transport in Inorganic and Organic Semiconductors
by Seema Morab, Manickam Minakshi Sundaram and Almantas Pivrikas
Coatings 2023, 13(9), 1657; https://doi.org/10.3390/coatings13091657 - 21 Sep 2023
Cited by 3 | Viewed by 1978
Abstract
Inorganic semiconductors like silicon and germanium are the foundation of modern electronic devices. However, they have certain limitations, such as high production costs, limited flexibility, and heavy weight. Additionally, the depletion of natural resources required for inorganic semiconductor production raises concerns about sustainability. [...] Read more.
Inorganic semiconductors like silicon and germanium are the foundation of modern electronic devices. However, they have certain limitations, such as high production costs, limited flexibility, and heavy weight. Additionally, the depletion of natural resources required for inorganic semiconductor production raises concerns about sustainability. Therefore, the exploration and development of organic semiconductors offer a promising solution to overcome these challenges and pave the way for a new era of electronics. New applications for electronic and optoelectronic devices have been made possible by the recent emergence of organic semiconductors. Numerous innovative results on the performance of charge transport have been discovered with the growth of organic electronics. These discoveries have opened up new possibilities for the development of organic electronic devices, such as organic solar cells, organic light-emitting diodes, and organic field-effect transistors. The use of organic materials in these devices has the potential to revolutionise the electronics industry by providing low-cost, flexible, and lightweight alternatives to traditional inorganic materials. The understanding of charge carrier transport in organic semiconductors is crucial for the development of efficient organic electronic devices. This review offers a thorough overview of the charge carrier transport phenomenon in semiconductors with a focus on the underlying physical mechanisms and how it affects device performance. Additionally, the processes of carrier generation and recombination are given special attention. Furthermore, this review provides valuable insights into the fundamental principles that govern the behaviour of charge carriers in these materials, which can inform the design and optimisation of future devices. Full article
►▼ Show Figures

Figure 1

19 pages, 6125 KiB  
Article
Structural and Luminescence Properties of Eu-Doped PMO Films with Ethylene Bridge and Methyl Terminal Groups
by Md Rasadujjaman, Jinming Zhang, Alexey S. Vishnevskiy, Jing Zhang and Mikhail R. Baklanov
Coatings 2023, 13(9), 1656; https://doi.org/10.3390/coatings13091656 - 21 Sep 2023
Viewed by 722
Abstract
Eu-doped periodic mesoporous organosilicate (PMO) films with terminal methyl and ethylene bridging groups have been synthesized using sol-gel technology and spin-coating, employing evaporation-induced self-assembly (EISA), on silicon wafers. Eu doping is achieved by the dissolution of Eu(NO3)3·6H2O [...] Read more.
Eu-doped periodic mesoporous organosilicate (PMO) films with terminal methyl and ethylene bridging groups have been synthesized using sol-gel technology and spin-coating, employing evaporation-induced self-assembly (EISA), on silicon wafers. Eu doping is achieved by the dissolution of Eu(NO3)3·6H2O in the precursor solution. The deposited films are characterized using Fourier transform infrared (FTIR) spectroscopy, ellipsometric porosimetry (EP), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy. It is observed that Eu doping reduces the concentration of terminal methyl groups, makes the films more hydrophilic and reduces the pore size and open porosity. The reduction reaction Eu3+ → Eu2+ occurs in the pores of organosilicate glass (OSG) films, which was confirmed by the depth profiling XPS. Eu3+ was still present on the top surface of the films. The presence of Eu3+ and Eu2+ gives luminescence emission in the range of 600–630 nm (Eu3+) and 290–400 nm (Eu2+). The Eu2+/Eu3+ concentrations ratio depends on CH3 groups concentration in the films. The concentration of Eu2+ ions in the pores can be reduced by exposure to inductively coupled (ICP) oxygen plasma. The observed shift in the luminescence spectra towards the UV region, in comparison to previously reported Eu-doped organosilicate films, can be attributed to the energy transfer occurring between the host material and Eu2+ ions. Full article
(This article belongs to the Special Issue Organic Synthesis and Characteristics of Thin Films Second Volume)
►▼ Show Figures

Graphical abstract

17 pages, 15995 KiB  
Article
Microstructural Evolution of Irradiated Cr-Coated Zr-4 under In Situ Transmission Electron Microscopy Heating
by Yuxin Zhong, Xiaoyong Wu, Lu Wu, Sha Zhao, Hanxuan Su, Zhien Ning, Wei Zhang, Ning Liu and Jijun Yang
Coatings 2023, 13(9), 1655; https://doi.org/10.3390/coatings13091655 - 21 Sep 2023
Viewed by 718
Abstract
The structural evolution of Cr-coated Zr-4 after irradiation was studied via in situ TEM in the temperature range from room temperature to 1000 °C. The results show that the krypton bubbles appeared at ~700 °C, and their size increased with increasing temperatures. The [...] Read more.
The structural evolution of Cr-coated Zr-4 after irradiation was studied via in situ TEM in the temperature range from room temperature to 1000 °C. The results show that the krypton bubbles appeared at ~700 °C, and their size increased with increasing temperatures. The grain size and shape of the irradiated Zr-4 substrate changed with increasing temperature, and finally, columnar crystals appeared, which was related to the compressive stress induced via irradiation. The Cr2Zr C14 phases formed at both the interface and the substrate at 700 °C and 1000 °C. Moreover, the accelerated failure process of irradiated Cr coating at high temperatures was observed via in situ TEM analysis. Full article
►▼ Show Figures

Figure 1

15 pages, 6110 KiB  
Article
Influence of Bilayer Thickness on Mechanical and Tribological Properties of (Ti-Al)N/MoN Nanostructured Hard Coatings Deposited by Cathodic Arc Ion Plating
by Muhammad I. Yousaf, Tushagu Abudouwufu, Bing Yang, Alexander Tolstoguzov and Dejun Fu
Coatings 2023, 13(9), 1654; https://doi.org/10.3390/coatings13091654 - 21 Sep 2023
Viewed by 832
Abstract
Deposition of (Ti-Al)N/MoN multilayered coatings was carried out through a cathodic ion-plating system in an argon and then nitrogen atmosphere. Bilayer thickness (Λ) of all the samples were achieved, from 22 to 104 nm, by organizing substrate holder rotational speed (SRS). To obtain [...] Read more.
Deposition of (Ti-Al)N/MoN multilayered coatings was carried out through a cathodic ion-plating system in an argon and then nitrogen atmosphere. Bilayer thickness (Λ) of all the samples were achieved, from 22 to 104 nm, by organizing substrate holder rotational speed (SRS). To obtain the optimum properties of the (Ti-Al)N/MoN coatings, the Ti and Al ratio was maintained at a level of 1:1. X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were utilized to analyze the crystal structure and morphology of the coatings. Mechanical and tribological properties were examined by nanohardness and atomic force microscopy (AFM). The preferred orientation of the (Ti-Al)N/MoN nanoscale multilayer films was TiAlN (200) and MoN (200), which had face centered cubic (fcc) and hexagonal structures, respectively. The hardness increased with the decrease in Λ (104 nm to 26 nm), and then it increased. The highest hardness of 37 GPa was revealed at Λ = 26 nm, whereas the least wear rate of 8.09 × 10−7 mm3/N.m was attained at Λ = 22 nm. Wear rate, roughness, and coefficient of friction were decreased with decreasing bilayer period. EDS results showed that Al and Ti contents were almost the same in all samples, as per design of the experiment. Full article
(This article belongs to the Collection Feature Paper Collection in Plasma Coatings, Surfaces & Interfaces)
►▼ Show Figures

Figure 1

16 pages, 5313 KiB  
Article
Assessment of Mechanical and Tribological Behavior of AA6061 Reinforced with B4C and Gr Hybrid Metal Matrix Composites
by Mohammed Yunus and Rami Alfattani
Coatings 2023, 13(9), 1653; https://doi.org/10.3390/coatings13091653 - 21 Sep 2023
Cited by 2 | Viewed by 895
Abstract
Aluminum alloy (AA6061)-based hybrid metal matrix composites (HMMCs) are manufactured using a dual stir casting method, with varying volume percentages of B4C (5%, 10%, and 15%) and Gr (10%, 15%, and 20%) incorporated. The resulting HMMC and reinforcement elements are uniformly [...] Read more.
Aluminum alloy (AA6061)-based hybrid metal matrix composites (HMMCs) are manufactured using a dual stir casting method, with varying volume percentages of B4C (5%, 10%, and 15%) and Gr (10%, 15%, and 20%) incorporated. The resulting HMMC and reinforcement elements are uniformly dispersed within the main matrix, forming a mechanically mixed layer with interfacial reactions. This layer reduces wear loss and friction coefficient compared to AA6061, especially with higher amounts of B4C and Gr, as they demonstrate little aggregation of reinforced material. The presence of Gr particles enabled the impact of different wear parameters (applied load, sliding speed, and distance) to be combined. Micro-hardness studies demonstrate that the hardness of HMMC increases as the volume fraction of reinforced particles and sliding distance increase. The compression test revealed a 22% improvement over AA6061. As a result, adding reinforcing materials to the matrix contributes to inducing greater strength by increasing wear resistance with a Gr-imparted lubrication effect. Full article
►▼ Show Figures

Figure 1

26 pages, 8436 KiB  
Article
Factors Affecting the Strength Formation Mechanism and Water Stability of Geopolymer Stabilized Phosphogypsum in Road Construction
by Yi Wu, Hanbin Zhang, Haikun Lin, Xueting Wu, Heng Li, Yamei Liu, Gonghui Gu, Jin Xu, Shengying Chen, Haojun Tang, Hualuo He, Wenkai Zheng and Fang Xu
Coatings 2023, 13(9), 1652; https://doi.org/10.3390/coatings13091652 - 20 Sep 2023
Cited by 1 | Viewed by 835
Abstract
By adjusting the content of geopolymer in geopolymer stabilized phosphogypsum (GSP) as roadbed filler, along with the mixing ratio, this paper mainly explores tendencies in the mechanical properties and water stability of GSP. This research is based on macro-mechanical properties such as unconfined [...] Read more.
By adjusting the content of geopolymer in geopolymer stabilized phosphogypsum (GSP) as roadbed filler, along with the mixing ratio, this paper mainly explores tendencies in the mechanical properties and water stability of GSP. This research is based on macro-mechanical properties such as unconfined compressive strength, resilience modulus, California bearing ratio and shear strength. It is also based on water stability tests, such as the water soaking test, dry and wet cycle test and expansion test, to explore changes in water stability. As for the durability of GSP, this paper is mainly based on the realization of a long time observation of mechanical properties and water stability. In the existing research, most of the stabilized phosphogypsum (PG) base material or roadbed filler consists of cement, lime, etc. In this paper, a new exploration is carried out on the composition of stabilized PG material, realized without the participation of cement. The 28 d compressive strength of GSP reaches 2.5 MPa, and over time this strength grows, which prevents the phenomenon of strength inversion that may occur in conventional cement-stabilized PG. In addition, a long-term soaking experiment was designed in this study based on the material after the strength was stabilized for up to 90 d. After the strength was steady, the GSP with the best water stability still had a softening coefficient of 80% after experiencing water immersion for 7 d. After determining the feasibility of the mechanical properties and water stability of GSP as roadbed filler, we further explored the strength formation mechanism of GSP by microscopic tests (XRD and SEM). This shows that geopolymer can stabilize PG in two main ways: one is the hydration reaction with PG to generate C-S-H gel and ettringite, and the other is to connect PG not involved in the chemical reaction to form a dense whole through generated hydration products. Geopolymer, stabilizing a high amount of PG, not only provides a new method for the consumption of PG, but also has more stable performance than cement, and has certain advantages in economy. In addition, the advantage of this study is that good performance can be achieved by simply sieving PG and adjusting the geopolymer ratio in practical engineering projects. Full article
(This article belongs to the Special Issue Novel Green Pavement Materials and Coatings)
►▼ Show Figures

Figure 1

17 pages, 5492 KiB  
Article
The Effect of Heat Treatment on Phase Structure and Mechanical and Corrosion Resistance Properties of High Tungsten Ni-W Alloy Coating
by Yingjun Xu, Deyong Wang, Minqi Sheng, Huihua Wang, Ruiqi Guo, Tianpeng Qu and Shaoyan Hu
Coatings 2023, 13(9), 1651; https://doi.org/10.3390/coatings13091651 - 20 Sep 2023
Cited by 1 | Viewed by 697
Abstract
The present study investigated the surface morphology, phase composition, mechanical properties, and corrosion resistance of Ni-W alloy coatings prepared under current densities of 1–5 A/dm², after undergoing heat treatment at 400 °C, 600 °C, and 900 °C. The grain size of the as-plated [...] Read more.
The present study investigated the surface morphology, phase composition, mechanical properties, and corrosion resistance of Ni-W alloy coatings prepared under current densities of 1–5 A/dm², after undergoing heat treatment at 400 °C, 600 °C, and 900 °C. The grain size of the as-plated Ni-W alloy coating was below 10 nm. After heat treatment at different temperatures, the grain size increased, reaching a maximum value of around 30 nm at 900 °C. Heat treatment crystallized and altered the structure of the coating. Different heat treatment temperatures yielded different precipitates, including Ni4W, Ni6W6C, and WC. The highest coating hardness (820–940 Hv) was achieved at 400 °C, while the best corrosion resistance was achieved at 600 °C. The precipitation hardening phase can be obtained by proper heat treatment temperature, yielding the desired properties of the composite coating. Full article
►▼ Show Figures

Figure 1

10 pages, 6140 KiB  
Article
High-Throughput Preparation and Mechanical Property Screening of Zr-Ti-Nb-Ta Multi-Principal Element Alloys via Multi-Target Sputtering
by Haochen Qiu, Xuehui Yan, Shuaishuai Wu, Wei Jiang, Baohong Zhu and Shengli Guo
Coatings 2023, 13(9), 1650; https://doi.org/10.3390/coatings13091650 - 20 Sep 2023
Viewed by 686
Abstract
Zr-Ti-Nb-Ta alloys were synthesized in parallel via multi-target co-sputtering deposition with physical masking in a pseudo-ternary Ti-Nb-ZrTa alloy system. Sixteen alloys with distinct compositions were obtained. Comprehensive characterization of phase structure, microstructure, Young’s modulus, and nanoindentation hardness was undertaken. The Ti-Nb-ZrTa alloys exhibited [...] Read more.
Zr-Ti-Nb-Ta alloys were synthesized in parallel via multi-target co-sputtering deposition with physical masking in a pseudo-ternary Ti-Nb-ZrTa alloy system. Sixteen alloys with distinct compositions were obtained. Comprehensive characterization of phase structure, microstructure, Young’s modulus, and nanoindentation hardness was undertaken. The Ti-Nb-ZrTa alloys exhibited two typical phase structures: a single-BCC solid-solution structure, and an amorphous structure. Nanoindentation quantification confirmed a Young’s modulus ranging from 110 to 130 GPa, alongside nanoindentation hardness spanning 3.6 to 5.0 GPa. The combination of good hardness and a relatively low Young’s modulus renders these alloys promising candidates for excellent biomedical materials. This work not only offers an effective method for the high-throughput synthesis of multi-principal element alloys, but also sheds light on a strategy for screening the phase structure and mechanical performance within a given alloy system. Full article
(This article belongs to the Special Issue High Entropy Alloy Films)
►▼ Show Figures

Figure 1

11 pages, 3934 KiB  
Article
The Effect of Water-Based Primer Pretreatment on the Performance of Water-Based Inkjet Coatings on Wood Surfaces
by Ruijuan Sang, Fei Yang and Zhenxian Fan
Coatings 2023, 13(9), 1649; https://doi.org/10.3390/coatings13091649 - 20 Sep 2023
Cited by 2 | Viewed by 947
Abstract
Wood surface staining suffers from volatile organic gas (VOC) emissions and uneven staining at knots, and these environmental and decorative performance issues are the main restrictions in the application of wood products, indoors and outdoors. Herein, the method of wood-based panel surface staining [...] Read more.
Wood surface staining suffers from volatile organic gas (VOC) emissions and uneven staining at knots, and these environmental and decorative performance issues are the main restrictions in the application of wood products, indoors and outdoors. Herein, the method of wood-based panel surface staining is presented for improving environmental and decorative performance using environmentally friendly water-based inks, water-based primers, and digital inkjet coloring technology. The wood-based panels’ dye coatings were prepared with oak plank as the sample substrate, a one-component water-based primer as the interfacial adhesive, and a water-based ink as a coating agent. The application amount of water-based primer was 15 g per square meter, applied twice by a roller, and the coating thickness reached approximately 20 μm. The influence of the one-component water-based primer on the interfacial properties of water-based inkjet coatings was investigated via Fourier-transform infrared (FTIR) spectroscopy, a video contact angle analyzer, and environmental scanning electron microscopy (SEM). The results showed that the one-component water-based primer connected the plain board to the inkjet-printed coating. The addition of a water-based primer coating reduced the contact angle of the wood surface from 41.69° to 37.28° and increased wettability. This helped enhance the adhesion of the water-based inkjet coating, and the primer treatment in the semi-closed state covered the scar defects of the plain board while preserving the path of grain holes on the wood surface. With image editing and inkjet dyeing, the surface of the oak plank obtained a uniform staining effect on the primer coating while maintaining the original natural pore texture of the wood. This study proves that a one-component water-based primer pretreatment process for water-based inkjet printing coatings on wood surfaces has excellent modification ability and interface adhesion. It provides a feasible method of color modification for artificial panel surfaces. Full article
►▼ Show Figures

Figure 1

19 pages, 5381 KiB  
Article
Initial Multidisciplinary Study of Oxidized Chromium-Coated Zirconium Alloy for Fuel Cladding of SCW-SMR Concept: Weight-Gain and Thermal Conductivity Measurements and Coating Cost Evaluation
by Kittima Khumsa-Ang, Alberto Mendoza, Armando Nava-Dominguez, Chukwudi Azih and Hussam Zahlan
Coatings 2023, 13(9), 1648; https://doi.org/10.3390/coatings13091648 - 20 Sep 2023
Viewed by 857
Abstract
One of the challenges of small modular reactors (SMRs) in comparison with large reactors is the greater difficulty in achieving high burnups in smaller cores. With greater neutron leakage through the periphery, a key factor is the neutron economy of the fuel cladding. [...] Read more.
One of the challenges of small modular reactors (SMRs) in comparison with large reactors is the greater difficulty in achieving high burnups in smaller cores. With greater neutron leakage through the periphery, a key factor is the neutron economy of the fuel cladding. However, all large supercritical water-cooled reactor (SCWR) concepts have employed neutron-absorbing stainless steels and nickel-based alloys in order to meet all the requirements in terms of corrosion and thermalhydraulics. In order to achieve higher burnups and extend the time between refueling in a SCW-SMR, the use of chromium-coated zirconium alloy as a potential fuel cladding candidate has been explored. Chromium coatings up to a few micrometers thick have shown improved oxidation resistance of zirconium-based claddings under operating conditions relevant to SCWR concepts. In this study, Zr-2.5Nb alloy (UNS R60904) from pressure tube samples was coated using a physical vapor-deposition (PVD) method. Oxidation tests were performed on coated samples at 500 °C and approximately 25 MPa in a refreshed autoclave. The effects of the oxide on heat transfer and hydraulic resistance are also discussed in this study. Last, but not least, this study evaluates the coating cost of the fuel cladding with chromium in a vacuum plasma spray process. Full article
(This article belongs to the Special Issue Behavior of Materials (Alloys, Coatings) in Conditions Specific to Gen IV Nuclear Reactors)
►▼ Show Figures

Figure 1

16 pages, 7274 KiB  
Article
Low-Stress Abrasion of Novel Ni-P-Tribaloy Composite Coating
by Ahmed Mabrouk, Zoheir Farhat and Md. Aminul Islam
Coatings 2023, 13(9), 1647; https://doi.org/10.3390/coatings13091647 - 20 Sep 2023
Viewed by 909
Abstract
Degradation of industrial machinery through wear can be mitigated with the deposition of protective coatings to reduce maintenance costs and prolong their service lifespans. Electroless nickel-based composite coatings is one possible method used to provide this protection. The addition of Tribaloy (CoMoCrSi alloy) [...] Read more.
Degradation of industrial machinery through wear can be mitigated with the deposition of protective coatings to reduce maintenance costs and prolong their service lifespans. Electroless nickel-based composite coatings is one possible method used to provide this protection. The addition of Tribaloy (CoMoCrSi alloy) particles has been found to produce composite coatings with high toughness. In this work, electroless Ni-P-Tribaloy composite coatings were plated on AISI 1018 steel substrates and subjected to low-stress abrasion tests following ASTM G65 standards to investigate the abrasion of the coating. The test was performed at 10 revolution increments, with a 45 N applied load, until coating failure was observed and the measured abrasion was reported as volume loss. The two Ni-P-Tribaloy coating samples lasted for 90 and 100 revolutions, exhibiting a wear rate of 0.170 mm3 per revolution, compared to 0.135 mm3 per revolution for the Ni-P coatings. The abrasive wear mechanism in the Ni-P-Tribaloy coating was found to be plowing of the matrix around the Tribaloy particles, followed by the removal of the particles once they are protruding, which subsequently contributes to the three-body wear of the coating. The particle removal was accelerated at the coating particle-matrix interface. It is concluded that the size of the Tribaloy is a major factor, and we recommend that further studies be carried out using finer particles to improve the wear resistance of the Ni-P-Tribaloy coating. Full article
(This article belongs to the Special Issue Tribological Coatings: Properties, Mechanisms, and Applications in Surface Engineering)
►▼ Show Figures

Figure 1

18 pages, 13323 KiB  
Article
High-Temperature Oxidation Properties of Ti-Hf-Mo-Ta-Nb-B Composite Coating Deposited on Ti60 Alloy with Laser Cladding
by Kaijin Huang and Xianchao Han
Coatings 2023, 13(9), 1646; https://doi.org/10.3390/coatings13091646 - 20 Sep 2023
Cited by 1 | Viewed by 799
Abstract
In order to improve the high-temperature oxidation resistance of Ti60 alloy, a Ti-Hf-Mo-Ta-Nb-B composite coating was prepared on Ti60 alloy with Ti, Hf, Mo, Ta and Nb powder and B powder as raw materials using laser cladding. The microstructure and oxidation behavior of [...] Read more.
In order to improve the high-temperature oxidation resistance of Ti60 alloy, a Ti-Hf-Mo-Ta-Nb-B composite coating was prepared on Ti60 alloy with Ti, Hf, Mo, Ta and Nb powder and B powder as raw materials using laser cladding. The microstructure and oxidation behavior of the coating before and after oxidation at 1100 °C × 120 h in static air were studied with XRD, SEM, EDS and isothermal oxidation techniques. The results show that the coating was mainly composed of six phases, (Ti0.2Hf0.2Mo0.2Ta0.2 Nb0.2)B2, TiB, HfB2, Mo4.00 B3.40, TiHf and Hf1.86Mo0.14. The high-temperature oxidation of the coating and Ti60 alloy followed parabolic law, and the oxidation weight gain rate of the coating after 110 °C × 120 h was only 1/4.8 of that of the Ti60 alloy. The improvement of the high-temperature oxidation resistance of the coating may benefit from high-temperature oxidation resistance (Ti0.2Hf0.2 Mo0.2Ta0.2Nb0.2)B2, HfB2 and TiB boride ceramic phases. Full article
(This article belongs to the Special Issue Laser-Assisted Coating Techniques and Surface Modifications)
►▼ Show Figures

Figure 1

11 pages, 3788 KiB  
Article
Wearing Resistance of Metal Coating Layers after Laser Beam Heat Treatment
by Arthur Oláh, Teodor Machedon-Pisu and Petrică Vizureanu
Coatings 2023, 13(9), 1645; https://doi.org/10.3390/coatings13091645 - 20 Sep 2023
Viewed by 926
Abstract
Laser heat treatment (LHT) is applied herein after coating. Evaluation of the results was performed by studying the microstructures via metallographic SEM/EDX microscopy, and the mechanical properties were analyzed in terms of microscopic hardness and abrasion resistance. The objective of this study was [...] Read more.
Laser heat treatment (LHT) is applied herein after coating. Evaluation of the results was performed by studying the microstructures via metallographic SEM/EDX microscopy, and the mechanical properties were analyzed in terms of microscopic hardness and abrasion resistance. The objective of this study was to investigate the effect of LHT on the wear resistance of metal coatings. The results indicate the influence of the microstructure and chemical composition of the electrodes on the microhardness and wear resistance of the metal coatings (MCs). Full article
(This article belongs to the Special Issue Surface Treatment on Metals and Their Alloys)
►▼ Show Figures

Figure 1

17 pages, 1128 KiB  
Review
Application of Mineralized Chitosan Scaffolds in Bone Tissue Engineering
by Yiyuan Li, Yufeng Meng, Yuning Wang, Yun Wang and Zuolin Wang
Coatings 2023, 13(9), 1644; https://doi.org/10.3390/coatings13091644 - 20 Sep 2023
Viewed by 1092
Abstract
Chitosan (CS) is a natural cationic polysaccharide obtained via the N-deacetylation of chitin. It has various outstanding biological properties such as nontoxicity, biodegradability, biocompatibility, and antimicrobial properties. Minerals can be deposited on the CS template using different methods to construct composites with structures [...] Read more.
Chitosan (CS) is a natural cationic polysaccharide obtained via the N-deacetylation of chitin. It has various outstanding biological properties such as nontoxicity, biodegradability, biocompatibility, and antimicrobial properties. Minerals can be deposited on the CS template using different methods to construct composites with structures and functions similar to those of natural bone tissue. These ideal scaffolds can produce bone via osteogenesis, osteoinduction, and osteoconduction, with good biocompatibility and mechanical properties, and are thus considered promising novel biomaterials for repairing hard tissue defects. In the last decade, the field of mineralized CS scaffolds has provided novel fundamental knowledge and techniques to better understand the aforementioned fascinating phenomenon. This study mainly focused on the basic structures and properties of mineralized CS scaffolds to understand the current research progress and explore further development. Further, it summarizes the types, preparation methods, components, properties, and applications of mineralized CS scaffolds in bone tissue engineering during the last 5 years. The defects and shortcomings of the scaffolds are discussed, and possible improvement measures are put forward. We aimed to provide complete research progress on mineralized CS scaffolds in bone tissue engineering for researchers and clinicians, and also ideas for the next generation of mineralized CS scaffolds. Full article
►▼ Show Figures

Figure 1

15 pages, 4283 KiB  
Article
The Synthesis and Synergistic Effect of Heterocyclic Groups Grafted on Acrylic Polymers by Ester Groups for Marine Antifouling
by Dazhuang Wang, Ruotong Liu, Xiaohui Liu, Guangwen Hu, Zhineng Fu, Miao Dong, Liju Liu, Xinrui Lin, Ping Zhang, Junhua Chen, Jianxin Yang and Xinghua Xue
Coatings 2023, 13(9), 1643; https://doi.org/10.3390/coatings13091643 - 19 Sep 2023
Cited by 1 | Viewed by 780
Abstract
Using a synthetic antifoulant is an alternative technique to using a natural antifoulant for its economical and large-scale production characteristics. In this study, we synthesized allyl 3-oxzo[d]isothiazole-2(3H)-carboxylate (BIT-C) and a series of other heterocyclic compounds, including triazole, pyridine, and thiazole derivatives. These heterocyclic [...] Read more.
Using a synthetic antifoulant is an alternative technique to using a natural antifoulant for its economical and large-scale production characteristics. In this study, we synthesized allyl 3-oxzo[d]isothiazole-2(3H)-carboxylate (BIT-C) and a series of other heterocyclic compounds, including triazole, pyridine, and thiazole derivatives. These heterocyclic monomers were used to prepare a new series of acrylic polymers by grafting them onto the side chains. The weight change on the 42nd day was less than −0.091 mg/cm−2, indicating that antifoulants can be released into seawater consistently and enduringly. The antibacterial and anti-algae tests revealed that all the polymers had exceptional inhibition rates on E. coli, S. aureus, Chlorella, and Chaetoceros curvisetus, with the highest inhibition rates of 99.81%, 99.22%, 92.70%, and 95.42%, respectively. Furthermore, the oyster and barnacle density and algae coverage rate were only about 200 per square meter and 10%, compared to 1800 per square meter and 100% of a blank plate after 90 days hanging in a real marine environment, showing a promising antifouling performance. This work verifies the possibility of a method for grafting different heterocycles on a single polymer to make a series of polymers that can be useful as an environmentally friendly antifouling coating. Full article
(This article belongs to the Topic Multi-Process and Interdisciplinary Approaches in Modern Coating and Surface Design)
►▼ Show Figures

Figure 1

14 pages, 69217 KiB  
Article
Tribological Examination of Anodized Al-356 for Automotive Use
by Alexandra Musza, Márk Windisch, Mátyás Török, Tamás Molnár, Sándor Kovács, Szonja Sátán-Papp, Krisztián Szegedi, Dávid Ugi, Nguyen Quang Chinh and Ádám Vida
Coatings 2023, 13(9), 1642; https://doi.org/10.3390/coatings13091642 - 18 Sep 2023
Cited by 1 | Viewed by 955
Abstract
The A356 alloy is commonly used in the foundry industry to produce high-stressed automotive components, such as motor frames and cylinder heads. The aim of this work was to investigate how the mechanical and tribological properties of this alloy can be improved by [...] Read more.
The A356 alloy is commonly used in the foundry industry to produce high-stressed automotive components, such as motor frames and cylinder heads. The aim of this work was to investigate how the mechanical and tribological properties of this alloy can be improved by applying an anodizing process. The properties of the oxide layer formed by anodizing using oxalic acid at low temperatures were characterized by different analytical and tribological methods. The combination of tribological methods with standard measurement techniques—such as hardness measurement, layer thickness measurement, as well as the analysis of the morphological characteristics—was used to track the layer evolution during wear developments. Full article
(This article belongs to the Section Corrosion, Wear and Erosion)
►▼ Show Figures

Figure 1

11 pages, 6396 KiB  
Article
The Influence of Chitosan on Water Absorption and Solubility of Calcium Phosphate Cement
by Ioana Lacan, Mărioara Moldovan and Ioan Ardelean
Coatings 2023, 13(9), 1641; https://doi.org/10.3390/coatings13091641 - 18 Sep 2023
Viewed by 654
Abstract
Calcium phosphate cements are widely used biomaterials for bone regeneration due to their biological properties, such as biocompatibility, biodegradability, and bioactivity. The presence of chitosan in cement composition influences the resorption rate of the material and its mechanical properties. In the present work, [...] Read more.
Calcium phosphate cements are widely used biomaterials for bone regeneration due to their biological properties, such as biocompatibility, biodegradability, and bioactivity. The presence of chitosan in cement composition influences the resorption rate of the material and its mechanical properties. In the present work, the water absorption and solubility of a tricalcium phosphate bone cement, prepared with and without chitosan addition, was comparatively evaluated. The absorption and solubility properties were monitored for 21 days by immersing the samples in water at room temperature and then weighing them. A morphological analysis of the samples was carried out via scanning electron microscopy (SEM). The absorption dynamics and pore evolution were investigated with low-field nuclear magnetic resonance (NMR) relaxometry. It was demonstrated that the presence of chitosan accelerates the hardening dynamics, reduces water absorption, and influences the solubility and degradation behavior of the cement. It was also observed that, independent of the presence of chitosan, the polymerization process is not completed even after one hour, which influences the solubility process. It was also shown that the presence of chitosan reduces the amount of microcracks and improves the functional properties of the hardened cement. Full article
►▼ Show Figures

Figure 1

12 pages, 9747 KiB  
Article
Four-Polarisation Camera for Anisotropy Mapping at Three Orientations: Micro-Grain of Olivine
by Shuji Kamegaki, Daniel Smith, Meguya Ryu, Soon Hock Ng, Hsin-Hui Huang, Pegah Maasoumi, Jitraporn Vongsvivut, Daniel Moraru, Tomas Katkus, Saulius Juodkazis and Junko Morikawa
Coatings 2023, 13(9), 1640; https://doi.org/10.3390/coatings13091640 - 18 Sep 2023
Cited by 1 | Viewed by 1502
Abstract
A four-polarisation camera was used to map the absorbance of olivine micro-grains before and after high-temperature annealing (HTA). It is shown that HTA of olivine xenoliths at above 1200 °C in O2 flow makes them magnetised. Different modes of operation of [...] Read more.
A four-polarisation camera was used to map the absorbance of olivine micro-grains before and after high-temperature annealing (HTA). It is shown that HTA of olivine xenoliths at above 1200 °C in O2 flow makes them magnetised. Different modes of operation of the polariscope with polarisation control before and after the sample in transmission and reflection modes were used. The reflection type was assembled for non-transparent samples of olivine after HTA. The sample for optical observation in transmission was placed on an achromatic, plastic, quarter-wavelength waveplate as a sample holder. Inspection of the sample’s birefringence (retardance), as well as absorbance, was undertaken. The best fit for the transmitted intensity or transmittance T (hence, absorbance A=−log10T) is obtainable using a simple best fit with only three orientations (from the four orientations measured by the camera). When the intensity of transmitted light at one of the orientations is very low due to a cross-polarised condition (polariser–analyser arrangement), the three-point fit can be used. The three-point fit in transmission and reflection modes was validated for T(θ)=Amp×cos(2θ−2θshift)+offset, where the amplitude Amp, offset offset, and orientation azimuth θshift were extracted for each pixel via the best fit. Full article
(This article belongs to the Special Issue New Advances in Novel Optical Materials and Devices)
►▼ Show Figures

Figure 1

12 pages, 1160 KiB  
Article
Green Application of Isolated Colorant from Neem Bark for Mordant-Coated Wool: Optimization of Dyeing and Mordanting for Shade Development
by Shahid Adeel, Muhammad Zuber, Mustafa Kınık, Aydın Zor, Semih Büyükkol, Ayşe Derya Kahraman, Meral Ozomay, Attila Döl, Zafer Lehimler and Shahnaz Parveen Khattak
Coatings 2023, 13(9), 1639; https://doi.org/10.3390/coatings13091639 - 18 Sep 2023
Cited by 1 | Viewed by 1016
Abstract
This study aimed to assess the effectiveness of utilizing a tannin-based natural brown colorant from neem bark for dyeing wool under microwave treatment, specifically evaluating its coloring efficiency. The colorant was extracted in a methanol solution that had been acidified both before and [...] Read more.
This study aimed to assess the effectiveness of utilizing a tannin-based natural brown colorant from neem bark for dyeing wool under microwave treatment, specifically evaluating its coloring efficiency. The colorant was extracted in a methanol solution that had been acidified both before and after being subjected to microwave treatment for up to 6 min. The dyeing variables were optimized to create new shades of dye with desirable fastness properties, and sustainable chemical and bio-mordants ranging from 1 to 10 g/100 mL were employed. Through experimentation, it was determined that when an unirradiated acidic methanolic extract (AME) with a salt concentration of 3 g/100 mL was applied onto wool fabric (RWF) and subjected to microwave treatment for 4 min, it resulted in a high color yield. This was achieved by heating the solution to 65 °C and allowing it to remain in contact with the fabric for a duration of 65 min. Favorable color characteristics were achieved when utilizing a pre-chemical mordant of 5% Fe and a post-chemical mordant of 5% Fe. In contrast, the utilization of 7% henna as a pre-bio-mordant in combination with 3% turmeric extract as a meta-bio-mordant resulted in favorable color characteristics. The study concludes that microwave treatment exhibits outstanding sustainable efficacy in isolating colorants from neem bark powder for wool dyeing. Incorporating bio-mordants further enhanced the process’s sustainability and eco-friendliness. Full article
(This article belongs to the Special Issue Eco-Friendly and Sustainable Textile Processes)
►▼ Show Figures

Figure 1

12 pages, 5590 KiB  
Article
Effect of Vanadium Layer on Microstructure and Properties of TC4 (Ti-6Al-4V)/TiAl (Ti-48Al-2Cr-2Nb) Dissimilar Metals Produced by Laser Additive Manufacturing
by Haijiang Wang, Zhanqi Liu, Jianhui Liang, Wei Wei and Guili Yin
Coatings 2023, 13(9), 1638; https://doi.org/10.3390/coatings13091638 - 18 Sep 2023
Cited by 2 | Viewed by 784
Abstract
Dissimilar metal samples of TC4/TiAl were successfully prepared by laser additive manufacturing (LAM) technology, with pure vanadium as the interlayer. The microstructure, phase composition, element distribution and mechanical properties at the interface of TC4/V and TiAl/V were analyzed by optical microscope (OM), scanning [...] Read more.
Dissimilar metal samples of TC4/TiAl were successfully prepared by laser additive manufacturing (LAM) technology, with pure vanadium as the interlayer. The microstructure, phase composition, element distribution and mechanical properties at the interface of TC4/V and TiAl/V were analyzed by optical microscope (OM), scanning electron microscope (SEM) and backscattering diffraction (EBSD). The experimental results showed that the interface microstructure of TiAl/V is mainly composed of γ, α2 phase and V solid solution. The microstructure of the TC4/V interface is mainly composed of β-Ti and V solid solution. There are no holes, metallurgical defects or microcracks at the above two interfaces, and the interface is bonded well. With the increase in the number of deposition layers, the interface bonding depth increases, and its thickness increases from 30 μm to 80 μm. The mechanical properties tests showed that the tensile strength and elongation of dissimilar metals with two layers of V interlayer TC4/TiAl are the highest, and their values are 483 MPa and 0.35%, respectively. Compared with the one-layer V intermediate layer sample (tensile strength 405 MPa, elongation 0.24%), the tensile strength and elongation are increased by 19.2% and 45%, respectively. The tensile strength and elongation of dissimilar metals in three-layer V interlayer TC4/TiAl are the lowest, and their values are 350 MPa and 0.16%. Full article
(This article belongs to the Topic Additive Manufacturing of Architected Metallic Materials)
►▼ Show Figures

Figure 1

12 pages, 7644 KiB  
Article
Effects of Nitrogen Doping on Pulling Rate Range of Defect-Free Crystal in CZ Silicon
by Chenguang Sun, Zhongshi Lou, Xingtian Ai, Zixuan Xue, Hui Zhang and Guifeng Chen
Coatings 2023, 13(9), 1637; https://doi.org/10.3390/coatings13091637 - 18 Sep 2023
Cited by 1 | Viewed by 1162
Abstract
We investigated the effect of nitrogen doping on the pulling rate range of defect-free crystal in silicon with a diameter of 200 mm. It was found that the pulling rate range of defect-free crystal in nitrogen-doped Czochralski silicon is wider and the pulling [...] Read more.
We investigated the effect of nitrogen doping on the pulling rate range of defect-free crystal in silicon with a diameter of 200 mm. It was found that the pulling rate range of defect-free crystal in nitrogen-doped Czochralski silicon is wider and the pulling rate (defect free) is lower than it is in non-nitrogen-doped Czochralski silicon. Under the experiment, the pull rate was from 0.67 mm/min~0.58 mm/min to 0.65 mm/min~0.54 mm/min. To further confirm the above experimental analysis, a numerical simulation process of nitrogen-doped Czochralski and non-nitrogen-doped Czochralski in an industrial system was performed. The V/G value along the S/L interface was the same for both models, but the distribution of Cvi (concentration of vacancy–concentration of self-interstitial) for nitrogen-doped Czochralski crystal silicon was more uniform and flat in a nitrogen-doped single crystal. Furthermore, the nitrogen-doped Czochralski crystal silicon had a smaller void size and a higher oxygen precipitation density. The experimental results are in good agreement with the numerical simulation results. Full article
(This article belongs to the Special Issue Advanced Semiconductor Materials and Films: Properties and Applications)
►▼ Show Figures

Figure 1

16 pages, 6629 KiB  
Article
Influential Mechanism of Cr3C2 Content and Process Parameters on Crack Generation of Fe3Al/Cr3C2 Composites
by Yingkai Feng, Shaoquan Liu, Jiayu Zhao, Lin Zhao and Zhenbo Liu
Coatings 2023, 13(9), 1636; https://doi.org/10.3390/coatings13091636 - 18 Sep 2023
Viewed by 680
Abstract
In this paper, a brake cylinder coating comprising composite material of Fe3Al and Cr3C2 mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure of the cladding materials was investigated through X-ray diffraction (XRD), scanning [...] Read more.
In this paper, a brake cylinder coating comprising composite material of Fe3Al and Cr3C2 mixed powder was prepared by laser cladding onto carbon structural steel. The microstructure of the cladding materials was investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The influence mechanism of the Cr3C2 content and process parameters on crack generation of Fe3Al/Cr3C2 composites were studied. The crack is mainly caused by the mismatch between the plastic phase of Fe2AlCr, the brittle phase of Fe3Al, and Cr7C3 in the cladding layer. With the increase in Cr3C2 content, Fe2AlCr and Cr7C3 in the cladding layer increased, while Fe3Al decreased. When the content of Cr7C3 is low, the cladding layer mainly reflects the plastic increase brought by Fe2AlCr; when the content of Cr7C3 is too much, the property of the cladding layer is reflected as the brittleness of Cr7C3. The number of cracks reached the lowest value at 15 wt.%. The process parameters mainly affect the dilution rate of the cladding layer and thus affect the content of Fe2AlCr. Full article
►▼ Show Figures

Figure 1

14 pages, 1903 KiB  
Article
The Effectiveness of a 10-Methacryloyloxydecyl Dihydrogen Phosphate (10-MDP)-Containing Hydrophilic Primer on Orthodontic Molar Tubes Bonded under Moisture Contamination: A Randomized Controlled Trial
by Ahmed Abduljawad, Harraa Mohammed-Salih, Majid Jabir and Ahmed Almahdy
Coatings 2023, 13(9), 1635; https://doi.org/10.3390/coatings13091635 - 18 Sep 2023
Viewed by 892
Abstract
The debonding of orthodontic attachments adversely affects orthodontic treatment. This randomized controlled trial aims to compare the effectiveness of 10-MDP-containing hydrophilic primers under moisture contamination and hydrophobic primers under non-contaminated conditions. One hundred thirty-six molar tubes of thirty-four recruits were randomly bonded in [...] Read more.
The debonding of orthodontic attachments adversely affects orthodontic treatment. This randomized controlled trial aims to compare the effectiveness of 10-MDP-containing hydrophilic primers under moisture contamination and hydrophobic primers under non-contaminated conditions. One hundred thirty-six molar tubes of thirty-four recruits were randomly bonded in a split-mouth cross-quadrant design. For the control group, a conventional hydrophobic primer on non-contaminated enamel was used; tubes of the test group were bonded on saliva-contaminated enamel using a 10-MDP-containing hydrophilic primer. The number of debonded molar tubes and their survival rates were recorded after a six-month follow-up. A chi-square test compared the number of failures and adhesive remnant index scores, using the Kaplan–Meier test for survival rates and Multinomial logistic regression to detect the influence of covariates. Thirty-two patients completed the trial; out of 128 tubes, 10 debonded within six months, the conventional primer scored eight failures with an 87.5% survival rate, and the 10-MDP-containing hydrophilic primer scored two failures with a 96.9% survival rate. The difference in survival rates and the adhesive remnant index between the two groups were statistically significant. Age and gender did not show a statistically significant influence on the number of bond failures. 10-MDP-containing hydrophilic primers may reduce bond failures and increase survival rates, especially in poorly isolated conditions. Full article
►▼ Show Figures

Figure 1

15 pages, 4819 KiB  
Article
Investigation of Oxygen Behavior under Different Melt Flow, Diffusion Boundary Layer, and Crystal-Melt Interface in a 300 mm Silicon Crystal Growth with Cusp Magnetic Field
by Chenguang Sun, Xingtian Ai, Hui Zhang, Hungpang Chou, Huiyun Lyu and Guifeng Chen
Coatings 2023, 13(9), 1634; https://doi.org/10.3390/coatings13091634 - 18 Sep 2023
Viewed by 1350
Abstract
The silicon single crystals for semiconductor application are usually grown by the Czochralski (CZ) method. In this paper, we studied a 300 mm Czochralski silicon crystal grown with a cusp magnetic field to be used for an insulated gate bipolar transistor (IGBT). Different [...] Read more.
The silicon single crystals for semiconductor application are usually grown by the Czochralski (CZ) method. In this paper, we studied a 300 mm Czochralski silicon crystal grown with a cusp magnetic field to be used for an insulated gate bipolar transistor (IGBT). Different positions of the zero-Gauss plane (ZGP) under a cusp magnetic field were simulated and compared to numerical analysis. We investigated three factors that affected the oxygen concentration in the crystal, including (1) melt convection, (2) melt flow velocity near the quartz crucible wall, and (3) the diffusion boundary layer. We also studied the shape of the solid/liquid interface at the same time. The simulation results show that a change in the ZGP of the cusp magnetic field (CMF) strongly affects the convection in the melt, which leads to a difference in the thickness of the boundary layer near the wall of the quartz crucible. We investigated the relationship of the ZGP, convection in the melt, and the thickness of the boundary layer. In this way, we determined how to reduce oxygen diffusing into the melt and finally into the crystal. After simulation results were obtained, we pulled single crystals under the three configurations. The results show that the experimental data of the oxygen content and shape of the solid/liquid interfaces are consistent with the simulation results. Full article
(This article belongs to the Special Issue Advanced Semiconductor Materials and Films: Properties and Applications)
►▼ Show Figures

Figure 1

5 pages, 205 KiB  
Editorial
Special Issue: Functional Nanoparticles for Environmental Contaminants Removal and Agricultural Application
by Ran Tao, Mengmeng Kong, Yinlong Zhang and Yu Shen
Coatings 2023, 13(9), 1633; https://doi.org/10.3390/coatings13091633 - 18 Sep 2023
Viewed by 822
Abstract
Currently, increasing demands are being placed on agricultural production, presented with the challenge of finding sustainable ways to meet the needs of the world’s growing population [...] Full article
(This article belongs to the Special Issue Functional Nanoparticles for Environmental Contaminants Removal and Agricultural Application)
17 pages, 5621 KiB  
Article
Study on Cavitation Corrosion Properties of Titanium Alloy Radiation Rod with Different Roughnesses for Ultrasonic Casting
by Yilong Yang, Ya Zhang, Xuhe Liu and Haoming Zhang
Coatings 2023, 13(9), 1632; https://doi.org/10.3390/coatings13091632 - 18 Sep 2023
Cited by 1 | Viewed by 835
Abstract
To determine the mechanism of corrosion damage caused by cavitation, the properties of titanium alloy radiation rods with different roughnesses in 2A14 aluminum melt for ultrasonic casting were studied. The corrosion morphology, weight loss/cavitated area, reaction layer and microhardness of surface section were [...] Read more.
To determine the mechanism of corrosion damage caused by cavitation, the properties of titanium alloy radiation rods with different roughnesses in 2A14 aluminum melt for ultrasonic casting were studied. The corrosion morphology, weight loss/cavitated area, reaction layer and microhardness of surface section were observed, and the collapse of a single cavitation bubble was simulated. The weight loss/cavitated area caused by the physical impact of cavitation accounted for 6.4% to 8.6% of the total weight loss/cavitated area. The corrosion product was TiAl3. The reactant appeared at the Al/Ti solid–liquid interface in 4 min and the reaction layer appeared in 10 min under different roughnesses. The thickness of the work hardening layer on the surface of the material could reach 160 μm. The results show that the greater the roughness of titanium alloy in aluminum melt, the greater the rate of weight loss/cavitated area and the greater the maximum pressure in the process of cavitation bubble collapse. The evolution of the hardened layer depended on the stripping rate of the surface material caused by cavitation corrosion and the work hardening rate of the surface layer. This study provides insights to develop a new homemade Ti alloy radiation rod with better resistance to corrosion in the ultrasonic casting. Full article
(This article belongs to the Special Issue Enhanced Mechanical Properties of Metals by Surface Treatments)
►▼ Show Figures

Figure 1

13 pages, 6614 KiB  
Article
Characterization and Electrochemical Analysis of Acidic Condensate-Induced Corrosion on Aluminized Coating on Steel in Residential Heaters
by Dino Sulejmanovic, Jiheon Jun, Zhiming Gao and Yi-Feng Su
Coatings 2023, 13(9), 1631; https://doi.org/10.3390/coatings13091631 - 17 Sep 2023
Viewed by 605
Abstract
Condensing furnace residential heaters are starting to replace outdated and less efficient non-condensing units in homes across the US. However, the burning of natural gas in these new units produces acidic gases, which can form acid droplets (H2SO4, HNO [...] Read more.
Condensing furnace residential heaters are starting to replace outdated and less efficient non-condensing units in homes across the US. However, the burning of natural gas in these new units produces acidic gases, which can form acid droplets (H2SO4, HNO3, H2CO3, etc.) that are corrosive to low-grade heat exchanger metallic materials. Type-1 aluminized steel has been used in industrial applications, such as marine, heating, and automobile parts, due to its resistance to oxidation at elevated temperature. Many components of the condensing furnaces, including heat exchangers, are made from type-1 aluminized steel. We investigated the interaction of type-1 aluminized steel substrates with two acidic condensate liquids by 500 h corrosion exposures as well as short-term electrochemical impedance measurements. SEM plan and cross-sectional view images revealed damage to the Al-Si rich layer and exposure of the steel substrate. The non-uniform damage in the Al-Si rich layer was likely attributed to a pitting corrosion mechanism and induced by high acidity of the condensate liquid. Electrochemical impedance measurements in an acidic condensate revealed lower corrosion resistance of the aluminized steel surface with a weld line, identifying welded sections as preferential corrosion initiation sites. Full article
(This article belongs to the Topic Properties of the Corroding Interface)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-185
Previous Issue
Next Issue
Back to TopTop