Nanomaterials

19 pages, 3536 KiB

Open AccessArticle

Antibacterial Electrospun Membrane with Hierarchical Bead-on-String Structured Fibres for Wound Infections

by Yu Xuan Fong, Catherine Pakrath, Fathima Shana Pattar Kadavan, Tien Thanh Nguyen, Trong Quan Luu, Borislav Stoilov, Richard Bright, Manh Tuong Nguyen, Neethu Ninan, Youhong Tang, Krasimir Vasilev and Vi Khanh Truong

Nanomaterials 2024, 14(17), 1429; https://doi.org/10.3390/nano14171429 (registering DOI) - 31 Aug 2024

Abstract

Chronic wounds often result in multiple infections with various kinds of bacteria and uncontrolled wound exudate, resulting in several healthcare issues. Advanced medicated nanofibres prepared by electrospinning have gained much attention for their topical application on infected chronic wounds. The objective of this [...] Read more.

Chronic wounds often result in multiple infections with various kinds of bacteria and uncontrolled wound exudate, resulting in several healthcare issues. Advanced medicated nanofibres prepared by electrospinning have gained much attention for their topical application on infected chronic wounds. The objective of this work is to enhance the critical variables of ciprofloxacin-loaded polycaprolactone-silk sericin (PCL/SS-PVA-CIP) nanofibre production via the process of electrospinning. To examine the antibacterial effectiveness of PCL/SS-PVA-CIP nanocomposites, the material was tested against P. aeruginosa and S. aureus. The combination of PCL/SS-PVA-CIP exhibited potent inhibitory properties, with the most effective concentrations of ciprofloxacin (CIP) being 3 μg/g and 7.0 μg/g for each bacterium, respectively. The biocompatibility was evaluated by conducting cell reduction and proliferation studies using the human epidermal keratinocyte (HaCaT) cells and human gingival fibroblasts (HGFs) in vitro cell lines. The PCL/SS-PVA-CIP showed good cell compatibility with HaCaT and HGF cells, with effective proliferation even at antibiotic doses of up to 7.0 μg/g. The drug release effectiveness of the nanocomposites was assessed at various concentrations of CIP, resulting in a maximum cumulative release of 76.5% and 74.4% after 72 h for CIP concentrations of 3 μg/g and 7 μg/g, respectively. In summary, our study emphasizes the possibility of combining silk sericin (SS) and polycaprolactone (PCL) loading with CIP nanocomposite for wound management. Full article

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25 pages, 10028 KiB

Open AccessReview

Ultrafast Laser Processing for High-Aspect-Ratio Structures

by Muyang Qin, Xinjing Zhao, Hanyue Fan, Ruizhe Leng, Yanhao Yu, Aiwu Li and Bingrong Gao

Nanomaterials 2024, 14(17), 1428; https://doi.org/10.3390/nano14171428 (registering DOI) - 31 Aug 2024

Abstract

Over the past few decades, remarkable breakthroughs and progress have been achieved in ultrafast laser processing technology. Notably, the remarkable high-aspect-ratio processing capabilities of ultrafast lasers have garnered significant attention to meet the stringent performance and structural requirements of materials in specific applications. [...] Read more.

Over the past few decades, remarkable breakthroughs and progress have been achieved in ultrafast laser processing technology. Notably, the remarkable high-aspect-ratio processing capabilities of ultrafast lasers have garnered significant attention to meet the stringent performance and structural requirements of materials in specific applications. Consequently, high-aspect-ratio microstructure processing relying on nonlinear effects constitutes an indispensable aspect of this field. In the paper, we review the new features and physical mechanisms underlying ultrafast laser processing technology. It delves into the principles and research achievements of ultrafast laser-based high-aspect-ratio microstructure processing, with a particular emphasis on two pivotal technologies: filamentation processing and Bessel-like beam processing. Furthermore, the current challenges and future prospects for achieving both high precision and high aspect ratios simultaneously are discussed, aiming to provide insights and directions for the further advancement of high-aspect-ratio processing. Full article

(This article belongs to the Special Issue Light-Matter Interaction in Nano Systems: Fundamentals and Applications)

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13 pages, 1517 KiB

Open AccessArticle

Characterization of Food-Additive Titanium Dioxide and Dietary Exposure to Titanium Dioxide Nanoparticles among the Chinese Population

by Yue Cao, Huali Wang, Chunlai Liang, Qing Liu, Tong Ou, Ling Yong, Xiao Xiao, Haixia Sui, Dingguo Jiang, Zhaoping Liu, Sheng Wei and Yan Song

Nanomaterials 2024, 14(17), 1427; https://doi.org/10.3390/nano14171427 (registering DOI) - 31 Aug 2024

Abstract

Titanium dioxide (TiO₂) is a prevalent food additive, yet comprehensive data on particle size and dietary exposure are lacking in China. Transmission electron microscopy results revealed that the quantitative proportion of nanoparticles (NPs) in food-additive TiO₂ was 37.7%, with a [...] Read more.

Titanium dioxide (TiO₂) is a prevalent food additive, yet comprehensive data on particle size and dietary exposure are lacking in China. Transmission electron microscopy results revealed that the quantitative proportion of nanoparticles (NPs) in food-additive TiO₂ was 37.7%, with a mass fraction of 9.89%. Laboratory test results showed that among the domestic products surveyed, candies excluding gum-based candies contained the highest content of TiO₂. Using consumption data from the China Health and Nutrition Survey in 2018, the average dietary exposure for TiO₂ and TiO₂ NPs in the Chinese population were calculated at 34.84 and 3.44 μg/kg bw/day, respectively. The primary dietary sources were puffed food and powdered drinks. Exposure varied significantly across age and region, with children and Inner Mongolia residents having the highest intake. TiO₂ NP exposure showed a negative correlation with age. Despite this, the dietary exposure risk of TiO₂ NPs for the Chinese population remains deemed acceptable. Full article

(This article belongs to the Special Issue Advanced Nanomaterials and Nanotechnology for Environmental Remediation and Food Safety)

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14 pages, 9712 KiB

Open AccessArticle

Study on the Technology and Properties of Green Laser Sintering Nano-Copper Paste Ink

by Pengkun Li, Zilin Tang, Kaibo Guo, Guifeng Luo, Xihuai Wang, Shengbin Zhao and Mingdi Wang

Nanomaterials 2024, 14(17), 1426; https://doi.org/10.3390/nano14171426 (registering DOI) - 31 Aug 2024

Abstract

With the rapid development of integrated circuits, glass substrates are frequently utilized for prototyping various functional electronic circuits due to their superior stability, transparency, and signal integrity. In this experiment, copper wire was printed on a glass substrate using inkjet printing, and the [...] Read more.

With the rapid development of integrated circuits, glass substrates are frequently utilized for prototyping various functional electronic circuits due to their superior stability, transparency, and signal integrity. In this experiment, copper wire was printed on a glass substrate using inkjet printing, and the electronic circuit was sintered through laser irradiation with a 532 nm continuous green laser. The relationship between resistivity and microstructure was analyzed after laser sintering at different intensities, scanning speeds, and iterations. The experimental results indicate that the conductivity of the sintered lines initially increases and then decreases with an increase in laser power and scanning speed. At the same power level, multiple sintering runs at a lower scanning speed pose a risk of increased porosity leading to reduced conductivity. Conversely, when the scanning speed exceeds the optimal sintering speed, multiple sintering runs have minimal impact on porosity and conductivity without altering the power. Full article

(This article belongs to the Special Issue Trends and Prospects in Laser Nanofabrication)

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37 pages, 3241 KiB

Open AccessReview

Silver Nanoparticles: Synthesis, Structure, Properties and Applications

by Rimsha Abbas, Jingjing Luo, Xue Qi, Adeela Naz, Imtiaz Ahmad Khan, Haipeng Liu, Suzhu Yu and Jun Wei

Nanomaterials 2024, 14(17), 1425; https://doi.org/10.3390/nano14171425 (registering DOI) - 31 Aug 2024

Abstract

Silver nanoparticles (Ag NPs) have accumulated significant interest due to their exceptional physicochemical properties and remarkable applications in biomedicine, electronics, and catalysis sensing. This comprehensive review provides an in-depth study of synthetic approaches such as biological synthesis, chemical synthesis, and physical synthesis with [...] Read more.

Silver nanoparticles (Ag NPs) have accumulated significant interest due to their exceptional physicochemical properties and remarkable applications in biomedicine, electronics, and catalysis sensing. This comprehensive review provides an in-depth study of synthetic approaches such as biological synthesis, chemical synthesis, and physical synthesis with a detailed overview of their sub-methodologies, highlighting advantages and disadvantages. Additionally, structural properties affected by synthesis methods are discussed in detail by examining the dimensions and surface morphology. The review explores the distinctive properties of Ag NPs, including optical, electrical, catalytic, and antimicrobial properties, which render them beneficial for a range of applications. Furthermore, this review describes the diverse applications in several fields, such as medicine, environmental science, electronics, and optoelectronics. However, with numerous applications, several kinds of issues still exist. Future attempts need to address difficulties regarding synthetic techniques, environmental friendliness, and affordability. In order to ensure the secure utilization of Ag NPs, it is necessary to establish sustainability in synthetic techniques and eco-friendly production methods. This review aims to give a comprehensive overview of the synthesis, structural analysis, properties, and multifaceted applications of Ag NPs. Full article

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44 pages, 3570 KiB

Open AccessReview

Applicability of Quantum Dots in Breast Cancer Diagnostic and Therapeutic Modalities—A State-of-the-Art Review

by Dominika Kunachowicz, Karolina Kłosowska, Natalia Sobczak and Marta Kepinska

Nanomaterials 2024, 14(17), 1424; https://doi.org/10.3390/nano14171424 (registering DOI) - 31 Aug 2024

Abstract

The increasing incidence of breast cancers (BCs) in the world population and their complexity and high metastatic ability are serious concerns for healthcare systems. Despite the significant progress in medicine made in recent decades, the efficient treatment of invasive cancers still remains challenging. [...] Read more.

The increasing incidence of breast cancers (BCs) in the world population and their complexity and high metastatic ability are serious concerns for healthcare systems. Despite the significant progress in medicine made in recent decades, the efficient treatment of invasive cancers still remains challenging. Chemotherapy, a fundamental systemic treatment method, is burdened with severe adverse effects, with efficacy limited by resistance development and risk of disease recurrence. Also, current diagnostic methods have certain drawbacks, attracting attention to the idea of developing novel, more sensitive detection and therapeutic modalities. It seems the solution for these issues can be provided by nanotechnology. Particularly, quantum dots (QDs) have been extensively evaluated as potential targeted drug delivery vehicles and, simultaneously, sensing and bioimaging probes. These fluorescent nanoparticles offer unlimited possibilities of surface modifications, allowing for the attachment of biomolecules, such as antibodies or proteins, and drug molecules, among others. In this work, we discuss the potential applicability of QDs in breast cancer diagnostics and treatment in light of the current knowledge. We begin with introducing the molecular and histopathological features of BCs, standard therapeutic regimens, and current diagnostic methods. Further, the features of QDs, along with their uptake, biodistribution patterns, and cytotoxicity, are described. Based on the reports published in recent years, we present the progress in research on possible QD use in improving BC diagnostics and treatment efficacy as chemotherapeutic delivery vehicles and photosensitizing agents, along with the stages of their development. We also address limitations and open questions regarding this topic. Full article

(This article belongs to the Special Issue Advances in the Investigation of Semiconductor Quantum Dots)

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15 pages, 4555 KiB

Open AccessArticle

Description of Short-Range Interactions of Carbon-Based Materials with a Combined AIREBO and ZBL Potential

by Jing Li, Tan Shi, Yichao Sun, Xintian Cai, Rui Gao, Qing Peng, Peng Lu and Chenyang Lu

Nanomaterials 2024, 14(17), 1423; https://doi.org/10.3390/nano14171423 (registering DOI) - 31 Aug 2024

Abstract

An accurate description of short-range interactions among atoms is crucial for simulating irradiation effects in applications related to ion modification techniques. A smooth integration of the Ziegler–Biersack–Littmark (ZBL) potential with the adaptive intermolecular reactive empirical bond-order (AIREBO) potential was achieved to accurately describe [...] Read more.

An accurate description of short-range interactions among atoms is crucial for simulating irradiation effects in applications related to ion modification techniques. A smooth integration of the Ziegler–Biersack–Littmark (ZBL) potential with the adaptive intermolecular reactive empirical bond-order (AIREBO) potential was achieved to accurately describe the short-range interactions for carbon-based materials. The influence of the ZBL connection on potential energy, force, and various AIREBO components, including reactive empirical bond-order (REBO), Lennard–Jones (LJ), and the torsional component, was examined with configurations of the dimer structure, tetrahedron structure, and monolayer graphene. The REBO component is primarily responsible for the repulsive force, while the LJ component is mainly active in long-range interactions. It is shown that under certain conditions, the torsional energy can lead to a strong repulsive force at short range. Molecular dynamics simulations were performed to study the collision process in configurations of the C-C dimer and bulk graphite. Cascade collisions in graphite with kinetic energies of 1 keV and 10 keV for primary knock-on atoms showed that the short-range description can greatly impact the number of generated defects and their morphology. Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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14 pages, 8744 KiB

Open AccessArticle

High-Performance Bimetallic Electrocatalysts for Hydrogen Evolution Reaction Using N-Doped Graphene-Supported N-Co₆Mo₆C

by Renzhe Jin, Shilong Su, Ju Li, Dehai Ping, Yuanyuan Li, Mengyuan He, Xiaomei Yu, Zhengyu Wei, Yong Liu, Songjie Li and Jinyou Zheng

Nanomaterials 2024, 14(17), 1422; https://doi.org/10.3390/nano14171422 (registering DOI) - 30 Aug 2024

Abstract

Hydrogen has garnered considerable attention as a promising energy source for addressing contemporary environmental degradation and energy scarcity challenges. Electrocatalytic water splitting for hydrogen production has emerged as an environmentally friendly and versatile method, offering high purity. However, the development of cost-effective electrocatalytic [...] Read more.

Hydrogen has garnered considerable attention as a promising energy source for addressing contemporary environmental degradation and energy scarcity challenges. Electrocatalytic water splitting for hydrogen production has emerged as an environmentally friendly and versatile method, offering high purity. However, the development of cost-effective electrocatalytic catalysts using abundant and inexpensive materials is crucial. In this study, we successfully synthesized nitrogen-doped Co₆Mo₆C supported on nitrogen-doped graphene (N-Co₆Mo₆C/NC). The catalyst exhibited high performance and durability in alkaline electrolytes (1.0 M KOH) for hydrogen evolution, showcasing an overpotential of 185 mV at a current density of 100 mA cm⁻² and a Tafel slope of 80 mV dec⁻¹. These findings present a novel avenue for the fabrication of efficient bimetallic carbide catalysts. Full article

(This article belongs to the Special Issue Advances in Nanostructured Catalysts for Energy and Environmental Applications)

9 pages, 2551 KiB

Open AccessArticle

Optimization of Thermoelectric Properties and Physical Mechanisms of Cu₂Se-Based Thin Films via Heat Treatment

by Haobin Li, Fu Li, Yuexing Chen, Guangxing Liang, Jingting Luo, Meng Wei, Zhi Zheng and Zhuanghao Zheng

Nanomaterials 2024, 14(17), 1421; https://doi.org/10.3390/nano14171421 - 30 Aug 2024

Abstract

Cu₂Se is an attractive thermoelectric material due to its layered structure, low cost, environmental compatibility, and non-toxicity. These traits make it a promising replacement for conventional thermoelectric materials in large-scale applications. This study focuses on preparing Cu₂Se flexible thin [...] Read more.

Cu₂Se is an attractive thermoelectric material due to its layered structure, low cost, environmental compatibility, and non-toxicity. These traits make it a promising replacement for conventional thermoelectric materials in large-scale applications. This study focuses on preparing Cu₂Se flexible thin films through in situ magnetron sputtering technology while carefully optimizing key preparation parameters, and explores the physical mechanism of thermoelectric property enhancement, especially the power factor. The films are deposited onto flexible polyimide substrates. Experimental findings demonstrate that films grown at a base temperature of 200 °C exhibit favorable performance. Furthermore, annealing heat treatment effectively regulates the Cu element content in the film samples, which reduces carrier concentration and enhances the Seebeck coefficient, ultimately improving the power factor of the materials. Compared to the unannealed samples, the sample annealed at 300 °C exhibited a significant increase in room temperature Seebeck coefficient, rising from 9.13 μVK⁻¹ to 26.73 μVK⁻¹. Concurrently, the power factor improved from 0.33 μWcm⁻¹K⁻² to 1.43 μWcm⁻¹K⁻². Full article

(This article belongs to the Section Synthesis, Interfaces and Nanostructures)

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15 pages, 3868 KiB

Open AccessArticle

Enhanced Carrier Transport Performance of Monolayer Hafnium Disulphide by Strain Engineering

by Yun-Fang Chung and Shu-Tong Chang

Nanomaterials 2024, 14(17), 1420; https://doi.org/10.3390/nano14171420 - 30 Aug 2024

Abstract

For semiconducting two-dimensional transition metal dichalcogenides (TMDs), the carrier transport properties of the material are affected by strain engineering. In this study, we investigate the carrier mobility of monolayer hafnium disulphide (HfS₂) under different biaxial strains by first-principles calculations combined with [...] Read more.

For semiconducting two-dimensional transition metal dichalcogenides (TMDs), the carrier transport properties of the material are affected by strain engineering. In this study, we investigate the carrier mobility of monolayer hafnium disulphide (HfS₂) under different biaxial strains by first-principles calculations combined with the Kubo–Greenwood mobility approach and the compact band model. The decrease/increase in the effective mass of the conduction band (CB) of monolayer HfS₂ caused by biaxial tensile/compressive strain is the major reason for the enhancement/degradation of its electron mobility. The lower hole effective mass of the valence bands (VB) in monolayer HfS₂ under biaxial compressive strain improves its hole transport performance compared to that under biaxial tensile strain. In summary, biaxial compressive strain causes a decrease in both the effective mass and phonon scattering rate of monolayer HfS₂, resulting in an increase in its carrier mobility. Under the biaxial compressive strain reaches 4%, the electron mobility enhancement ratio of the CB of monolayer HfS₂ is ~90%. For the VB of monolayer HfS₂, the maximum hole mobility enhancement ratio appears to be ~13% at a biaxial compressive strain of 4%. Our results indicate that the carrier transport performance of monolayer HfS₂ can be greatly improved by strain engineering. Full article

(This article belongs to the Special Issue Theoretical Calculation Study of Nanomaterials: 2nd Edition)

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19 pages, 5359 KiB

Open AccessArticle

Cellulose Nanofibrils Dewatered with Poly(Lactic Acid) for Improved Bio-Polymer Nanocomposite Processing

by Alexander Collins and Mehdi Tajvidi

Nanomaterials 2024, 14(17), 1419; https://doi.org/10.3390/nano14171419 - 30 Aug 2024

Abstract

Cellulose nanofibrils (CNFs) have theoretically ideal properties for bio-based composite applications; however, the incorporation of these materials into polymers is made challenging by the strong binding of water to CNFs and the irreversible agglomeration of CNFs during drying. Previous methods used “contact dewatering”, [...] Read more.

Cellulose nanofibrils (CNFs) have theoretically ideal properties for bio-based composite applications; however, the incorporation of these materials into polymers is made challenging by the strong binding of water to CNFs and the irreversible agglomeration of CNFs during drying. Previous methods used “contact dewatering”, wherein the addition of wood flour (WF) to CNFs facilitated the mechanical removal of water from the system via cold pressing, which showed potential in producing dried CNF fibrils attached to wood fibers for biocomposite applications. In this work, the viability of contact dewatering with poly(lactic) acid (PLA) powder for PLA/CNF composites was evaluated. The energy efficiency of dewatering, preservation of nanoscale CNF morphology, and mechanical properties were examined by mixing wet CNFs with pulverized PLA at various loading levels, pressing water out of the system, and compression molding and shear mixing composites for testing. The most impressive results from this dewatering method were the preservation of micron-to-nanoscale fibers with high aspect ratios in PLA-CNF composites; increased strength and modulus of 1.7% and 4.2%, respectively, compared to neat PLA; equivalent or better properties than spray-dried nanocellulose at similar loading levels; and an 11-194x reduction in drying energy compared to spray-drying CNFs. Full article

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13 pages, 5646 KiB

Open AccessArticle

Controlling Gold-Assisted Exfoliation of Large-Area MoS₂ Monolayers with External Pressure

by Sikai Chen, Bingrui Li, Chaoqi Dai, Lemei Zhu, Yan Shen, Fei Liu, Shaozhi Deng and Fangfei Ming

Nanomaterials 2024, 14(17), 1418; https://doi.org/10.3390/nano14171418 - 30 Aug 2024

Abstract

Gold-assisted exfoliation can fabricate centimeter- or larger-sized monolayers of van der Waals (vdW) semiconductors, which is desirable for their applications in electronic and optoelectronic devices. However, there is still a lack of control over the exfoliation processes and a limited understanding of the [...] Read more.

Gold-assisted exfoliation can fabricate centimeter- or larger-sized monolayers of van der Waals (vdW) semiconductors, which is desirable for their applications in electronic and optoelectronic devices. However, there is still a lack of control over the exfoliation processes and a limited understanding of the atomic-scale mechanisms. Here, we tune the MoS₂-Au interface using controlled external pressure and reveal two atomic-scale prerequisites for successfully producing large-area monolayers of MoS₂. The first is the formation of strong MoS₂-Au interactions to anchor the top MoS₂ monolayer to the Au surface. The second is the integrity of the covalent network of the monolayer, as the majority of the monolayer is non-anchored and relies on the covalent network to be exfoliated from the bulk MoS₂. Applying pressure or using smoother Au films increases the MoS₂-Au interaction, but may cause the covalent network of the MoS₂ monolayer to break due to excessive lateral strain, resulting in nearly zero exfoliation yield. Scanning tunneling microscopy measurements of the MoS₂ monolayer-covered Au show that even the smallest atomic-scale imperfections can disrupt the MoS₂-Au interaction. These findings can be used to develop new strategies for fabricating vdW monolayers through metal-assisted exfoliation, such as in cases involving patterned or non-uniform surfaces. Full article

(This article belongs to the Section 2D and Carbon Nanomaterials)

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19 pages, 3685 KiB

Open AccessReview

Development and Application of Surface-Enhanced Raman Scattering (SERS)

by Zhenkai Huang, Jianping Peng, Liguo Xu and Peijiang Liu

Nanomaterials 2024, 14(17), 1417; https://doi.org/10.3390/nano14171417 - 29 Aug 2024

Abstract

Since the discovery of the phenomenon of surface-enhanced Raman scattering (SERS), it has gradually become an important tool for the analysis of material compositions and structures. The applications of SERS have been expanded from the fields of environmental and materials science to biomedicine [...] Read more.

Since the discovery of the phenomenon of surface-enhanced Raman scattering (SERS), it has gradually become an important tool for the analysis of material compositions and structures. The applications of SERS have been expanded from the fields of environmental and materials science to biomedicine due to the extremely high sensitivity and non-destructiveness of SERS-based analytical technology that even allows single-molecule detection. This article provides a comprehensive overview of the surface-enhanced Raman scattering (SERS) phenomenon. The content is divided into several main sections: basic principles and the significance of Raman spectroscopy; historical advancements and technological progress in SERS; and various practical applications across different fields. We also discuss how electromagnetic fields contribute to the SERS effect, the role of chemical interactions in enhancing Raman signals, a modeling and computational approaches to understand and predict SERS effects. Full article

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12 pages, 5268 KiB

Open AccessArticle

Enhancing Perovskite Solar Cell Performance through Propylamine Hydroiodide Passivation

by Fulin Sun, Ting Zhu, Chenhui Zhang, Yi Dong, Yuzhu Guo, Dan Li, Fangtian You and Chunjun Liang

Nanomaterials 2024, 14(17), 1416; https://doi.org/10.3390/nano14171416 - 29 Aug 2024

Abstract

In recent years, the power conversion efficiency of perovskite solar cells has increased rapidly. Perovskites can be prepared using simple and cost-effective solution methods. However, the perovskite films obtained are usually polycrystalline and contain numerous defects. Passivation of these defects is crucial for [...] Read more.

In recent years, the power conversion efficiency of perovskite solar cells has increased rapidly. Perovskites can be prepared using simple and cost-effective solution methods. However, the perovskite films obtained are usually polycrystalline and contain numerous defects. Passivation of these defects is crucial for enhancing the performance of solar cells. Here, we report the use of propylamine hydroiodide (PAI) for defect passivation. We found that PAI can result in higher-efficiency cells by reducing the defects and suppressing non-radiative recombination. Consequently, n-i-p perovskite solar cells with a certificated efficiency of 21% were obtained. In addition, PAI exhibited excellent performance in p-i-n devices by serving as a buried interface layer, leading to an improved efficiency of 23%. Full article

(This article belongs to the Section Solar Energy and Solar Cells)

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13 pages, 8361 KiB

Open AccessCommunication

Regeneration of Antifog Performance of Laser-Induced Copper-Based Micro-Nano Structured Surfaces by Rapid Thermal Treatment

by Huixing Zhang, Xinyi Xie, Xiaowen Qi, Chengling Liu, Chenrui Wang, Xiaolong Fang, Youfu Wang, Hongtao Cui and Ji Dong

Nanomaterials 2024, 14(17), 1415; https://doi.org/10.3390/nano14171415 - 29 Aug 2024

Abstract

In this investigation, the laser marker ablation technique was employed on Cu-coated glass to fabricate micro-nanostructured antifog glass. The resulting surfaces exhibited a quasi-periodic micron hillock-hollow structure with dispersed nanoparticles distributed throughout, which played a role in the antifog property and superhydrophilicity. However, [...] Read more.

In this investigation, the laser marker ablation technique was employed on Cu-coated glass to fabricate micro-nanostructured antifog glass. The resulting surfaces exhibited a quasi-periodic micron hillock-hollow structure with dispersed nanoparticles distributed throughout, which played a role in the antifog property and superhydrophilicity. However, airborne organic pollutant deposition degraded the superhydrophilicity of ablated glass surfaces and, therefore, their antifog performance, which cannot be circumvented. Conventionally, furnace annealing for at least 1 h was used to decompose the organic pollutants and restore the superhydrophilicity, limiting the throughput and application scenario. Remarkably, the rapid regeneration of this property was achieved through either a 5 min rapid thermal treatment at 400 °C or a 1 s flame treatment. These are interventions that are hitherto unreported. Such short and simple treatment methods underscore the potential of laser-ablated glass for diverse practical applications. Full article

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18 pages, 12472 KiB

Open AccessFeature PaperArticle

Persistent Luminescent Nanoparticle-Loaded Filaments for Identification of Fabrics in the Visible and Infrared

by Brian G. Yust, Abdur Rahaman Sk, Antonios Kontsos and Brian George

Nanomaterials 2024, 14(17), 1414; https://doi.org/10.3390/nano14171414 - 29 Aug 2024

Abstract

Persistent luminescent materials are those which can store an amount of energy locally and release it slowly in the form of light. In this work, persistent luminescent nanoparticles (PLNPs) were synthesized and incorporated into polypropylene (PP) filaments at various loading percentages. We investigated [...] Read more.

Persistent luminescent materials are those which can store an amount of energy locally and release it slowly in the form of light. In this work, persistent luminescent nanoparticles (PLNPs) were synthesized and incorporated into polypropylene (PP) filaments at various loading percentages. We investigated the optical properties of both the as-prepared PLNPs and the PLNP-loaded filaments, focusing on any changes resulting from the integration into the filaments. Specifically, visible and near-infrared spectroscopy were used to analyze the emission, excitation, and persistent luminescence of the PLNPs and PLNP-loaded filaments. The tensile properties of the extruded filaments were also investigated through breaking tenacity, elongation at break, Young’s modulus, and secant modulus. All PLNP-loaded filaments were shown to exhibit persistent luminescence when exposed to ultraviolet light. While there were no significant changes in the elongation at break or Young’s modulus for the loading percentages tested, there was a slight increase in breaking tenacity and a decrease in the secant modulus. Finally, the filaments were shown to maintain their optical properties and persistent luminescence even after abrasion testing used to simulate the normal wear and tear that fabric experiences during use. These results show that PLNPs can be successfully incorporated into filaments which can be used in fabrics and will maintain the persistent luminescent properties. Full article

(This article belongs to the Special Issue Nanomaterials and Textiles)

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12 pages, 2681 KiB

Open AccessArticle

Interpretable Structural Evaluation of Metal-Oxide Nanostructures in Scanning Transmission Electron Microscopy (STEM) Images via Persistent Homology

by Ryuto Eguchi, Yu Wen, Hideki Abe and Ayako Hashimoto

Nanomaterials 2024, 14(17), 1413; https://doi.org/10.3390/nano14171413 - 29 Aug 2024

Abstract

Persistent homology is a powerful tool for quantifying various structures, but it is equally crucial to maintain its interpretability. In this study, we extracted interpretable geometric features from the persistent diagrams (PDs) of scanning transmission electron microscopy (STEM) images of self-assembled Pt-CeO₂ [...] Read more.

Persistent homology is a powerful tool for quantifying various structures, but it is equally crucial to maintain its interpretability. In this study, we extracted interpretable geometric features from the persistent diagrams (PDs) of scanning transmission electron microscopy (STEM) images of self-assembled Pt-CeO₂ nanostructures synthesized under different annealing conditions. We focused on PD quadrants and extracted five interpretable features from the zeroth and first PDs of nanostructures ranging from maze-like to striped patterns. A combination of hierarchical clustering and inverse analysis of PDs reconstructed by principal component analysis through vectorization of the PDs highlighted the importance of the number of arc-like structures of the CeO₂ phase in the first PDs, particularly those that were smaller than a characteristic size. This descriptor enabled us to quantify the degree of disorder, namely the density of bends, in nanostructures formed under different conditions. By using this descriptor along with the width of the CeO₂ phase, we classified 12 Pt-CeO₂ nanostructures in an interpretable way. Full article

(This article belongs to the Special Issue Nanostructured Oxides: Advances in Synthesis, Characterization, and Applications)

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10 pages, 4693 KiB

Open AccessArticle

Audio Signal-Stimulated Multilayered HfO_x/TiO_y Spiking Neuron Network for Neuromorphic Computing

by Shengbo Gao, Mingyuan Ma, Bin Liang, Yuan Du, Li Du and Kunji Chen

Nanomaterials 2024, 14(17), 1412; https://doi.org/10.3390/nano14171412 - 29 Aug 2024

Abstract

As the key hardware of a brain-like chip based on a spiking neuron network (SNN), memristor has attracted more attention due to its similarity with biological neurons and synapses to deal with the audio signal. However, designing stable artificial neurons and synapse devices [...] Read more.

As the key hardware of a brain-like chip based on a spiking neuron network (SNN), memristor has attracted more attention due to its similarity with biological neurons and synapses to deal with the audio signal. However, designing stable artificial neurons and synapse devices with a controllable switching pathway to form a hardware network is a challenge. For the first time, we report that artificial neurons and synapses based on multilayered HfO_x/TiO_y memristor crossbar arrays can be used for the SNN training of audio signals, which display the tunable threshold switching and memory switching characteristics. It is found that tunable volatile and nonvolatile switching from the multilayered HfO_x/TiO_y memristor is induced by the size-controlled atomic oxygen vacancy pathway, which depends on the atomic sublayer in the multilayered structure. The successful emulation of the biological neuron’s integrate-and-fire function can be achieved through the utilization of the tunable threshold switching characteristic. Based on the stable performance of the multilayered HfO_x/TiO_y neuron and synapse, we constructed a hardware SNN architecture for processing audio signals, which provides a base for the recognition of audio signals through the function of integration and firing. Our design of an atomic conductive pathway by using a multilayered TiO_y/HfO_x memristor supplies a new method for the construction of an artificial neuron and synapse in the same matrix, which can reduce the cost of integration in an AI chip. The implementation of synaptic functionalities by the hardware of SNNs paves the way for novel neuromorphic computing paradigms in the AI era. Full article

(This article belongs to the Section Nanocomposite Materials)

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14 pages, 5319 KiB

Open AccessArticle

Ultrahigh Electrostrictive Effect in Lead-Free Sodium Bismuth Titanate-Based Relaxor Ferroelectric Thick Film

by Yizhuo Li, Jinyan Zhao, Zhe Wang, Kun Zheng, Jie Zhang, Chuying Chen, Lingyan Wang, Genshui Wang, Xin Li, Yulong Zhao, Gang Niu and Wei Ren

Nanomaterials 2024, 14(17), 1411; https://doi.org/10.3390/nano14171411 - 29 Aug 2024

Abstract

In recent years, the development of environmentally friendly, lead-free ferroelectric films with prominent electrostrictive effects have been a key area of focus due to their potential applications in micro-actuators, sensors, and transducers for advanced microelectromechanical systems (MEMS). This work investigated the enhanced electrostrictive [...] Read more.

In recent years, the development of environmentally friendly, lead-free ferroelectric films with prominent electrostrictive effects have been a key area of focus due to their potential applications in micro-actuators, sensors, and transducers for advanced microelectromechanical systems (MEMS). This work investigated the enhanced electrostrictive effect in lead-free sodium bismuth titanate-based relaxor ferroelectric films. The films, composed of (Bi_0.5Na_0.5)_0.8−xBa_xSr_0.2TiO₃ (BNBST, x = 0.02, 0.06, and 0.11), with thickness around 1 μm, were prepared using a sol-gel method on Pt/TiO₂/SiO₂/Si substrates. By varying the Ba²⁺ content, the crystal structure, morphology, and electrical properties, including dielectric, ferroelectric, strain, and electromechanical performance, were investigated. The films exhibited a single pseudocubic structure without preferred orientation. A remarkable strain response (S > 0.24%) was obtained in the films (x = 0.02, 0.06) with the coexistence of nonergodic and ergodic relaxor phases. Further, in the x = 0.11 thick films with an ergodic relaxor state, an ultrahigh electrostrictive coefficient Q of 0.32 m⁴/C² was achieved. These findings highlight the potential of BNBST films as high-performance, environmentally friendly electrostrictive films for advanced microelectromechanical systems (MEMS) and electronic devices. Full article

(This article belongs to the Special Issue Synthesis and Ferroelectric, Photoelectric, Magnetic Properties of Thin Films)

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