Nanomaterials

11 pages, 5225 KiB

Open AccessArticle

Electrospinning and Partial Etching Behaviors of Core–Shell Nanofibers Directly Electrospun on Mesh Substrates for Application in a Cover-Free Compact Air Filter

by Yujung Lee, Seungwoo Jung and Ji Sun Yun

Nanomaterials 2024, 14(13), 1152; https://doi.org/10.3390/nano14131152 (registering DOI) - 5 Jul 2024

Viewed by 134

Abstract

The exposure of workers to propylene glycol monomethyl ether acetate (PGMEA) in manufacturing environments can result in potential health risks. Therefore, systems for PGMEA removal are required for indoor air quality control. In this study, core–shell zeolite socony mobil-5 (ZSM-5)/polyvinylpyrrolidone–polyvinylidene fluoride nanofibers were [...] Read more.

The exposure of workers to propylene glycol monomethyl ether acetate (PGMEA) in manufacturing environments can result in potential health risks. Therefore, systems for PGMEA removal are required for indoor air quality control. In this study, core–shell zeolite socony mobil-5 (ZSM-5)/polyvinylpyrrolidone–polyvinylidene fluoride nanofibers were directly electrospun and partially wet-etched on a mesh substrate to develop a cover-free compact PGMEA air filter. The electrospinning behaviors of the core–shell nanofibers were investigated to optimize the electrospinning time and humidity and to enable the manufacture of thin and light air-filter layers. The partial wet etching of the nanofibers was undertaken using different etching solvents and times to ensure the exposure of the active sites of ZSM-5. The performances of the ZSM-5/PVDF nanofiber air filters were assessed by measuring five consecutive PGMEA adsorption–desorption cycles at different desorption temperatures. The synthesized material remained stable upon repeated adsorption–desorption cycles and could be regenerated at a low desorption temperature (80 °C), demonstrating a consistent adsorption performance upon prolonged adsorption–desorption cycling and low energy consumption during regeneration. The results of this study provide new insights into the design of industrial air filters using functional ceramic/polymer nanofibers and the application of these filters. Full article

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17 pages, 6042 KiB

Open AccessArticle

Synthesis and Superficial Modification “In Situ” of Copper Selenide (Cu_2-x Se) Nanoparticles and Their Antibacterial Activity

by José Manuel Mata-Padilla, José Ángel Ledón-Smith, Marissa Pérez-Alvarez, Gregorio Cadenas-Pliego, Enrique Díaz Barriga-Castro, Odilia Pérez-Camacho, Christian Javier Cabello-Alvarado and Rodolfo Silva

Nanomaterials 2024, 14(13), 1151; https://doi.org/10.3390/nano14131151 - 4 Jul 2024

Viewed by 378

Abstract

Copper selenide nanoparticles (Cu_2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization [...] Read more.

Copper selenide nanoparticles (Cu_2-x Se NPs) have received a lot of attention in recent decades due to their interesting properties and potential applications in various areas such as electronics, health, solar cells, etc. In this study, details of the synthesis and characterization of copper selenide nanoparticles modified with gum arabic (GA) are reported. Also, through transmission electronic microscopy (TEM) analysis, the transformation of the morphology and particle size of copper selenide nanoparticles in aqueous solution was studied. In addition, we present an antimicrobial study with different microorganisms such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albiacans (C. albicans). Copper selenide nanoparticles were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry analysis (DSC) and TEM. XRD confirmed the crystal-line structure of the nanoparticles such as cubic berzelanite with a particle size of 6 nm ± 0.5. FTIR and TGA corroborated the surface modification of copper selenide nanoparticles with gum arabic, and DSC suggested a change in the structural phase from cubic to hexagonal. TEM analysis demonstrated that the surface modification of the Cu_2-x Se NPs stabilized the nanostructure of the particles, preventing changes in the morphology and particle size. The antimicrobial susceptibility analysis of copper selenide nanoparticles indicated that they have the ability to inhibit the microbial growth of Staphylococcus aureus, Escherichia coli and Candida albicans. Full article

(This article belongs to the Special Issue Biosynthesis and Green Synthesis of Nanomaterials: New Methodologies and Results, 2nd Edition)

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14 pages, 6723 KiB

Open AccessArticle

A Novel Terahertz Metamaterial Microfluidic Sensing Chip for Ultra-Sensitive Detection

by Yuan Zhang, Keke Jia, Hongyi Ge, **aodi Ji, Yuying Jiang, Yuwei Bu, Yujie Zhang and Qingcheng Sun

Nanomaterials 2024, 14(13), 1150; https://doi.org/10.3390/nano14131150 - 4 Jul 2024

Viewed by 298

Abstract

A terahertz metamaterial microfluidic sensing chip for ultrasensitive detection is proposed to investigate the response of substances to terahertz radiation in liquid environments and enhance the molecular fingerprinting of trace substances. The structure consists of a cover layer, a metal microstructure, a microfluidic [...] Read more.

A terahertz metamaterial microfluidic sensing chip for ultrasensitive detection is proposed to investigate the response of substances to terahertz radiation in liquid environments and enhance the molecular fingerprinting of trace substances. The structure consists of a cover layer, a metal microstructure, a microfluidic channel, a metal reflective layer, and a buffer layer from top to bottom, respectively. The simulation results show that there are three obvious resonance absorption peaks in the range of 1.5–3.0 THz and the absorption intensities are all above 90%. Among them, the absorption intensity at M1 = 1.971 THz is 99.99%, which is close to the perfect absorption, and its refractive index sensitivity and Q-factor are 859 GHz/RIU and 23, respectively, showing excellent sensing characteristics. In addition, impedance matching and equivalent circuit theory are introduced in this paper to further analyze the physical mechanism of the sensor. Finally, we perform numerical simulations using refractive index data of normal and cancer cells, and the results show that the sensor can distinguish different types of cells well. The chip can reduce the sample pretreatment time as well as enhance the interaction between terahertz waves and matter, which can be used for early disease screening and food quality and safety detection in the future. Full article

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16 pages, 9245 KiB

Open AccessArticle

Melanin-Based Nanoparticles for Lymph Node Tattooing: Experimental, Histopathological and Ultrastructural Study

by Marta Baselga, Antonio Güemes, Cristina Yus, Teresa Alejo, Víctor Sebastián, Dolores Arribas, Gracia Mendoza, Eva Monleón and Manuel Arruebo

Nanomaterials 2024, 14(13), 1149; https://doi.org/10.3390/nano14131149 - 4 Jul 2024

Viewed by 209

Abstract

In breast cancer, Targeted Axillary Dissection (TAD) allows for the selective excision of the sentinel lymph node (SLN) during primary tumor surgery. TAD consists of the resection of labelled SLNs prior to neoadjuvant chemotherapy (NACT). Numerous clinical and preclinical studies have explored the [...] Read more.

In breast cancer, Targeted Axillary Dissection (TAD) allows for the selective excision of the sentinel lymph node (SLN) during primary tumor surgery. TAD consists of the resection of labelled SLNs prior to neoadjuvant chemotherapy (NACT). Numerous clinical and preclinical studies have explored the use of carbon-based colloids for SLN tattooing prior to NACT. However, carbon vectors show varying degrees of inflammatory reactions and, in about one fifth of cases, carbon particles migrate via the lymphatic pathway to other nodes, causing the SLN to mismatch the tattooed node. To overcome these limitations, in this study, we explored the use of melanin as a staining endogenous pigment. We synthesized and characterized melanin-loaded polymeric nanoparticles (Mel-NPs) and used them to tattoo lymph nodes in pig animal models given the similarity in the size of the human and pig nodes. Mel-NPs tattooed lymph nodes showed high identification rates, reaching 83.3% positive identification 16 weeks after tattooing. We did not observe any reduction in the identification as time increased, implying that the colloid is stable in the lymph node tissue. In addition, we performed histological and ultrastructural studies to characterize the biological behavior of the tag. We observed foreign-body-like granulomatous inflammatory responses associated with Mel-NPs, characterized by the formation of multinucleated giant cells. In addition, electron microscopy studies showed that uptake is mainly performed by macrophages, and that macrophages undergo cellular damage associated with particle uptake. Full article

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25 pages, 14032 KiB

Open AccessArticle

Effect of Co-Sputtered Copper and Titanium Oxide Coatings on Bacterial Resistance and Cytocompatibility of Osteoblast Cells

by Maria P. Nikolova, Iliyan Tzvetkov, Tanya V. Dimitrova, Veronika L. Ivanova, Yordan Handzhiyski, Andreana Andreeva, Stefan Valkov, Maria Ormanova and Margarita D. Apostolova

Nanomaterials 2024, 14(13), 1148; https://doi.org/10.3390/nano14131148 - 4 Jul 2024

Viewed by 228

Abstract

One of the primary risk factors for implant failure is thought to be implant-related infections during the early healing phase. Develo** coatings with cell stimulatory behaviour and bacterial adhesion control is still difficult for bone implants. This study proposes an approach for one-step [...] Read more.

One of the primary risk factors for implant failure is thought to be implant-related infections during the early healing phase. Develo** coatings with cell stimulatory behaviour and bacterial adhesion control is still difficult for bone implants. This study proposes an approach for one-step deposition of biocompatible and antimicrobial Cu-doped TiO₂ coatings via glow-discharge sputtering of a mosaic target. During the deposition, the bias of the Ti6Al4V substrates was changed. Structure examination, phase analysis, and surface morphology were carried out using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The hardness values and hydrophilic and corrosion performance were also evaluated together with cytocompatible and antibacterial examinations against E. coli and S. aureus. The results show great chemical and phase control of the bias identifying rutile, anatase, CuO, or ternary oxide phases. It was found that by increasing the substrate bias from 0 to −50 V the Cu content increased from 15.3 up to 20.7 at% while at a high bias of −100 V, the copper content reduced to 3 at%. Simultaneously, apart from the Cu²⁺ state, Cu¹⁺ is also found in the biased samples. Compared with the bare alloy, the hardness, the water contact angle and corrosion resistance of the biased coatings increased. According to an assessment of in vitro cytocompatibility, all coatings were found to be nontoxic to MG-63 osteoblast cells over the time studied. Copper release and cell-surface interactions generated an antibacterial effect against E. coli and S. aureus strains. The −50 V biased coating combined the most successful results in inhibiting bacterial growth and eliciting the proper responses from osteoblastic cells because of its phase composition, electrochemical stability, hydrophilicity, improved substrate adhesion, and surface roughness. Using this novel surface modification approach, we achieved multifunctionality through controlled copper content and oxide phase composition in the sputtered films. Full article

(This article belongs to the Special Issue 2D Nanomaterials for Medical Applications)

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12 pages, 4425 KiB

Open AccessArticle

Green Synthesis of Silver Nanoparticles from Anthocyanin Extracts of Peruvian Purple Potato INIA 328—Kulli papa

by Antony Alexander Neciosup-Puican, Luz Pérez-Tulich, Wiliam Trujillo and Carolina Parada-Quinayá

Nanomaterials 2024, 14(13), 1147; https://doi.org/10.3390/nano14131147 - 4 Jul 2024

Viewed by 348

Abstract

In this work, AgNPs were synthesized using an anthocyanin extract from Peruvian purple potato INIA 328—Kulli papa. The anthocyanin extract was obtained through a conventional extraction with acidified ethanolic aqueous solvent. This extract acted as both a reducing and stabilizing agent [...] Read more.

In this work, AgNPs were synthesized using an anthocyanin extract from Peruvian purple potato INIA 328—Kulli papa. The anthocyanin extract was obtained through a conventional extraction with acidified ethanolic aqueous solvent. This extract acted as both a reducing and stabilizing agent for the reduction of silver ions. Optimization of synthesis parameters, including pH, reaction time, and silver nitrate (AgNO₃) concentration, led to the optimal formation of AgNPs at pH 10, with a reaction time of 30 min and an AgNO₃ concentration of 5 mM. Characterization techniques such as X-ray diffraction (XRD) and dynamic light scattering (DLS) revealed that the AgNPs had a crystallite size of 9.42 nm and a hydrodynamic diameter of 21.6 nm, with a zeta potential of −42.03 mV, indicating favorable colloidal stability. Fourier Transform Infrared (FTIR) analysis confirmed the presence of anthocyanin functional groups on the surface of the AgNPs, contributing to their stability. Furthermore, the bacterial activity of the AgNPs was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). For E. coli, the MIC was 0.5 mM (0.05 mg/mL) and the MBC was 4.5 mM (0.49 mg/mL). Similarly, for S. aureus, the MIC was 0.5 mM (0.05 mg/mL) and the MBC was 4.0 mM (0.43 mg/mL). These results highlight the potential benefits of AgNPs synthesized from Peruvian purple potato anthocyanin extract, both in biomedical and environmental contexts. Full article

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

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13 pages, 2517 KiB

Open AccessArticle

Optimizing P3HT/PCBM-Based Organic Photodetector Performance: Insights from SCAPS 1D Simulation Studies

by Ahmet Sait Alali, Murat Oduncuoglu and Farid Touati

Nanomaterials 2024, 14(13), 1146; https://doi.org/10.3390/nano14131146 - 4 Jul 2024

Viewed by 239

Abstract

Organic electronics have great potential due to their flexible structure, high performance, and their ability to build effective and low-cost photodetectors. We investigated the parameters of the P3HT and PCBM layers for device performance and optimization. SCAPS-1D simulations were employed to optimize the [...] Read more.

Organic electronics have great potential due to their flexible structure, high performance, and their ability to build effective and low-cost photodetectors. We investigated the parameters of the P3HT and PCBM layers for device performance and optimization. SCAPS-1D simulations were employed to optimize the thicknesses of the P3HT and PCBM layers, investigate the effects of shallow do** in the P3HT layer, and assess the influence of the back contact electrode’s work function on device performance. Furthermore, this study explored the impact of interface defect layer density on the characteristics of the device. Through systematic analyses, the optimal parameters for enhancing device responsivity were identified. The findings indicate that a P3HT layer thickness of 1200 nm, a PCBM layer thickness of 20 nm, and a back contact electrode with a work function of 4.9 eV achieve the highest responsivity. Notably, at a bias of −0.5 V, the responsivity exceeds 0.4 A/W within the wavelength range of 450 nm to 630 nm. These optimized parameters underscore the significant potential of the developed device as an organic photodetector, particularly for visible light detection. Full article

(This article belongs to the Special Issue Modeling, Simulation and Optimization of Nanomaterials)

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11 pages, 5814 KiB

Open AccessArticle

Porous CuO Microspheres as Long-Lifespan Cathode Materials for Aqueous Zinc-Ion Batteries

by Yuqing Ai, Qiang Pang, **nyu Liu, Fangyun **n, Hong Wang, Mingming **ng, Yao Fu and Ying Tian

Nanomaterials 2024, 14(13), 1145; https://doi.org/10.3390/nano14131145 - 3 Jul 2024

Viewed by 328

Abstract

Cathode materials with conversion mechanisms for aqueous zinc-ion batteries (AZIBs) have shown a great potential as next-generation energy storage materials due to their high discharge capacity and high energy density. However, improving their cycling stability has been the biggest challenge plaguing researchers. In [...] Read more.

Cathode materials with conversion mechanisms for aqueous zinc-ion batteries (AZIBs) have shown a great potential as next-generation energy storage materials due to their high discharge capacity and high energy density. However, improving their cycling stability has been the biggest challenge plaguing researchers. In this study, CuO microspheres were prepared using a simple hydrothermal reaction, and the morphology and crystallinity of the samples were modulated by controlling the hydrothermal reaction time. The as-synthesized materials were used as cathode materials for AZIBs. The electrochemical experiments showed that the CuO-4h sample, undergoing a hydrothermal reaction for 4 h, had the longest lifecycle and the best rate of capability. A discharge capacity of 131.7 mAh g⁻¹ was still available after 700 cycles at a current density of 500 mA g⁻¹. At a high current density of 1.5 A g⁻¹, the maintained capacity of the cell is 85.4 mA h g⁻¹. The structural evolutions and valence changes in the CuO-4h cathode material were carefully explored by using ex situ XRD and ex situ XPS. CuO was reduced to Cu₂O and Cu after the initial discharge, and Cu was oxidized to Cu₂O instead of CuO during subsequent charging processes. We believe that these findings could introduce a novel approach to exploring high-performance cathode materials for AZIBs. Full article

(This article belongs to the Special Issue Application of Nanomaterials in Solid-State Energy Storage Materials and Batteries)

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23 pages, 11300 KiB

Open AccessArticle

Vibration Analysis of Porous Cu-Si Microcantilever Beams in Fluids Based on Modified Couple Stress Theory

by Jize Jiang, Feixiang Tang, Siyu He, Fang Dong and Sheng Liu

Nanomaterials 2024, 14(13), 1144; https://doi.org/10.3390/nano14131144 - 3 Jul 2024

Viewed by 252

Abstract

The vibrations in functionally graded porous Cu-Si microcantilever beams are investigated based on physical neutral plane theory, modified coupled stress theory, and scale distribution theory (MCST&SDT). Porous microcantilever beams define four pore distributions. Considering the physical neutral plane theory, the material properties of [...] Read more.

The vibrations in functionally graded porous Cu-Si microcantilever beams are investigated based on physical neutral plane theory, modified coupled stress theory, and scale distribution theory (MCST&SDT). Porous microcantilever beams define four pore distributions. Considering the physical neutral plane theory, the material properties of the beams are computed through four different power-law distributions. The material properties of microcantilever beams are corrected by scale effects based on modified coupled stress theory. Considering the fluid driving force, the amplitude-frequency response spectra and resonant frequencies of the porous microcantilever beam in three different fluids are obtained based on the Euler–Bernoulli beam theory. The quality factors of porous microcantilever beams in three different fluids are derived by estimating the equation. The computational analysis shows that the presence of pores in microcantilever beams leads to a decrease in Young’s modulus. Different pore distributions affect the material properties to different degrees. The gain effect of the scale effect is weakened, but the one-dimensional temperature field and amplitude-frequency response spectra show an increasing trend. The quality factor is decreased by porosity, and the degree of influence of porosity increases as the beam thickness increases. The gradient factor n has a greater effect on the resonant frequency. The effect of porosity on the resonant frequency is negatively correlated when the gradient factor is small (

n < 1

) but positively correlated when the gradient factor is large (

n > 1

). Full article

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

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27 pages, 8622 KiB

Open AccessFeature PaperArticle

Synthesis and Characterization of Silver-Modified Nanoporous Silica Materials for Enhanced Iodine Removal

by Ahmed Elmekawy, Qui Quach and Tarek M. Abdel-Fattah

Nanomaterials 2024, 14(13), 1143; https://doi.org/10.3390/nano14131143 - 3 Jul 2024

Viewed by 277

Abstract

In aquatic environments, the presence of iodine species, including radioactive isotopes like ¹²⁹I and I₂, poses significant environmental and health concerns. Iodine can enter water resources from various sources, including nuclear accidents, medical procedures, and natural occurrences. To address this [...] Read more.

In aquatic environments, the presence of iodine species, including radioactive isotopes like ¹²⁹I and I₂, poses significant environmental and health concerns. Iodine can enter water resources from various sources, including nuclear accidents, medical procedures, and natural occurrences. To address this issue, the use of natural occurring nanoporous minerals, such as zeolitic materials, for iodine removal will be explored. This study focuses on the adsorption of iodine by silver-modified zeolites (13X-Ag, 5A-Ag, Chabazite-Ag, and Clinoptilolite-Ag) and evaluates their performance under different conditions. All materials were characterized using scanning electron microscopey (SEM), energy-dispersive X-ray spectroscopy (EDS), powdered X-ray diffraction (P-XRD), Fourier-transform infrared spectrometry (FTIR), and nitrogen adsorption studies. The results indicate that Chabazite-Ag exhibited the highest iodine adsorption capacity, with an impressive 769 mg/g, making it a viable option for iodine removal applications. 13X-Ag and 5A-Ag also demonstrated substantial adsorption capacities of 714 mg/g and 556 mg/g, respectively, though their behavior varied according to different models. In contrast, Clinoptilolite-Ag exhibited strong pH-dependent behavior, rendering it less suitable for neutral to slightly acidic conditions. Furthermore, this study explored the impact of ionic strength on iodine adsorption, revealing that Chabazite-Ag is efficient in low-salinity environments with an iodine adsorption capacity of 51.80 mg/g but less effective in saline conditions. 5A-Ag proved to be a versatile option for various water treatments, maintaining its iodine adsorption capacity across different salinity levels. In contrast, Clinoptilolite-Ag exhibited high sensitivity to ionic competition, virtually losing its iodine adsorption ability at a NaCl concentration of 0.1 M. Kinetic studies indicated that the pseudo-second-order model best describes the adsorption process, suggesting chemisorption mechanisms dominate iodine removal. Chabazite-Ag exhibited the highest initial adsorption rate with a k₂ value of 0.002 mg g⁻¹ h⁻¹, emphasizing its superior adsorption capabilities. Chabazite and Clinoptilolite, naturally occurring minerals, provide eco-friendly solutions for iodine adsorption. Chabazite superior iodine removal highlights its value in critical applications and its potential for addressing pressing environmental challenges. Full article

(This article belongs to the Special Issue Metallic Nanomaterial Applications in Selective Catalysis and Clean Energy)

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11 pages, 5185 KiB

Open AccessArticle

Analysis of Fluorescent Carbon Nanodot Formation during Pretzel Production

by Dávid Semsey, Duyen H. H. Nguyen, Gréta Törős, Arjun Muthu, Safa Labidi, Hassan El-Ramady, Áron Béni, Mahendra Rai and Prokisch József

Nanomaterials 2024, 14(13), 1142; https://doi.org/10.3390/nano14131142 - 3 Jul 2024

Viewed by 250

Abstract

Baked pretzels are a popular choice for a quick snack, easily identifiable by their classic twisted shape, glossy exterior, and small salt crystals sprinkled on top, making them a standout snack. However, it is not commonly known that compounds with fluorescent properties can [...] Read more.

Baked pretzels are a popular choice for a quick snack, easily identifiable by their classic twisted shape, glossy exterior, and small salt crystals sprinkled on top, making them a standout snack. However, it is not commonly known that compounds with fluorescent properties can be formed during their production. Carbon nanodots (CNDs) with an average size of 3.5 nm were isolated and identified in bakery products. This study delved into the formation of CNDs in pretzel production using a fractional factorial experimental design. The research revealed that the baking temperature had the most significant impact on the concentration of CNDs, followed by the concentration of NaOH in the immersion solution, and then the baking time. This study highlights the unique role of the NaOH immersion step, which is not typically present in bread-making processes, in facilitating the formation of CNDs. This discovery highlights the strong correlation between the formation of CNDs and the heat treatment process. Monitoring and controlling these factors is crucial for regulating the concentration of CNDs in pretzel production and understanding nanoparticle formation in processed foods for food safety. Full article

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

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14 pages, 9321 KiB

Open AccessArticle

One-Pot Synthesis of Cellulose-Based Carbon Aerogel Loaded with TiO₂ and g-C₃N₄ and Its Photocatalytic Degradation of Rhodamine B

by Fangqin Liu, Mingjie Fan, **a Liu and **yang Chen

Nanomaterials 2024, 14(13), 1141; https://doi.org/10.3390/nano14131141 - 2 Jul 2024

Viewed by 316

Abstract

A cellulose-based carbon aerogel (CTN) loaded with titanium dioxide (TiO₂) and graphitic carbon nitride (g-C₃N₄) was prepared using sol–gel, freeze-drying, and high-temperature carbonization methods. The formation of the sol–gel was carried out through a one-pot method using [...] Read more.

A cellulose-based carbon aerogel (CTN) loaded with titanium dioxide (TiO₂) and graphitic carbon nitride (g-C₃N₄) was prepared using sol–gel, freeze-drying, and high-temperature carbonization methods. The formation of the sol–gel was carried out through a one-pot method using refining papermaking pulp, tetrabutyl titanate, and urea as raw materials and hectorite as a cross-linking and reinforcing agent. Due to the cross-linking ability of hectorite, the carbonized aerogel maintained a porous structure and had a large specific surface area with low density (0.0209 g/cm³). The analysis of XRD, XPS, and Raman spectra revealed that the titanium dioxide (TiO₂) and graphitic carbon nitride (g-C₃N₄) were uniformly distributed in the CTN, while TEM and SEM observations demonstrated the uniformly distributed three-dimensional porous structure of CTN. The photocatalytic activity of the CTN was determined according to its ability to degrade rhodamine B. The removal rate reached 89% under visible light after 120 min. In addition, the CTN was still stable after five reuse cycles. The proposed catalyst exhibits excellent photocatalytic performance under visible light conditions. Full article

(This article belongs to the Special Issue Nanoscale Material Catalysis for Environmental Protection)

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15 pages, 2843 KiB

Open AccessArticle

p-Type Schottky Contacts for Graphene Adjustable-Barrier Phototransistors

by Carsten Strobel, Carlos Alvarado Chavarin, Martin Knaut, Matthias Albert, André Heinzig, Likhith Gummadi, Christian Wenger and Thomas Mikolajick

Nanomaterials 2024, 14(13), 1140; https://doi.org/10.3390/nano14131140 - 2 Jul 2024

Viewed by 324

Abstract

The graphene adjustable-barriers phototransistor is an attractive novel device for potential high speed and high responsivity dual-band photodetection. In this device, graphene is embedded between the semiconductors silicon and germanium. Both n-type and p-type Schottky contacts between graphene and the semiconductors are required [...] Read more.

The graphene adjustable-barriers phototransistor is an attractive novel device for potential high speed and high responsivity dual-band photodetection. In this device, graphene is embedded between the semiconductors silicon and germanium. Both n-type and p-type Schottky contacts between graphene and the semiconductors are required for this device. While n-type Schottky contacts are widely investigated, reports about p-type Schottky contacts between graphene and the two involved semiconductors are scarce. In this study, we demonstrate a p-type Schottky contact between graphene and p-germanium. A clear rectification with on–off ratios of close to 10³ (±5 V) and a distinct photoresponse at telecommunication wavelengths in the infrared are achieved. Further, p-type silicon is transferred to or deposited on graphene, and we also observe rectification and photoresponse in the visible range for some of these p-type Schottky junctions. These results are an important step toward the realization of functional graphene adjustable-barrier phototransistors. Full article

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

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3 pages, 172 KiB

Open AccessEditorial

Advanced Spintronic and Electronic Nanomaterials

by Gang **ang and Hongtao Ren

Nanomaterials 2024, 14(13), 1139; https://doi.org/10.3390/nano14131139 - 2 Jul 2024

Viewed by 303

Abstract

Since single-layer graphene [...] Full article

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

14 pages, 3979 KiB

Open AccessArticle

Influence of Polypyrrole on Phosphorus- and TiO₂-Based Anode Nanomaterials for Li-Ion Batteries

by Chiwon Kang, Kibum Song, Seungho Ha, Yu** Sung, Ye** Kim, Keun-Young Shin and Byung Hyo Kim

Nanomaterials 2024, 14(13), 1138; https://doi.org/10.3390/nano14131138 - 2 Jul 2024

Viewed by 317

Abstract

Phosphorus (P) and TiO₂ have been extensively studied as anode materials for lithium-ion batteries (LIBs) due to their high specific capacities. However, P is limited by low electrical conductivity and significant volume changes during charge and discharge cycles, while TiO₂ is [...] Read more.

Phosphorus (P) and TiO₂ have been extensively studied as anode materials for lithium-ion batteries (LIBs) due to their high specific capacities. However, P is limited by low electrical conductivity and significant volume changes during charge and discharge cycles, while TiO₂ is hindered by low electrical conductivity and slow Li-ion diffusion. To address these issues, we synthesized organic–inorganic hybrid anode materials of P–polypyrrole (PPy) and TiO₂–PPy, through in situ polymerization of pyrrole monomer in the presence of the nanoscale inorganic materials. These hybrid anode materials showed higher cycling stability and capacity compared to pure P and TiO₂. The enhancements are attributed to the electrical conductivity and flexibility of PPy polymers, which improve the conductivity of the anode materials and effectively buffer volume changes to sustain structural integrity during the charge and discharge processes. Additionally, PPy can undergo polymerization to form multi-component composites for anode materials. In this study, we successfully synthesized a ternary composite anode material, P–TiO₂–PPy, achieving a capacity of up to 1763 mAh/g over 1000 cycles. Full article

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

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23 pages, 8693 KiB

Open AccessArticle

Enhancement in Heat Transfer Performance of Water Vapor Condensation on Graphene-Coated Copper Surfaces: A Molecular Dynamics Study

by Nurrohman Nurrohman, Hind Almisbahi, Elena Tocci, Hani Abulkhair, Mohammed Albeirutty, Ramzi Othman and Omar Bamaga

Nanomaterials 2024, 14(13), 1137; https://doi.org/10.3390/nano14131137 - 1 Jul 2024

Viewed by 307

Abstract

The condensation of water vapor plays a crucial role in various applications, including combating water scarcity. In this study, by employing molecular dynamics simulations, we delved into the impact of graphene coatings on water vapor condensation on copper surfaces. Unique to this work [...] Read more.

The condensation of water vapor plays a crucial role in various applications, including combating water scarcity. In this study, by employing molecular dynamics simulations, we delved into the impact of graphene coatings on water vapor condensation on copper surfaces. Unique to this work was the exploration of various levels of graphene coverage and distribution, a facet largely unexplored in prior investigations. The findings demonstrated a notable increase in the rate of water vapor condensation and heat transfer performance as the graphene coverage was reduced. Using graphene coverages of 84%, 68%, and 52%, the numbers of condensed water molecules were 664, 735, and 880 molecules/ns, respectively. One of the most important findings was that when using the same graphene coverage of 68%, the rate of water vapor condensation and heat transfer performance increased as the graphene coating became more distributed. The overall performance of the water condensation correlated well with the energy and vibrational interaction between the graphene and the copper. This phenomenon suggests how a hybrid surface can enhance the nucleation and growth of a droplet, which might be beneficial for tailoring graphene-coated copper surfaces for applications demanding efficient water vapor condensation. Full article

(This article belongs to the Special Issue Nanomaterials for Water-Food-Energy Nexus)

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15 pages, 7729 KiB

Open AccessArticle

The Hydrothermal-Assisted Approach Improves the Photocatalytic and Energy Storage Performance of Novel CuSe-TiO₂-GO Composite

by Afaq Ullah Khan, Kamran Tahir, Muhammad Zia Ullah Shah, Hissah Saedoon Albaqawi, Zainab M. Almarhoon, Abdulaziz A. Alanazi, Nora Awad Alkudaisi, Talal M. Althagafi, Nacer Badi and Magdi E. A. Zaki

Nanomaterials 2024, 14(13), 1136; https://doi.org/10.3390/nano14131136 - 1 Jul 2024

Viewed by 335

Abstract

This study reports a novel CuSe-TiO₂-GO composite, synthesized by a facile hydrothermal method at a controlled temperature, and investigates its electrochemical performance for supercapacitors (SCs) and photocatalytic behavior for degrading methylene blue (MB) dye. The compositional phase structure and chemical bond [...] Read more.

This study reports a novel CuSe-TiO₂-GO composite, synthesized by a facile hydrothermal method at a controlled temperature, and investigates its electrochemical performance for supercapacitors (SCs) and photocatalytic behavior for degrading methylene blue (MB) dye. The compositional phase structure and chemical bond interaction were thoroughly investigated. The as-fabricated pristine, binary, and ternary composites underwent comprehensive characterization employing spectroscopic techniques and electrochemical analysis. Compared with pure and binary compounds (CuSe, TiO₂, and binary CuSe-TiO₂ composites), the ternary CuSe-TiO₂-GO composites demonstrated a high degradation efficiency while degrading MB in less than just 80 min (240 min, 100 min, and 140 min, respectively). The photocatalytic activity of the ternary CuSe-TiO₂-GO composites is enhanced due to the highly positive conduction band of CuSe, leading to the quick excitation of electrons to the conduction band of CuSe. Subsequently, graphene oxide (GO) left holes on the photocatalyst surface for MB, as GO assisted the photoexcited electron–hole pairs, resulting in enhanced photocatalytic performance. The CuSe-TiO₂-GO electrode for the supercapacitor indicates a 310.6 F/g and 135.2 F/g capacitance when the discharge current upsurges from 1 to 12 A/g. The good photocatalytic and energy storage performance is due to the smaller charge transfer resistance, which promotes efficient separation of electron–hole pairs. Full article

(This article belongs to the Special Issue Nanomaterials and Nanotechnology for Energy Conversion and Storage)

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16 pages, 6613 KiB

Open AccessArticle

Innovative AI-Enhanced Ice Detection System Using Graphene-Based Sensors for Enhanced Aviation Safety and Efficiency

by Dario Farina, Hatim Machrafi, Patrick Queeckers, Patrice D. Dongo and Carlo Saverio Iorio

Nanomaterials 2024, 14(13), 1135; https://doi.org/10.3390/nano14131135 - 1 Jul 2024

Viewed by 406

Abstract

Ice formation on aircraft surfaces poses significant safety risks, and current detection systems often struggle to provide accurate, real-time predictions. This paper presents the development and comprehensive evaluation of a smart ice control system using a suite of machine learning models. The system [...] Read more.

Ice formation on aircraft surfaces poses significant safety risks, and current detection systems often struggle to provide accurate, real-time predictions. This paper presents the development and comprehensive evaluation of a smart ice control system using a suite of machine learning models. The system utilizes various sensors to detect temperature anomalies and signal potential ice formation. We trained and tested supervised learning models (Logistic Regression, Support Vector Machine, and Random Forest), unsupervised learning models (K-Means Clustering), and neural networks (Multilayer Perceptron) to predict and identify ice formation patterns. The experimental results demonstrate that our smart system, driven by machine learning, accurately predicts ice formation in real time, optimizes deicing processes, and enhances safety while reducing power consumption. This solution holds the potential for improving ice detection accuracy in aviation and other critical industries requiring robust predictive maintenance. Full article

(This article belongs to the Special Issue Graphene and Other 2D Layer-Based Nanomaterials for Energy and Sensing Applications)

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11 pages, 915 KiB

Open AccessArticle

Rocket Dynamics of Capped Nanotubes: A Molecular Dynamics Study

by Mustafa S. Hamad, Matteo Morciano and Matteo Fasano

Nanomaterials 2024, 14(13), 1134; https://doi.org/10.3390/nano14131134 - 30 Jun 2024

Viewed by 469

Abstract

The study of nanoparticle motion has fundamental relevance in a wide range of nanotechnology-based fields. Molecular dynamics simulations offer a powerful tool to elucidate the dynamics of complex systems and derive theoretical models that facilitate the invention and optimization of novel devices. This [...] Read more.

The study of nanoparticle motion has fundamental relevance in a wide range of nanotechnology-based fields. Molecular dynamics simulations offer a powerful tool to elucidate the dynamics of complex systems and derive theoretical models that facilitate the invention and optimization of novel devices. This research contributes to this ongoing effort by investigating the motion of one-end capped carbon nanotubes within an aqueous environment through extensive molecular dynamics simulations. By exposing the carbon nanotubes to localized heating, propelled motion with velocities reaching up to ≈0.08 nm ps⁻¹ was observed. Through systematic exploration of various parameters such as temperature, nanotube diameter, and size, we were able to elucidate the underlying mechanisms driving propulsion. Our findings demonstrate that the propulsive motion predominantly arises from a rocket-like mechanism facilitated by the progressive evaporation of water molecules entrapped within the carbon nanotube. Therefore, this study focuses on the complex interplay between nanoscale geometry, environmental conditions, and propulsion mechanisms in capped nanotubes, providing relevant insights into the design and optimization of nanoscale propulsion systems with various applications in nanotechnology and beyond. Full article

(This article belongs to the Special Issue Modelling and Mechanical Behaviour of Nanostructured Materials)

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13 pages, 863 KiB

Open AccessArticle

Exploring Disulfiram’s Anticancer Potential: PLGA Nano-Carriers for Prolonged Drug Delivery and Potential Improved Therapeutic Efficacy

by Ibrahim Dumbuya, Ana Maria Pereira, Ibrahim Tolaymat, Adnan Al Dalaty, Basel Arafat, Matt Webster, Barbara Pierscionek, Mouhamad Khoder and Mohammad Najlah

Nanomaterials 2024, 14(13), 1133; https://doi.org/10.3390/nano14131133 - 30 Jun 2024

Viewed by 405

Abstract

Disulfiram (DS) has been shown to have potent anti-cancer activity; however, it is also characterised by its low water solubility and rapid metabolism in vivo. Biodegradable polylactic-co-glycolic acid (PLGA) polymers have been frequently employed in the manufacturing of PLGA nano-carrier drug delivery systems. [...] Read more.

Disulfiram (DS) has been shown to have potent anti-cancer activity; however, it is also characterised by its low water solubility and rapid metabolism in vivo. Biodegradable polylactic-co-glycolic acid (PLGA) polymers have been frequently employed in the manufacturing of PLGA nano-carrier drug delivery systems. Thus, to develop DS-loaded PLGA nanoparticles (NPs) capable of overcoming DS’s limitations, two methodologies were used to formulate the NPs: direct nanoprecipitation (DNP) and single emulsion/solvent evaporation (SE), followed by particle size reduction. The DNP method was demonstrated to produce NPs of superior characteristics in terms of size (151.3 nm), PDI (0.083), charge (−37.9 mV), and loading efficiency (65.3%). Consequently, NPs consisting of PLGA and encapsulated DS coated with mPEG_2k-PLGA at adjustable ratios were prepared using the DNP method. Formulations were then characterised, and their stability in horse serum was assessed. Results revealed the PEGylated DS-loaded PLGA nano-carriers to be more efficient; hence, in-vitro studies testing these formulations were subsequently performed using two distinct breast cancer cell lines, showing great potential to significantly enhance cancer therapy. Full article

(This article belongs to the Special Issue Nanoparticles in Drug Delivery Applications)

13 pages, 2622 KiB

Open AccessArticle

Synthesis of Ordered Mesoporous Molecular Sieve-Supported Cobalt Catalyst via Organometallic Complexation for Propane Non-Oxidative Dehydrogenation

by Yanliang Zhai, Lisha Chen, Ruihan Wu, **anggang Lu, Jun Wang, Gaolong Li, Bicheng Tang, Wei Zhang, Shaolong Zhang and Zhijun Li

Nanomaterials 2024, 14(13), 1132; https://doi.org/10.3390/nano14131132 - 30 Jun 2024

Viewed by 362

Abstract

Co-based catalysts have shown great promise for propane dehydrogenation (PDH) reactions due to their merits of environmental friendliness and low cost. In this study, ordered mesoporous molecular sieve-supported CoO_x species (CoO_x/Al-SBA-15 catalyst) were prepared by one-step organometallic complexation. The catalysts [...] Read more.

Co-based catalysts have shown great promise for propane dehydrogenation (PDH) reactions due to their merits of environmental friendliness and low cost. In this study, ordered mesoporous molecular sieve-supported CoO_x species (CoO_x/Al-SBA-15 catalyst) were prepared by one-step organometallic complexation. The catalysts show worm-like morphology with regular straight-through mesoporous pores and high external specific surface area. These typical features can substantially enhance the dispersion of CoO_x species and mass transfer of reactants and products. Compared with the conventional impregnation method, the 10CSOC (10 wt.% Co/Al-SBA-15 prepared by the organometallic complexation method) sample presents a smaller CoO_x size and higher Co²⁺/Co³⁺ ratio. When applied to PDH reaction, the 10CSOC delivers higher propane conversion and propylene selectivity. Under the optimal conditions (625 °C and 4500 h⁻¹), 10CSOC achieves high propane conversion (43%) and propylene selectivity (83%). This is attributed to the smaller and better dispersion of CoO_x nanoparticles, more suitable acid properties, and higher content of Co²⁺ species. This work paves the way for the rational design of high-performance catalysts for industrially important reactions. Full article

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14 pages, 11752 KiB

Open AccessArticle

Ultra-Sensitive Simultaneous Detection of Dopamine and Acetaminophen over Hollow Porous AuAg Alloy Nanospheres

by Menghua Li, **nzheng Liu, Changhui Sun, **aorong Cao, Yuanyuan Zhang, Linrui Hou, Hongxiao Yang and Caixia Xu

Nanomaterials 2024, 14(13), 1131; https://doi.org/10.3390/nano14131131 - 30 Jun 2024

Viewed by 295

Abstract

Hollow porous AuAg nanospheres (AuAg HPNSs) were obtained through a simple solvothermal synthesis, complemented by a dealloying strategy. The hollow interior, open pore voids, and integral interconnected skeleton shell in AuAg HPNSs are beneficial for providing sufficient electrolyte diffusion and contacts, abundant active [...] Read more.

Hollow porous AuAg nanospheres (AuAg HPNSs) were obtained through a simple solvothermal synthesis, complemented by a dealloying strategy. The hollow interior, open pore voids, and integral interconnected skeleton shell in AuAg HPNSs are beneficial for providing sufficient electrolyte diffusion and contacts, abundant active sites, and efficient electron transport. This specific structure and the favorable alloy synergism contribute to the superior electrocatalytic activity toward dopamine (DA) and acetaminophen (AC). AuAg HPNSs show high sensitivity, good selectivity, excellent sensing durability, and outstanding repeatability for amperometric assays of AC and DA. In particular, the AuAg-based sensors achieve effective ultrasensitive simultaneous analyses of AC and DA, exhibiting the characteristics of the wide linear range and low detection limit. With their prominent electrocatalytic activity and simple preparation methods, AuAg HPNSs present broad application prospects for constructing a highly responsive electrochemical sensing system. Full article

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

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19 pages, 4885 KiB

Open AccessArticle

TiO₂ Nanoparticles with Adjustable Phase Composition Prepared by an Inverse Microemulsion Method: Physicochemical Characterization and Photocatalytic Properties

by Bogna D. Napruszewska, Anna Walczyk, Dorota Duraczyńska, Joanna Kryściak-Czerwenka, Robert Karcz, Adam Gaweł, Paweł Nowak and Ewa M. Serwicka

Nanomaterials 2024, 14(13), 1130; https://doi.org/10.3390/nano14131130 - 30 Jun 2024

Viewed by 380

Abstract

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO₂ NPs corresponding to anatase, rutile, [...] Read more.

Titania nanoparticles (NPs) find wide application in photocatalysis, photovoltaics, gas sensing, lithium batteries, etc. One of the most important synthetic challenges is maintaining control over the polymorph composition of the prepared nanomaterial. In the present work, TiO₂ NPs corresponding to anatase, rutile, or an anatase/rutile/brookite mixture were obtained at 80 °C by an inverse microemulsion method in a ternary system of water/cetyltrimethylammonium bromide/1-hexanol in a weight ratio of 17:28:55. The only synthesis variables were the preparation of the aqueous component and the nature of the Ti precursor (Ti(IV) ethoxide, isopropoxide, butoxide, or chloride). The materials were characterized with X-ray diffraction, scanning/transmission electron microscopy, N₂ adsorption–desorption isotherms, FTIR and Raman vibrational spectroscopies, and diffuse reflectance spectroscopy. The synthesis products differed significantly not only in phase composition, but also in crystallinity, textural properties, and adsorption properties towards water. All TiO₂ NPs were active in the photocatalytic decomposition of rhodamine B, a model dye pollutant of wastewater streams. The mixed-phase anatase/rutile/brookite nanopowders obtained from alkoxy precursors showed the best photocatalytic performance, comparable to or better than the P25 reference. The exceptionally high photoactivity was attributed to the advantageous electronic effects known to accompany multiphase titania composition, namely high specific surface area and strong surface hydration. Among the single-phase materials, anatase samples showed better photoactivity than rutile ones, and this effect was associated, primarily, with the much higher specific surface area of anatase photocatalysts. Full article

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14 pages, 3793 KiB

Open AccessArticle

Energy Storage Application of CaO/Graphite Nanocomposite Powder Obtained from Waste Eggshells and Used Lithium-Ion Batteries as a Sustainable Development Approach

by Kathalingam Adaikalam, Aviraj M. Teli, Karuppasamy Pandian Marimuthu, Sivalingam Ramesh, Hyungyil Lee, Heung Soo Kim and Hyun-Seok Kim

Nanomaterials 2024, 14(13), 1129; https://doi.org/10.3390/nano14131129 - 30 Jun 2024

Viewed by 365

Abstract

The reuse of waste materials has recently become appealing due to pollution and cost reduction factors. Using waste materials can reduce environmental pollution and product costs, thus promoting sustainability. Approximately 95% of calcium carbonate-containing waste eggshells end up in landfills, unused. These eggshells, [...] Read more.

The reuse of waste materials has recently become appealing due to pollution and cost reduction factors. Using waste materials can reduce environmental pollution and product costs, thus promoting sustainability. Approximately 95% of calcium carbonate-containing waste eggshells end up in landfills, unused. These eggshells, a form of bio-waste, can be repurposed as catalytic electrode material for various applications, including supercapacitors, after being converted into CaO. Similarly, used waste battery electrode materials pose environmental hazards if not properly recycled. Various types of batteries, particularly lithium-ion batteries, are extensively used worldwide. The recycling of used lithium-ion batteries has become less important considering its low economic benefits. This necessitates finding alternative methods to recover and reuse the graphite rods of spent batteries. Therefore, this study reports the conversion of waste eggshell into calcium oxide by high-temperature calcination and extraction of nanographite from spent batteries for application in energy storage fields. Both CaO and CaO/graphite were characterized for their structural, morphological, and chemical compositions using XRD, SEM, TEM, and XPS techniques. The prepared CaO/graphite nanocomposite material was evaluated for its efficiency in electrochemical supercapacitor applications. CaO and its composite with graphite powder obtained from used lithium-ion batteries demonstrated improved performance compared to CaO alone for energy storage applications. Using these waste materials for electrochemical energy storage and conversion devices results in cheaper, greener, and sustainable processes. This approach not only aids in energy storage but also promotes sustainability through waste management by reducing landfills. Full article

(This article belongs to the Special Issue Application of Nanomaterials as Catalysts for Energy Storage and Conversion)

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27 pages, 7097 KiB

Open AccessReview

Hydrogel Extinguishants

by Guineng Li, Qiaobo Wang, Guiqun Liu, Mutian Yao, Yue Wang, Yeying Li, Kaiwen Lin and **mei Liu

Nanomaterials 2024, 14(13), 1128; https://doi.org/10.3390/nano14131128 - 30 Jun 2024

Viewed by 294

Abstract

The exploitation of clean and efficient fire extinguishing materials has substantial implications for improving disaster prevention, mitigation, and relief capabilities, maintaining public safety, and protecting people’s lives and property as well as the natural environment. Natural polymer hydrogel with high water containment, excellent [...] Read more.

The exploitation of clean and efficient fire extinguishing materials has substantial implications for improving disaster prevention, mitigation, and relief capabilities, maintaining public safety, and protecting people’s lives and property as well as the natural environment. Natural polymer hydrogel with high water containment, excellent film formation, high heat insulation, ecofriendliness, and degradability has huge potential in achieving new breakthroughs for develo** clean and efficient fire extinguishing materials and products. In recent years, the exploitation of hydrogel extinguishing materials and the fabrication of products has attracted great attention, gradually replacing traditional fire extinguishing products. In this perspective, an in-depth review of the evolution of hydrogels applied for fire extinguishing and prevention is presented. Firstly, the extinguishing principles of hydrogel extinguishants are explained. Secondly, the preparation strategies and evaluation system of the hydrogel extinguishants are emphatically discussed. Although great progress has been made in develo** high-performance hydrogel extinguishants, it remains challenging to develop cost-effective, degradable, and easy-to-use hydrogel extinguishants. Additionally, we highlight the importance of considering the commercial aspects of hydrogel extinguishants. Looking into the future, hydrogel extinguishants are promising, but continued investment in research and development is necessary to overcome the challenges. Full article

(This article belongs to the Special Issue Advanced Nanoscale Materials and (Flexible) Devices)

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12 pages, 2386 KiB

Open AccessArticle

A Label-Free Photoelectrochemical Biosensor Based on ZnO/Cs₃MnBr₅ Heterogeneous Films for Alpha-Fetoprotein Detection

by Long Shao, Biyu Zhang, Wei Wu, Gengyan Cui and Mao Liu

Nanomaterials 2024, 14(13), 1127; https://doi.org/10.3390/nano14131127 - 29 Jun 2024

Viewed by 368

Abstract

Highly sensitive and specific biomarker detection is of outstanding importance for the diagnosis and treatment of cancers. Herein, we developed robust photoelectrochemical (PEC) biosensors with low background noise and high sensitivity based on a heterojunction, which can improve semiconductor photoelectric properties by limiting [...] Read more.

Highly sensitive and specific biomarker detection is of outstanding importance for the diagnosis and treatment of cancers. Herein, we developed robust photoelectrochemical (PEC) biosensors with low background noise and high sensitivity based on a heterojunction, which can improve semiconductor photoelectric properties by limiting the recombination of photogenerated electron–hole pairs and successfully widening the range of light absorption. Alpha-fetoprotein (AFP) was used as a target model to examine the analytical performances of the designed PEC biosensors. ZnO/Cs₃MnBr₅ heterogeneous film with a uniform porous structure and large surface area enhanced electron transfer and biomolecule immobilization, and significantly increased the photocurrent response. Under the optimal conditions, the designed PEC biosensor exhibited a linear detection range of 0.01–500 ng/mL and a detection limit of 12 pg/mL. In addition, this PEC biosensor performed well when testing human serum samples and exhibited good repeatability, stability over time, and specificity, showing enormous potential for the detection of cancer markers in future biological and clinical research. Full article

(This article belongs to the Special Issue Nano-Enabled Sensors for High Performance in Detection and Monitoring)

29 pages, 9125 KiB

Open AccessReview

Advancements in Nanomaterial Dispersion and Stability and Thermophysical Properties of Nano-Enhanced Phase Change Materials for Biomedical Applications

by Qian Zhang, Tkhu Chang Le, Shuang Zhao, Chenxi Shang, Menglin Hu, Su Zhang, Yushi Liu and Shuang Pan

Nanomaterials 2024, 14(13), 1126; https://doi.org/10.3390/nano14131126 - 29 Jun 2024

Viewed by 344

Abstract

Phase change materials (PCMs) are materials that exhibit thermal response characteristics, allowing them to be utilized in the biological field for precise and controllable temperature regulation. Due to considerations of biosafety and the spatial limitations within human tissue, the amount of PCMs used [...] Read more.

Phase change materials (PCMs) are materials that exhibit thermal response characteristics, allowing them to be utilized in the biological field for precise and controllable temperature regulation. Due to considerations of biosafety and the spatial limitations within human tissue, the amount of PCMs used in medical applications is relatively small. Therefore, researchers often augment PCMs with various materials to enhance their performance and increase their practical value. The dispersion of nanoparticles to modify the thermophysical properties of PCMs has emerged as a mature concept. This paper aims to elucidate the role of nanomaterials in addressing deficiencies and enhancing the performance of PCMs. Specifically, it discusses the dispersion methods and stabilization mechanisms of nanoparticles within PCMs, as well as their effects on thermophysical properties such as thermal conductivity, latent heat, and specific heat capacity. Furthermore, it explores how various nano-additives contribute to improved thermal conductivity and the mechanisms underlying enhanced latent heat and specific heat. Additionally, the potential applications of PCMs in biomedical fields are proposed. Finally, this paper provides a comprehensive analysis and offers suggestions for future research to maximize the utilization of nanomaterials in enhancing the thermophysical properties of PCMs for biomedical applications. Full article

(This article belongs to the Special Issue Advances in Nano-Engineered Composite Materials for Thermal Management)

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9 pages, 542 KiB

Open AccessArticle

Random Field Ising Model Criticality in a Complex Binary Liquid System

by Henrich Frielinghaus, Purushottam S. Dubey, Debasish Saha, Eunjoo Shin, Olaf Holderer, Jan V. Sengers and Stephan Förster

Nanomaterials 2024, 14(13), 1125; https://doi.org/10.3390/nano14131125 - 29 Jun 2024

Viewed by 325

Abstract

While Ising criticality in classical liquids has been firmly established both theoretically and experimentally, much less is known about criticality in liquids in which the growth of the correlation length is frustrated by finite-size effects. A theoretical approach for dealing with this issue [...] Read more.

While Ising criticality in classical liquids has been firmly established both theoretically and experimentally, much less is known about criticality in liquids in which the growth of the correlation length is frustrated by finite-size effects. A theoretical approach for dealing with this issue is the random-field Ising model (RFIM). While experimental critical-exponent values have been reported for magnetic samples (here, we consider

γ

,

ν

and

η

), little experimental information is available for critical fluctuations in corresponding liquid systems. In this paper, we present a study on a binary liquid consisting of 3-methyl pyridine and heavy water in a very light-weight porous gel. We find that the experimental results are in agreement with the theoretical predictions from the RFIM. Full article

(This article belongs to the Topic Multifunctional Porous Materials: Preparation, Structure, Modeling and Applications)

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12 pages, 6110 KiB

Open AccessArticle

Investigation of Ripple Formation on Surface of Silicon by Low-Energy Gallium Ion Bombardment

by Márk Windisch, Dániel Selmeczi, Ádám Vida and Zoltán Dankházi

Nanomaterials 2024, 14(13), 1124; https://doi.org/10.3390/nano14131124 (registering DOI) - 29 Jun 2024

Viewed by 310

Abstract

Regular wave patterns were created by a 2 kV gallium ion on Si(111) monocrystals at incidence angles between 60° and 80° with respect to the surface normal. The characteristic wavelength and surface roughness of the structured surfaces were determined to be between 35–75 [...] Read more.

Regular wave patterns were created by a 2 kV gallium ion on Si(111) monocrystals at incidence angles between 60° and 80° with respect to the surface normal. The characteristic wavelength and surface roughness of the structured surfaces were determined to be between 35–75 nm and 0.5–2.5 nm. The local slope distribution of the created periodic structures was also studied. These topography results were compared with the predictions of the Bradley–Harper model. The amorphised surface layers were investigated by a spectroscopic ellipsometer. According to the results, the amorphised thicknesses were changed in the range of 8 nm to 4 nm as a function of ion incidence angles. The reflectance of the structured surfaces was simulated using ellipsometric results and measured with a reflectometer. Based on the spectra, a controlled modification of reflectance within 45% and 50% can be achieved on Si(111) at 460 nm wavelength. According to the measured results, the characteristic sizes (periodicity and amplitude) and optical property of silicon can be fine-tuned by low-energy focused ion irradiation at the given interval of incidence angles. Full article

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23 pages, 6089 KiB

Open AccessArticle

Nanofibrous Conductive Sensor for Limonene: One-Step Synthesis via Electrospinning and Molecular Imprinting

by Antonella Macagnano, Fabricio Nicolas Molinari, Paolo Papa, Tiziana Mancini, Stefano Lupi, Annalisa D’Arco, Anna Rita Taddei, Simone Serrecchia and Fabrizio De Cesare

Nanomaterials 2024, 14(13), 1123; https://doi.org/10.3390/nano14131123 - 29 Jun 2024

Viewed by 434

Abstract

Detecting volatile organic compounds (VOCs) emitted from different plant species and their organs can provide valuable information about plant health and environmental factors that affect them. For example, limonene emission can be a biomarker to monitor plant health and detect stress. Traditional methods [...] Read more.

Detecting volatile organic compounds (VOCs) emitted from different plant species and their organs can provide valuable information about plant health and environmental factors that affect them. For example, limonene emission can be a biomarker to monitor plant health and detect stress. Traditional methods for VOC detection encounter challenges, prompting the proposal of novel approaches. In this study, we proposed integrating electrospinning, molecular imprinting, and conductive nanofibers to fabricate limonene sensors. In detail, polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) served here as fiber and cavity formers, respectively, with multiwalled carbon nanotubes (MWCNT) enhancing conductivity. We developed one-step monolithic molecularly imprinted fibers, where S(−)-limonene was the target molecule, using an electrospinning technique. The functional cavities were fixed using the UV curing method, followed by a target molecule washing. This procedure enabled the creation of recognition sites for limonene within the nanofiber matrix, enhancing sensor performance and streamlining manufacturing. Humidity was crucial for sensor working, with optimal conditions at about 50% RH. The sensors rapidly responded to S(−)-limonene, reaching a plateau within 200 s. Enhancing fiber density improved sensor performance, resulting in a lower limit of detection (LOD) of 137 ppb. However, excessive fiber density decreased accessibility to active sites, thus reducing sensitivity. Remarkably, the thinnest mat on the fibrous sensors created provided the highest selectivity to limonene (Selectivity Index: 72%) compared with other VOCs, such as EtOH (used as a solvent in nanofiber development), aromatic compounds (toluene), and two other monoterpenes (α-pinene and linalool) with similar structures. These findings underscored the potential of the proposed integrated approach for selective VOC detection in applications such as precision agriculture and environmental monitoring. Full article

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

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