Nanomaterials

13 pages, 3748 KiB

Open AccessArticle

Enhancing Charge Trapping Performance of Hafnia Thin Films Using Sequential Plasma Atomic Layer Deposition

by So-Won Kim, Jae-Hoon Yoo, Won-Ji Park, Chan-Hee Lee, Joung-Ho Lee, Jong-Hwan Kim, Sae-Hoon Uhm and Hee-Chul Lee

Nanomaterials 2024, 14(20), 1686; https://doi.org/10.3390/nano14201686 - 21 Oct 2024

Viewed by 923

Abstract

We aimed to fabricate reliable memory devices using HfO₂, which is gaining attention as a charge-trapping layer material for next-generation NAND flash memory. To this end, a new atomic layer deposition process using sequential remote plasma (RP) and direct plasma (DP) [...] Read more.

We aimed to fabricate reliable memory devices using HfO₂, which is gaining attention as a charge-trapping layer material for next-generation NAND flash memory. To this end, a new atomic layer deposition process using sequential remote plasma (RP) and direct plasma (DP) was designed to create charge-trapping memory devices. Subsequently, the operational characteristics of the devices were analyzed based on the thickness ratio of thin films deposited using the sequential RP and DP processes. As the thickness of the initially RP-deposited thin film increased, the memory window and retention also increased, while the interface defect density and leakage current decreased. When the thickness of the RP-deposited thin film was 7 nm, a maximum memory window of 10.1 V was achieved at an operating voltage of ±10 V, and the interface trap density (D_it) reached a minimum value of 1.0 × 10¹² eV⁻¹cm⁻². Once the RP-deposited thin film reaches a certain thickness, the ion bombardment effect from DP on the substrate is expected to decrease, improving the Si/SiO₂/HfO₂ interface and thereby enhancing device endurance and reliability. This study confirmed that the proposed sequential RP and DP deposition processes could resolve issues related to unstable interface layers, improve device performance, and enhance process throughput. Full article

(This article belongs to the Section Nanofabrication and Nanomanufacturing)

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26 pages, 6642 KiB

Open AccessEditor’s ChoiceReview

Ligands of Nanoparticles and Their Influence on the Morphologies of Nanoparticle-Based Films

by Jungwook Choi and Byung Hyo Kim

Nanomaterials 2024, 14(20), 1685; https://doi.org/10.3390/nano14201685 - 21 Oct 2024

Viewed by 1001

Abstract

Nanoparticle-based thin films are increasingly being used in various applications. One of the key factors that determines the properties and performances of these films is the type of ligands attached to the nanoparticle surfaces. While long-chain surfactants, such as oleic acid, are commonly [...] Read more.

Nanoparticle-based thin films are increasingly being used in various applications. One of the key factors that determines the properties and performances of these films is the type of ligands attached to the nanoparticle surfaces. While long-chain surfactants, such as oleic acid, are commonly employed to stabilize nanoparticles and ensure high monodispersity, these ligands often hinder charge transport due to their insulating nature. Although thermal annealing can remove the long-chain ligands, the removal process often introduces defects such as cracks and voids. In contrast, the use of short-chain organic or inorganic ligands can minimize interparticle distance, improving film conductivity, though challenges such as incomplete ligand exchange and residual barriers remain. Polymeric ligands, especially block copolymers, can also be employed to create films with tailored porosity. This review discusses the effects of various ligand types on the morphology and performance of nanoparticle-based films, highlighting the trade-offs between conductivity, structural integrity, and functionality. Full article

(This article belongs to the Section Nanofabrication and Nanomanufacturing)

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20 pages, 2016 KiB

Open AccessArticle

Phonon Drag Contribution to Thermopower for a Heated Metal Nanoisland on a Semiconductor Substrate

by Alexander Arkhipov, Karina Trofimovich, Nikolay Arkhipov and Pavel Gabdullin

Nanomaterials 2024, 14(20), 1684; https://doi.org/10.3390/nano14201684 - 21 Oct 2024

Viewed by 515

Abstract

The possible contribution of phonon drag effect to the thermoelectrically sustained potential of a heated nanoisland on a semiconductor surface was estimated in a first principal consideration. We regarded electrons and phonons as interacting particles, and the interaction cross-section was derived from the [...] Read more.

The possible contribution of phonon drag effect to the thermoelectrically sustained potential of a heated nanoisland on a semiconductor surface was estimated in a first principal consideration. We regarded electrons and phonons as interacting particles, and the interaction cross-section was derived from the basic theory of semiconductors. The solution of the equation of motion for average electrons under the simultaneous action of phonon drag and electric field gave the distributions of phonon flux, density of charge carriers and electric potential. Dimensional suppression of thermal conductance and electron-phonon interaction were accounted for but found to be less effective than expected. The developed model predicts the formation of a layer with a high density of charge carriers that is practically independent of the concentration of dopant ions. This layer can effectively intercept the phonon flow propagating from the heated nanoisland. The resulting thermoEMF can have sufficient magnitudes to explain the low-voltage electron emission capability of nanoisland films of metals and sp²-bonded carbon, previously studied by our group. The phenomenon predicted by the model can be used in thermoelectric converters with untypical parameters or in systems for local cooling. Full article

(This article belongs to the Section Theory and Simulation of Nanostructures)

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8 pages, 4392 KiB

Open AccessArticle

Flexible All-Carbon Nanoarchitecture Built from In Situ Formation of Nanoporous Graphene Within “Skeletal-Capillary” Carbon Nanotube Networks for Supercapacitors

by Tao Chen, Hongyan Li, Jiaziyi Wang and Xilai Jia

Nanomaterials 2024, 14(20), 1683; https://doi.org/10.3390/nano14201683 - 21 Oct 2024

Viewed by 541

Abstract

It is difficult for carbonaceous materials to combine a large specific surface area with flexibility. Here, a flexible all-carbon nanoarchitecture based on the in situ growth of nanoporous graphene within “skeletal-capillary” carbon nanotube (CNT) networks has been achieved by a chemical vapor deposition [...] Read more.

It is difficult for carbonaceous materials to combine a large specific surface area with flexibility. Here, a flexible all-carbon nanoarchitecture based on the in situ growth of nanoporous graphene within “skeletal-capillary” carbon nanotube (CNT) networks has been achieved by a chemical vapor deposition (CVD) process. Multi-path long-range conductivity is established, and the porous graphene provides a large specific surface area for charge storage. The flexibility of the films allows them to be directly used as binder-free electrodes for supercapacitors. Since the polymeric binders are saved, the supercapacitors exhibit a higher overall storage density. Full article

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

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17 pages, 4634 KiB

Open AccessArticle

On the Synthesis of Graphene Oxide/Titanium Dioxide (GO/TiO₂) Nanorods and Their Application as Saturable Absorbers for Passive Q-Switched Fiber Lasers

by Zain ul Abedin, Ajaz ul Haq, Rizwan Ahmed, Tahani A. Alrebdi, Ali M. Alshehri, Muhammad Irfan and Haroon Asghar

Nanomaterials 2024, 14(20), 1682; https://doi.org/10.3390/nano14201682 - 20 Oct 2024

Viewed by 936

Abstract

We report passively Q-switched pulse operation through an erbium-doped fiber laser (EDFL) utilizing graphene oxide/titania (GO/TiO₂) nanorods as a saturable absorber. The GO/TiO₂ nanorods were fabricated using a Sol–gel-assisted hydrothermal method. The optical and physical characterization of the GO/TiO₂ [...] Read more.

We report passively Q-switched pulse operation through an erbium-doped fiber laser (EDFL) utilizing graphene oxide/titania (GO/TiO₂) nanorods as a saturable absorber. The GO/TiO₂ nanorods were fabricated using a Sol–gel-assisted hydrothermal method. The optical and physical characterization of the GO/TiO₂ was then characterized using a field-emission-scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and diffuses reflectance spectroscopy (DRS). To investigate the performance of the Q-switched EDFL based on the GO/TiO₂ SA, the prepared nanorods were mechanically deposited on the fiber ferrule employing adhesion effects of in-dex-matching gel. This integration of the nanorod SA resulted in a self-starting Q-switching opera-tion initiated at a pump power of 17.5 mW and sustained up to 306.9 mW. When the pump range was tuned from 17.5 to 306.9 mW, the emission wavelength varied from 1564.2 to 1562.9 nm, pulse repetition rates increased from 13.87 kHz to 83.33 kHz, and pulse width decreased from 30.27 µs to 3.75 µs. Moreover, at the maximum pump power of 306.9 mW, the laser exhibited an average output power of 0.74 mW, a peak power of 1.54 mW, and a pulse energy of 8.88 nJ. Furthermore, this study investigates the GO/TiO₂ damage threshold and prolonged stability of the proposed EDFL system. Full article

(This article belongs to the Special Issue Nonlinear Optical Property and Sensing Applications of Nanomaterials)

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14 pages, 4167 KiB

Open AccessEditor’s ChoiceArticle

Silver-Doped Reduced Graphene Oxide/PANI-DBSA-PLA Composite 3D-Printed Supercapacitors

by Claudia Cirillo, Mariagrazia Iuliano, Davide Scarpa, Pierpaolo Iovane, Carmela Borriello, Sabrina Portofino, Sergio Galvagno and Maria Sarno

Nanomaterials 2024, 14(20), 1681; https://doi.org/10.3390/nano14201681 - 20 Oct 2024

Viewed by 836

Abstract

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for [...] Read more.

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for additive manufacturing. The composite was extruded into filaments and printed into circular disc electrodes using fused deposition modeling (FDM). These electrodes were assembled into symmetric supercapacitor devices with a solid-state electrolyte. Electrochemical characterization, including cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) tests, demonstrated considerable mass-specific capacitance values of 136.2 F/g and 133 F/g at 20 mV/s and 1 A/g, respectively. The devices showed excellent stability, retaining 91% of their initial capacitance after 5000 cycles. The incorporation of silver nanoparticles enhanced the conductivity of rGO, while PANI-DBSA improved electrochemical stability and performance. This study highlights the potential of combining advanced materials with 3D printing to optimize energy storage devices, offering a significant advancement over traditional manufacturing methods. Full article

(This article belongs to the Special Issue Hybrid Nano Polymer Composites (2nd Edition))

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20 pages, 11854 KiB

Open AccessArticle

Printability Metrics and Engineering Response of HDPE/Si₃N₄ Nanocomposites in MEX Additive Manufacturing

by Vassilis M. Papadakis, Markos Petousis, Nikolaos Michailidis, Maria Spyridaki, Ioannis Valsamos, Apostolos Argyros, Katerina Gkagkanatsiou, Amalia Moutsopoulou and Nectarios Vidakis

Nanomaterials 2024, 14(20), 1680; https://doi.org/10.3390/nano14201680 - 19 Oct 2024

Viewed by 741

Abstract

Herein, silicon nitride (Si₃N₄) was the selected additive to be examined for its reinforcing properties on high-density polyethylene (HDPE) by exploiting techniques of the popular material extrusion (MEX) 3D printing method. Six different HDPE/Si₃N₄ composites with [...] Read more.

Herein, silicon nitride (Si₃N₄) was the selected additive to be examined for its reinforcing properties on high-density polyethylene (HDPE) by exploiting techniques of the popular material extrusion (MEX) 3D printing method. Six different HDPE/Si₃N₄ composites with filler percentages ranging between 0.0–10.0 wt. %, having a 2.0 step, were produced initially in compounds, then in filaments, and later in the form of specimens, to be examined by a series of tests. Thermal, rheological, mechanical, structural, and morphological analyses were also performed. For comprehensive mechanical characterization, tensile, flexural, microhardness (M-H), and Charpy impacts were included. Scanning electron microscopy (SME) was used for morphological assessments and microcomputed tomography (μ-CT). Raman spectroscopy was conducted, and the elemental composition was assessed using energy-dispersive spectroscopy (EDS). The HDPE/Si₃N₄ composite with 6.0 wt. % was the one with an enhancing performance higher than the rest of the composites, in the majority of the mechanical metrics (more than 20% in the tensile and flexural experiment), showing a strong potential for Si₃N₄ as a reinforcement additive in 3D printing. This method can be easily industrialized by further exploiting the MEX 3D printing method. Full article

(This article belongs to the Special Issue From Biomass to Nanomaterials)

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49 pages, 17202 KiB

Open AccessReview

A Review of Wide Bandgap Semiconductors: Insights into SiC, IGZO, and Their Defect Characteristics

by Qiwei Shangguan, Yawei Lv and Changzhong Jiang

Nanomaterials 2024, 14(20), 1679; https://doi.org/10.3390/nano14201679 - 19 Oct 2024

Viewed by 854

Abstract

Although the irreplaceable position of silicon (Si) semiconductor materials in the field of information has become a consensus, new materials continue to be sought to expand the application range of semiconductor devices. Among them, research on wide bandgap semiconductors has already achieved preliminary [...] Read more.

Although the irreplaceable position of silicon (Si) semiconductor materials in the field of information has become a consensus, new materials continue to be sought to expand the application range of semiconductor devices. Among them, research on wide bandgap semiconductors has already achieved preliminary success, and the relevant achievements have been applied in the fields of energy conversion, display, and storage. However, similar to the history of Si, the immature material grown and device manufacturing processes at the current stage seriously hinder the popularization of wide bandgap semiconductor-based applications, and one of the crucial issues behind this is the defect problem. Here, we take amorphous indium gallium zinc oxide (a-IGZO) and 4H silicon carbide (4H-SiC) as two representatives to discuss physical/mechanical properties, electrical performance, and stability from the perspective of defects. Relevant experimental and theoretical works on defect formation, evolution, and annihilation are summarized, and the impacts on carrier transport behaviors are highlighted. State-of-the-art applications using the two materials are also briefly reviewed. This review aims to assist researchers in elucidating the complex impacts of defects on electrical behaviors of wide bandgap semiconductors, enabling them to make judgments on potential defect issues that may arise in their own processes. It aims to contribute to the effort of using various post-treatment methods to control defect behaviors and achieve the desired material and device performance. Full article

(This article belongs to the Special Issue Simulation Study of Nanoelectronics)

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14 pages, 1725 KiB

Open AccessArticle

Toxicological Characteristics of Bacterial Nanocellulose in an In Vivo Experiment—Part 2: Immunological Endpoints, Influence on the Intestinal Barrier and Microbiome

by Vladimir A. Shipelin, Ekaterina A. Skiba, Vera V. Budaeva, Antonina A. Shumakova, Eleonora N. Trushina, Oksana K. Mustafina, Yuliya M. Markova, Nikolay A. Riger, Ivan V. Gmoshinski, Svetlana A. Sheveleva, Sergey A. Khotimchenko and Dmitry B. Nikityuk

Nanomaterials 2024, 14(20), 1678; https://doi.org/10.3390/nano14201678 - 19 Oct 2024

Viewed by 561

Abstract

Bacterial nanocellulose (BNC) is considered a promising alternative to microcrystalline cellulose, as well as an ingredient in low-calorie dietary products. However, the risks of BNC when consumed with food are not well characterized. The aim of this study is to investigate the impact [...] Read more.

Bacterial nanocellulose (BNC) is considered a promising alternative to microcrystalline cellulose, as well as an ingredient in low-calorie dietary products. However, the risks of BNC when consumed with food are not well characterized. The aim of this study is to investigate the impact of BNC on immune function, the intestinal microbiome, intestinal barrier integrity, and allergic sensitization in subacute experiments on rats. Male Wistar rats received BNC with a diet for eight weeks in a dose range of 1–100 mg/kg of body weight. The measurements of serum levels of cytokines, adipokines, iFABP2, indicators of cellular immunity, composition of the intestinal microbiome, and a histological study of the ileal mucosa were performed. In a separate four-week experiment on a model of systemic anaphylaxis to food antigen, BNC at a dose of 100 mg/kg of body weight did not increase the severity of the reaction or change the response of IgG antibodies. Based on dose–response effects on immune function, the non-observed adverse effect level for BNC was less than 100 mg/kg of body weight per day. The effects of BNC on the gut microbiome and the intestinal mucosal barrier were not dose-dependent. Data on the possible presence of prebiotic effects in BNC have been obtained. Full article

(This article belongs to the Special Issue Nanosafety and Nanotoxicology: Current Opportunities and Challenges)

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13 pages, 3320 KiB

Open AccessCommunication

Colossal Dielectric Constant of Nanocrystalline/Amorphous Homo-Composite BaTiO₃ Films Deposited via Pulsed Laser Deposition Technique

by Shinya Kondo, Taichi Murakami, Loick Pichon, Joël Leblanc-Lavoie, Takashi Teranishi, Akira Kishimoto and My Ali El Khakani

Nanomaterials 2024, 14(20), 1677; https://doi.org/10.3390/nano14201677 - 18 Oct 2024

Viewed by 689

Abstract

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO₃ (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (ε_r) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (T [...] Read more.

We report the pulsed laser deposition (PLD) of nanocrystalline/amorphous homo-composite BaTiO₃ (BTO) films exhibiting an unprecedented combination of a colossal dielectric constant (ε_r) and extremely low dielectric loss (tan δ). By varying the substrate deposition temperature (T_d) over a wide range (300–800 °C), we identified T_d = 550 °C as the optimal temperature for growing BTO films with an ε_r as high as ~3060 and a tan δ as low as 0.04 (at 20 kHz). High-resolution transmission electron microscopy revealed that the PLD-BTO films consist of BTO nanocrystals (~20–30 nm size) embedded within an otherwise amorphous BTO matrix. The impressive dielectric behavior is attributed to the combination of highly crystallized small BTO nanograins, which amplify interfacial polarization, and the surrounding amorphous matrix, which effectively isolates the nanograins from charge carrier transport. Our findings could facilitate the development of next-generation integrated dielectric devices. Full article

(This article belongs to the Section Nanocomposite Materials)

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3 pages, 161 KiB

Open AccessEditorial

Nanomaterials Toward CO₂ Reduction and Conversion

by Rafael Camarillo

Nanomaterials 2024, 14(20), 1676; https://doi.org/10.3390/nano14201676 - 18 Oct 2024

Viewed by 606

Abstract

The increasing concentration of CO₂ in the atmosphere is one of the main factors contributing to global climate change [...] Full article

(This article belongs to the Special Issue Nanomaterials toward CO₂ Reduction and Conversion)

13 pages, 4260 KiB

Open AccessArticle

Unraveling Oxygen Vacancies Effect on Chemical Composition, Electronic Structure and Optical Properties of Eu Doped SnO₂

by Maxim A. Mashkovtsev, Anastasiya S. Kosykh, Alexey V. Ishchenko, Andrey V. Chukin, Andrey I. Kukharenko, Pavel A. Troshin and Ivan S. Zhidkov

Nanomaterials 2024, 14(20), 1675; https://doi.org/10.3390/nano14201675 - 18 Oct 2024

Viewed by 586

Abstract

The influence of Eu doping (0.5, 1 and 2 mol.%) and annealing in an oxygen-deficient atmosphere on the structure and optical properties of SnO₂ nanoparticles were investigated in relation to electronic structure. The X-ray diffraction (XRD) patterns revealed single-phase tetragonal rutile structure [...] Read more.

The influence of Eu doping (0.5, 1 and 2 mol.%) and annealing in an oxygen-deficient atmosphere on the structure and optical properties of SnO₂ nanoparticles were investigated in relation to electronic structure. The X-ray diffraction (XRD) patterns revealed single-phase tetragonal rutile structure for both synthesized and annealed Eu-doped SnO₂ samples, except for the annealed sample with 2 mol.% Eu. The results of X-ray photoelectron spectroscopy (XPS) emphasized that europium incorporated into the SnO₂ host lattice with an oxidation state of 3+, which was accompanied by the formation of oxygen vacancies under cation substitution of tetravalent Sn. Moreover, XPS spectra showed the O/Sn ratio, which has been reduced under annealing for creating additional oxygen vacancies. The pulse cathodoluminescence (PCL) demonstrated the concentration dependence of Eu site symmetry. Combination of XRD, XPS and PCL revealed that Eu doping and following annealing induce strongly disordering of the SnO₂ crystal lattice. Our findings provide new insight into the interaction of rare-earth metals (Eu) with host SnO₂ matrix and new evidence for the importance of oxygen vacancies for optical and electronic structure formation. Full article

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

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21 pages, 5788 KiB

Open AccessArticle

Using Femtosecond Laser Light to Investigate the Concentration- and Size-Dependent Nonlinear Optical Properties of Laser-Ablated CuO Quantum Dots

by Mohamed Ashour, Rasha Ibrahim, Yasmin Abd El-Salam, Fatma Abdel Samad, Alaa Mahmoud and Tarek Mohamed

Nanomaterials 2024, 14(20), 1674; https://doi.org/10.3390/nano14201674 - 18 Oct 2024

Viewed by 625

Abstract

In this work, the nonlinear optical (NLO) properties of CuO nanoparticles (CuO NPs) were studied experimentally using the pulsed laser ablation (PLA) technique. A nanosecond Nd: YAG laser was employed as the ablation excitation source to create CuO NPs in distilled water. Various [...] Read more.

In this work, the nonlinear optical (NLO) properties of CuO nanoparticles (CuO NPs) were studied experimentally using the pulsed laser ablation (PLA) technique. A nanosecond Nd: YAG laser was employed as the ablation excitation source to create CuO NPs in distilled water. Various CuO NPs samples were prepared at ablation periods of 20, 30, and 40 min. Utilizing HR-TEM, the structure of the synthesized CuO NPs samples was verified. In addition, a UV–VIS spectrophotometer was used to investigate the linear features of the samples. The Z-scan technique was utilized to explore the NLO properties of CuO NPs samples, including the nonlinear absorption coefficient (

β

) and nonlinear refractive index (

n_{2}

). An experimental study on the NLO features was conducted at a variety of excitation wavelengths (750–850 nm), average excitation powers (0.8–1.2 W), and CuO NPs sample concentrations and sizes. The reverse saturable absorption (RSA) behavior of all CuO NPs samples differed with the excitation wavelength and average excitation power. In addition, the CuO NPs samples demonstrated excellent optical limiters at various excitation wavelengths, with limitations dependent on the size and concentration of CuO NPs. Full article

(This article belongs to the Special Issue Characterization and Properties of Nanostructures in Liquids and Liquid/Liquid Interfaces)

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17 pages, 10837 KiB

Open AccessArticle

T1/T2 Proportional Magnetic Resonance Nanoprobe Monitoring Tumor Autophagy during Chemotherapy

by Jia Cui, Taixing Zhang, Fei Wang, Lingzi Feng, Guangjun Deng, Ting Wu, Le Yin and Yong Hu

Nanomaterials 2024, 14(20), 1673; https://doi.org/10.3390/nano14201673 - 18 Oct 2024

Viewed by 628

Abstract

Autophagy leads to cellular tolerance of the therapeutic pressure of chemotherapeutic drugs, resulting in treatment resistance. Therefore, the effective monitoring of the autophagy status of tumors in vivo and the regulating of the autophagy level are crucial for improving the efficacy of chemotherapy. [...] Read more.

Autophagy leads to cellular tolerance of the therapeutic pressure of chemotherapeutic drugs, resulting in treatment resistance. Therefore, the effective monitoring of the autophagy status of tumors in vivo and the regulating of the autophagy level are crucial for improving the efficacy of chemotherapy. In this work, we grafted nitroxide radicals onto the surface of iron oxide nanoparticles (Fe₃O₄ NPs) using dendrimer polymers, yielding Fe₃O₄-NO· NPs that are responsive to reactive oxygen species (ROS) and possess enhanced T1 and T2 signal capabilities in a magnetic resonance imaging (MRI) measurement. The ROS in tumor cells generated by autophagy quenches the nitroxide radicals, thereby weakening the T1 signal. In contrast, Fe₃O₄ NPs are unaffected by intracellular ROS, leading to a stable T2 signal. By comparing the intensity ratio of T1 to T2 in Fe₃O₄-NO· NPs, we can evaluate the in vivo autophagy status within tumors in real time. It also revealed that Fe₃O₄-NO· NPs loaded with doxorubicin (Dox) and combining the autophagy inhibitor exhibited high antitumor activity in cells and tumor-bearing mice. This system, which combines real-time monitoring of tumor cell autophagy with the delivery of chemotherapeutic drugs, provides an innovative and effective strategy for tumor treatment with potential clinical application prospects. Full article

(This article belongs to the Section Biology and Medicines)

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17 pages, 5287 KiB

Open AccessArticle

Exploring the Potential of Bimetallic PtPd/C Cathode Catalysts to Enhance the Performance of PEM Fuel Cells

by Vladimir Guterman, Anastasia Alekseenko, Sergey Belenov, Vladislav Menshikov, Elizaveta Moguchikh, Irina Novomlinskaya, Kirill Paperzh and Ilya Pankov

Nanomaterials 2024, 14(20), 1672; https://doi.org/10.3390/nano14201672 - 18 Oct 2024

Viewed by 849

Abstract

Bimetallic platinum-containing catalysts are deemed promising for electrolyzers and proton-exchange membrane fuel cells (PEMFCs). A significant number of laboratory studies and commercial offers are related to PtNi/C and PtCo/C electrocatalysts. The behavior of PtPd/C catalysts has been studied much less, although palladium itself [...] Read more.

Bimetallic platinum-containing catalysts are deemed promising for electrolyzers and proton-exchange membrane fuel cells (PEMFCs). A significant number of laboratory studies and commercial offers are related to PtNi/C and PtCo/C electrocatalysts. The behavior of PtPd/C catalysts has been studied much less, although palladium itself is the metal closest to platinum in its properties. Using a series of characterization methods, this paper presents a comparative study of structural characteristics of the commercial PtPd/C catalysts containing 38% wt. of precious metals and the well-known HiSpec4000 Pt/C catalyst. The electrochemical behavior of the catalysts was studied both in a three-electrode electrochemical cell and in the membrane electrode assemblies (MEAs) of hydrogen–air PEMFCs. Both PtPd/C samples demonstrated higher values of the electrochemically active surface area, as well as greater specific and mass activity in the oxygen reduction reaction in comparison with conventional Pt/C, while not being inferior to the latter in durability. The MEA based on the best of the PtPd/C catalysts also exhibited higher performance in single tests and long-term durability testing. The results of this study conducted indicate the prospects of using bimetallic PtPd/C materials for cathode catalysts in PEMFCs. Full article

(This article belongs to the Section Energy and Catalysis)

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20 pages, 3549 KiB

Open AccessReview

Rare-Earth Metal-Based Materials for Hydrogen Storage: Progress, Challenges, and Future Perspectives

by Yaohui Xu, Xi Yang, Yuting Li, Yu Zhao, Xing Shu, Guoying Zhang, Tingna Yang, Yitao Liu, Pingkeng Wu and Zhao Ding

Nanomaterials 2024, 14(20), 1671; https://doi.org/10.3390/nano14201671 - 18 Oct 2024

Viewed by 1413

Abstract

Rare-earth-metal-based materials have emerged as frontrunners in the quest for high-performance hydrogen storage solutions, offering a paradigm shift in clean energy technologies. This comprehensive review delves into the cutting-edge advancements, challenges, and future prospects of these materials, providing a roadmap for their development [...] Read more.

Rare-earth-metal-based materials have emerged as frontrunners in the quest for high-performance hydrogen storage solutions, offering a paradigm shift in clean energy technologies. This comprehensive review delves into the cutting-edge advancements, challenges, and future prospects of these materials, providing a roadmap for their development and implementation. By elucidating the fundamental principles, synthesis methods, characterization techniques, and performance enhancement strategies, we unveil the immense potential of rare-earth metals in revolutionizing hydrogen storage. The unique electronic structure and hydrogen affinity of these elements enable diverse storage mechanisms, including chemisorption, physisorption, and hydride formation. Through rational design, nanostructuring, surface modification, and catalytic doping, the hydrogen storage capacity, kinetics, and thermodynamics of rare-earth-metal-based materials can be significantly enhanced. However, challenges such as cost, scalability, and long-term stability need to be addressed for their widespread adoption. This review not only presents a critical analysis of the state-of-the-art but also highlights the opportunities for multidisciplinary research and innovation. By harnessing the synergies between materials science, nanotechnology, and computational modeling, rare-earth-metal-based hydrogen storage materials are poised to accelerate the transition towards a sustainable hydrogen economy, ushering in a new era of clean energy solutions. Full article

(This article belongs to the Special Issue Featured Reviews in Physical Chemistry at Nanoscale)

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13 pages, 3978 KiB

Open AccessArticle

DNA: Novel Crystallization Regulator for Solid Polymer Electrolytes in High-Performance Lithium-Ion Batteries

by Xiong Cheng and Joonho Bae

Nanomaterials 2024, 14(20), 1670; https://doi.org/10.3390/nano14201670 - 17 Oct 2024

Viewed by 584

Abstract

In this work, we designed a novel polyvinylidene fluoride (PVDF)@DNA solid polymer electrolyte, wherein DNA, as a plasticizer-like additive, reduced the crystallinity of the solid polymer electrolyte and improved its ionic conductivity. At the same time, due to its Lewis acid effect, DNA [...] Read more.

In this work, we designed a novel polyvinylidene fluoride (PVDF)@DNA solid polymer electrolyte, wherein DNA, as a plasticizer-like additive, reduced the crystallinity of the solid polymer electrolyte and improved its ionic conductivity. At the same time, due to its Lewis acid effect, DNA promotes the dissociation of lithium salts when interacting with lithium salt anions and can also fix the anions, creating more free lithium ions in the electrolyte and thus improving its ionic conductivity. However, owing to hydrogen bonding between DNA and PVDF, excess DNA occupies the lone pairs of electrons of the fluorine atoms on the PVDF molecular chains, affecting the conduction of lithium ions and the conductivity of the solid electrolyte. Hence, in this study, we investigated the effects of adding different DNA amounts to solid polymer electrolytes. The results show that 1% DNA addition resulted in the best improvement in the electrochemical performance of the electrolyte, demonstrating a high ionic conductivity of 3.74 × 10⁻⁵ S/cm (25 °C). The initial capacity reached 120 mAh/g; moreover, after 500 cycles, the all-solid-state batteries exhibited a capacity retention of approximately 71%, showing an outstanding cycling performance. Full article

(This article belongs to the Special Issue Preparation of Energy Storage Nanomaterials and Their Applications in Supercapacitors and Batteries)

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22 pages, 5485 KiB

Open AccessArticle

Peptide-Conjugated Vascular Endothelial Extracellular Vesicles Encapsulating Vinorelbine for Lung Cancer Targeted Therapeutics

by Isha Gaurav, Abhimanyu Thakur, Kui Zhang, Sudha Thakur, Xin Hu, Zhijie Xu, Gaurav Kumar, Ravindran Jaganathan, Ashok Iyaswamy, Min Li, Ge Zhang and Zhijun Yang

Nanomaterials 2024, 14(20), 1669; https://doi.org/10.3390/nano14201669 - 17 Oct 2024

Viewed by 831

Abstract

Lung cancer is one of the major cancer types and poses challenges in its treatment, including lack of specificity and harm to healthy cells. Nanoparticle-based drug delivery systems (NDDSs) show promise in overcoming these challenges. While conventional NDDSs have drawbacks, such as immune [...] Read more.

Lung cancer is one of the major cancer types and poses challenges in its treatment, including lack of specificity and harm to healthy cells. Nanoparticle-based drug delivery systems (NDDSs) show promise in overcoming these challenges. While conventional NDDSs have drawbacks, such as immune response and capture by the reticuloendothelial system (RES), extracellular vesicles (EVs) present a potential solution. EVs, which are naturally released from cells, can evade the RES without surface modification and with minimal toxicity to healthy cells. This makes them a promising candidate for developing a lung-cancer-targeting drug delivery system. EVs isolated from vascular endothelial cells, such as human umbilical endothelial-cell-derived EVs (HUVEC-EVs), have shown anti-angiogenic activity in a lung cancer mouse model; therefore, in this study, HUVEC-EVs were chosen as a carrier for drug delivery. To achieve lung-cancer-specific targeting, HUVEC-EVs were engineered to be decorated with GE11 peptides (GE11-HUVEC-EVs) via a postinsertional technique to target the epidermal growth factor receptor (EGFR) that is overexpressed on the surface of lung cancer cells. The GE11-HUVEC-EVs were loaded with vinorelbine (GE11-HUVEC-EVs-Vin), and then characterized and evaluated in in vitro and in vivo lung cancer models. Further, we examined the binding affinity of ABCB1, encoding P-glycoprotein, which plays a crucial role in chemoresistance via the efflux of the drug. Our results indicate that GE11-HUVEC-EVs-Vin effectively showed tumoricidal effects against cell and mouse models of lung cancer. Full article

(This article belongs to the Special Issue Extracellular Vesicles: Nanotechnology-Based Isolations, Characterizations, and Applications for Cancer Diagnostics and Monitoring)

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3 pages, 139 KiB

Open AccessEditorial

Advanced Nanomaterials in Biomedical Applications (2nd Edition)

by Goran N. Kaluđerović and Nebojša Đ. Pantelić

Nanomaterials 2024, 14(20), 1668; https://doi.org/10.3390/nano14201668 - 17 Oct 2024

Viewed by 495

Abstract

Scientific research into new functional materials for nanotechnology has attracted worldwide interest, driving substantial efforts to discovering a variety of nanomaterials [...] Full article

(This article belongs to the Special Issue Advanced Nanomaterials in Biomedical Application (2nd Edition))

9 pages, 2339 KiB

Open AccessArticle

Demonstration of Steep Switching Behavior Based on Band Modulation in WSe₂ Feedback Field-Effect Transistor

by Seung-Mo Kim, Jae Hyeon Jun, Junho Lee, Muhammad Taqi, Hoseong Shin, Sungwon Lee, Haewon Lee, Won Jong Yoo and Byoung Hun Lee

Nanomaterials 2024, 14(20), 1667; https://doi.org/10.3390/nano14201667 - 17 Oct 2024

Viewed by 663

Abstract

Feedback field-effect transistors (FBFETs) have been studied to obtain near-zero subthreshold swings at 300 K with a high on/off current ratio ~10¹⁰. However, their structural complexity, such as an epitaxy process after an etch process for a Si channel with a [...] Read more.

Feedback field-effect transistors (FBFETs) have been studied to obtain near-zero subthreshold swings at 300 K with a high on/off current ratio ~10¹⁰. However, their structural complexity, such as an epitaxy process after an etch process for a Si channel with a thickness of several nanometers, has limited broader research. We demonstrated a FBFET using in-plane WSe₂ p−n homojunction. The WSe₂ FBFET exhibited a minimum subthreshold swing of 153 mV/dec with 30 nm gate dielectric. Our modeling-based projection indicates that the swing of this device can be reduced to 14 mV/dec with 1 nm EOT. Also, the gain of the inverter using the WSe₂ FBFET can be improved by up to 1.53 times compared to a silicon CMOS inverter, and power consumption can be reduced by up to 11.9%. Full article

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21 pages, 4174 KiB

Open AccessArticle

Mandarin Peels-Derived Carbon Dots: A Multifaceted Fluorescent Probe for Cu(II) Detection in Tap and Drinking Water Samples

by Marwa El-Azazy, Alaa AlReyashi, Khalid Al-Saad, Nessreen Al-Hashimi, Mohammad A. Al-Ghouti, Mohamed F. Shibl, Abdulrahman Alahzm and Ahmed S. El-Shafie

Nanomaterials 2024, 14(20), 1666; https://doi.org/10.3390/nano14201666 - 17 Oct 2024

Viewed by 867

Abstract

Carbon dots (CDs) derived from mandarin peel biochar (MBC) at different pyrolysis temperatures (200, 400, 600, and 800 °C) have been synthesized and characterized. This high-value transformation of waste materials into fluorescent nanoprobes for environmental monitoring represents a step forward towards a circular [...] Read more.

Carbon dots (CDs) derived from mandarin peel biochar (MBC) at different pyrolysis temperatures (200, 400, 600, and 800 °C) have been synthesized and characterized. This high-value transformation of waste materials into fluorescent nanoprobes for environmental monitoring represents a step forward towards a circular economy. In this itinerary, CDs produced via one-pot hydrothermal synthesis were utilized for the detection of copper (II) ions. The study looked at the spectroscopic features of biochar-derived CDs. The selectivity of CDs obtained from biochar following carbonization at 400 °C (MBC400-CDs towards various heavy metal ions resulted in considerable fluorescence quenching with copper (II) ions, showcasing their potential as selective detectors. Transmission electron microscopic (TEM) analysis validated the MBC-CDs’ consistent spherical shape, with a particle size of <3 nm. The Plackett–Burman Design (PBD) was used to study three elements that influence the F₀/F ratio, with the best ratio obtained with a pH of 10, for 10 min, and an aqueous reaction medium. Cu (II) was detected over a dynamic range of 4.9–197.5 μM and limit of detection (LOD) of 0.01 μM. Validation testing proved the accuracy and precision for evaluating tap and mountain waters with great selectivity and no interference from coexisting metal ions. Full article

(This article belongs to the Special Issue Carbon Nanostructures as Promising Future Materials: 2nd Edition)

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12 pages, 4877 KiB

Open AccessEditor’s ChoiceArticle

Bubble Printing of Liquid Metal Colloidal Particles for Conductive Patterns

by Masaru Mukai, Tatsuya Kobayashi, Mitsuki Sato, Juri Asada, Kazuhide Ueno, Taichi Furukawa and Shoji Maruo

Nanomaterials 2024, 14(20), 1665; https://doi.org/10.3390/nano14201665 - 17 Oct 2024

Viewed by 1632

Abstract

Bubble printing is a patterning method in which particles are accumulated by the convection of bubbles generated by laser focusing. It is attracting attention as a method that enables the high-speed, high-precision patterning of various micro/nanoparticles. Although the bubble printing method is used [...] Read more.

Bubble printing is a patterning method in which particles are accumulated by the convection of bubbles generated by laser focusing. It is attracting attention as a method that enables the high-speed, high-precision patterning of various micro/nanoparticles. Although the bubble printing method is used for metallic particles and organic particles, most reports have focused on the patterning of solid particles and not on the patterning of liquid particles. In this study, liquid metal wiring patterns were fabricated using a bubble printing method in which eutectic gallium‒indium alloy (EGaIn) colloidal particles (≈diameter 0.7 µm) were fixed on a glass substrate by generating microbubbles through heat generation by focusing a femtosecond laser beam on the EGaIn colloidal particles. The wiring was then made conductive by replacing gallium oxide, which served as a resistance layer on the surface of the EGaIn colloidal particles, with silver via galvanic replacement. Fine continuous lines of liquid metal colloids with a line width of 3.4 µm were drawn by reducing the laser power. Liquid metal wiring with a conductivity of ≈1.5 × 10⁵ S/m was formed on a glass substrate. It was confirmed that the conductivity remained consistent even when the glass substrate was bent to a curvature of 0.02 m⁻¹. Full article

(This article belongs to the Special Issue Laser-Based Nano Fabrication and Nano Lithography: Second Edition)

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15 pages, 3323 KiB

Open AccessArticle

Chemistry of Reduced Graphene Oxide: Implications for the Electrophysical Properties of Segregated Graphene–Polymer Composites

by Maxim K. Rabchinskii, Kseniya A. Shiyanova, Maria Brzhezinskaya, Maksim V. Gudkov, Sviatoslav D. Saveliev, Dina Yu. Stolyarova, Mikhail K. Torkunov, Ratibor G. Chumakov, Artem Yu. Vdovichenko, Polina D. Cherviakova, Nikolai I. Novosadov, Diana Z. Nguen, Natalia G. Ryvkina, Alexander V. Shvidchenko, Nikita D. Prasolov and Valery P. Melnikov

Nanomaterials 2024, 14(20), 1664; https://doi.org/10.3390/nano14201664 - 16 Oct 2024

Viewed by 813

Abstract

Conductive polymer composites (CPCs) with nanocarbon fillers are at the high end of modern materials science, advancing current electronic applications. Herein, we establish the interplay between the chemistry and electrophysical properties of reduced graphene oxide (rGO), separately and as a filler for CPCs [...] Read more.

Conductive polymer composites (CPCs) with nanocarbon fillers are at the high end of modern materials science, advancing current electronic applications. Herein, we establish the interplay between the chemistry and electrophysical properties of reduced graphene oxide (rGO), separately and as a filler for CPCs with the segregated structure conferred by the chemical composition of the initial graphene oxide (GO). A set of experimental methods, namely X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy, van der Paw and temperature-dependent sheet resistance measurements, along with dielectric spectroscopy, are employed to thoroughly examine the derived materials. The alterations in the composition of oxygen groups along with their beneficial effect on nitrogen doping upon GO reduction by hydrazine are tracked with the help of XPS. The slight defectiveness of the graphene network is found to boost the conductivity of the material due to facilitating the impact of the nitrogen lone-pair electrons in charge transport. In turn, a sharp drop in material conductivity is indicated upon further disruption of the π-conjugated network, predominantly governing the charge transport. Particularly, the transition from the Mott variable hopping transport mechanism to the Efros–Shklovsky one is signified. Finally, the impact of rGO chemistry and physics on the electrophysical properties of CPCs with the segregated structure is evaluated. Taken together, our results give a hint at how GO chemistry manifests the properties of rGO and the CPC derived from it, offering compelling opportunities for their practical applications. Full article

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

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18 pages, 7530 KiB

Open AccessArticle

Investigating the Synergistic Effect of Decoration and Doping in Silver/Strontium Titanate for Air Remediation

by Marcela Frías Ordóñez, Elisabetta Sacco, Marco Scavini, Giuseppina Cerrato, Alessia Giordana, Ermelinda Falletta and Claudia Letizia Bianchi

Nanomaterials 2024, 14(20), 1663; https://doi.org/10.3390/nano14201663 - 16 Oct 2024

Viewed by 642

Abstract

Strontium titanate (STO) and its variants have emerged as leading materials in photocatalysis, particularly for degrading nitrogen oxides (NOx), due to their non-toxic nature, structural adaptability, and exceptional thermal stability. Although the one-pot sol-gel method leads to high-quality photocatalysts, areas remain for improvement. [...] Read more.

Strontium titanate (STO) and its variants have emerged as leading materials in photocatalysis, particularly for degrading nitrogen oxides (NOx), due to their non-toxic nature, structural adaptability, and exceptional thermal stability. Although the one-pot sol-gel method leads to high-quality photocatalysts, areas remain for improvement. This study examines the impact of ethanol as a cosolvent in STO synthesis, focusing on optimizing the water-to-ethanol volume ratio. The findings reveal that a 1:3 ratio significantly enhances macropore formation and photocatalytic efficiency, achieving 42% NOx degradation under LED within three hours. Furthermore, incorporating 8.0 wt.% Ag into STO substantially improves visible light absorption and enables complete NOx elimination, thanks to enhanced charge separation and localized surface plasmon resonance. Even at high temperatures (1100 °C), the Ag-STO photocatalyst maintains partial activity, despite exceeding silver’s melting point. These results highlight the potential of STO-based materials for industrial applications, positioning them as a promising solution for effective NOx mitigation. Full article

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

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13 pages, 3517 KiB

Open AccessArticle

Tailoring the Spin Reorientation Transition of Co Films by Pd Monolayer Capping

by Benito Santos Burgos, Raúl López-Martín, José A. De Toro, Chris Binns, Andreas K. Schmid and Juan de la Figuera

Nanomaterials 2024, 14(20), 1662; https://doi.org/10.3390/nano14201662 - 16 Oct 2024

Viewed by 605

Abstract

We have characterized the magnetization easy-axis of ultra-thin Co films (2–5 atomic layers, AL) grown on Ru(0001) when they are capped with a monolayer of Pd. The addition of a Pd monolayer turns the magnetization of 3 and 4 AL-thick Co films from [...] Read more.

We have characterized the magnetization easy-axis of ultra-thin Co films (2–5 atomic layers, AL) grown on Ru(0001) when they are capped with a monolayer of Pd. The addition of a Pd monolayer turns the magnetization of 3 and 4 AL-thick Co films from an in-plane to an out-of-plane alignment, but not that of a 5 AL-thick film. These observations are explained in terms of an enhancement of the surface anisotropy. The exposure of the sample to hydrogen, CO or a combination of both gases does not overcome this effect. Full article

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

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11 pages, 2864 KiB

Open AccessArticle

Interface Synergistic Effect of NiFe-LDH/3D GA Composites on Efficient Electrocatalytic Water Oxidation

by Jiangcheng Zhang, Qiuhan Cao, Xin Yu, Hu Yao, Baolian Su and Xiaohui Guo

Nanomaterials 2024, 14(20), 1661; https://doi.org/10.3390/nano14201661 - 16 Oct 2024

Viewed by 663

Abstract

Currently, NiFe-LDH exhibits an excellent oxygen evolution reaction (OER) due to the interaction of the two metal elements on the layered double hydroxide (LDH) platform. However, such interaction is still insufficient to compensate for its poor electrical conductivity, limited number of active sites [...] Read more.

Currently, NiFe-LDH exhibits an excellent oxygen evolution reaction (OER) due to the interaction of the two metal elements on the layered double hydroxide (LDH) platform. However, such interaction is still insufficient to compensate for its poor electrical conductivity, limited number of active sites and sluggish dynamics. Herein, a feasible two-step hydrothermal strategy that involves coupling low-conductivity NiFe-LDH with 3D porous graphene aerogel (GA) is proposed. The optimized NiFe-LDH/GA (1:1) produced possesses a 257 mV (10 mA cm⁻²) overpotential and could operate stably for 56 h in an OER. Our investigation demonstrates that the NiFe-LDH/GA has a three-dimensional mesoporous structure, and that there is synergistic interaction between LDH and GA and interfacial reconstruction of NiOOH. Such an interface synergistic coupling effect promotes fast mass transfer and facilitates OER kinetics, and this work offers new insights into designing efficient and stable GA-based electrocatalysts. Full article

(This article belongs to the Special Issue Nanostructured Electrocatalysts for Hydrogen/Oxygen Evolution Reaction)

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3 pages, 164 KiB

Open AccessEditorial

The Development of Nanomaterials in Adsorption, Separation and Purification

by Daniela Cristina Culita

Nanomaterials 2024, 14(20), 1660; https://doi.org/10.3390/nano14201660 - 16 Oct 2024

Viewed by 506

Abstract

In an era marked by growing concerns about environmental pollution, resource scarcity, and energy demand, nanomaterials are emerging as powerful tools for addressing challenges in water treatment, air purification, and industrial separations [...] Full article

(This article belongs to the Special Issue The Development of Nanomaterials in Adsorption, Separation and Purification)

17 pages, 39089 KiB

Open AccessArticle

Electronic and Optical Properties of 2D Heterostructure Bilayers of Graphene, Borophene and 2D Boron Carbides from First Principles

by Lu Niu, Oliver J. Conquest, Carla Verdi and Catherine Stampfl

Nanomaterials 2024, 14(20), 1659; https://doi.org/10.3390/nano14201659 - 16 Oct 2024

Viewed by 807

Abstract

In the present work the atomic, electronic and optical properties of two-dimensional graphene, borophene, and boron carbide heterojunction bilayer systems (Graphene–BC₃, Graphene–Borophene and Graphene–B₄C₃) as well as their constituent monolayers are investigated on the basis of first-principles [...] Read more.

In the present work the atomic, electronic and optical properties of two-dimensional graphene, borophene, and boron carbide heterojunction bilayer systems (Graphene–BC₃, Graphene–Borophene and Graphene–B₄C₃) as well as their constituent monolayers are investigated on the basis of first-principles calculations using the HSE06 hybrid functional. Our calculations show that while borophene is metallic, both monolayer BC₃ and B₄C₃ are indirect semiconductors, with band-gaps of 1.822 eV and 2.381 eV as obtained using HSE06. The Graphene–BC₃ and Graphene–B₄C₃ bilayer heterojunction systems maintain the Dirac point-like character of graphene at the K-point with the opening of a very small gap (20–50 meV) and are essentially semi-metals, while Graphene–Borophene is metallic. All bilayer heterostructure systems possess absorbance in the visible region where the resonance frequency and resonance absorption peak intensity vary between structures. Remarkably, all heterojunctions support plasmons within the range 16.5–18.5 eV, while Graphene–B₄C₃ and Graphene–Borophene exhibit a

π

-type plasmon within the region 4–6 eV, with the latter possessing an additional plasmon at the lower energy of 1.5–3 eV. The dielectric tensor for Graphene–B₄C₃ exhibits complex off-diagonal elements due to the lower P3 space group symmetry indicating it has anisotropic dielectric properties and could exhibit optically active (chiral) effects. Our study shows that the two-dimensional heterostructures have desirable optical properties broadening the potential applications of the constituent monolayers. Full article

(This article belongs to the Special Issue 2D Layered Nanomaterials and Heterostructures for Electronics, Optoelectronics and Sensing)

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16 pages, 2784 KiB

Open AccessArticle

Salmon-IgM Functionalized-PLGA Nanosystem for Florfenicol Delivery as an Antimicrobial Strategy against Piscirickettsia salmonis

by Felipe Velásquez, Mateus Frazao, Arturo Diez, Felipe Villegas, Marcelo Álvarez-Bidwell, J. Andrés Rivas-Pardo, Eva Vallejos-Vidal, Felipe Reyes-López, Daniela Toro-Ascuy, Manuel Ahumada and Sebastián Reyes-Cerpa

Nanomaterials 2024, 14(20), 1658; https://doi.org/10.3390/nano14201658 - 16 Oct 2024

Viewed by 894

Abstract

Salmonid rickettsial septicemia (SRS), caused by Piscirickettsia salmonis, has been the most severe health concern for the Chilean salmon industry. The efforts to control P. salmonis infections have focused on using antibiotics and vaccines. However, infected salmonids exhibit limited responses to the [...] Read more.

Salmonid rickettsial septicemia (SRS), caused by Piscirickettsia salmonis, has been the most severe health concern for the Chilean salmon industry. The efforts to control P. salmonis infections have focused on using antibiotics and vaccines. However, infected salmonids exhibit limited responses to the treatments. Here, we developed a poly (D, L-lactide-glycolic acid) (PLGA)-nanosystem functionalized with Atlantic salmon IgM (PLGA-IgM) to specifically deliver florfenicol into infected cells. Polymeric nanoparticles (NPs) were prepared via the double emulsion solvent-evaporation method in the presence of florfenicol. Later, the PLGA-NPs were functionalized with Atlantic salmon IgM through carbodiimide chemistry. The nanosystem showed an average size of ~380–410 nm and a negative surface charge. Further, florfenicol encapsulation efficiency was close to 10%. We evaluated the internalization of the nanosystem and its impact on bacterial load in SHK-1 cells by using confocal microscopy and qPCR. The results suggest that stimulation with the nanosystem elicits a decrease in the bacterial load of P. salmonis when it infects Atlantic salmon macrophages. Overall, the IgM-functionalized PLGA-based nanosystem represents an alternative to the administration of antibiotics in salmon farming, complementing the delivery of antibiotics with the stimulation of the immune response of infected macrophages. Full article

(This article belongs to the Special Issue Antimicrobial and Antioxidant Activity of Nanoparticles)

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18 pages, 5253 KiB

Open AccessArticle

Targeted PHA Microsphere-Loaded Triple-Drug System with Sustained Drug Release for Synergistic Chemotherapy and Gene Therapy

by Shuo Wang, Chao Zhang, Huandi Liu, Xueyu Fan, Shuangqing Fu, Wei Li and Honglei Zhang

Nanomaterials 2024, 14(20), 1657; https://doi.org/10.3390/nano14201657 - 16 Oct 2024

Viewed by 891

Abstract

The combination of paclitaxel (PTX) with other chemotherapy drugs (e.g., gemcitabine, GEM) or genetic drugs (e.g., siRNA) has been shown to enhance therapeutic efficacy against tumors, reduce individual drug dosages, and prevent drug resistance associated with single-drug treatments. However, the varying solubility of [...] Read more.

The combination of paclitaxel (PTX) with other chemotherapy drugs (e.g., gemcitabine, GEM) or genetic drugs (e.g., siRNA) has been shown to enhance therapeutic efficacy against tumors, reduce individual drug dosages, and prevent drug resistance associated with single-drug treatments. However, the varying solubility of chemotherapy drugs and genetic drugs presents a challenge in co-delivering these agents. In this study, nanoparticles loaded with PTX were prepared using the biodegradable polymer material poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx). These nanoparticles were surface-modified with target proteins (Affibody molecules) and RALA cationic peptides to create core-shell structured microspheres with targeted and cationic functionalization. A three-drug co-delivery system (PTX@PHBHHx-ARP/siRNA_GEM) were developed by electrostatically adsorbing siRNA chains containing GEM onto the microsphere surface. The encapsulation efficiency of PTX in the nanodrug was found to be 81.02%, with a drug loading of 5.09%. The chemogene adsorption capacity of siRNA_GEM was determined to be 97.3%. Morphological and size characterization of the nanodrug revealed that PTX@PHBHHx-ARP/siRNA_GEM is a rough-surfaced microsphere with a particle size of approximately 150 nm. This nanodrug exhibited targeting capabilities toward BT474 cells with HER2 overexpression while showing limited targeting ability toward MCF-7 cells with low HER2 expression. Results from the MTT assay demonstrated that PTX@PHBHHx-ARP/siRNA_GEM exhibits high cytotoxicity and excellent combination therapy efficacy compared to physically mixed PTX/GEM/siRNA. Additionally, Western blot analysis confirmed that siRNA-mediated reduction of Bcl-2 expression significantly enhanced cell apoptosis mediated by PTX or GEM in tumor cells, thereby increasing cell sensitivity to PTX and GEM. This study presents a novel targeted nanosystem for the co-delivery of chemotherapy drugs and genetic drugs. Full article

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Nanomaterials, Volume 14, Issue 20 (October-2 2024) – 73 articles

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