Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (118)

Search Parameters:
Keywords = fibrous metal

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
16 pages, 2901 KiB  
Article
SiO2-Al2O3-ZrO2-Ag Composite and Its Signal Enhancement Capacity on Raman Spectroscopy
by Jesús Alberto Garibay-Alvarado, Pedro Pizá-Ruiz, Armando Erasto Zaragoza-Contreras, Francisco Espinosa-Magaña and Simón Yobanny Reyes-López
Chemosensors 2025, 13(7), 266; https://doi.org/10.3390/chemosensors13070266 - 21 Jul 2025
Viewed by 301
Abstract
A ceramic–metal composite was synthesized using sol–gel and electrospinning methods to serve as a SERS substrate. The precursors used were tetraethyl orthosilicate, aluminum nitrate, and zirconium, and polyvinylpyrrolidone was added to electrospun nonwoven fibrous membranes. The membranes were sintered, decorated with silver nanoparticles. [...] Read more.
A ceramic–metal composite was synthesized using sol–gel and electrospinning methods to serve as a SERS substrate. The precursors used were tetraethyl orthosilicate, aluminum nitrate, and zirconium, and polyvinylpyrrolidone was added to electrospun nonwoven fibrous membranes. The membranes were sintered, decorated with silver nanoparticles. The enhancement substrates were made of fibers of cylindric morphology with an average diameter of approximately 190 nm, a smooth surface, and 9 nm spherical particles decorating the surface of the fibers. The enhancement capacity of the substrates was tested using pyridine, methyl orange, methylene blue, crystal violet, and Eriochrome black T at different concentrations with Raman spectroscopy to determine whether the size and complexity of the analyte has an impact on the enhancement capacity. Enhancement factors of 2.53 × 102, 3.06 × 101, 2.97 × 103, 4.66 × 103, and 1.45 × 103 times were obtained for the signal of pyridine, methyl orange, methylene blue, crystal violet, and Eriochrome black T at concentrations of 1 nM. Full article
(This article belongs to the Special Issue Spectroscopic Techniques for Chemical Analysis)
Show Figures

Graphical abstract

22 pages, 4829 KiB  
Article
Development of a Flexible and Conductive Heating Membrane via BSA-Assisted Electroless Plating on Electrospun PVDF-HFP Nanofibers
by Mun Jeong Choi, Dae Hyeob Yoon, Yoo Sei Park, Hyoryung Nam and Geon Hwee Kim
Appl. Sci. 2025, 15(14), 8023; https://doi.org/10.3390/app15148023 - 18 Jul 2025
Viewed by 275
Abstract
Planar heaters are designed to deliver uniform heat across broad surfaces and serve as critical components in applications requiring energy efficiency, safety, and mechanical flexibility, such as wearable electronics and smart textiles. However, conventional metal-based heaters are limited by poor adaptability to curved [...] Read more.
Planar heaters are designed to deliver uniform heat across broad surfaces and serve as critical components in applications requiring energy efficiency, safety, and mechanical flexibility, such as wearable electronics and smart textiles. However, conventional metal-based heaters are limited by poor adaptability to curved or complex surfaces, low mechanical compliance, and susceptibility to oxidation-induced degradation. To overcome these challenges, we applied a protein-assisted electroless copper (Cu) plating strategy to electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber substrates to fabricate flexible, conductive planar heating membranes. For interfacial functionalization, a protein-based engineering approach using bovine serum albumin (BSA) was employed to facilitate palladium ion coordination and seed formation. The resulting membrane exhibited a dense, continuous Cu coating, low sheet resistance, excellent durability under mechanical deformation, and stable heating performance at low voltages. These results demonstrate that the BSA-assisted strategy can be effectively extended to complex three-dimensional fibrous membranes, supporting its scalability and practical potential for next-generation conformal and wearable planar heaters. Full article
(This article belongs to the Section Applied Thermal Engineering)
Show Figures

Figure 1

20 pages, 1816 KiB  
Review
Recent Achievements of Epicardial Patch Electronics Using Adhesive and Conductive Hydrogels
by Su Hyeon Lee, Jong Won Lee, Daehyeon Kim, Gi Doo Cha and Sung-Hyuk Sunwoo
Gels 2025, 11(7), 530; https://doi.org/10.3390/gels11070530 - 9 Jul 2025
Viewed by 417
Abstract
Implantable cardiac devices are critical in improving patients’ quality of life through precise and continuous interaction between the device and pathological cardiac tissue. Due to the inherently rigid nature of conventional devices, several complications arise when interacting with soft cardiac tissue, caused by [...] Read more.
Implantable cardiac devices are critical in improving patients’ quality of life through precise and continuous interaction between the device and pathological cardiac tissue. Due to the inherently rigid nature of conventional devices, several complications arise when interacting with soft cardiac tissue, caused by a mechanical mismatch between the device and myocardium. This leads to the excessive formation of fibrous tissue around the implanted device, ultimately compromising both device functionality and tissue health. To address these challenges, flexible electronics based on polymers and elastomers significantly softer than conventional rigid metals and silicon have been explored. The epicardial approach enables the device to conform to the curved myocardial surface and deform synchronously with cardiac motion, thereby improving mechanical compatibility. However, modulus mismatches between soft polymers and cardiac tissue can still lead to mechanical instability and non-uniform adhesion, potentially affecting long-term performance. This review comprehensively summarizes recent research advancements in epicardial patch electronics based on bioadhesive and conductive hydrogels. We emphasize current research directions, highlighting the potential of hydrogels in epicardial electronics applications. Critical discussion includes recent trends, ongoing challenges, and emerging strategies aimed at improving the properties of hydrogel-based epicardial patches. Future research directions to facilitate clinical translation are also outlined. Full article
(This article belongs to the Special Issue Novel Gels for Biomedical Applications)
Show Figures

Figure 1

17 pages, 2146 KiB  
Article
Synthesis and Antiviral Activity of Nanowire Polymers Activated with Ag, Zn, and Cu Nanoclusters
by Thomas Thomberg, Hanna Bulgarin, Andres Lust, Jaak Nerut, Tavo Romann and Enn Lust
Pharmaceutics 2025, 17(7), 887; https://doi.org/10.3390/pharmaceutics17070887 - 6 Jul 2025
Viewed by 484
Abstract
Background/Objectives: Airborne viral diseases pose a health risk, due to which there is a growing interest in developing filter materials capable of capturing fine particles containing virions from the air and that also have a virucidal effect. Nanofiber membranes made of poly(vinylidene fluoride) [...] Read more.
Background/Objectives: Airborne viral diseases pose a health risk, due to which there is a growing interest in developing filter materials capable of capturing fine particles containing virions from the air and that also have a virucidal effect. Nanofiber membranes made of poly(vinylidene fluoride) dissolved in N,N-dimethylacetamide and functionalized with copper, silver, and zinc nanoclusters were fabricated via electrospinning. This study aims to evaluate and compare the virucidal effects of nanofibers functionalized with metal nanoclusters against the human influenza A virus A/WSN/1933 (H1N1) and SARS-CoV-2. Methods: A comprehensive characterization of materials, including X-ray diffraction, scanning electron microscopy, microwave plasma atomic emission spectroscopy, thermogravimetric analysis, contact angle measurements, nitrogen sorption analysis, mercury intrusion porosimetry, filtration efficiency, and virucidal tests, was used to understand the interdependence of the materials’ physical characteristics and biological effects, as well as to determine their suitability for application as antiviral materials in air filtration systems. Results: All the filter materials tested demonstrated very high particle filtration efficiency (≥98.0%). The material embedded with copper nanoclusters showed strong virucidal efficacy against the SARS-CoV-2 alpha variant, achieving an approximately 1000-fold reduction in infectious virions within 12 h. The fibrous nanowire polymer functionalized with zinc nanoclusters was the most effective material against the human influenza A virus strain A/WSN/1933 (H1N1). Conclusions: The materials with Cu nanoclusters can be used with high efficiency to passivate and kill the SARS-CoV-2 alpha variant virions, and Zn nanoclusters modified activated porous membranes for killing human influenza A virus A7WSN/1933 (H1N1) virions. Full article
Show Figures

Figure 1

13 pages, 2792 KiB  
Article
Engineering C–S–H Sorbents via Hydrothermal Synthesis of PV Glass and Carbide Sludge for Chromium(III) Removal
by Tran Ngo Quan, Le Phan Hoang Chieu and Pham Trung Kien
Coatings 2025, 15(6), 733; https://doi.org/10.3390/coatings15060733 - 19 Jun 2025
Viewed by 599
Abstract
This study investigates the hydrothermal synthesis of calcium silicate hydrate (C-S-H) from photovoltaic (PV) waste glass and carbide sludge as a strategy for resource recovery and sustainable chromium removal from wastewater. Waste-derived precursors were co-ground, blended at controlled Ca/Si molar ratios (0.8, 1.0, [...] Read more.
This study investigates the hydrothermal synthesis of calcium silicate hydrate (C-S-H) from photovoltaic (PV) waste glass and carbide sludge as a strategy for resource recovery and sustainable chromium removal from wastewater. Waste-derived precursors were co-ground, blended at controlled Ca/Si molar ratios (0.8, 1.0, 1.2), and hydrothermally treated at 180 °C for 96 h to yield C-S-H with tunable morphology and crystallinity. Comprehensive characterization using XRD, FT-IR, SEM-EDX, and UV-Vis spectroscopy revealed that a Ca/Si ratio of 1.0 produced a well-ordered tobermorite/xonotlite structure with a high surface area and fibrous network, which is optimal for adsorption. Batch adsorption experiments showed that this material achieved rapid and efficient Cr(III) removal, exceeding 90% uptake within 9 h through a combination of surface complexation, ion exchange (Ca2+/Na+ ↔ Cr3+), and precipitation of CaCrO4 phases. Morphological and structural evolution during adsorption was confirmed by SEM, FT-IR, and XRD, while EDX mapping established the progressive incorporation of Cr into the C-S-H matrix. These findings highlight the viability of upcycling industrial waste into advanced C-S-H sorbents for heavy metal remediation. Further work is recommended to address sorbent regeneration, long-term stability, and application to other contaminants, providing a foundation for circular approaches in advanced wastewater treatment. Full article
Show Figures

Figure 1

29 pages, 5717 KiB  
Review
Alkali-Activated Materials Reinforced via Fibrous Biochar: Modification Mechanisms, Environmental Benefits, and Challenges
by Yukai Wang, Kai Zheng, Lilin Yang, Han Li, Yang Liu, Ning Xie and Guoxiang Zhou
J. Compos. Sci. 2025, 9(6), 298; https://doi.org/10.3390/jcs9060298 - 11 Jun 2025
Viewed by 758
Abstract
Alkali-activated materials, as a low-carbon cementitious material, are widely known for their excellent durability and mechanical properties. In recent years, the modification of alkali-activated materials using biochar has gradually attracted attention. Fibrous biochar has a highly porous structure and large specific surface area, [...] Read more.
Alkali-activated materials, as a low-carbon cementitious material, are widely known for their excellent durability and mechanical properties. In recent years, the modification of alkali-activated materials using biochar has gradually attracted attention. Fibrous biochar has a highly porous structure and large specific surface area, which can effectively adsorb alkaline ions in alkali-activated materials, thereby improving their pore structure and density. Additionally, the surface of the biochar contains abundant functional groups and chemically reactive sites. These can interact with the active components in alkali-activated materials, forming stable composite phases. This interaction further enhances the material’s mechanical strength and durability. Moreover, the incorporation of biochar endows alkali-activated materials with special adsorption capabilities and environmental remediation functions. For instance, they can adsorb heavy metal ions and organic pollutants from water, offering significant environmental benefits. However, research on biochar-modified alkali-activated materials is still in the exploratory phase. There are several challenges, such as the unclear mechanisms of how biochar preparation conditions and performance parameters affect the modification outcomes, and the need for further investigation into the compatibility and long-term stability of biochar with alkali-activated materials. Future research should focus on these issues to promote the widespread application of biochar-modified alkali-activated materials. Full article
Show Figures

Figure 1

22 pages, 5233 KiB  
Article
A Novel Green In Situ Amine-Functionalized Aerogel UiO-66-NH2/TOCNF for the Removal of Azo Anionic Dyes
by Rabia Amen, Islam Elsayed, Yunsang Kim, Gregory T. Schueneman, Emad M. El-Giar and El Barbary Hassan
Gels 2025, 11(5), 365; https://doi.org/10.3390/gels11050365 - 15 May 2025
Viewed by 1061
Abstract
UiO-66-NH2 is a metal–organic framework (MOF) with open metal sites, making it a promising candidate for adsorption and catalysis. However, the powdery texture of MOFs and the use of toxic solvents during synthesis limit their application. A novel solution to this issue [...] Read more.
UiO-66-NH2 is a metal–organic framework (MOF) with open metal sites, making it a promising candidate for adsorption and catalysis. However, the powdery texture of MOFs and the use of toxic solvents during synthesis limit their application. A novel solution to this issue is to create a layered porous composite by encasing the MOF within a flexible and structurally robust aerogel substrate using safe, eco-friendly, and green solvents such as ethanol. The fibrous MOF aerogels, characterized by a desirable macroscopic shape of cylindrical block and hierarchical porosity, were synthesized by two approaches: in situ growth of amine-functionalized UiO-66-NH2 crystals on a TEMPO-oxidized cellulose nanofiber (TOCNF) and ex situ crosslinking of UiO-66-NH2 crystals onto a TOCNF network to form UiO-66-NH2/TOCNF. The incorporation of MOF into the cellulose nanofibrils via the in situ method reduces their aggregation potential, alters the nucleation/growth balance to produce smaller MOF crystals, and enhances mechanical flexibility, as evidenced by SEM images. The three adsorbents, including UiO-66-NH2, ex situ UiO-66-NH2/TOCNF, and in situ UiO-66-NH2/TOCNF, were synthesized and used in this study. The effects of pH, time, temperature, and initial concentration were studied. A maximum adsorption capacity (Qmax) of 549.45 mg/g for Congo Red (CR) and 171.23 mg/g for Orange II (ORII) was observed at pH 6, using 10 mg of in situ UiO-66-NH2/TOCNF at 40 °C with a contact time of 75 min for CR and 2 h for ORII. The adsorption of both dyes primarily occurs through monolayer chemisorption on the in situ UiO-66-NH2/TOCNF. The main removal mechanisms were hydrogen bonding and surface complexation. The noteworthy adsorption capacity of in situ UiO-66-NH2/TOCNF coupled with environment-friendly fabrication techniques indicates its potential applications on a large scale in real wastewater systems. Full article
(This article belongs to the Special Issue Cellulose-Based Gels: Synthesis, Properties, and Applications)
Show Figures

Figure 1

15 pages, 5200 KiB  
Article
A Comprehensive Study on the Physicochemical Characterisation of Plant-Based By-Products
by Filipa Costa, Daniel Mendanha, Joana M. Gomes, Juliana A. S. A. Oliveira, Cecília Ribeiro, Ana Francisca Miranda, José R. M. Barbosa, Olívia Salomé G. P. Soares, Manuel Fernando R. Pereira, Jorge Santos, Beatriz Freitas and Carla J. Silva
Materials 2025, 18(9), 2054; https://doi.org/10.3390/ma18092054 - 30 Apr 2025
Cited by 1 | Viewed by 516
Abstract
The rapid growth of the global population has led to significant environmental impacts, driven by the unsustainable extraction of resources and waste generation. To address these challenges, the valorisation of by-products from different industries is crucial for maximising resource efficiency, reducing waste, and [...] Read more.
The rapid growth of the global population has led to significant environmental impacts, driven by the unsustainable extraction of resources and waste generation. To address these challenges, the valorisation of by-products from different industries is crucial for maximising resource efficiency, reducing waste, and promoting sustainable practices. In this study, a comprehensive characterisation of the physicochemical properties of plant-based by-products, including rice husk (RH), oregano stalks (OS), eucalyptus leaves (EL), and almond shells (AS), was conducted. The analyses of the residues showed that, despite the similarities regarding cellulose and lignin content in all materials, RH and OS present a higher cellulose content, while EL and AS contain a greater percentage of oils. Additionally, calcium and potassium were identified as the metals at higher concentrations in all residues. The EL and RH present significant hydrophobic properties compared to the other analysed residues, showcased by their lower wettability. The morphological analyses of the waste residues revealed that OS and RH particles exhibit fibrous characteristics with heterogeneous sizes, while EL is a blend of fibrous and amorphous particles, and AS is composed of smaller particles with irregular shapes. All the residues retained their antioxidant properties over a 12-month storage period, with no degradation due to grinding. The composition and physicochemical properties of these residues highlight their potential to be used in distinct industries, including construction, transport, and textiles, promoting a circular economy and supporting a more sustainable environment. Full article
(This article belongs to the Special Issue Sustainable Materials: Preparation, Characterization and Applications)
Show Figures

Figure 1

18 pages, 4789 KiB  
Article
Mineralogical and Chemical Characterization of Greek Natural Zeolite-Rich Rocks and Their Oviposition Deterrent Effect on the Olive Fruit Fly Bactrocera oleae (Rossi) (Diptera: Tephritidae)
by Soultana Kyriaki Kovaiou, Anastasia Kokkari, Christina Mytiglaki, Nikos A. Kouloussis, Anestis Filippidis, Nikolaos Kantiranis and Dimitrios Koveos
Minerals 2025, 15(5), 458; https://doi.org/10.3390/min15050458 - 28 Apr 2025
Viewed by 477
Abstract
High quality natural zeolites may have insecticidal effects and could be used for pest control. We determined the mineralogical and chemical composition of four representative samples of zeolite-rich rocks (zeot1–zeot4) collected from north-eastern Greece and their oviposition deterrent effect for the olive fruit [...] Read more.
High quality natural zeolites may have insecticidal effects and could be used for pest control. We determined the mineralogical and chemical composition of four representative samples of zeolite-rich rocks (zeot1–zeot4) collected from north-eastern Greece and their oviposition deterrent effect for the olive fruit fly Bactrocera oleae (Rossi) (Diptera: Tephritidae). Samples zeot1–zeot4 contain 54–70 wt.% clinoptilolite (HEU-type zeolite) and are free of fibrous minerals. Regarding the chemical composition, samples zeot1–zeot4 contain SiO2 between 64.29 (zeot4) and 68.03 wt.% (zeot3). The values of the sorption ability ranged from 134 to 195 meq/100 g, and the specific surface area ranged from 6.5 to 8.4 cm2/g. In addition, the concentration of toxic heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, V, and Zn) is very low and within the acceptable limits for the food sector. When females of the olive fruit fly had access to olive fruits treated with aqueous suspensions of zeot1–zeot4, a significant oviposition deterrent effect was observed. The highest oviposition deterrent effect was observed after the application of zeot3 on the olive fruits, i.e., the mean number of eggs laid by 5 females on the treated and non-treated (control) olive fruits after 8 days was 43.1 and 172.3, respectively. Among the tested zeolites, zeot3 had the highest levels of HEU-type zeolite (clinoptilolite), SiO2, Si, and Ca and the strongest sorption ability and specific surface area. The zeolites oviposition deterrent effect found in our experiments can be attributed to the creation of a thin layer (hymen) of natural zeolite on the surface of the olive fruits which inhibits females landing and egg laying. The oviposition deterrent effect of high-quality Greek zeolites with unique characteristics, if verified with field experiments, could improve the effective control of the olive fruit fly. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
Show Figures

Figure 1

27 pages, 1358 KiB  
Review
Exploring the E-Waste Crisis: Strategies for Sustainable Recycling and Circular Economy Integration
by Shanti Quinto, Noah Law, Christopher Fletcher, Justin Le, Subin Antony Jose and Pradeep L. Menezes
Recycling 2025, 10(2), 72; https://doi.org/10.3390/recycling10020072 - 14 Apr 2025
Viewed by 5127
Abstract
Electronic waste (e-waste) is the fastest-growing waste stream on the planet, yet it remains critically under-addressed in global waste management and recycling efforts. The rapid pace of technological advancement has led to increased consumption of electronic devices, many of which are challenging and [...] Read more.
Electronic waste (e-waste) is the fastest-growing waste stream on the planet, yet it remains critically under-addressed in global waste management and recycling efforts. The rapid pace of technological advancement has led to increased consumption of electronic devices, many of which are challenging and costly to recycle efficiently. Insufficient infrastructure for e-waste recycling has resulted in large quantities being exported to countries with minimal waste management capabilities. In these regions, waste is often processed manually, exposing workers to hazardous materials and toxic elements commonly found in electronic components, leading to serious health risks. E-waste consists primarily of fibrous composite materials and plastics mixed with valuable metals and reusable components. While metals are often recovered, the remaining materials are typically discarded, contributing to significant environmental harm. Addressing e-waste challenges requires more than just technological solutions. In the United States, limited policies promote large-scale reuse and recycling practices, particularly among corporations. To build a sustainable approach, a combination of next-generation, cost-effective chemical recycling technologies and forward-thinking policy reforms will be essential for the effective management and reduction of e-waste. This paper explores the global generation and composition of e-waste, highlighting its environmental and health impacts due to improper handling and disposal. It reviews current and emerging recycling technologies while examining the challenges and opportunities in e-waste management. Finally, it discusses sustainable solutions and future directions for improving e-waste recycling through innovative technologies and policy reforms, concluding with recommendations for a circular economy approach. Full article
Show Figures

Figure 1

16 pages, 4966 KiB  
Article
Polyetheretherketone Double Functionalization with Bioactive Peptides Improves Human Osteoblast Response
by Leonardo Cassari, Cristian Balducci, Grazia M. L. Messina, Giovanna Iucci, Chiara Battocchio, Federica Bertelà, Giovanni Lucchetta, Trevor Coward, Lucy Di Silvio, Giovanni Marletta, Annj Zamuner, Paola Brun and Monica Dettin
Biomimetics 2024, 9(12), 767; https://doi.org/10.3390/biomimetics9120767 - 17 Dec 2024
Cited by 1 | Viewed by 1206
Abstract
In recent years, the demand for orthopedic implants has surged due to increased life expectancy, necessitating the need for materials that better mimic the biomechanical properties of human bone. Traditional metal implants, despite their mechanical superiority and biocompatibility, often face challenges such as [...] Read more.
In recent years, the demand for orthopedic implants has surged due to increased life expectancy, necessitating the need for materials that better mimic the biomechanical properties of human bone. Traditional metal implants, despite their mechanical superiority and biocompatibility, often face challenges such as mismatched elastic modulus and ion release, leading to complications and implant failures. Polyetheretherketone (PEEK), a semi-crystalline polymer with an aromatic backbone, presents a promising alternative due to its adjustable elastic modulus and compatibility with bone tissue. This study explores the functionalization of sandblasted 3D-printed PEEK disks with the bioactive peptides Aoa-GBMP1α and Aoa-EAK to enhance human osteoblast response. Aoa-GBMP1α reproduces 48–69 trait of Bone Morphogenetic Protein 2 (BMP-2), whereas Aoa-EAK is a self-assembling peptide mimicking extracellular matrix (ECM) fibrous structure. Superficial characterization included X-ray photoelectron spectroscopy (XPS), white light interferometer analysis, static water contact angle (S-WCA), and force spectroscopy (AFM-FS). Biological assays demonstrated a significant increase in human osteoblast (HOB) proliferation, calcium deposition, and expression of osteogenic genes (RUNX2, SPP1, and VTN) on functionalized PEEK compared to non-functionalized controls. The findings suggest that dual peptide-functionalized PEEK holds significant potential for advancing orthopedic implant technology. Full article
Show Figures

Graphical abstract

12 pages, 7537 KiB  
Article
Comparison of Biocompatibility of 3D-Printed Ceramic and Titanium in Micropig Ankle Hemiarthroplasty
by Si-Wook Lee, Donghyun Lee, Junsik Kim, Sanghyun An, Chul-Hyun Park, Jung-Min Lee, Chang-Jin Yon and Yu-Ran Heo
Biomedicines 2024, 12(12), 2696; https://doi.org/10.3390/biomedicines12122696 - 26 Nov 2024
Cited by 1 | Viewed by 1179
Abstract
Background: Ankle arthritis is a common degenerative disease that progresses as cartilage damage in the lower tibia and upper talus progresses, resulting in loss of joint function. In addition to typical arthritis, there is also structural bone loss in the talus due to [...] Read more.
Background: Ankle arthritis is a common degenerative disease that progresses as cartilage damage in the lower tibia and upper talus progresses, resulting in loss of joint function. In addition to typical arthritis, there is also structural bone loss in the talus due to diseases such as talar avascular necrosis. Total talus replacement surgery is the procedure of choice in end-stage ankle arthritis and consists of a tibial, talar component and an insert. However, in cases of severe cartilage and bone damage to the talar bone with less damage to the tibial cartilage, a talar component hemiarthroplasty may be considered. Although the application of total talus replacement surgery using ceramics has been studied, reports on the application of metal 3D printing technology are limited. We aimed to investigate the feasibility of partial talar components using ceramic and titanium 3D printing technology in terms of biocompatibility and stability through animal experiments. Methods: Preoperative 3D CT was acquired and converted to STL files to fabricate a partial talus component for ankle hemiarthroplasty using ceramic and titanium. Six minipigs with an average age of 17 months were implanted with three ceramic (C-group) and three titanium talar components (T-group) in the hind limb ankle joint. The surgery was performed under anesthesia in a sterile operating room and was performed by two experienced foot and ankle specialist orthopedic surgeons. Blood analysis and CT were performed before surgery and every month for 3 months after surgery to assess the extent of inflammatory response and physical stability, sacrifices were performed 3 months after surgery, and H&E staining and micro-CT analysis were performed to compare histological biocompatibility. A grading score was calculated to semi-quantitative assess and compare the two groups. Results: In the postsurgical evaluation, blood analysis revealed that both groups had increased white blood cell counts on the postoperative day after surgery. The white blood cell count increased more in the titanium group (1.85-fold) than in the ceramic group (1.45-fold). After 3 months, all values normalized. During the study, CT analysis confirmed that all artificial samples were displaced from their initial positions. In micro-CT analysis, the adhesive tissue score of the ceramic artificial sample was better than that of the titanium sample (average threshold = 3027.18 ± 405.92). In histologic and grading scores for the inflammatory reactions, the average inflammation indices of the ceramic and titanium groups were 2.0 and 1.21, respectively. Also, the average grade score confirmed based on the results of fibrous tissue proliferation and new blood vessels was 18.4 in the ceramic application group and 12.3 in the titanium application group. Conclusions: In conclusion, both titanium and ceramics have excellent biocompatibility for artificial joints, and ceramic materials can be used as novel artificial joints. Further research on the strength and availability of these ceramics is required. Full article
(This article belongs to the Special Issue Osteoarthritis: Molecular Pathways and Novel Therapeutic Strategies)
Show Figures

Figure 1

13 pages, 14616 KiB  
Article
Impedance Spectroscopy Study of Charge Transfer in the Bulk and Across the Interface in Networked SnO2/Ga2O3 Core–Shell Nanobelts in Ambient Air
by Maciej Krawczyk, Ryszard Korbutowicz and Patrycja Suchorska-Woźniak
Sensors 2024, 24(19), 6173; https://doi.org/10.3390/s24196173 - 24 Sep 2024
Viewed by 1137
Abstract
Metal oxide core–shell fibrous nanostructures are promising gas-sensitive materials for the detection of a wide variety of both reducing and oxidizing gases. In these structures, two dissimilar materials with different work functions are brought into contact to form a coaxial heterojunction. The influence [...] Read more.
Metal oxide core–shell fibrous nanostructures are promising gas-sensitive materials for the detection of a wide variety of both reducing and oxidizing gases. In these structures, two dissimilar materials with different work functions are brought into contact to form a coaxial heterojunction. The influence of the shell material on the transportation of the electric charge carriers along these structures is still not very well understood. This is due to homo-, hetero- and metal/semiconductor junctions, which make it difficult to investigate the electric charge transfer using direct current methods. However, in order to improve the gas-sensing properties of these complex structures, it is necessary to first establish a good understanding of the electric charge transfer in ambient air. In this article, we present an impedance spectroscopy study of networked SnO2/Ga2O3 core–shell nanobelts in ambient air. Tin dioxide nanobelts were grown directly on interdigitated gold electrodes, using the thermal sublimation method, via the vapor–liquid–solid (VLS) mechanism. Two forms of a gallium oxide shell of varying thickness were prepared via halide vapor-phase epitaxy (HVPE), and the impedance spectra were measured at 189–768 °C. The bulk resistance of the core–shell nanobelts was found to be reduced due to the formation of an electron accumulation layer in the SnO2 core. At temperatures above 530 °C, the thermal reduction of SnO2 and the associated decrease in its work function caused electrons to flow from the accumulation layer into the Ga2O3 shell, which resulted in an increase in bulk resistance. The junction resistance of said core–shell nanostructures was comparable to that of SnO2 nanobelts, as both structures are likely connected through existing SnO2/SnO2 homojunctions comprising thin amorphous layers. Full article
Show Figures

Figure 1

16 pages, 4934 KiB  
Article
Modified Cellulose-Based Waste for Enhanced Adsorption of Selected Heavy Metals from Wastewater
by Katarina Trivunac, Snežana Mihajlović, Marija Vukčević, Marina Maletić, Biljana Pejić, Ana Kalijadis and Aleksandra Perić Grujić
Polymers 2024, 16(18), 2610; https://doi.org/10.3390/polym16182610 - 14 Sep 2024
Cited by 4 | Viewed by 1950
Abstract
Due to industrial growth and its impact on the environment, the increasing amount of industrial waste requires a comprehensive approach aligned with the principles of sustainable development. The main goals are not only to preserve natural resources but also to encourage innovation in [...] Read more.
Due to industrial growth and its impact on the environment, the increasing amount of industrial waste requires a comprehensive approach aligned with the principles of sustainable development. The main goals are not only to preserve natural resources but also to encourage innovation in the reuse of waste materials. In an attempt to reduce the problems regarding waste disposal and wastewater treatment in the textile industry, fibrous textile waste was used as a starting material to obtain carbon adsorbents for the removal of pollutants from wastewater. Waste cotton and mixed yarns, mainly consisting of polysaccharide cellulose, were hydrothermally carbonized and activated with KOH to convert them into efficient carbon adsorbents for heavy metal removal from water. Characterization of carbonized material showed that after activation, an increase in specific surface area (up to 872 m2/g) and content of surface oxygen groups (6.04 mmol/g) leads to a higher affinity towards heavy metal ions, especially lead ions, and high adsorption capacity of 19.98 mg/g obtained for activated cotton yarns. The results of this research represent a contribution to the reduction of waste materials by modifying them into adsorbents, while the regeneration of adsorbents is an example of the practical application of polysaccharide-based materials in the purification of wastewater containing various heavy metal ions. Full article
(This article belongs to the Special Issue Polysaccharide-Based Materials: Developments and Properties)
Show Figures

Figure 1

14 pages, 19586 KiB  
Article
Advanced Electrospun Composites Based on Polycaprolactone Fibers Loaded with Micronized Tungsten Powders for Radiation Shielding
by Chiara Giuliani, Ilaria De Stefano, Mariateresa Mancuso, Noemi Fiaschini, Luis Alexander Hein, Daniele Mirabile Gattia, Elisa Scatena, Eleonora Zenobi, Costantino Del Gaudio, Federica Galante, Giuseppe Felici and Antonio Rinaldi
Polymers 2024, 16(18), 2590; https://doi.org/10.3390/polym16182590 - 13 Sep 2024
Cited by 4 | Viewed by 1707
Abstract
Exposure to high levels of radiation can cause acute, long-term health effects, such as acute radiation syndrome, cancer, and cardiovascular disease. This is an important occupational hazard in different fields, such as the aerospace and healthcare industry, as well as a crucial burden [...] Read more.
Exposure to high levels of radiation can cause acute, long-term health effects, such as acute radiation syndrome, cancer, and cardiovascular disease. This is an important occupational hazard in different fields, such as the aerospace and healthcare industry, as well as a crucial burden to overcome to boost space applications and exploration. Protective bulky equipment made of heavy metals is not suitable for many advanced purporses, such as mobile devices, wearable shields, and manned spacecrafts. In the latter case, the in-space manufacturing of protective shields is highly desirable and remains an unmet need. Composites made of polymers and high atomic number fillers are potential means for radiation protection due to their low weight, good flexibility, and good processability. In the present work, we developed electrospun composites based on polycaprolactone (polymer matrix) and tungsten powder for application as shielding materials. Electrospinning is a versatile technology that is easily scalable at an industrial level and allows obtaining very lightweight, flexible sheet materials for wearables. By controlling tungsten powder size, we engineered homogeneous, stable and processable suspensions to fabricate radiation composite shielding sheets. The shielding capability was assessed by an in vivo model on prototype composite sheets containing 80 w% of W filler in a polycaprolactone (PCL) fibrous matrix by means of irradiation tests (X-rays) on mice. The obtained results are promising; as expected, the shielding effectivity of the developed composite material increases with the thickness/number of stacked layers. It is worth noting that a thin barrier consisting of 24 layers of the innovative shielding material reduces the extent of apoptosis by 1.5 times compared to the non-shielded mice. Full article
(This article belongs to the Special Issue Advances in Functional Polymers and Composites)
Show Figures

Figure 1

Back to TopTop