Nanomaterials

21 pages, 6643 KiB

Open AccessArticle

Strengthening a Medium-Carbon Low-Alloy Steel by Nanosized Grains: The Role of Asymmetrical Rolling

by Youzhi Li, Yongfeng Shen, Sixin Zhao, Weina Zhang and Wenying Xue

Nanomaterials 2023, 13(5), 956; https://doi.org/10.3390/nano13050956 - 6 Mar 2023

Cited by 6 | Viewed by 1908

A medium-carbon low-alloy steel was prepared via the asymmetric rolling process with different ratios of upper and down roll velocities. Subsequently, the microstructure and mechanical properties were explored by using SEM, EBSD, TEM, tensile tests and nanoindentation. The results show that asymmetrical rolling [...] Read more.

A medium-carbon low-alloy steel was prepared via the asymmetric rolling process with different ratios of upper and down roll velocities. Subsequently, the microstructure and mechanical properties were explored by using SEM, EBSD, TEM, tensile tests and nanoindentation. The results show that asymmetrical rolling (ASR) can significantly improve strength while retaining good ductility compared with conventional symmetrical rolling. The yield strength and tensile strength of the ASR-steel are 1292 ± 10 MPa and 1357 ± 10 MPa, respectively, which are higher than the values of 1113 ± 10 MPa and 1185 ± 10 MPa for the SR-steel. The ASR-steel retains good ductility of 16.5 ± 0.5%. The significant increase in strength is related to the joint actions of the ultrafine grains, dense dislocations and a large number of nanosized precipitates. This is mainly because of the introduction of extra shear stress on the edge under asymmetric rolling, which induces gradient structural changes hence increasing the density of geometrically necessary dislocations. Full article

► Show Figures

Figure 1

27 pages, 3050 KiB

Open AccessReview

Properties and Characterization Techniques of Graphene Modified Asphalt Binders

by Rodrigo Polo-Mendoza, Tatiana Navarro-Donado, Daniela Ortega-Martinez, Emilio Turbay, Gilberto Martinez-Arguelles and Rita Peñabaena-Niebles

Nanomaterials 2023, 13(5), 955; https://doi.org/10.3390/nano13050955 - 6 Mar 2023

Cited by 31 | Viewed by 4127

Abstract

Graphene is a carbon-based nanomaterial used in various industries to improve the performance of hundreds of materials. For instance, graphene-like materials have been employed as asphalt binder modifying agents in pavement engineering. In the literature, it has been reported that (in comparison to [...] Read more.

Graphene is a carbon-based nanomaterial used in various industries to improve the performance of hundreds of materials. For instance, graphene-like materials have been employed as asphalt binder modifying agents in pavement engineering. In the literature, it has been reported that (in comparison to an unmodified binder) the Graphene Modified Asphalt Binders (GMABs) exhibit an enhanced performance grade, a lower thermal susceptibility, a higher fatigue life, and a decreased accumulation of permanent deformations. Nonetheless, although GMABs stand out significantly from traditional alternatives, there is still no consensus on their behavior regarding chemical, rheological, microstructural, morphological, thermogravimetric, and surface topography properties. Therefore, this research conducted a literature review on the properties and advanced characterization techniques of GMABs. Thus, the laboratory protocols covered by this manuscript are atomic force microscopy, differential scanning calorimetry, dynamic shear rheometer, elemental analysis, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. Consequently, the main contribution of this investigation to the state-of-the-art is the identification of the prominent trends and gaps in the current state of knowledge. Full article

(This article belongs to the Special Issue Low-Dimensional Nanocarbon Multifunctional Composites)

► Show Figures

Figure 1

19 pages, 8336 KiB

Open AccessArticle

A Self-Powered High-Responsivity, Fast-Response-Speed Solar-Blind Ultraviolet Photodetector Based on CuO/β-Ga₂O₃ Heterojunction with Built-In Potential Control

by Sangbin Park, Younghwa Yoon, Hyungmin Kim, Taejun Park, Kyunghwan Kim and Jeongsoo Hong

Nanomaterials 2023, 13(5), 954; https://doi.org/10.3390/nano13050954 - 6 Mar 2023

Cited by 17 | Viewed by 2748

Abstract

Controlling built-in potential can enhance the photoresponse performance of self-powered photodetectors. Among the methods for controlling the built-in potential of self-powered devices, postannealing is simpler, more efficient, and less expensive than ion doping and alternative material research. In this study, a CuO film [...] Read more.

Controlling built-in potential can enhance the photoresponse performance of self-powered photodetectors. Among the methods for controlling the built-in potential of self-powered devices, postannealing is simpler, more efficient, and less expensive than ion doping and alternative material research. In this study, a CuO film was deposited on a β-Ga₂O₃ epitaxial layer via reactive sputtering with an FTS system, and a self-powered solar-blind photodetector was fabricated through a CuO/β-Ga₂O₃ heterojunction and postannealed at different temperatures. The postannealing process reduced the defects and dislocations at the interface between each layer and affected the electrical and structural properties of the CuO film. After postannealing at 300 °C, the carrier concentration of the CuO film increased from 4.24 × 10¹⁸ to 1.36 × 10²⁰ cm⁻³, bringing the Fermi level toward the valence band of the CuO film and increasing the built-in potential of the CuO/β-Ga₂O₃ heterojunction. Thus, the photogenerated carriers were rapidly separated, increasing the sensitivity and response speed of the photodetector. The as-fabricated photodetector with 300 °C postannealing exhibited a photo-to-dark current ratio of 1.07 × 10³; responsivity and detectivity of 30.3 mA/W and 1.10 × 10¹² Jones, respectively; and fast rise and decay times of 12 ms and 14 ms, respectively. After three months of storage in an open-air space, the photocurrent density of the photodetector was maintained, indicating good stability with aging. These results suggest that the photocharacteristics of CuO/β-Ga₂O₃ heterojunction self-powered solar-blind photodetectors can be improved through built-in potential control using a postannealing process. Full article

(This article belongs to the Section Nanoelectronics, Nanosensors and Devices)

► Show Figures

Graphical abstract

43 pages, 10323 KiB

Open AccessReview

BioMOF-Based Anti-Cancer Drug Delivery Systems

by Sandy Elmehrath, Ha L. Nguyen, Sherif M. Karam, Amr Amin and Yaser E. Greish

Nanomaterials 2023, 13(5), 953; https://doi.org/10.3390/nano13050953 - 6 Mar 2023

Cited by 25 | Viewed by 5237

Abstract

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, [...] Read more.

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided. Full article

(This article belongs to the Special Issue Advanced Metal-Organic Frameworks)

► Show Figures

Graphical abstract

16 pages, 4024 KiB

Open AccessArticle

Asymmetric Alternative Current Electrochemical Method Coupled with Amidoxime-Functionalized Carbon Felt Electrode for Fast and Efficient Removal of Hexavalent Chromium from Wastewater

by Yunze Yang, Lun Lu, Yi Shen, Jun Wang, Liangzhong Li, Ruixue Ma, Zahid Ullah, Mingdeng Xiang and Yunjiang Yu

Nanomaterials 2023, 13(5), 952; https://doi.org/10.3390/nano13050952 - 6 Mar 2023

Cited by 6 | Viewed by 2379

Abstract

A large amount of Cr (VI)-polluted wastewater produced in electroplating, dyeing and tanning industries seriously threatens water ecological security and human health. Due to the lack of high-performance electrodes and the coulomb repulsion between hexavalent chromium anion and cathode, the traditional DC-mediated electrochemical [...] Read more.

A large amount of Cr (VI)-polluted wastewater produced in electroplating, dyeing and tanning industries seriously threatens water ecological security and human health. Due to the lack of high-performance electrodes and the coulomb repulsion between hexavalent chromium anion and cathode, the traditional DC-mediated electrochemical remediation technology possesses low Cr (VI) removal efficiency. Herein, by modifying commercial carbon felt (O-CF) with amidoxime groups, amidoxime-functionalized carbon felt electrodes (Ami-CF) with high adsorption affinity for Cr (VI) were prepared. Based on Ami-CF, an electrochemical flow-through system powered by asymmetric AC was constructed. The mechanism and influencing factors of efficient removal of Cr (VI) contaminated wastewater by an asymmetric AC electrochemical method coupling Ami-CF were studied. Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) characterization results showed that Ami-CF was successfully and uniformly loaded with amidoxime functional groups, and the adsorption capacity of Cr (VI) was more than 100 times higher than that of O-CF. In particular, the Coulomb repulsion effect and the side reaction of electrolytic water splitting were inhibited by the high-frequency anode and cathode switching (asymmetric AC), the mass transfer rate of Cr (VI) from electrode solution was increased, the reduction efficiency of Cr (VI) to Cr (III) was significantly promoted and a highly efficient removal of Cr (VI) was achieved. Under optimal operating conditions (positive bias 1 V, negative bias 2.5 V, duty ratio 20%, frequency 400 Hz, solution pH = 2), the asymmetric AC electrochemistry based on Ami-CF can achieve fast (30 s) and efficient removal (>99.11%) for 0.5–100 mg·L⁻¹ Cr (VI) with a high flux of 300 L h⁻¹ m⁻². At the same time, the durability test verified the sustainability of the AC electrochemical method. For Cr (VI)-polluted wastewater with an initial concentration of 50 mg·L⁻¹, the effluent concentration could still reach drinking water grade (<0.05 mg·L⁻¹) after 10 cycling experiments. This study provides an innovative approach for the rapid, green and efficient removal of Cr (VI) containing wastewater at low and medium concentrations. Full article

(This article belongs to the Section Environmental Nanoscience and Nanotechnology)

► Show Figures

Figure 1

13 pages, 5739 KiB

Open AccessArticle

Humidity Sensing Properties of (In+Nb) Doped HfO₂ Ceramics

by Jiahao Yao, Jingsong Wang, Wenjun Cao, Li Li, Mingxiang Luo and Chunchang Wang

Nanomaterials 2023, 13(5), 951; https://doi.org/10.3390/nano13050951 - 6 Mar 2023

Cited by 8 | Viewed by 1869

Abstract

(In+Nb) co-doped HfO₂ ceramics, Hf_1-x(In_0.5Nb_0.5)_xO₂ (x = 0, 0.005, 0.05, and 0.1), were prepared via a solid-state reaction method. Dielectric measurements reveal that the environmental moisture has an obvious influence on [...] Read more.

(In+Nb) co-doped HfO₂ ceramics, Hf_1-x(In_0.5Nb_0.5)_xO₂ (x = 0, 0.005, 0.05, and 0.1), were prepared via a solid-state reaction method. Dielectric measurements reveal that the environmental moisture has an obvious influence on the dielectric properties of the samples. The best humidity response was found in a sample with the doping level of x = 0.005. This sample was therefore selected as a model sample to further investigate its humidity properties. In doing so, nanosized particles of Hf_0.995(In_0.5Nb_0.5)_0.005O₂ were fabricated via a hydrothermal method and the humidity sensing properties of this material were studied in the relative humidity range of 11–94% based on impedance sensor. Our results show that the material exhibits a large impedance change of nearly four orders of magnitude over the tested humidity range. It was argued that the humidity-sensing properties were related to the defects created by doping, which improves the adsorption capacity for water molecules. Full article

(This article belongs to the Special Issue Nanoelectronics: Materials, Devices and Applications)

► Show Figures

Figure 1

11 pages, 1950 KiB

Open AccessArticle

Coherence Characteristics of a GaAs Single Heavy-Hole Spin Qubit Using a Modified Single-Shot Latching Readout Technique

by Victor Marton, Andrew Sachrajda, Marek Korkusinski, Alex Bogan and Sergei Studenikin

Nanomaterials 2023, 13(5), 950; https://doi.org/10.3390/nano13050950 - 6 Mar 2023

Cited by 5 | Viewed by 2015

Abstract

We present an experimental study of the coherence properties of a single heavy-hole spin qubit formed in one quantum dot of a gated GaAs/AlGaAs double quantum dot device. We use a modified spin-readout latching technique in which the second quantum dot serves both [...] Read more.

We present an experimental study of the coherence properties of a single heavy-hole spin qubit formed in one quantum dot of a gated GaAs/AlGaAs double quantum dot device. We use a modified spin-readout latching technique in which the second quantum dot serves both as an auxiliary element for a fast spin-dependent readout within a 200 ns time window and as a register for storing the spin-state information. To manipulate the single-spin qubit, we apply sequences of microwave bursts of various amplitudes and durations to make Rabi, Ramsey, Hahn-echo, and CPMG measurements. As a result of the qubit manipulation protocols combined with the latching spin readout, we determine and discuss the achieved qubit coherence times:

T_{1}

,

T_{R a b i}

,

T_{2}^{*}

, and

T_{2}^{C P M G}

vs. microwave excitation amplitude, detuning, and additional relevant parameters. Full article

(This article belongs to the Special Issue Semiconductor Quantum Wells and Nanostructures)

► Show Figures

Figure 1

11 pages, 3414 KiB

Open AccessArticle

All Fiber Vector Magnetometer Based on Nitrogen-Vacancy Center

by Man Zhao, Qijing Lin, Qingzhi Meng, Wenjun Shan, Liangquan Zhu, Yao Chen, Tao Liu, Libo Zhao and Zhuangde Jiang

Nanomaterials 2023, 13(5), 949; https://doi.org/10.3390/nano13050949 - 6 Mar 2023

Cited by 5 | Viewed by 3536

Abstract

Magnetometers based on nitrogen-vacancy (NV) centers in diamonds have promising applications in fields of living systems biology, condensed matter physics, and industry. This paper proposes a portable and flexible all-fiber NV center vector magnetometer by using fibers to substitute all conventional spatial optical [...] Read more.

Magnetometers based on nitrogen-vacancy (NV) centers in diamonds have promising applications in fields of living systems biology, condensed matter physics, and industry. This paper proposes a portable and flexible all-fiber NV center vector magnetometer by using fibers to substitute all conventional spatial optical elements, realizing laser excitation and fluorescence collection of micro-diamond with multi-mode fibers simultaneously and efficiently. An optical model is established to investigate multi-mode fiber interrogation of micro-diamond to estimate the optical performance of NV center system. A new analysis method is proposed to extract the magnitude and direction of the magnetic field, combining the morphology of the micro-diamond, thus realizing μm-scale vector magnetic field detection at the tip of the fiber probe. Experimental testing shows our fabricated magnetometer has a sensitivity of 0.73 nT/Hz^1/2, demonstrating its feasibility and performance in comparison with conventional confocal NV center magnetometers. This research presents a robust and compact magnetic endoscopy and remote-magnetic measurement approach, which will substantially promote the practical application of magnetometers based on NV centers. Full article

► Show Figures

Figure 1

11 pages, 2827 KiB

Open AccessFeature PaperArticle

Wavelength-Tunable Narrow-Linewidth Laser Diode Based on Self-Injection Locking with a High-Q Lithium Niobate Microring Resonator

by Ting Huang, Yu Ma, Zhiwei Fang, Junxia Zhou, Yuan Zhou, Zhe Wang, Jian Liu, Zhenhua Wang, Haisu Zhang, Min Wang, Jian Xu and Ya Cheng

Nanomaterials 2023, 13(5), 948; https://doi.org/10.3390/nano13050948 - 6 Mar 2023

Cited by 8 | Viewed by 3903

Abstract

We demonstrate a narrow linewidth 980 nm laser by self-injection locking of an electrically pumped distributed-feedback (DFB) laser diode to a high quality (Q) factor (>10⁵) lithium niobate (LN) microring resonator. The lithium niobate microring resonator is fabricated by photolithography-assisted chemo-mechanical [...] Read more.

We demonstrate a narrow linewidth 980 nm laser by self-injection locking of an electrically pumped distributed-feedback (DFB) laser diode to a high quality (Q) factor (>10⁵) lithium niobate (LN) microring resonator. The lithium niobate microring resonator is fabricated by photolithography-assisted chemo-mechanical etching (PLACE) technique, and the Q factor of lithium niobate microring is measured as high as 6.91 × 10⁵. The linewidth of the multimode 980 nm laser diode, which is ~2 nm measured from its output end, is narrowed down to 35 pm with a single-mode characteristic after coupling with the high-Q LN microring resonator. The output power of the narrow-linewidth microlaser is about 4.27 mW, and the wavelength tuning range reaches 2.57 nm. This work explores a hybrid integrated narrow linewidth 980 nm laser that has potential applications in high-efficient pump laser, optical tweezers, quantum information, as well as chip-based precision spectroscopy and metrology. Full article

(This article belongs to the Special Issue Nanophotonics Enabled by Femtosecond Lasers)

► Show Figures

Figure 1

21 pages, 7675 KiB

Open AccessFeature PaperArticle

A Laser-Induced Graphene-Titanium(IV) Oxide Composite for Adsorption Enhanced Photodegradation of Methyl Orange

by Brhane A. Tesfahunegn, Maurício Nunes Kleinberg, Camilah D. Powell and Christopher J. Arnusch

Nanomaterials 2023, 13(5), 947; https://doi.org/10.3390/nano13050947 - 5 Mar 2023

Cited by 4 | Viewed by 2924

Abstract

Numerous treatment methods such as biological digestion, chemical oxidation, and coagulation have been used to treat organic micropollutants. However, such wastewater treatment methods can be either inefficient, expensive, or environmentally unsound. Here, we embedded TiO₂ nanoparticles in laser-induced graphene (LIG) and obtained [...] Read more.

Numerous treatment methods such as biological digestion, chemical oxidation, and coagulation have been used to treat organic micropollutants. However, such wastewater treatment methods can be either inefficient, expensive, or environmentally unsound. Here, we embedded TiO₂ nanoparticles in laser-induced graphene (LIG) and obtained a highly efficient photocatalyst composite with pollutant adsorption properties. TiO₂ was added to LIG and lased to form a mixture of rutile and anatase TiO₂ with a decreased band gap (2.90 ± 0.06 eV). The LIG/TiO₂ composite adsorption and photodegradation properties were tested in solutions of a model pollutant, methyl orange (MO), and compared to the individual and mixed components. The adsorption capacity of the LIG/TiO₂ composite was 92 mg/g using 80 mg/L MO, and together the adsorption and photocatalytic degradation resulted in 92.8% MO removal in 10 min. Adsorption enhanced photodegradation, and a synergy factor of 2.57 was seen. Understanding how LIG can modify metal oxide catalysts and how adsorption can enhance photocatalysis might lead to more effective pollutant removal and offer alternative treatment methods for polluted water. Full article

(This article belongs to the Special Issue Laser-Induced Nanomaterials)

► Show Figures

Figure 1

17 pages, 5327 KiB

Open AccessFeature PaperArticle

Nanoporous Hollow Carbon Spheres Derived from Fullerene Assembly as Electrode Materials for High-Performance Supercapacitors

by Lok Kumar Shrestha, Zexuan Wei, Gokulnath Subramaniam, Rekha Goswami Shrestha, Ravi Singh, Marappan Sathish, Renzhi Ma, Jonathan P. Hill, Junji Nakamura and Katsuhiko Ariga

Nanomaterials 2023, 13(5), 946; https://doi.org/10.3390/nano13050946 - 5 Mar 2023

Cited by 7 | Viewed by 5072

Abstract

The energy storage performances of supercapacitors are expected to be enhanced by the use of nanostructured hierarchically micro/mesoporous hollow carbon materials based on their ultra-high specific surface areas and rapid diffusion of electrolyte ions through the interconnected channels of their mesoporous structures. In [...] Read more.

The energy storage performances of supercapacitors are expected to be enhanced by the use of nanostructured hierarchically micro/mesoporous hollow carbon materials based on their ultra-high specific surface areas and rapid diffusion of electrolyte ions through the interconnected channels of their mesoporous structures. In this work, we report the electrochemical supercapacitance properties of hollow carbon spheres prepared by high-temperature carbonization of self-assembled fullerene-ethylenediamine hollow spheres (FE-HS). FE-HS, having an average external diameter of 290 nm, an internal diameter of 65 nm, and a wall thickness of 225 nm, were prepared by using the dynamic liquid-liquid interfacial precipitation (DLLIP) method at ambient conditions of temperature and pressure. High temperature carbonization (at 700, 900, and 1100 °C) of the FE-HS yielded nanoporous (micro/mesoporous) hollow carbon spheres with large surface areas (612 to 1616 m² g⁻¹) and large pore volumes (0.925 to 1.346 cm³ g⁻¹) dependent on the temperature applied. The sample obtained by carbonization of FE-HS at 900 °C (FE-HS_900) displayed optimum surface area and exhibited remarkable electrochemical electrical double-layer capacitance properties in aq. 1 M sulfuric acid due to its well-developed porosity, interconnected pore structure, and large surface area. For a three-electrode cell setup, a specific capacitance of 293 F g⁻¹ at a 1 A g⁻¹ current density, which is approximately 4 times greater than the specific capacitance of the starting material, FE-HS. The symmetric supercapacitor cell was assembled using FE-HS_900 and attained 164 F g⁻¹ at 1 A g⁻¹ with sustained 50% capacitance at 10 A g⁻¹ accompanied by 96% cycle life and 98% coulombic efficiency after 10,000 consecutive charge/discharge cycles. The results demonstrate the excellent potential of these fullerene assemblies in the fabrication of nanoporous carbon materials with the extensive surface areas required for high-performance energy storage supercapacitor applications. Full article

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

► Show Figures

Graphical abstract

19 pages, 3817 KiB

Open AccessArticle

An Analysis of the Toxicity, Antioxidant, and Anti-Cancer Activity of Cinnamon Silver Nanoparticles in Comparison with Extracts and Fractions of Cinnamomum Cassia at Normal and Cancer Cell Levels

by Y. G. El-Baz, A. Moustafa, M. A. Ali, G. E. El-Desoky, S. M. Wabaidur and M. M. Faisal

Nanomaterials 2023, 13(5), 945; https://doi.org/10.3390/nano13050945 - 5 Mar 2023

Cited by 6 | Viewed by 3073

Abstract

In this work, the extract of cinnamon bark was used for the green synthesis of cinnamon-Ag nanoparticles (CNPs) and other cinnamon samples, including ethanolic (EE) and aqueous (CE) extracts, chloroform (CF), ethyl acetate (EF), and methanol (MF) fractions. The polyphenol (PC) and flavonoid [...] Read more.

In this work, the extract of cinnamon bark was used for the green synthesis of cinnamon-Ag nanoparticles (CNPs) and other cinnamon samples, including ethanolic (EE) and aqueous (CE) extracts, chloroform (CF), ethyl acetate (EF), and methanol (MF) fractions. The polyphenol (PC) and flavonoid (FC) contents in all the cinnamon samples were determined. The synthesized CNPs were tested for the antioxidant activity (as DPPH radical scavenging percentage) in Bj-1 normal cells and HepG-2 cancer cells. Several antioxidant enzymes, including biomarkers, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and reduced glutathione (GSH), were verified for their effects on the viability and cytotoxicity of normal and cancer cells. The anti-cancer activity depended on apoptosis marker protein levels (Caspase3, P53, Bax, and Pcl2) in normal and cancerous cells. The obtained data showed higher PC and FC contents in CE samples, while CF showed the lowest levels. The IC₅₀ values of all investigated samples were higher, while their antioxidant activities were lower than those of vitamin C (5.4 g/mL). The CNPs showed lower IC₅₀ value (55.6 µg/mL), whereas the antioxidant activity inside or outside the Bj-1 or HepG-2 was found to be higher compared with other samples. All samples execrated a dose-dependent cytotoxicity by decreasing the cells’ viability percent of Bj-1 and HepG-2. Similarly, the anti-proliferative potency of CNPs on Bj-1 or HepG-2 at different concentrations was more effective than that of other samples. Higher concentrations of the CNPs (16 g/mL) showed greater cell death in Bj-1 (25.68%) and HepG-2 (29.49%), indicating powerful anti-cancer properties of the nanomaterials. After 48 h of CNPs treatment, both Bj-1 and HepG-2 showed significant increases in biomarker enzyme activities and reduced glutathione compared with other treated samples or untreated controls (p < 0.05). The anti-cancer biomarker activities of Caspas-3, P53, Bax, and Bcl-2 levels were significantly changed in Bj-1 or HepG-2 cells. The cinnamon samples were significantly increased in Caspase-3, Bax, and P53, while there were decreased Bcl-2 levels compared with control. Full article

(This article belongs to the Special Issue Green Synthesis of Nanomaterials for Environmental and Biomedical Applications)

► Show Figures

Figure 1

14 pages, 4666 KiB

Open AccessArticle

Hybrid Metal-Organic Frameworks/Carbon Fibers Reinforcements for Additively Manufactured Composites

by Marwan Al-Haik, Suma Ayyagari, Yixin Ren, Andrew Abbott, Bing Qian Zheng and Hilmar Koerner

Nanomaterials 2023, 13(5), 944; https://doi.org/10.3390/nano13050944 - 5 Mar 2023

Viewed by 2396

Abstract

Additively manufactured (AM) composites based on short carbon fibers possess strength and stiffness far less than their continuous fiber counterparts due to the fiber’s small aspect ratio and inadequate interfaces with the epoxy matrix. This investigation presents a route for preparing hybrid reinforcements [...] Read more.

Additively manufactured (AM) composites based on short carbon fibers possess strength and stiffness far less than their continuous fiber counterparts due to the fiber’s small aspect ratio and inadequate interfaces with the epoxy matrix. This investigation presents a route for preparing hybrid reinforcements for AM that comprise short carbon fibers and nickel-based metal-organic frameworks (Ni-MOFs). The porous MOFs furnish the fibers with tremendous surface area. Additionally, the MOFs growth process is non-destructive to the fibers and easily scalable. This investigation also demonstrates the viability of using Ni-based MOFs as a catalyst for growing multi-walled carbon nanotubes (MWCNTs) on carbon fibers. The changes to the fiber were examined via electron microscopy, X-ray scattering techniques, and Fourier-transform infrared spectroscopy (FTIR). The thermal stabilities were probed by thermogravimetric analysis (TGA). Tensile and dynamic mechanical analysis (DMA) tests were utilized to explore the effect of MOFs on the mechanical properties of 3D-printed composites. Composites with MOFs exhibited improvements in stiffness and strength by 30.2% and 19.0%, respectively. The MOFs enhanced the damping parameter by 700%. Full article

(This article belongs to the Special Issue Additive Manufacturing of Hybrid and Nanomaterials)

► Show Figures

Figure 1

14 pages, 5395 KiB

Open AccessArticle

Synthesis of Microwave Functionalized, Nanostructured Polylactic Co-Glycolic Acid (nfPLGA) for Incorporation into Hydrophobic Dexamethasone to Enhance Dissolution

by Mohammad Saiful Islam and Somenath Mitra

Nanomaterials 2023, 13(5), 943; https://doi.org/10.3390/nano13050943 - 5 Mar 2023

Cited by 3 | Viewed by 2176

Abstract

The low solubility and slow dissolution of hydrophobic drugs is a major challenge for the pharmaceutical industry. In this paper, we present the synthesis of surface-functionalized poly(lactic-co-glycolic acid) (PLGA) nanoparticles for incorporation into corticosteroid dexamethasone to improve its in vitro dissolution profile. The [...] Read more.

The low solubility and slow dissolution of hydrophobic drugs is a major challenge for the pharmaceutical industry. In this paper, we present the synthesis of surface-functionalized poly(lactic-co-glycolic acid) (PLGA) nanoparticles for incorporation into corticosteroid dexamethasone to improve its in vitro dissolution profile. The PLGA crystals were mixed with a strong acid mixture, and their microwave-assisted reaction led to a high degree of oxidation. The resulting nanostructured, functionalized PLGA (nfPLGA), was quite water-dispersible compared to the original PLGA, which was non-dispersible. SEM-EDS analysis showed 53% surface oxygen concentration in the nfPLGA compared to the original PLGA, which had only 25%. The nfPLGA was incorporated into dexamethasone (DXM) crystals via antisolvent precipitation. Based on SEM, RAMAN, XRD, TGA and DSC measurements, the nfPLGA-incorporated composites retained their original crystal structures and polymorphs. The solubility of DXM after nfPLGA incorporation (DXM–nfPLGA) increased from 6.21 mg/L to as high as 87.1 mg/L and formed a relatively stable suspension with a zeta potential of −44.3 mV. Octanol–water partitioning also showed a similar trend as the logP reduced from 1.96 for pure DXM to 0.24 for DXM–nfPLGA. In vitro dissolution testing showed 14.0 times higher aqueous dissolution of DXM–nfPLGA compared to pure DXM. The time for 50% (T₅₀) and 80% (T₈₀) of gastro medium dissolution decreased significantly for the nfPLGA composites; T₅₀ reduced from 57.0 to 18.0 min and T₈₀ reduced from unachievable to 35.0 min. Overall, the PLGA, which is an FDA-approved, bioabsorbable polymer, can be used to enhance the dissolution of hydrophobic pharmaceuticals and this can lead to higher efficacy and lower required dosage. Full article

(This article belongs to the Special Issue Nanotransporters for Drug Delivery and Precise Medicine)

► Show Figures

Figure 1

14 pages, 15847 KiB

Open AccessArticle

Enhanced Piezoelectricity and Thermal Stability of Electrostrain Performance in BiFeO₃-Based Lead-Free Ceramics

by Hongwei Shi, Kai Li, Feng Li, Jianxing Ma, Yubing Tu, Mingsheng Long, Yilin Lu, Weiping Gong, Chunchang Wang and Lei Shan

Nanomaterials 2023, 13(5), 942; https://doi.org/10.3390/nano13050942 - 5 Mar 2023

Cited by 7 | Viewed by 1957

Abstract

BiFeO₃–based ceramics possess an advantage over large spontaneous polarization and high Curie temperature, and are thus widely explored in the field of high–temperature lead–free piezoelectrics and actuators. However, poor piezoelectricity/resistivity and thermal stability of electrostrain make them less competitive. To address [...] Read more.

BiFeO₃–based ceramics possess an advantage over large spontaneous polarization and high Curie temperature, and are thus widely explored in the field of high–temperature lead–free piezoelectrics and actuators. However, poor piezoelectricity/resistivity and thermal stability of electrostrain make them less competitive. To address this problem, (1 − x) (0.65BiFeO₃–0.35BaTiO₃)–xLa_0.5Na_0.5TiO₃ (BF–BT–xLNT) systems are designed in this work. It is found that piezoelectricity is significantly improved with LNT addition, which is contributed by the phase boundary effect of rhombohedral and pseudocubic phase coexistence. The small–signal and large–signal piezoelectric coefficient (d₃₃ and

d_{33}^{*}

) peaks at x = 0.02 with 97 pC/N and 303 pm/V, respectively. The relaxor property and resistivity are enhanced as well. This is verified by Rietveld refinement, dielectric/impedance spectroscopy and piezoelectric force microscopy (PFM) technique. Interestingly, a good thermal stability of electrostrain is obtained at x = 0.04 composition with fluctuation η = 31% (

\frac{S_{\max}^{'} - S_{RT}}{S_{RT}} \times 100 %

), in a wide temperature range of 25–180 °C, which is considered as a compromise of negative temperature dependent electrostrain for relaxors and the positive one for ferroelectric matrix. This work provides an implication for designing high–temperature piezoelectrics and stable electrostrain materials. Full article

(This article belongs to the Special Issue Nanoelectronics: Materials, Devices and Applications)

► Show Figures

Figure 1

18 pages, 10109 KiB

Open AccessArticle

Mechanism of Double-Diffusive Convection on Peristaltic Transport of Thermally Radiative Williamson Nanomaterials with Slip Boundaries and Induced Magnetic Field: A Bio-Nanoengineering Model

by Safia Akram, Maria Athar, Khalid Saeed, Alia Razia, Taseer Muhammad and Huda Ahmed Alghamdi

Nanomaterials 2023, 13(5), 941; https://doi.org/10.3390/nano13050941 - 5 Mar 2023

Cited by 16 | Viewed by 1943

Abstract

The present work has mathematically modeled the peristaltic flow in nanofluid by using thermal radiation, induced a magnetic field, double-diffusive convection, and slip boundary conditions in an asymmetric channel. Peristalsis propagates the flow in an asymmetric channel. Using the linear mathematical link, the [...] Read more.

The present work has mathematically modeled the peristaltic flow in nanofluid by using thermal radiation, induced a magnetic field, double-diffusive convection, and slip boundary conditions in an asymmetric channel. Peristalsis propagates the flow in an asymmetric channel. Using the linear mathematical link, the rheological equations are translated from fixed to wave frames. Next, the rheological equations are converted to nondimensional forms with the help of dimensionless variables. Further, the flow evaluation is determined under two scientific assumptions: a finite Reynolds number and a long wavelength. Mathematica software is used to solve the numerical value of rheological equations. Lastly, the impact of prominent hydromechanical parameters on trapping, velocity, concentration, magnetic force function, nanoparticle volume fraction, temperature, pressure gradient, and pressure rise are evaluated graphically. Full article

(This article belongs to the Special Issue Theory and Computational Model of Nanofluids)

► Show Figures

Figure 1

16 pages, 3031 KiB

Open AccessArticle

Novel Sol-Gel Route to Prepare Eu³⁺-Doped 80SiO₂-20NaGdF₄ Oxyfluoride Glass-Ceramic for Photonic Device Applications

by María Eugenia Cruz, Thi Ngoc Lam Tran, Alessandro Chiasera, Alicia Durán, Joaquín Fernandez, Rolindes Balda and Yolanda Castro

Nanomaterials 2023, 13(5), 940; https://doi.org/10.3390/nano13050940 - 5 Mar 2023

Cited by 2 | Viewed by 1851

Abstract

Oxyfluoride glass-ceramics (OxGCs) with the molar composition 80SiO₂-20(1.5Eu³⁺: NaGdF₄) were prepared with sol-gel following the “pre-crystallised nanoparticles route” with promising optical results. The preparation of 1.5 mol % Eu³⁺-doped NaGdF₄ nanoparticles, named 1.5Eu³⁺ [...] Read more.

Oxyfluoride glass-ceramics (OxGCs) with the molar composition 80SiO₂-20(1.5Eu³⁺: NaGdF₄) were prepared with sol-gel following the “pre-crystallised nanoparticles route” with promising optical results. The preparation of 1.5 mol % Eu³⁺-doped NaGdF₄ nanoparticles, named 1.5Eu³⁺: NaGdF₄, was optimised and characterised using XRD, FTIR and HRTEM. The structural characterisation of 80SiO₂-20(1.5Eu³⁺: NaGdF₄) OxGCs prepared from these nanoparticles’ suspension was performed by XRD and FTIR revealing the presence of hexagonal and orthorhombic NaGdF₄ crystalline phases. The optical properties of both nanoparticles’ phases and the related OxGCs were studied by measuring the emission and excitation spectra together with the lifetimes of the ⁵D₀ state. The emission spectra obtained by exciting the Eu³⁺-O²⁻ charge transfer band showed similar features in both cases corresponding the higher emission intensity to the ⁵D₀→⁷F₂ transition that indicates a non-centrosymmetric site for Eu³⁺ ions. Moreover, time-resolved fluorescence line-narrowed emission spectra were performed at a low temperature in OxGCs to obtain information about the site symmetry of Eu³⁺ in this matrix. The results show that this processing method is promising for preparing transparent OxGCs coatings for photonic applications. Full article

► Show Figures

Figure 1

13 pages, 5183 KiB

Open AccessFeature PaperArticle

Ball-Mill-Inspired Durable Triboelectric Nanogenerator for Wind Energy Collecting and Speed Monitoring

by Qinghao Qin, Xia Cao and Ning Wang

Nanomaterials 2023, 13(5), 939; https://doi.org/10.3390/nano13050939 - 5 Mar 2023

Cited by 16 | Viewed by 2645

Abstract

Triboelectric nanogenerators have attracted extensive attention in energy harvesting due to its light weight, low cost, high flexibility, and diversity of function. However, deterioration in terms of mechanical durability and electrical stability of the triboelectric interface during operation, which are the results of [...] Read more.

Triboelectric nanogenerators have attracted extensive attention in energy harvesting due to its light weight, low cost, high flexibility, and diversity of function. However, deterioration in terms of mechanical durability and electrical stability of the triboelectric interface during operation, which are the results of material abrasion, severely limits their practical applications. In this paper, a durable triboelectric nanogenerator inspired by a ball mill was designed by using metal balls in hollow drums as carriers for charge generation and transfer. Composite nanofibers were deposited onto the balls, increasing the triboelectrification with the interdigital electrodes in the inner surface of the drum for higher output and electrostatic repulsion to each other for lower wear. Such a rolling design cannot only increase mechanical durability and maintenance convenience, where the filler can be easily replaced and recycled but also collect wind power with the decreased wearing of materials and sound efficiency in comparison with the typical rotation TENG. In addition, the short circuit current shows a strong linear relationship with the rotation speed in a wide range, which can be used to detect wind speed, thus showing potential applications in distributed energy conversion and self-powered environmental monitoring systems. Full article

(This article belongs to the Special Issue Early-Career Researchers in Nanomaterials for Energy and Catalysis)

► Show Figures

Figure 1

14 pages, 5603 KiB

Open AccessArticle

In Situ Polycondensation Synthesis of NiS-g-C₃N₄ Nanocomposites for Catalytic Hydrogen Generation from NaBH₄

by Alhulw H. Alshammari, Khulaif Alshammari, Turki Alotaibi, Majed Alshammari, Sultan Alhassan and Taha Abdel Mohaymen Taha

Nanomaterials 2023, 13(5), 938; https://doi.org/10.3390/nano13050938 - 5 Mar 2023

Cited by 14 | Viewed by 3508

Abstract

The nanocomposites of S@g-C₃N₄ and NiS-g-C₃N₄ were synthesized for catalytic hydrogen production from the methanolysis of sodium borohydride (NaBH₄). Several experimental methods were applied to characterize these nanocomposites such as X-ray diffraction (XRD), Fourier transform [...] Read more.

The nanocomposites of S@g-C₃N₄ and NiS-g-C₃N₄ were synthesized for catalytic hydrogen production from the methanolysis of sodium borohydride (NaBH₄). Several experimental methods were applied to characterize these nanocomposites such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and environmental scanning electron microscopy (ESEM). The calculation of NiS crystallites revealed an average size of 8.0 nm. The ESEM and TEM images of S@g-C₃N₄ showed a 2D sheet structure and NiS-g-C₃N₄ nanocomposites showed the sheet materials that were broken up during the growth process, revealing more edge sites. The surface areas were 40, 50, 62, and 90 m²/g for S@g-C₃N₄, 0.5 wt.% NiS, 1.0 wt.% NiS, and 1.5 wt.% NiS, respectively. The pore volume of S@g-C₃N₄ was 0.18 cm³, which was reduced to 0.11 cm³ in 1.5 wt.% NiS owing to the incorporation of NiS particles into the nanosheet. We found that the in situ polycondensation preparation of S@g-C₃N₄ and NiS-g-C₃N₄ nanocomposites increased the porosity of the composites. The average values of the optical energy gap for S@g-C₃N₄ were 2.60 eV and decreased to 2.50, 2.40, and 2.30 eV as the NiS concentration increased from 0.5 to 1.5 wt.%. All NiS-g-C₃N₄ nanocomposite catalysts had an emission band that was visible in the 410–540 nm range and the intensity of this peak decreased as the NiS concentration increased from 0.5 to 1.5 wt.%. The hydrogen generation rates increased with increasing content of NiS nanosheet. Moreover, the sample 1.5 wt.% NiS showed the highest production rate of 8654 mL/g·min due to the homogeneous surface organization. Full article

► Show Figures

Figure 1

24 pages, 2796 KiB

Open AccessFeature PaperReview

A Comprehensive Review of Nanofluid Heat Transfer in Porous Media

by Hossam A. Nabwey, Taher Armaghani, Behzad Azizimehr, Ahmed M. Rashad and Ali J. Chamkha

Nanomaterials 2023, 13(5), 937; https://doi.org/10.3390/nano13050937 - 4 Mar 2023

Cited by 20 | Viewed by 3597

Abstract

In the present paper, recent advances in the application of nanofluids in heat transfer in porous materials are reviewed. Efforts have been made to take a positive step in this field by scrutinizing the top papers published between 2018 and 2020. For that [...] Read more.

In the present paper, recent advances in the application of nanofluids in heat transfer in porous materials are reviewed. Efforts have been made to take a positive step in this field by scrutinizing the top papers published between 2018 and 2020. For that purpose, the various analytical methods used to describe the flow and heat transfer in different types of porous media are first thoroughly reviewed. In addition, the various models used to model nanofluids are described in detail. After reviewing these analysis methods, papers concerned with the natural convection heat transfer of nanofluids in porous media are evaluated first, followed by papers on the subject of forced convection heat transfer. Finally, we discuss articles related to mixed convection. Statistical results from the reviewed research regarding the representation of various parameters, such as the nanofluid type and the flow domain geometry, are analyzed, and directions for future research are finally suggested. The results reveal some precious facts. For instance, a change in the height of the solid and porous medium results in a change in the flow regime within the chamber; as a dimensionless permeability, the effect of Darcy’s number on heat transfer is direct; and the effect of the porosity coefficient has a direct relationship with heat transfer: when the porosity coefficient is increased or decreased, the heat transfer will also increase or decrease. Additionally, a comprehensive review of nanofluid heat transfer in porous media and the relevant statical analysis are presented for the first time. The results show that Al2O3 nanoparticles in a base fluid of water with a proportion of 33.9% have the highest representation in the papers. Regarding the geometries studied, a square geometry accounted for 54% of the studies. Full article

(This article belongs to the Special Issue The Role of Nanofluids in Renewable Energy Engineering)

► Show Figures

Figure 1

19 pages, 13598 KiB

Open AccessArticle

Rhodium-Based Catalysts: An Impact of the Support Nature on the Catalytic Cyclohexane Ring Opening

by Kristina E. Kartavova, Mikhail Yu. Mashkin, Mikhail Yu. Kostin, Elena D. Finashina, Konstantin B. Kalmykov, Gennady I. Kapustin, Petr V. Pribytkov, Olga P. Tkachenko, Igor V. Mishin, Leonid M. Kustov and Alexander L. Kustov

Nanomaterials 2023, 13(5), 936; https://doi.org/10.3390/nano13050936 - 4 Mar 2023

Cited by 4 | Viewed by 1639

Abstract

Because of the growing demand for high-quality fuels, the light cycle oil fraction improvement including cetane number improvement is important. The main way to reach this improvement is the ring opening of cyclic hydrocarbons, and a highly effective catalyst should be found. Cyclohexane [...] Read more.

Because of the growing demand for high-quality fuels, the light cycle oil fraction improvement including cetane number improvement is important. The main way to reach this improvement is the ring opening of cyclic hydrocarbons, and a highly effective catalyst should be found. Cyclohexane ring openings are a possible option to investigate the catalyst activity. In this work, we investigated rhodium-loaded catalysts prepared using the commercially available industrial supports: single-component ones, SiO₂ and Al₂O₃; and mixed oxides CaO + MgO + Al₂O₃ and Na₂O + SiO₂ + Al₂O₃. The catalysts were prepared by incipient wetness impregnation and investigated by N₂ low-temperature adsorption-desorption, XRD, XPS, DRS UV-Vis and DRIFT spectroscopy, SEM, and TEM with EDX. The catalytic tests were performed in cyclohexane ring opening in the range of 275–325 °C. The best result was demonstrated by the sample 1Rh/CaMgAlO: the selectivity to n-hexane was about 75% while the cyclohexane conversion was about 25% at 275 °C. The space-time yield was up to 12 mmol_n_-hexane g_cat⁻¹h⁻¹. Full article

(This article belongs to the Special Issue Chemical-Physical Properties and Applications of Nano-Scaled Oxides)

► Show Figures

Figure 1

14 pages, 3187 KiB

Open AccessArticle

Sulfidogenic Bioreactor-Mediated Formation of ZnS Nanoparticles with Antimicrobial and Photocatalytic Activity

by Aileen Segura, Araceli Rodriguez, Pedro Hernández, Hector Pesenti, Jacobo Hernández-Montelongo, Antonio Arranz, Noelia Benito, José Bitencourt, Luis Vergara-González, Iván Nancucheo and Gonzalo Recio-Sánchez

Nanomaterials 2023, 13(5), 935; https://doi.org/10.3390/nano13050935 - 4 Mar 2023

Cited by 6 | Viewed by 2258

Abstract

The use of sulfidogenic bioreactors is a biotechnology trend to recover valuable metals such as copper and zinc as sulfide biominerals from mine-impacted waters. In the present work, ZnS nanoparticles were produced using “green” H₂S gas generated by a sulfidogenic bioreactor. [...] Read more.

The use of sulfidogenic bioreactors is a biotechnology trend to recover valuable metals such as copper and zinc as sulfide biominerals from mine-impacted waters. In the present work, ZnS nanoparticles were produced using “green” H₂S gas generated by a sulfidogenic bioreactor. ZnS nanoparticles were physico-chemically characterized by UV-vis and fluorescence spectroscopy, TEM, XRD and XPS. The experimental results showed spherical-like shape nanoparticles with principal zinc-blende crystalline structure, a semiconductor character with an optical band gap around 3.73 eV, and fluorescence emission in the UV-visible range. In addition, the photocatalytic activity on the degradation of organic dyes in water, as well as bactericidal properties against several bacterial strains, were studied. ZnS nanoparticles were able to degrade methylene blue and rhodamine in water under UV radiation, and also showed high antibacterial activity against different bacterial strains including Escherichia coli and Staphylococcus aureus. The results open the way to obtain valorous ZnS nanoparticles from the use of dissimilatory reduction of sulfate using a sulfidogenic bioreactor. Full article

(This article belongs to the Special Issue Engineering Nanoparticles for Photocatalytic Applications)

► Show Figures

Figure 1

13 pages, 1209 KiB

Open AccessArticle

Design Optimization and Characterization with Fabrication of Nanomaterials-Based Photo Diode Cell for Subretinal Implant Application

by Vijai M. Moorthy, Joseph D. Rathnasami and Viranjay M. Srivastava

Nanomaterials 2023, 13(5), 934; https://doi.org/10.3390/nano13050934 - 4 Mar 2023

Cited by 2 | Viewed by 1990

Abstract

An ultrathin nano photodiode array fabricated in a flexible substrate can be an ideal therapeutic replacement for degenerated photoreceptor cells damaged by Age-related Macula Degeneration (AMD) and Retinitis Pigmentosa (RP), such as retinal infections. Silicon-based photodiode arrays have been attempted as artificial retinas. [...] Read more.

An ultrathin nano photodiode array fabricated in a flexible substrate can be an ideal therapeutic replacement for degenerated photoreceptor cells damaged by Age-related Macula Degeneration (AMD) and Retinitis Pigmentosa (RP), such as retinal infections. Silicon-based photodiode arrays have been attempted as artificial retinas. Considering the difficulties caused by hard silicon subretinal implants, researchers have diverted their attention towards organic photovoltaic cells-based subretinal implants. Indium-Tin Oxide (ITO) has been a favorite choice as an anode electrode. A mix of poly(3-hexylthiophene) and [6,6]-phenyl C61-butyric acid methyleste (P3HT: PCBM) has been utilized as an active layer in such nanomaterial-based subretinal implants. Though encouraging results have been obtained during the trial of such retinal implants, the need to replace ITO with a suitable transparent conductive electrode will be a suitable substitute. Further, conjugated polymers have been used as active layers in such photodiodes and have shown delamination in the retinal space over time despite their biocompatibility. This research attempted to fabricate and characterize Bulk Hetero Junction (BHJ) based Nano Photo Diode (NPD) utilizing Graphene–polyethylene terephthalate (G–PET)/semiconducting Single-Wall Carbon Nano Tubes (s-SWCNT): fullerene (C₆₀) blend/aluminium (Al) structure to determine the issues in the development of subretinal prosthesis. An effective design approach adopted in this analysis has resulted in developing an NPD with an Efficiency of 10.1% in a non-ITO-driven NPD structure. Additionally, the results show that the efficiency can be further improved by increasing active layer thickness. Full article

► Show Figures

Figure 1

26 pages, 13456 KiB

Open AccessArticle

Magnetic Nanoclusters Stabilized with Poly[3,4-Dihydroxybenzhydrazide] as Efficient Therapeutic Agents for Cancer Cells Destruction

by Ioana Baldea, Anca Petran, Adrian Florea, Alexandra Sevastre-Berghian, Iuliana Nenu, Gabriela Adriana Filip, Mihai Cenariu, Maria Teodora Radu and Cristian Iacovita

Nanomaterials 2023, 13(5), 933; https://doi.org/10.3390/nano13050933 - 3 Mar 2023

Cited by 4 | Viewed by 2276

Abstract

Magnetic structures exhibiting large magnetic moments are sought after in theranostic approaches that combine magnetic hyperthermia treatment (MH) and diagnostic magnetic resonance imaging in oncology, since they offer an enhanced magnetic response to an external magnetic field. We report on the synthesized production [...] Read more.

Magnetic structures exhibiting large magnetic moments are sought after in theranostic approaches that combine magnetic hyperthermia treatment (MH) and diagnostic magnetic resonance imaging in oncology, since they offer an enhanced magnetic response to an external magnetic field. We report on the synthesized production of a core–shell magnetic structure using two types of magnetite nanoclusters (MNC) based on a magnetite core and polymer shell. This was achieved through an in situ solvothermal process, using, for the first time, 3,4-dihydroxybenzhydrazide (DHBH) and poly[3,4-dihydroxybenzhydrazide] (PDHBH) as stabilizers. Transmission electron microscopy (TEM) analysis showed the formation of spherical MNC, X-ray photoelectronic spectroscopy (XPS) and Fourier transformed infrared (FT-IR) analysis proved the existence of the polymer shell. Magnetization measurement showed saturation magnetization values of 50 emu/g for PDHBH@MNC and 60 emu/g for DHBH@MNC with very low coercive field and remanence, indicating that the MNC are in a superparamagnetic state at room temperature and are thus suitable for biomedical applications. MNCs were investigated in vitro, on human normal (dermal fibroblasts-BJ) and tumor (colon adenocarcinoma-CACO2, and melanoma-A375) cell lines, in view of toxicity, antitumor effectiveness and selectivity upon magnetic hyperthermia. MNCs exhibited good biocompatibility and were internalized by all cell lines (TEM), with minimal ultrastructural changes. By means of flowcytometry apoptosis detection, fluorimetry, spectrophotometry for mitochondrial membrane potential, oxidative stress, ELISA-caspases, and Western blot–p53 pathway, we show that MH efficiently induced apoptosis mostly via the membrane pathway and to a lower extent by the mitochondrial pathway, the latter mainly observed in melanoma. Contrarily, the apoptosis rate was above the toxicity limit in fibroblasts. Due to its coating, PDHBH@MNC showed selective antitumor efficacy and can be further used in theranostics since the PDHBH polymer provides multiple reaction sites for the attachment of therapeutic molecules. Full article

(This article belongs to the Special Issue Advances in Toxicity of Nanoparticles in Organisms)

► Show Figures

Figure 1

16 pages, 4207 KiB

Open AccessArticle

Fabrication of Glutaraldehyde Vapor Treated PVA/SA/GO/ZnO Electrospun Nanofibers with High Liquid Absorbability for Antimicrobial of Staphylococcus aureus

by Yi-Hsin Chien, Meng-Tzu Ho, Chin-Hsign Feng, Jung-Hsign Yen, Yi-Chan Chang, Chih-Sheng Lai and Rong-Fuh Louh

Nanomaterials 2023, 13(5), 932; https://doi.org/10.3390/nano13050932 - 3 Mar 2023

Cited by 5 | Viewed by 2647

Abstract

In this study, we aim to develop organic–inorganic hybrid nanofibers containing high moisture retention and good mechanical performance as an antimicrobial dressing platform. The main theme of this work focuses on several technical tasks including (a) the electrospinning process (ESP) to produce organic [...] Read more.

In this study, we aim to develop organic–inorganic hybrid nanofibers containing high moisture retention and good mechanical performance as an antimicrobial dressing platform. The main theme of this work focuses on several technical tasks including (a) the electrospinning process (ESP) to produce organic polyvinyl alcohol/sodium alginate (PVA/SA) nanofibers with an excellent diameter uniformity and fibrous orientation, (b) the fabrication of inorganic nanoparticles (NPs) as graphene oxide (GO) and ZnO NPs to be added to PVA/SA nanofibers for enhancement of the mechanical properties and an antibacterial function to Staphylococcus aureus (S. aureus), and then (c) the crosslinking process for PVA/SA/GO/ZnO hybrid nanofibers in glutaraldehyde (GA) vapor atmosphere to improve the hydrophilicity and moisture absorption of specimens. Our results clearly indicate that the uniformity nanofiber with 7 wt% PVA and 2 wt% SA condition demonstrates 199 ± 22 nm in diameter using an electrospinning precursor solution of 355 cP in viscosity by the ESP process. Moreover, the mechanical strength of nanofibers was enhanced by 17% after the handling of a 0.5 wt% GO nanoparticles addition. Significantly, the morphology and size of ZnO NPs can be affected by NaOH concentration, where 1 M NaOH was used in the synthesis of 23 nm ZnO NPs corresponding to effective inhibition of S. aureus strains. The PVA/SA/GO/ZnO mixture successfully performed an antibacterial ability with an 8 mm inhibition zone in S. aureus strains. Furthermore, the GA vapor as a crosslinking agent acting on PVA/SA/GO/ZnO nanofiber provided both swelling behavior and structural stability performance. The swelling ratio increased up to 1.406%, and the mechanical strength was 1.87 MPa after 48 h of GA vapor treatment. Finally, we successfully synthesized the hybrid nanofibers of GA-treated PVA/SA/GO/ZnO accompanied with high moisturizing, biocompatibility, and great mechanical properties, which will be a novel multi-functional candidate for wound dressing composites for patients receiving surgical operations and first aid treatments. Full article

(This article belongs to the Special Issue Hybrid Nanofibers: Fabrication, Properties and Applications)

► Show Figures

Figure 1

16 pages, 4769 KiB

Open AccessArticle

Synthesis and Spectroelectrochemical Investigation of Anodic Black TiO_x Nanotubes

by Sebastian Kotarba, Grzegorz D. Sulka and Karolina Syrek

Nanomaterials 2023, 13(5), 931; https://doi.org/10.3390/nano13050931 - 3 Mar 2023

Cited by 3 | Viewed by 1554

Abstract

Anodic TiO₂ nanotubes were transformed into anatase at 400 °C for 2 h in air and subjected to electrochemical reduction at different conditions. It revealed that the reduced black TiO_x nanotubes were not stable in contact with air; however, their lifetime [...] Read more.

Anodic TiO₂ nanotubes were transformed into anatase at 400 °C for 2 h in air and subjected to electrochemical reduction at different conditions. It revealed that the reduced black TiO_x nanotubes were not stable in contact with air; however, their lifetime was considerably extended to even a few hours when isolated from the influence of atmospheric oxygen. The order of polarization-induced reduction and spontaneous reverse oxidation reactions were determined. Upon irradiation with simulated sunlight, the reduced black TiO_x nanotubes generated lower photocurrents than non-reduced TiO₂, but a lower rate of electron-hole recombination and better charge separation were observed. In addition, the conduction band edge and energy level (Fermi level), responsible for trapping electrons from the valence band during the reduction of TiO₂ nanotubes, were determined. The methods presented in this paper can be used for determination of the spectroelectrochemical and photoelectrochemical properties of electrochromic materials. Full article

(This article belongs to the Special Issue Ceramics and Nanostructures for Energy Harvesting and Storage)

► Show Figures

Figure 1

14 pages, 4518 KiB

Open AccessArticle

Tunable Electromagnetic and Microwave Absorption Properties of Magnetic FeNi₃ Alloys

by Yu Zheng, Mei Wu, Congyi Qian, Yuxin Jin, Wei Xiao and Xiaohui Liang

Nanomaterials 2023, 13(5), 930; https://doi.org/10.3390/nano13050930 - 3 Mar 2023

Cited by 13 | Viewed by 1928

Abstract

Magnetic materials have a very broad application prospect in the field of microwave absorption, among which soft magnetic materials become the focus of magnetic materials research because of their high saturation magnetization and low coercivity. FeNi₃ alloy has been widely used in [...] Read more.

Magnetic materials have a very broad application prospect in the field of microwave absorption, among which soft magnetic materials become the focus of magnetic materials research because of their high saturation magnetization and low coercivity. FeNi₃ alloy has been widely used in soft magnetic materials because of its excellent ferromagnetism and electrical conductivity. In this work, FeNi₃ alloy was prepared by the liquid reduction method. The effect of the filling ratio of FeNi₃ alloy on the electromagnetic properties of absorbing materials was studied. It is found that the impedance matching ability of FeNi₃ alloy is better when the filling ratio is 70 wt% than that of other samples with different filling ratios (30–60 wt%), showing better microwave absorption characteristics. When the matching thickness is 2.35 mm, the minimum reflection loss (RL) of FeNi₃ alloy with a 70 wt% filling ratio reaches −40.33 dB, and the effective absorption bandwidth is 5.5 GHz. When the matching thickness is between 2 and 3 mm, the effective absorption bandwidth ranges from 7.21 GHz to 17.81 GHz, almost covering the whole X and Ku bands (8–18 GHz). The results show that FeNi₃ alloy has adjustable electromagnetic properties and microwave absorption properties with different filling ratios, which is conducive to selecting excellent microwave absorption materials. Full article

(This article belongs to the Special Issue Electromagnetic and Microwave Absorption Properties of Magnetic Nanomaterials and Superstructure)

► Show Figures

Figure 1

19 pages, 2833 KiB

Open AccessArticle

Transfersome Encapsulated with the R-carvedilol Enantiomer for Skin Cancer Chemoprevention

by Md Abdullah Shamim, Ayaz Shahid, Pabitra K. Sardar, Steven Yeung, Jeremiah Reyes, Jenny Kim, Cyrus Parsa, Robert Orlando, Jeffrey Wang, Kristen M. Kelly, Frank L. Meyskens, Jr., Bradley T. Andresen and Ying Huang

Nanomaterials 2023, 13(5), 929; https://doi.org/10.3390/nano13050929 - 3 Mar 2023

Cited by 8 | Viewed by 2776

Abstract

The R-carvedilol enantiomer, present in the racemic mixture of the chiral drug carvedilol, does not bind to the β-adrenergic receptors, but exhibits skin cancer preventive activity. For skin delivery, R-carvedilol-loaded transfersomes were prepared using various ratios of drug, lipids, and surfactants, and characterized [...] Read more.

The R-carvedilol enantiomer, present in the racemic mixture of the chiral drug carvedilol, does not bind to the β-adrenergic receptors, but exhibits skin cancer preventive activity. For skin delivery, R-carvedilol-loaded transfersomes were prepared using various ratios of drug, lipids, and surfactants, and characterized for particle size, zeta potential, encapsulation efficiency, stability, and morphology. Transfersomes were compared for in vitro drug release and ex vivo skin penetration and retention. Skin irritation was evaluated by viability assay on murine epidermal cells and reconstructed human skin culture. Single-dose and repeated-dose dermal toxicity was determined in SKH-1 hairless mice. Efficacy was evaluated in SKH-1 mice exposed to single or multiple ultraviolet (UV) radiations. Transfersomes released the drug at a slower rate, but significantly increased skin drug permeation and retention compared with the free drug. The transfersome with a drug–lipid–surfactant ratio of 1:3:0.5 (T-RCAR-3) demonstrated the highest skin drug retention and was selected for further studies. T-RCAR-3 at 100 µM did not induce skin irritation in vitro and in vivo. Topical treatment with T-RCAR-3 at 10 µM effectively attenuated acute UV-induced skin inflammation and chronic UV-induced skin carcinogenesis. This study demonstrates feasibility of using R-carvedilol transfersome for preventing UV-induced skin inflammation and cancer. Full article

► Show Figures

Figure 1

17 pages, 6377 KiB

Open AccessArticle

Successful Growth of TiO₂ Nanocrystals with {001} Facets for Solar Cells

by Saif M. H. Qaid, Hamid M. Ghaithan, Huda S. Bawazir, Abrar F. Bin Ajaj, Khulod K. AlHarbi and Abdullah S. Aldwayyan

Nanomaterials 2023, 13(5), 928; https://doi.org/10.3390/nano13050928 - 3 Mar 2023

Cited by 14 | Viewed by 2550

Abstract

The growth of nanocrystals (NCs) from metal oxide-based substrates with exposed high-energy facets is of particular importance for many important applications, such as solar cells as photoanodes due to the high reactivity of these facets. The hydrothermal method remains a current trend for [...] Read more.

The growth of nanocrystals (NCs) from metal oxide-based substrates with exposed high-energy facets is of particular importance for many important applications, such as solar cells as photoanodes due to the high reactivity of these facets. The hydrothermal method remains a current trend for the synthesis of metal oxide nanostructures in general and titanium dioxide (TiO₂) in particular since the calcination of the resulting powder after the completion of the hydrothermal method no longer requires a high temperature. This work aims to use a rapid hydrothermal method to synthesize numerous TiO₂-NCs, namely, TiO₂ nanosheets (TiO₂-NSs), TiO₂ nanorods (TiO₂-NRs), and nanoparticles (TiO₂-NPs). In these ideas, a simple non-aqueous one-pot solvothermal method was employed to prepare TiO₂-NSs using tetrabutyl titanate Ti(OBu)₄ as a precursor and hydrofluoric acid (HF) as a morphology control agent. Ti(OBu)₄ alone was subjected to alcoholysis in ethanol, yielding only pure nanoparticles (TiO₂-NPs). Subsequently, in this work, the hazardous chemical HF was replaced by sodium fluoride (NaF) as a means of controlling morphology to produce TiO₂-NRs. The latter method was required for the growth of high purity brookite TiO₂ NRs structure, the most difficult TiO₂ polymorph to synthesize. The fabricated components are then morphologically evaluated using equipment, such as transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), electron diffraction (SAED), and X-ray diffraction (XRD). In the results, the TEM image of the developed NCs shows the presence of TiO₂-NSs with an average side length of about 20–30 nm and a thickness of 5–7 nm. In addition, the image TEM shows TiO₂-NRs with diameters between 10 and 20 nm and lengths between 80 and 100 nm, together with crystals of smaller size. The phase of the crystals is good, confirmed by XRD. The anatase structure, typical of TiO₂-NS and TiO₂-NPs, and the high-purity brookite-TiO₂-NRs structure, were evident in the produced nanocrystals, according to XRD. SAED patterns confirm that the synthesis of high quality single crystalline TiO₂-NSs and TiO₂-NRs with the exposed {001} facets are the exposed facets, which have the upper and lower dominant facets, high reactivity, high surface energy, and high surface area. TiO₂-NSs and TiO₂-NRs could be grown, corresponding to about 80% and 85% of the {001} outer surface area in the nanocrystal, respectively. Full article

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

► Show Figures

Figure 1

22 pages, 7454 KiB

Open AccessArticle

Ecotoxicological Properties of Titanium Dioxide Nanomorphologies in Daphnia magna

by Freddy Mendoza-Villa, Noemi-Raquel Checca-Huaman and Juan A. Ramos-Guivar

Nanomaterials 2023, 13(5), 927; https://doi.org/10.3390/nano13050927 - 3 Mar 2023

Cited by 9 | Viewed by 2322

Abstract

In this work, the structural, vibrational, morphological, and colloidal properties of commercial 15.1 nm TiO₂ nanoparticles (NPs) and nanowires (NWs, 5.6 thickness, 74.6 nm length) were studied with the purpose of determining their ecotoxicological properties. This was achieved by evaluating acute ecotoxicity [...] Read more.

In this work, the structural, vibrational, morphological, and colloidal properties of commercial 15.1 nm TiO₂ nanoparticles (NPs) and nanowires (NWs, 5.6 thickness, 74.6 nm length) were studied with the purpose of determining their ecotoxicological properties. This was achieved by evaluating acute ecotoxicity experiments carried out in the environmental bioindicator Daphnia magna, where their 24-h lethal concentration (LC₅₀) and morphological changes were evaluated using a TiO₂ suspension (pH = 7) with point of zero charge at 6.5 for TiO₂ NPs (hydrodynamic diameter of 130 nm) and 5.3 for TiO₂ NWs (hydrodynamic diameter of 118 nm). Their LC₅₀ values were 157 and 166 mg L⁻¹ for TiO₂ NWs and TiO₂ NPs, respectively. The reproduction rate of D. magna after fifteen days of exposure to TiO₂ nanomorphologies was delayed (0 pups for TiO₂ NWs and 45 neonates for TiO₂ NPs) in comparison with the negative control (104 pups). From the morphological experiments, we may conclude that the harmful effects of TiO₂ NWs are more severe than those of 100% anatase TiO₂ NPs, likely associated with brookite (36.5 wt. %) and protonic trititanate (63.5 wt. %) presented in TiO₂ NWs according to Rietveld quantitative phase analysis. Specifically, significant change in the heart morphological parameter was observed. In addition, the structural and morphological properties of TiO₂ nanomorphologies were investigated using X-ray diffraction and electron microscopy techniques to confirm the physicochemical properties after the ecotoxicological experiments. The results reveal that no alteration in the chemical structure, size (16.5 nm for TiO2 NPs and 6.6 thickness and 79.2 nm length for NWs), and composition occurred. Hence, both TiO₂ samples can be stored and reused for future environmental purposes, e.g., water nanoremediation. Full article

(This article belongs to the Special Issue Ecotoxicology and Risk Assessment of Engineered Nanomaterials)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Nanomaterials, Volume 13, Issue 5 (March-1 2023) – 171 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI