Nanomaterials

37 pages, 6476 KiB

Open AccessReview

Recent Advances in Biomass-Based Materials for Oil Spill Cleanup

by Dan Ouyang, Xiaotian Lei and Honglei Zheng

Nanomaterials 2023, 13(3), 620; https://doi.org/10.3390/nano13030620 - 3 Feb 2023

Cited by 12 | Viewed by 5247

Oil spill on sea surfaces, which mainly produced by the oil leakage accident happened on tankers, offshore platforms, drilling rigs and wells, has bring irreversible damage to marine environments and ecosystems. Among various spill oil handling methods, using sorbents to absorb and recover [...] Read more.

Oil spill on sea surfaces, which mainly produced by the oil leakage accident happened on tankers, offshore platforms, drilling rigs and wells, has bring irreversible damage to marine environments and ecosystems. Among various spill oil handling methods, using sorbents to absorb and recover spill oils is a perspective method because they are cost-effective and enable a high recovery and without secondary pollution to the ecosystem. Currently, sorbents based on biomass materials have aroused extensively attention thanks to their features of inexpensive, abundant, biodegradable, and sustainable. Herein, we comprehensively review the state-of-the-art development of biomass-based sorbents for spill oil cleanup in the recent five years. After briefly introducing the background, the basic theory and material characteristics for the separation of oil from water and the adsorption of oils is also presented. Various modification methods for biomass materials are summarized in section three. Section four discusses the recent progress of biomass as oil sorbents for oil spill cleanup, in which the emphasis is placed on the oil sorption capacity and the separation efficiency. Finally, the challenge and future development directions is outlined. Full article

(This article belongs to the Special Issue Advances in Engineered Nanostructures for Detection, Control and Removal of Environmental Pollutants)

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13 pages, 4595 KiB

Open AccessArticle

Highly Efficient and Stable Self-Powered Perovskite Photodiode by Cathode-Side Interfacial Passivation with Poly(Methyl Methacrylate)

by Wonsun Kim, JaeWoo Park, Yushika Aggarwal, Shital Sharma, Eun Ha Choi and Byoungchoo Park

Nanomaterials 2023, 13(3), 619; https://doi.org/10.3390/nano13030619 - 3 Feb 2023

Cited by 7 | Viewed by 2885

Abstract

For several years now, organic–inorganic hybrid perovskite materials have shown remarkable progress in the field of opto-electronic devices. Herein, we introduce a cathode-side passivation layer of poly(methyl methacrylate) (PMMA) for a highly efficient and stable self-powered CH₃NH₃PbI₃ perovskite-based [...] Read more.

For several years now, organic–inorganic hybrid perovskite materials have shown remarkable progress in the field of opto-electronic devices. Herein, we introduce a cathode-side passivation layer of poly(methyl methacrylate) (PMMA) for a highly efficient and stable self-powered CH₃NH₃PbI₃ perovskite-based photodiode. For effective noise–current suppression, the PMMA passivation layer was employed between a light-absorbing layer of CH₃NH₃PbI₃ (MAPbI₃) perovskite and an electron transport layer of [6,6]-phenyl-C61-butyric acid methyl ester. Due to its passivation effect on defects in perovskite film, the PMMA passivation layer can effectively suppress interface recombination and reduce the leakage/noise current. Without external bias, the MAPbI₃ photodiode with the PMMA layer demonstrated a significantly high specific detectivity value (~1.07 × 10¹² Jones) compared to that of a conventional MAPbI₃ photodiode without a PMMA layer. Along with the enhanced specific detectivity, a wide linear dynamic response (~127 dB) with rapid rise (~50 μs) and decay (~17 μs) response times was obtained. Furthermore, highly durable dynamic responses of the PMMA-passivated MAPbI₃ photodiode were observed even after a long storage time of 500 h. The results achieved with the cathode-side PMMA-passivated perovskite photodiodes represent a new means by which to realize highly sensitive and stable self-powered photodiodes for use in developing novel opto-electronic devices. Full article

(This article belongs to the Special Issue Advance in Energy Harvesters/Nanogenerators and Self-Powered Sensors II)

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15 pages, 2828 KiB

Open AccessArticle

Polyindole Embedded Nickel/Zinc Oxide Nanocomposites for High-Performance Energy Storage Applications

by Huriya Humayun, Bushra Begum, Salma Bilal, Anwar ul Haq Ali Shah and Philipp Röse

Nanomaterials 2023, 13(3), 618; https://doi.org/10.3390/nano13030618 - 3 Feb 2023

Cited by 15 | Viewed by 2571

Abstract

Conducting polymers integrated with metal oxides create opportunities for hybrid capacitive electrodes. In this work, we report a one-pot oxidative polymerization for the synthesis of integrated conductive polyindole/nickel oxide (PIn/NiO), polyindole/zinc oxide (PIn/ZnO), and polyindole/nickel oxide/zinc oxide (PNZ). The polymers were analyzed thoroughly [...] Read more.

Conducting polymers integrated with metal oxides create opportunities for hybrid capacitive electrodes. In this work, we report a one-pot oxidative polymerization for the synthesis of integrated conductive polyindole/nickel oxide (PIn/NiO), polyindole/zinc oxide (PIn/ZnO), and polyindole/nickel oxide/zinc oxide (PNZ). The polymers were analyzed thoroughly for their composition and physical as well as chemical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis), and thermogravimetric analysis (TGA). The PIn and its composites were processed into electrodes, and their use in symmetrical supercapacitors in two- and three-electrode setups was evaluated by cyclic voltammetry (CV), galvanostatic discharge (GCD), and electrochemical impedance spectroscopy (EIS). The best electrochemical charge storage capability was found for the ternary PNZ composite. The high performance directly correlates with its uniformly shaped nanofibrous structure and high crystallinity. For instance, the symmetrical supercapacitor fabricated with PNZ hybrid electrodes shows a high specific capacitance of 310.9 F g⁻¹ at 0.5 A g⁻¹ with an energy density of 42.1 Wh kg⁻¹, a power density of 13.2 kW kg⁻¹, and a good cycling stability of 78.5% after 5000 cycles. This report presents new electrode materials for advanced supercapacitor technology based on these results. Full article

(This article belongs to the Special Issue Advanced Nanocomposites for Batteries and Supercapacitors)

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23 pages, 1939 KiB

Open AccessReview

Nanoencapsulation of Cyanidin 3-O-Glucoside: Purpose, Technique, Bioavailability, and Stability

by Oscar Zannou, Kouame F. Oussou, Ifagbémi B. Chabi, Nour M. H. Awad, Midimahu V. Aïssi, Gulden Goksen, Mustafa Mortas, Fatih Oz, Charalampos Proestos and Adéchola P. P. Kayodé

Nanomaterials 2023, 13(3), 617; https://doi.org/10.3390/nano13030617 - 3 Feb 2023

Cited by 11 | Viewed by 3153

Abstract

The current growing attractiveness of natural dyes around the world is a consequence of the increasing rejection of synthetic dyes whose use is increasingly criticized. The great interest in natural pigments from herbal origin such as cyanidin 3-O-glucoside (C3G) is due [...] Read more.

The current growing attractiveness of natural dyes around the world is a consequence of the increasing rejection of synthetic dyes whose use is increasingly criticized. The great interest in natural pigments from herbal origin such as cyanidin 3-O-glucoside (C3G) is due to their biological properties and their health benefits. However, the chemical instability of C3G during processing and storage and its low bioavailability limits its food application. Nanoencapsulation technology using appropriate nanocarriers is revolutionizing the use of anthocyanin, including C3G. Owing to the chemical stability and functional benefits that this new nanotechnology provides to the latter, its industrial application is now extending to the pharmaceutical and cosmetic fields. This review focuses on the various nanoencapsulation techniques used and the chemical and biological benefits induced to C3G. Full article

(This article belongs to the Special Issue Nanomaterials and Nanostructures for Food Processing and Preservation)

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17 pages, 4066 KiB

Open AccessArticle

Nickel—Alumina Catalysts for the Transformation of Vegetable Oils into Green Diesel: The Role of Preparation Method, Activation Temperature, and Reaction Conditions

by Ioannis Nikolopoulos, George Kogkos, Vasiliki D. Tsavatopoulou, Eleana Kordouli, Kyriakos Bourikas, Christos Kordulis and Alexis Lycourghiotis

Nanomaterials 2023, 13(3), 616; https://doi.org/10.3390/nano13030616 - 3 Feb 2023

Cited by 9 | Viewed by 2213

Abstract

Two nickel alumina catalysts containing 60 wt. % Ni were synthesized by wet impregnation and co-precipitation in order to study the effect of preparation methods on the catalytic efficiency concerning the transformation of sunflower oil into green diesel. The effect of activation temperature [...] Read more.

Two nickel alumina catalysts containing 60 wt. % Ni were synthesized by wet impregnation and co-precipitation in order to study the effect of preparation methods on the catalytic efficiency concerning the transformation of sunflower oil into green diesel. The effect of activation temperature on the catalytic efficiency of the most active catalyst was also studied. The catalysts were characterized using various techniques and which were evaluated in the aforementioned reaction using a semi-batch reactor. The catalyst prepared by co-precipitation exhibited a higher specific surface area and smaller mean crystal size of the nickel nanoparticle (higher nickel metallic surface). These justify its higher efficiency with respect to the corresponding catalyst synthesized by wet impregnation. The increase in the activation temperature from 400 to 600 °C increased the size of the nickel nanoparticles through sintering, thus destroying the small pores. These led to a decrease in the nickel surface and specific surface area and, thus, to a decrease in the catalytic efficiency. The optimization of the reaction conditions over the most active catalyst (prepared by co-precipitation and activated at 400 °C) leads to the complete transformation not only of the sunflower oil (edible oil) but also of waste cooking oil (non-edible oil) into green diesel. The liquid produced after the hydrotreatment for these two feedstocks for 7 h, at H₂ pressure 40 bar and temperature 350 °C using 100 mL of oil and 1 g of catalyst was composed of 97 and 96 wt. % of green diesel, respectively. Full article

(This article belongs to the Special Issue Nanocatalysis for Environmental Protection, Energy, and Green Chemistry)

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17 pages, 2915 KiB

Open AccessArticle

Therapeutic Applications of Biogenic Silver Nanomaterial Synthesized from the Paper Flower of Bougainvillea glabra (Miami, Pink)

by Mohammad Oves, Mohd Ahmar Rauf and Huda A. Qari

Nanomaterials 2023, 13(3), 615; https://doi.org/10.3390/nano13030615 - 3 Feb 2023

Cited by 19 | Viewed by 3291

Abstract

In this research, Bougainvillea glabra paper flower extract was used to quickly synthesize biogenic silver nanoparticles (BAgNPs) utilizing green chemistry. Using the flower extract as a biological reducing agent, silver nanoparticles were generated by the conversion of Ag⁺ cations to Ag⁰ [...] Read more.

In this research, Bougainvillea glabra paper flower extract was used to quickly synthesize biogenic silver nanoparticles (BAgNPs) utilizing green chemistry. Using the flower extract as a biological reducing agent, silver nanoparticles were generated by the conversion of Ag⁺ cations to Ag⁰ ions. Data patterns obtained from physical techniques for characterizing BAgNPs, employing UV-visible, scattering electron microscope (SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), suggested that the nanoparticles have a spherical to oval form with size ranging from 10 to 50 nm. Spectroscopy and microscopic analysis were used to learn more about the antibacterial properties of the biologically produced BAgNPs from Bougainvillea glabra. Further, the potential mechanism of action of nanoparticles was investigated by studying their interactions in vitro with several bacterial strains and mammalian cancer cell systems. Finally, we can conclude that BAgNPs can be functionalized to dramatically inhibit bacterial growth and the growth of cancer cells in culture conditions, suggesting that biologically produced nanomaterials will provide new opportunities for a wide range of biomedical applications in the near future. Full article

(This article belongs to the Special Issue Hybrid Nanomaterials: Applications in Energy, Environment and Biomedicine)

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14 pages, 3860 KiB

Open AccessArticle

Silver Nanoshells with Optimized Infrared Optical Response: Synthesis for Thin-Shell Formation, and Optical/Thermal Properties after Embedding in Polymeric Films

by Laurent Lermusiaux, Lucien Roach, Moncef Lehtihet, Marie Plissonneau, Laure Bertry, Valérie Buissette, Thierry Le Mercier, Etienne Duguet, Glenna L. Drisko, Jacques Leng and Mona Tréguer-Delapierre

Nanomaterials 2023, 13(3), 614; https://doi.org/10.3390/nano13030614 - 3 Feb 2023

Cited by 4 | Viewed by 2241

Abstract

We describe a new approach to making ultrathin Ag nanoshells with a higher level of extinction in the infrared than in the visible. The combination of near-infrared active ultrathin nanoshells with their isotropic optical properties is of interest for energy-saving applications. For such [...] Read more.

We describe a new approach to making ultrathin Ag nanoshells with a higher level of extinction in the infrared than in the visible. The combination of near-infrared active ultrathin nanoshells with their isotropic optical properties is of interest for energy-saving applications. For such applications, the morphology must be precisely controlled, since the optical response is sensitive to nanometer-scale variations. To achieve this precision, we use a multi-step, reproducible, colloidal chemical synthesis. It includes the reduction of Tollens’ reactant onto Sn²⁺-sensitized silica particles, followed by silver-nitrate reduction by formaldehyde and ammonia. The smooth shells are about 10 nm thick, on average, and have different morphologies: continuous, percolated, and patchy, depending on the quantity of the silver nitrate used. The shell-formation mechanism, studied by optical spectroscopy and high-resolution microscopy, seems to consist of two steps: the formation of very thin and flat patches, followed by their guided regrowth around the silica particle, which is favored by a high reaction rate. The optical and thermal properties of the core-shell particles, embedded in a transparent poly(vinylpyrrolidone) film on a glass substrate, were also investigated. We found that the Ag-nanoshell films can convert 30% of the power of incident near-infrared light into heat, making them very suitable in window glazing for radiative screening from solar light. Full article

(This article belongs to the Section Nanofabrication and Nanomanufacturing)

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Graphical abstract

10 pages, 3388 KiB

Open AccessArticle

Facile Preparation of Cellulose Aerogels with Controllable Pore Structure

by Jiahao Qiu, Xingzhong Guo, Wei Lei, Ronghua Ding, Yun Zhang and Hui Yang

Nanomaterials 2023, 13(3), 613; https://doi.org/10.3390/nano13030613 - 3 Feb 2023

Cited by 12 | Viewed by 3932

Abstract

Cellulose aerogels are the latest generation of aerogels and have also received extensive attention due to their renewable and biocompatible properties. Herein, cellulose aerogel was facilely prepared by using NaOH/urea solution as solvent, raising the temperature to control gelation and drying wet gel [...] Read more.

Cellulose aerogels are the latest generation of aerogels and have also received extensive attention due to their renewable and biocompatible properties. Herein, cellulose aerogel was facilely prepared by using NaOH/urea solution as solvent, raising the temperature to control gelation and drying wet gel sequentially. With NaOH/urea solution as solvent, the cellulose concentration has an important impact on the micromorphology of cellulose aerogels, while the aging time rarely affects the micromorphology. The appropriate solvent and drying method allow the formation of different cellulose crystalline structures. Different from the Cellulose Ⅰ crystalline structure of raw cellulose powder, the cellulose phase of as-prepared cellulose aerogels belongs to the Cellulose Ⅱ crystalline structure, and to some extent the pyrolysis temperature is also lower than that of raw cellulose powder. The resultant cellulose aerogel prepared by using NaOH/urea solution as solvent and freeze-drying has a uniform macroporous structure with a macropore size of 1~3 µm. Full article

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12 pages, 2352 KiB

Open AccessArticle

Multi-Spiral Laser Patterning of Azopolymer Thin Films for Generation of Orbital Angular Momentum Light

by Alexey P. Porfirev, Nikolay A. Ivliev, Sergey A. Fomchenkov and Svetlana N. Khonina

Nanomaterials 2023, 13(3), 612; https://doi.org/10.3390/nano13030612 - 3 Feb 2023

Cited by 3 | Viewed by 2185

Abstract

Recently, the realization of the spiral mass transfer of matter has attracted the attention of many researchers. Nano- and microstructures fabricated with such mass transfer can be used for the generation of light with non-zero orbital angular momentum (OAM) or the sensing of [...] Read more.

Recently, the realization of the spiral mass transfer of matter has attracted the attention of many researchers. Nano- and microstructures fabricated with such mass transfer can be used for the generation of light with non-zero orbital angular momentum (OAM) or the sensing of chiral molecules. In the case of metals and semiconductors, the chirality of formed spiral-shaped microstructures depends on the topological charge (TC) of the illuminating optical vortex (OV) beam. The situation is quite different with polarization-sensitive materials such as azopolymers, azobenzene-containing polymers. Azopolymers show polarization-sensitive mass transfer both at the meso and macro levels and have huge potential in diffractive optics and photonics. Previously, only one-spiral patterns formed in thin azopolymer films using circularly polarized OV beams and double-spiral patterns formed using linearly polarized OV beams have been demonstrated. In these cases, the TC of the used OV beams did not affect the number of formed spirals. In this study, we propose to use two-beam (an OV and a Gaussian beam with a spherical wavefront) interference lithography for realization spiral mass transfer with the desired number of formed spirals. The TC of the OV beam allows for controlling the number of formed spirals. We show the microstructures fabricated by the laser processing of thin azopolymer films can be used for the generation of OAM light at the microscale with the desired TC. The experimentally obtained results are in good agreement with the numerically obtained results and demonstrate the potential of the use of such techniques for the laser material processing of polarization-sensitive materials. Full article

(This article belongs to the Special Issue Novel Materials with Target Functionalities)

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3 pages, 223 KiB

Open AccessEditorial

Special Issue “Dynamics and Processes at Laser-Irradiated Surfaces—A Themed Issue in Honor of the 70th Birthday of Professor Jürgen Reif”

by Florenta Costache, Stéphane Valette and Jörn Bonse

Nanomaterials 2023, 13(3), 611; https://doi.org/10.3390/nano13030611 - 3 Feb 2023

Viewed by 1341

Abstract

The Special Issue “Dynamics and Processes at Laser-irradiated Surfaces” is dedicated to the 70th birthday of Jürgen Reif, retired full professor, former Chair of Experimental Physics II of the Faculty of Physics of the Brandenburg University of Technology Cottbus—Senftenberg in Germany [...] Full article

(This article belongs to the Special Issue Dynamics and Processes at Laser-Irradiated Surfaces—A Themed Issue in Honor of the 70th Birthday of Professor Jürgen Reif)

12 pages, 12658 KiB

Open AccessArticle

In Situ Growth of Ni-MOF Nanorods Array on Ti₃C₂T_x Nanosheets for Supercapacitive Electrodes

by Shengzhao Li, Yingyi Wang, Yue Li, Jiaqiang Xu, Tie Li and Ting Zhang

Nanomaterials 2023, 13(3), 610; https://doi.org/10.3390/nano13030610 - 3 Feb 2023

Cited by 13 | Viewed by 2848

Abstract

For the energy supply of smart and portable equipment, high performance supercapacitor electrode materials are drawing more and more concerns. Conductive Ni-MOF is a class of materials with higher conductivity compared with traditional MOFs, but it continues to lack stability. Specifically, MXene (Ti [...] Read more.

For the energy supply of smart and portable equipment, high performance supercapacitor electrode materials are drawing more and more concerns. Conductive Ni-MOF is a class of materials with higher conductivity compared with traditional MOFs, but it continues to lack stability. Specifically, MXene (Ti₃C₂T_x) has been employed as an electrochemical substrate for its high mechanical stability and abundant active sites, which can be combined with MOFs to improve its electrochemical performance. In this paper, a novel Ni-MOF nanorods array/Ti₃C₂T_x nanocomposite was prepared via a facile hydrothermal reaction, which makes good use of the advantages of conductive Ni-MOF and high strength Ti₃C₂T_x. The high density forest-like Ni-MOF array in situ grown on the surface of Ti₃C₂T_x can provide abundant active electrochemical sites and construct a pathway for effective ion transport. The formation of a “Ti-O···Ni” bond accomplished during an in situ growth reaction endows the strong interfacial interaction between Ni-MOF and Ti₃C₂T_x. As a result, the Ni-MOF/Ti₃C₂T_x nanocomposite can achieve a high specific capacitance of 497.6 F·g⁻¹ at 0.5 A·g⁻¹ and remain over 66% of the initial capacitance when the current density increases five times. In addition, the influence of the Ti₃C₂T_x concentration and reaction time on the morphology and performance of the resultant products were also investigated, leading to a good understanding of the formation process of the nanocomposite and the electrochemical mechanism for a supercapacitive reaction. Full article

(This article belongs to the Section Nanocomposite Materials)

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4 pages, 196 KiB

Open AccessEditorial

Development of Functional Nanomaterials for Applications in Chemical Engineering

by Meiwen Cao

Nanomaterials 2023, 13(3), 609; https://doi.org/10.3390/nano13030609 - 3 Feb 2023

Cited by 2 | Viewed by 1796

Abstract

Nanomaterials are materials with particle sizes of less than 100 nm in at least one of their dimensions [...] Full article

(This article belongs to the Special Issue Nanomaterials for Chemical Engineering)

14 pages, 2056 KiB

Open AccessArticle

Experimental Study of As-Cast and Heat-Treated Single-Crystal Ni-Based Superalloy Interface Using TEM

by Runjun He, Miao Li, Xiao Han, Wei Feng, Hongye Zhang, Huimin Xie and Zhanwei Liu

Nanomaterials 2023, 13(3), 608; https://doi.org/10.3390/nano13030608 - 2 Feb 2023

Cited by 2 | Viewed by 1888

Abstract

The interface plays an important role in determining strength and toughness in multiphase systems and the accurate measurement of the interface structure in single crystal (SX) Ni-based superalloy is also essential. In this work, the γ and γ′ lattice constant, γ/γ′ interface width [...] Read more.

The interface plays an important role in determining strength and toughness in multiphase systems and the accurate measurement of the interface structure in single crystal (SX) Ni-based superalloy is also essential. In this work, the γ and γ′ lattice constant, γ/γ′ interface width at dendritic and interdendritic region of casting and solution treatment SX Ni-based superalloy is measured. Various advanced equipment is used to characterize γ/γ′ interface nanostructure. A typical correlation between interface width and γ/γ′ misfit is also summarized. The interface width in the dendritic region of the as-cast sample is larger than that in the interdendritic region. The misfit in the dendritic region is larger than that in the interdendritic region, which has a trend of negative development. There is a common law of the as-cast interdendritic and dendrite interface sample, where the absolute value of the misfit between the two phases is increasing with the phase interface broadening. The comparison of the as-cast and heat-treated interdendritic sample shows that after heat treatment, the phase interface width increases, the misfit decreases, the lattice constant of γ phase increases, and the lattice constant of the γ′ phase decreases. By comparing the as-cast and heat treated dendrites, the absolute value of the misfit of the as-cast dendrite sample is significantly smaller than that of the heat-treated sample, and the misfit increases with the interface broadening. The comparison between interdendritic and dendritic heat-treated samples shows that the absolute value of the misfit between the two phases is smaller than that of the dendritic as-cast samples, and the absolute value of the misfit also increases with the phase interface broadening. In conclusion, property heat treatment can significantly increase the lattice constants of the γ and γ’ phases, reduce the lattice mismatch at the interface of the two phases, and improve the high temperature stability of the alloy. A better understanding of the microstructure of Ni-based single crystal superalloys will provide guidance for the subsequent design of more advanced nickel-based single-crystal superalloys. Full article

(This article belongs to the Special Issue Research on Nano-Lattice)

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3 pages, 176 KiB

Open AccessEditorial

Editorial for Special Issue “Luminescent Colloidal Nanocrystals”

by Aleksandr P. Litvin

Nanomaterials 2023, 13(3), 607; https://doi.org/10.3390/nano13030607 - 2 Feb 2023

Viewed by 1075

Abstract

The field of luminescent colloidal nanocrystals and the numerous nanosystems based on them has recently made a rapid breakthrough from initial basic research to real applications and devices [...] Full article

(This article belongs to the Special Issue Luminescent Colloidal Nanocrystals)

53 pages, 20150 KiB

Open AccessReview

Review of Ge(GeSn) and InGaAs Avalanche Diodes Operating in the SWIR Spectral Region

by Yuanhao Miao, Hongxiao Lin, Ben Li, Tianyu Dong, Chuangqi He, Junhao Du, Xuewei Zhao, Ziwei Zhou, Jiale Su, He Wang, Yan Dong, Bin Lu, Linpeng Dong and Henry H. Radamson

Nanomaterials 2023, 13(3), 606; https://doi.org/10.3390/nano13030606 - 2 Feb 2023

Cited by 21 | Viewed by 5429

Abstract

Among photodetectors, avalanche photodiodes (APDs) have an important place due to their excellent sensitivity to light. APDs transform photons into electrons and then multiply the electrons, leading to an amplified photocurrent. APDs are promising for faint light detection owing to this outstanding advantage, [...] Read more.

Among photodetectors, avalanche photodiodes (APDs) have an important place due to their excellent sensitivity to light. APDs transform photons into electrons and then multiply the electrons, leading to an amplified photocurrent. APDs are promising for faint light detection owing to this outstanding advantage, which will boost LiDAR applications. Although Si APDs have already been commercialized, their spectral region is very limited in many applications. Therefore, it is urgently demanded that the spectral region APDs be extended to the short-wavelength infrared (SWIR) region, which means better atmospheric transmission, a lower solar radiation background, a higher laser eye safety threshold, etc. Up until now, both Ge (GeSn) and InGaAs were employed as the SWIR absorbers. The aim of this review article is to provide a full understanding of Ge(GeSn) and InGaAs for PDs, with a focus on APD operation in the SWIR spectral region, which can be integrated onto the Si platform and is potentially compatible with CMOS technology. Full article

(This article belongs to the Special Issue Silicon-Based Nanostructures: Fabrication and Characterization)

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11 pages, 3384 KiB

Open AccessCommunication

Artificial HfO₂/TiO_x Synapses with Controllable Memory Window and High Uniformity for Brain-Inspired Computing

by Yang Yang, Xu Zhu, Zhongyuan Ma, Hongsheng Hu, Tong Chen, Wei Li, Jun Xu, Ling Xu and Kunji Chen

Nanomaterials 2023, 13(3), 605; https://doi.org/10.3390/nano13030605 - 2 Feb 2023

Cited by 5 | Viewed by 2378

Abstract

Artificial neural networks, as a game-changer to break up the bottleneck of classical von Neumann architectures, have attracted great interest recently. As a unit of artificial neural networks, memristive devices play a key role due to their similarity to biological synapses in structure, [...] Read more.

Artificial neural networks, as a game-changer to break up the bottleneck of classical von Neumann architectures, have attracted great interest recently. As a unit of artificial neural networks, memristive devices play a key role due to their similarity to biological synapses in structure, dynamics, and electrical behaviors. To achieve highly accurate neuromorphic computing, memristive devices with a controllable memory window and high uniformity are vitally important. Here, we first report that the controllable memory window of an HfO₂/TiO_x memristive device can be obtained by tuning the thickness ratio of the sublayer. It was found the memory window increased with decreases in the thickness ratio of HfO₂ and TiO_x. Notably, the coefficients of variation of the high-resistance state and the low-resistance state of the nanocrystalline HfO₂/TiO_x memristor were reduced by 74% and 86% compared with the as-deposited HfO₂/TiO_x memristor. The position of the conductive pathway could be localized by the nanocrystalline HfO₂ and TiO₂ dot, leading to a substantial improvement in the switching uniformity. The nanocrystalline HfO₂/TiO_x memristive device showed stable, controllable biological functions, including long-term potentiation, long-term depression, and spike-time-dependent plasticity, as well as the visual learning capability, displaying the great potential application for neuromorphic computing in brain-inspired intelligent systems. Full article

(This article belongs to the Special Issue Amorphous and Nanocrystalline Semiconductors: Selected Papers from ICANS 29)

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11 pages, 3722 KiB

Open AccessCommunication

Polyethylene Glycol Functionalized Silicon Nanowire Field-Effect Transistor Biosensor for Glucose Detection

by Yan Zhu, Qianhui Wei, Qingxi Jin, Gangrong Li, Qingzhu Zhang, Han Xiao, Tengfei Li, Feng Wei and Yingchun Luo

Nanomaterials 2023, 13(3), 604; https://doi.org/10.3390/nano13030604 - 2 Feb 2023

Cited by 4 | Viewed by 2257

Abstract

Accurate monitoring of blood glucose levels is crucial for the diagnosis of diabetes patients. In this paper, we proposed a simple “mixed-catalyzer layer” modified silicon nanowire field-effect transistor biosensor that enabled direct detection of glucose with low-charge in high ionic strength solutions. A [...] Read more.

Accurate monitoring of blood glucose levels is crucial for the diagnosis of diabetes patients. In this paper, we proposed a simple “mixed-catalyzer layer” modified silicon nanowire field-effect transistor biosensor that enabled direct detection of glucose with low-charge in high ionic strength solutions. A stable screening system was established to overcome Debye screening effect by forming a porous biopolymer layer with polyethylene glycol (PEG) modified on the surface of SiNW. The experimental results show that when the optimal ratio (APTMS:silane-PEG = 2:1) modified the surface of silicon nanowires, glucose oxidase can detect glucose in the concentration range of 10 nM to 10 mM. The sensitivity of the biosensor is calculated to be 0.47 μAcm⁻²mM⁻¹, its fast response time not exceeding 8 s, and the detection limit is up to 10 nM. This glucose sensor has the advantages of high sensitivity, strong specificity and fast real-time response. Therefore, it has a potential clinical application prospect in disease diagnosis. Full article

(This article belongs to the Special Issue Nanoparticles for Biosensor Application)

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11 pages, 4997 KiB

Open AccessFeature PaperArticle

Super-Branched PdCu Alloy for Efficiently Converting Carbon Dioxide to Carbon Monoxide

by Kaili Bao, Yunjie Zhou, Jie Wu, Zenan Li, Xiong Yan, Hui Huang, Yang Liu and Zhenhui Kang

Nanomaterials 2023, 13(3), 603; https://doi.org/10.3390/nano13030603 - 2 Feb 2023

Cited by 5 | Viewed by 2555

Abstract

The alloying of noble metals with Cu is one of the most effective strategies for improving catalytic performance and reducing cost in electrocatalytic carbon dioxide reduction reactions (CO₂RR). Previous works usually focused on the influence of morphology and composition on the [...] Read more.

The alloying of noble metals with Cu is one of the most effective strategies for improving catalytic performance and reducing cost in electrocatalytic carbon dioxide reduction reactions (CO₂RR). Previous works usually focused on the influence of morphology and composition on the catalytic activity, but lacked the study of the valence state ratio of metals and the electron transfer behavior on alloys. In this work, PdCu−2 alloy (Pd/Cu molar ratio is 1:2) was obtained by a simple one-step solvothermal method, which can effectively convert CO₂ to CO with a maximum Faradaic efficiency (FE) of 85% at −0.9 V (vs. RHE). Then, the effect of the chemical state of Pd and Cu on the catalytic performance was investigated. The X-ray photoelectron spectroscopy (XPS) shows that the binding energy of Pd in PdCu alloy has a negative shift, which has affected the adsorption of key intermediates. When the proportion of oxidized state and zero-valent metal in the alloy is about 1:2, the PdCu alloy shows the best catalytic activity. In addition, the transient photovoltage (TPV) measurements further demonstrate that due to the introduction of Cu, the electron transfer rate of PdCu−2 becomes the slowest, which helps the accumulation of electrons on PdCu−2 and leads to the improvement of catalytic performance for electrocatalytic CO₂RR. This work can provide more insights into the alloy catalysts of electrocatalytic CO₂RR. Full article

(This article belongs to the Special Issue Nano-Composites for Photo- and Electrocatalysis and Its Application)

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9 pages, 2398 KiB

Open AccessEditor’s ChoiceCommunication

Quasi-2D Mn₃Si₂Te₆ Nanosheet for Ultrafast Photonics

by Yan Lu, Zheng Zhou, Xuefen Kan, Zixin Yang, Haiqin Deng, Bin Liu, Tongtong Wang, Fangqi Liu, Xueyu Liu, Sicong Zhu, Qiang Yu and Jian Wu

Nanomaterials 2023, 13(3), 602; https://doi.org/10.3390/nano13030602 - 2 Feb 2023

Cited by 3 | Viewed by 2678

Abstract

The magnetic nanomaterial Mn₃Si₂Te₆ is a promising option for spin-dependent electronic and magneto-optoelectronic devices. However, its application in nonlinear optics remains fanciful. Here, we demonstrate a pulsed Er-doped fiber laser (EDFL) based on a novel quasi-2D Mn₃ [...] Read more.

The magnetic nanomaterial Mn₃Si₂Te₆ is a promising option for spin-dependent electronic and magneto-optoelectronic devices. However, its application in nonlinear optics remains fanciful. Here, we demonstrate a pulsed Er-doped fiber laser (EDFL) based on a novel quasi-2D Mn₃Si₂Te₆ saturable absorber (SA) with low pump power at 1.5 μm. The high-quality Mn₃Si₂Te₆ crystals were synthesized by the self-flux method, and the ultrathin Mn₃Si₂Te₆ nanoflakes were prepared by a simple mechanical exfoliation procedure. To the best of our knowledge, this is the first time laser pulses have been generated using quasi-2D Mn₃Si₂Te₆. A stable pulsed laser at 1562 nm with a low threshold pump power of 60 mW was produced by integrating the Mn₃Si₂Te₆ SA into an EDFL cavity. The maximum power of the output pulse is 783 μW. The repetition rate can vary from 24.16 to 44.44 kHz, with corresponding pulse durations of 5.64 to 3.41 µs. Our results indicate that the quasi-2D Mn₃Si₂Te₆ is a promising material for application in ultrafast photonics. Full article

(This article belongs to the Special Issue Advance in Nanophotonics)

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16 pages, 3890 KiB

Open AccessArticle

Hydrocarbon Sorption in Flexible MOFs—Part II: Understanding Adsorption Kinetics

by Hannes Preißler-Kurzhöfer, Andrei Kolesnikov, Marcus Lange, Jens Möllmer, Oliver Erhart, Merten Kobalz, Seungtaik Hwang, Christian Chmelik, Harald Krautscheid and Roger Gläser

Nanomaterials 2023, 13(3), 601; https://doi.org/10.3390/nano13030601 - 2 Feb 2023

Cited by 4 | Viewed by 1962

Abstract

The rate of sorption of n-butane on the structurally flexible metal-organic framework [Cu₂(H-Me-trz-ia)₂], including its complete structural transition between a narrow-pore phase and a large-pore phase, was studied by sorption gravimetry, IR spectroscopy, and powder X-ray diffraction at [...] Read more.

The rate of sorption of n-butane on the structurally flexible metal-organic framework [Cu₂(H-Me-trz-ia)₂], including its complete structural transition between a narrow-pore phase and a large-pore phase, was studied by sorption gravimetry, IR spectroscopy, and powder X-ray diffraction at close to ambient temperature (283, 298, and 313 K). The uptake curves reveal complex interactions of adsorption on the outer surface of MOF particles, structural transition, of which the overall rate depends on several factors, including pressure step, temperature, as well as particle size, and the subsequent diffusion into newly opened pores. With the aid of a kinetic model based on the linear driving force (LDF) approach, both rates of diffusion and structural transition were studied independently of each other. It is shown that temperature and applied pressure steps have a strong effect on the rate of structural transition and thus, the overall velocity of gas uptake. For pressure steps close to the upper boundary of the gate-opening, the rate of structural transition is drastically reduced. This feature enables a fine-tuning of the overall velocity of sorption, which can even turn into anti-Arrhenius behavior. Full article

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

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16 pages, 3213 KiB

Open AccessArticle

Laser-Induced Ion Formation and Electron Emission from a Nanostructured Gold Surface at Laser Fluence below the Threshold for Plasma Formation

by Andrey Pento, Ilya Kuzmin, Viacheslav Kozlovskiy, Lei Li, Polina Laptinskaya, Yaroslav Simanovsky, Boris Sartakov and Sergey Nikiforov

Nanomaterials 2023, 13(3), 600; https://doi.org/10.3390/nano13030600 - 2 Feb 2023

Cited by 1 | Viewed by 2142

Abstract

The laser formation of positive and negative ions on a nanostructured metal surface is observed at laser fluence below the plasma formation threshold. The laser radiation energy dependences of the yield of positive and negative Au ions and charged clusters as well as [...] Read more.

The laser formation of positive and negative ions on a nanostructured metal surface is observed at laser fluence below the plasma formation threshold. The laser radiation energy dependences of the yield of positive and negative Au ions and charged clusters as well as electrons from the laser-induced nanostructures on the surface of gold are obtained at laser fluence below the plasma formation threshold using a pulsed laser with a wavelength of 355 nm and a pulse duration of 0.37 ns. It is shown that the ratio of the signals of positive and negative ions is constant over the entire range of the laser radiation energies, while the ion signal dependence on the laser radiation energy is described by a power function with an exponent of 9. The role of gold nanoparticles with a size of less than 5 nm in the formation of Au ions and charged Au clusters is discussed. Full article

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27 pages, 8462 KiB

Open AccessReview

Recent Research Progress of Mn⁴⁺-Doped A₂MF₆ (A = Li, Na, K, Cs, or Rb; M = Si, Ti, Ge, or Sn) Red Phosphors Based on a Core–Shell Structure

by Yueping Xie, Tian Tian, Chengling Mao, Zhenyun Wang, Jingjia Shi, Li Yang and Cencen Wang

Nanomaterials 2023, 13(3), 599; https://doi.org/10.3390/nano13030599 - 2 Feb 2023

Cited by 17 | Viewed by 2878

Abstract

White light emitting diodes (WLEDs) are widely used due to their advantages of high efficiency, low electricity consumption, long service life, quick response time, environmental protection, and so on. The addition of red phosphor is beneficial to further improve the quality of WLEDs. [...] Read more.

White light emitting diodes (WLEDs) are widely used due to their advantages of high efficiency, low electricity consumption, long service life, quick response time, environmental protection, and so on. The addition of red phosphor is beneficial to further improve the quality of WLEDs. The search for novel red phosphors has focused mainly on Eu²⁺ ion- and Mn⁴⁺ ion-doped compounds. Both of them have emissions in the red region, absorption in blue region, and similar quantum yields. Eu²⁺-doped phosphors possess a rather broad-band emission with a tail in the deep red spectral range, where the sensitivity of the human eye is significantly reduced, resulting in a decrease in luminous efficacy of WLEDs. Mn⁴⁺ ions provide a narrow emission band ~670 nm in oxide hosts, which is still almost unrecognizable to the human eye. Mn⁴⁺-doped fluoride phosphors have become one of the research hotspots in recent years due to their excellent fluorescent properties, thermal stability, and low cost. They possess broad absorption in the blue region, and a series of narrow red emission bands at around 630 nm, which are suitable to serve as red emitting components of WLEDs. However, the problem of easy hydrolysis in humid environments limits their application. Recent studies have shown that constructing a core–shell structure can effectively improve the water resistance of Mn⁴⁺-doped fluorides. This paper outlines the research progress of Mn⁴⁺-doped fluoride A₂MF₆ (A = Li, Na, K, Cs, or Rb; M = Si, Ti, Ge or Sn), which has been based on the core–shell structure in recent years. From the viewpoint of the core–shell structure, this paper mainly emphasizes the shell layer classification, synthesis methods, luminescent mechanism, the effect on luminescent properties, and water resistance, and it also gives some applications in terms of WLEDs. Moreover, it proposes challenges and developments in the future. Full article

(This article belongs to the Special Issue Low Dimensional Luminescent Nanomaterials and Nanodevices)

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19 pages, 1918 KiB

Open AccessReview

Recent Advances in the Spintronic Application of Carbon-Based Nanomaterials

by Shweta Pawar, Hamootal Duadi and Dror Fixler

Nanomaterials 2023, 13(3), 598; https://doi.org/10.3390/nano13030598 - 2 Feb 2023

Cited by 11 | Viewed by 4983

Abstract

The term “carbon-based spintronics” mostly refers to the spin applications in carbon materials such as graphene, fullerene, carbon nitride, and carbon nanotubes. Carbon-based spintronics and their devices have undergone extraordinary development recently. The causes of spin relaxation and the characteristics of spin transport [...] Read more.

The term “carbon-based spintronics” mostly refers to the spin applications in carbon materials such as graphene, fullerene, carbon nitride, and carbon nanotubes. Carbon-based spintronics and their devices have undergone extraordinary development recently. The causes of spin relaxation and the characteristics of spin transport in carbon materials, namely for graphene and carbon nanotubes, have been the subject of several theoretical and experimental studies. This article gives a summary of the present state of research and technological advancements for spintronic applications in carbon-based materials. We discuss the benefits and challenges of several spin-enabled, carbon-based applications. The advantages include the fact that they are significantly less volatile than charge-based electronics. The challenge is in being able to scale up to mass production. Full article

(This article belongs to the Special Issue Advanced Spintronic and Electronic Nanomaterials)

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27 pages, 2686 KiB

Open AccessReview

Thermal Conductivity Enhancement of Metal Oxide Nanofluids: A Critical Review

by Humaira Yasmin, Solomon O. Giwa, Saima Noor and Mohsen Sharifpur

Nanomaterials 2023, 13(3), 597; https://doi.org/10.3390/nano13030597 - 2 Feb 2023

Cited by 40 | Viewed by 3891

Abstract

Advancements in technology related to energy systems, such as heat exchangers, electronics, and batteries, are associated with the generation of high heat fluxes which requires appropriate thermal management. Presently, conventional thermal fluids have found limited application owing to low thermal conductivity (TC). The [...] Read more.

Advancements in technology related to energy systems, such as heat exchangers, electronics, and batteries, are associated with the generation of high heat fluxes which requires appropriate thermal management. Presently, conventional thermal fluids have found limited application owing to low thermal conductivity (TC). The need for more efficient fluids has become apparent leading to the development of nanofluids as advanced thermal fluids. Nanofluid synthesis by suspending nano-size materials into conventional thermal fluids to improve thermal properties has been extensively studied. TC is a pivotal property to the utilization of nanofluids in various applications as it is strongly related to improved efficiency and thermal performance. Numerous studies have been conducted on the TC of nanofluids using diverse nanoparticles and base fluids. Different values of TC enhancement have been recorded which depend on various factors, such as nanoparticles size, shape and type, base fluid and surfactant type, temperature, etc. This paper attempts to conduct a state-of-the-art review of the TC enhancement of metal oxide nanofluids owing to the wide attention, chemical stability, low density, and oxidation resistance associated with this type of nanofluid. TC and TC enhancements of metal oxide nanofluids are presented and discussed herein. The influence of several parameters (temperature, volume/weight concentration, nano-size, sonication, shape, surfactants, base fluids, alignment, TC measurement techniques, and mixing ratio (for hybrid nanofluid)) on the TC of metal oil nanofluids have been reviewed. This paper serves as a frontier in the review of the effect of alignment, electric field, and green nanofluid on TC. In addition, the mechanisms/physics behind TC enhancement and techniques for TC measurement have been discussed. Results show that the TC enhancement of metal oxide nanofluids is affected by the aforementioned parameters with temperature and nanoparticle concentration contributing the most. TC of these nanofluids is observed to be actively enhanced using electric and magnetic fields with the former requiring more intense studies. The formulation of green nanofluids and base fluids as sustainable and future thermal fluids is recommended. Full article

(This article belongs to the Special Issue Highly Thermal Conductive Nanocomposites)

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12 pages, 1530 KiB

Open AccessArticle

The Characteristics of the Metal-Free and Non-Conjugated Polymer Film with Self-Assembled Nanoparticles

by Kwang-Ming Lee, Chung-Cheng Chang, Jia-Ming Wang, Chia-Yu Chang and Chia-Hong Huang

Nanomaterials 2023, 13(3), 596; https://doi.org/10.3390/nano13030596 - 2 Feb 2023

Cited by 1 | Viewed by 1574

Abstract

It is shown in this paper that a polymer, MA-PEG 1000-DGEBA (MP1D), exhibits antireflection, substrate-dependent photoluminescence (SDP), wide band-gap, and photoconduction characterization. MP1D was synthesized from maleic anhydride, polyethylene glycol 1000, and bisphenol-A diglycidyl ether. Self-assembled nanoparticles embedded in MP1D film and ranging [...] Read more.

It is shown in this paper that a polymer, MA-PEG 1000-DGEBA (MP1D), exhibits antireflection, substrate-dependent photoluminescence (SDP), wide band-gap, and photoconduction characterization. MP1D was synthesized from maleic anhydride, polyethylene glycol 1000, and bisphenol-A diglycidyl ether. Self-assembled nanoparticles embedded in MP1D film and ranging from 2.5 to 31.6 nm are observed, which could be expected as scatterers to enhance light trapping and extraction. The size of the nanoparticle increases with the concentration of the MP1D solution. Besides solution concentration, the nanoparticle dimension could be modified by the chain length of polyethylene glycol in the polymer synthesis. The effects of solution concentration, annealing temperature, annealing period, and substrate on the photoluminescence (PL) of MP1D films are examined. Increasing solution concentration increases PL intensity. However, aggregation-caused quenching is explicit as the solution concentration exceeds 100 mM. PL intensity increases with annealing temperature, which could be attributed to crystallinity improvement. PL intensity increases with increasing the annealing period from 0.5 to 2 h. Nonetheless, as the annealing period exceeds 2 h, PL quenching is emerging, which could be due to aggregation. It is expected that MP1D could be a promising candidate for host materials and MP1D film could play a multifunctional role (antireflective and light-trapping functions) in optoelectronics. Full article

(This article belongs to the Special Issue Applications of Optical Thin Films)

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22 pages, 11167 KiB

Open AccessEditor’s ChoiceReview

Nanomaterials and Devices for Harvesting Ambient Electromagnetic Waves

by Mircea Dragoman, Martino Aldrigo, Adrian Dinescu, Dan Vasilache, Sergiu Iordanescu and Daniela Dragoman

Nanomaterials 2023, 13(3), 595; https://doi.org/10.3390/nano13030595 - 2 Feb 2023

Cited by 7 | Viewed by 3002

Abstract

This manuscript presents an overview of the implications of nanomaterials in harvesting ambient electromagnetic waves. We show that the most advanced electromagnetic harvesting devices are based on oxides with a thickness of few nanometers, carbon nanotubes, graphene, and molybdenum disulfide thanks to their [...] Read more.

This manuscript presents an overview of the implications of nanomaterials in harvesting ambient electromagnetic waves. We show that the most advanced electromagnetic harvesting devices are based on oxides with a thickness of few nanometers, carbon nanotubes, graphene, and molybdenum disulfide thanks to their unique physical properties. These tiny objects can produce in the years to come a revolution in the harvesting of energy originating from the Sun, heat, or the Earth itself. Full article

(This article belongs to the Special Issue Nanomaterials for Energy Harvesting)

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14 pages, 2402 KiB

Open AccessArticle

Investigating the Cellular Uptake of Model Nanoplastics by Single-Cell ICP-MS

by Domenico Cassano, Alessia Bogni, Rita La Spina, Douglas Gilliland and Jessica Ponti

Nanomaterials 2023, 13(3), 594; https://doi.org/10.3390/nano13030594 - 1 Feb 2023

Cited by 10 | Viewed by 3187

Abstract

A synthetic route to producing gold-doped environmentally relevant nanoplastics and a method for the rapid and high-throughput qualitative investigation of their cellular interactions have been developed. Polyethylene (PE) and polyvinyl chloride (PVC) nanoparticles, doped with ultrasmall gold nanoparticles, were synthesized via an oil-in-water [...] Read more.

A synthetic route to producing gold-doped environmentally relevant nanoplastics and a method for the rapid and high-throughput qualitative investigation of their cellular interactions have been developed. Polyethylene (PE) and polyvinyl chloride (PVC) nanoparticles, doped with ultrasmall gold nanoparticles, were synthesized via an oil-in-water emulsion technique as models for floating and sedimenting nanoplastics, respectively. Gold nanoparticles were chosen as a dopant as they are considered to be chemically stable, relatively easy to obtain, interference-free for elemental analysis, and suitable for bio-applications. The suitability of the doped particles for quick detection via inductively coupled plasma mass spectrometry (ICP-MS), operating in single-cell mode (scICP-MS), was demonstrated. Specifically, the method was applied to the analysis of nanoplastics in sizes ranging from 50 to 350 nm, taking advantage of the low limit of detection of single-cell ICP-MS for gold nanoparticles. As an initial proof of concept, gold-doped PVC and PE nanoplastics were employed to quantify the interaction and uptake of nanoplastics by the RAW 264.7 mouse macrophage cell line, using scICP-MS and electron microscopy. Macrophages were chosen because their natural biological functions would make them likely to internalize nanoplastics and, thus, would produce samples to verify the test methodology. Finally, the method was applied to assess the uptake by CaCo-2 human intestinal cells, this being a more relevant model for humanexposure to those nanoplastics that are potentially available in the food chain. For both case studies, two concentrations of nanoplastics were employed to simulate both standard environmental conditions and exceptional circumstances, such as pollution hotspot areas. Full article

(This article belongs to the Special Issue Metal-Based Nanomaterials for Biomedical, Agricultural, and Environmental Applications: Prospects and Uncertainties)

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29 pages, 7058 KiB

Open AccessReview

Nude and Modified Electrospun Nanofibers, Application to Air Purification

by Patricio J. Espinoza-Montero, Marjorie Montero-Jiménez, Stalin Rojas-Quishpe, Christian David Alcívar León, Jorge Heredia-Moya, Alfredo Rosero-Chanalata, Carlos Orbea-Hinojosa and José Luis Piñeiros

Nanomaterials 2023, 13(3), 593; https://doi.org/10.3390/nano13030593 - 1 Feb 2023

Cited by 11 | Viewed by 4036

Abstract

Air transports several pollutants, including particulate matter (PM), which can produce cardiovascular and respiratory diseases. Thus, it is a challenge to control pollutant emissions before releasing them to the environment. Until now, filtration has been the most efficient processes for removing PM. Therefore, [...] Read more.

Air transports several pollutants, including particulate matter (PM), which can produce cardiovascular and respiratory diseases. Thus, it is a challenge to control pollutant emissions before releasing them to the environment. Until now, filtration has been the most efficient processes for removing PM. Therefore, the electrospinning procedure has been applied to obtain membranes with a high filtration efficiency and low pressure drop. This review addressed the synthesis of polymers that are used for fabricating high-performance membranes by electrospinning to remove air pollutants. Then, the most influential parameters to produce electrospun membranes are indicated. The main results show that electrospun membranes are an excellent alternative to having air filters due to the versatility of the process, the capacity for controlling the fiber diameter, porosity, high filtration efficiency and low-pressure drop. Full article

(This article belongs to the Special Issue Advance in Nanostructured Polymers)

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3 pages, 188 KiB

Open AccessEditorial

Superconductivity in Nanosystems: A Fruitful Path to New Phenomenology in Quantum Materials

by Manuel V. Ramallo

Nanomaterials 2023, 13(3), 592; https://doi.org/10.3390/nano13030592 - 1 Feb 2023

Viewed by 1412

Abstract

In the recent years, the landscape of the research in superconductivity has experienced a progressive focus on varied superconducting systems, which share as common primary characteristics the reduction of some of their dimensionalities and the emergence of qualitatively novel phenomenology with respect to [...] Read more.

In the recent years, the landscape of the research in superconductivity has experienced a progressive focus on varied superconducting systems, which share as common primary characteristics the reduction of some of their dimensionalities and the emergence of qualitatively novel phenomenology with respect to bulk superconducting materials [...] Full article

(This article belongs to the Special Issue Superconductivity in Nanosystems)

13 pages, 2327 KiB

Open AccessArticle

Antibiofilm Activity of 3D-Printed Nanocomposite Resin: Impact of ZrO₂ Nanoparticles

by Abdulrahman Khattar, Jawad A. Alghafli, Mohammed A. Muheef, Ali M. Alsalem, Mohammed A. Al-Dubays, Hussain M. AlHussain, Hussain M. AlShoalah, Soban Q. Khan, Doaa M. AlEraky and Mohammed M. Gad

Nanomaterials 2023, 13(3), 591; https://doi.org/10.3390/nano13030591 - 1 Feb 2023

Cited by 13 | Viewed by 2399

Abstract

Poly(methyl methacrylate) (PMMA) is a commonly used material, as it is biocompatible and relatively cheap. However, its mechanical properties and weak antibiofilm activity are major concerns. With the development of new technology, 3D-printed resins are emerging as replacements for PMMA. Few studies have [...] Read more.

Poly(methyl methacrylate) (PMMA) is a commonly used material, as it is biocompatible and relatively cheap. However, its mechanical properties and weak antibiofilm activity are major concerns. With the development of new technology, 3D-printed resins are emerging as replacements for PMMA. Few studies have investigated the antibiofilm activity of 3D-printed resins. Therefore, this study aimed to investigate the antibiofilm activity and surface roughness of a 3D-printed denture base resin modified with different concentrations of zirconium dioxide nanoparticles (ZrO₂ NPs). A total of 60 resin disc specimens (15 × 2 mm) were fabricated and divided into six groups (n = 10). The groups comprised a heat-polymerized resin (PMMA) group, an unmodified 3D-printed resin (NextDent) group, and four 3D-printed resin groups that were modified with ZrO₂ NPs at various concentrations (0.5 wt%, 1 wt%, 3 wt%, and 5 wt%). All specimens were polished using a conventional method and then placed in a thermocycler machine for 5000 cycles. Surface roughness (Ra, µm) was measured using a non-contact profilometer. The adhesion of Candida albicans (C. albicans) was measured using a fungal adhesion assay that consisted of a colony forming unit assay and a cell proliferation assay. The data were analyzed using Shapiro–Wilk and Kruskal–Wallis tests. A Mann–Whitney U test was used for pairwise comparison, and p-values of less than 0.05 were considered statistically significant. The lowest Ra value (0.88 ± 0.087 µm) was recorded for the PMMA group. In comparison to the PMMA group, the 3% ZrO₂ NPs 3D-printed group showed a significant increase in Ra (p < 0.025). For the 3D-printed resins, significant differences were found between the groups with 0% vs. 3% ZrO₂ NPs and 3% vs. 5% ZrO₂ NPs (p < 0.025). The highest Ra value (0.96 ± 0.06 µm) was recorded for the 3% ZrO₂ NPs group, and the lowest Ra values (0.91 ± 0.03 µm) were recorded for the 0.5% and 5% ZrO₂ NPs groups. In terms of antifungal activity, the cell proliferation assay showed a significant decrease in the C. albicans count for the 0.5% ZrO₂ NPs group when compared with PMMA and all other groups of 3D-printed resins. The group with the lowest concentration of ZrO₂ NPs (0.5%) showed the lowest level of C. albicans adhesion of all the tested groups and showed the lowest Candida count (0.29 ± 0.03). The addition of ZrO₂ NPs in low concentrations did not affect the surface roughness of the 3D-printed resins. These 3D-printed resins with low concentrations of nanocomposites could be used as possible materials for the prevention and treatment of denture stomatitis, due to their antibiofilm activities. Full article

(This article belongs to the Special Issue Biomedical Applications of Metallic Nanoparticles)

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