Search Results (165)

This study introduces a MATrix LABoratory (MATLAB, version R2024b, update 1 (24.2.0.2740171))-based automated system for the detection and measurement of indication areas in coated surfaces, enhancing the accuracy and efficiency of quality control processes in metal, polymeric and thermoplastic coatings. The developed code identifies various indication characteristics in the image and provides numerical results, assesses the size and quantity of indications and evaluates conformity to ISO standards. A comprehensive testing method, involving non-destructive penetrant testing (PT) and radiographic testing (RT), allowed for an in-depth analysis of surface and internal porosity across different coating methods, including aluminum-, copper-, polytetrafluoroethylene (PTFE)- and polyether ether ketone (PEEK)-based materials. Initial findings had a major impact on indicating a non-homogeneous surface of obtained coatings, manufactured using different technologies and materials. Whereas researchers using non-destructive testing (NDT) methods typically rely on visual inspection and manual counting, the system under study automates this process. Each sample image is loaded into MATLAB and analyzed using the Image Processing Tool, Computer Vision Toolbox, Statistics and Machine Learning Toolbox. The custom code performs essential tasks such as image conversion, filtering, boundary detection, layering operations and calculations. These processes are integral to rendering images with developed indications according to NDT method requirements, providing a detailed visual and numerical representation of the analysis. RT also validated the observations made through surface indication detection, revealing either the absence of hidden defects or, conversely, internal porosity correlating with surface conditions. Matrix and graphical representations were used to facilitate the comparison of test results, highlighting more advanced methods and materials as the superior choice for achieving optimal mechanical and structural integrity. This research contributes to addressing challenges in surface quality assurance, advancing digital transformation in inspection processes and exploring more advanced alternatives to traditional coating technologies and materials. Full article

Oral mucositis (OM) is a severe inflammatory condition of the oral mucosa that is commonly associated with cancer therapies. Traditional treatments typically have limited efficacy and significant side effects, necessitating alternative approaches. Nanobased drug delivery systems (DDSs) present promising solutions, enhancing therapeutic outcomes while minimizing side effects. This review aims to evaluate the use of nanobased DDSs to treat OM. To reach these aims, an extensive literature review was conducted using the following databases: BVS, PubMed, Scopus, and Web of Science. The search strategy included the keywords “microparticles,” “nanoparticles,” “drug delivery system,” “oral mucositis,” “therapy,” and “treatment,” combined with the Boolean operators “AND” and “OR.” After applying filters for language, relevance, full-text availability, exclusion of review articles, and removal of duplicates, a total of 32 articles were selected for analysis. Of the 32 studies included in this review, 25 employed polymeric micro- or nanosystems for the treatment of OM. Regarding the stage of investigation, 10 studies were conducted in vitro, 16 were conducted in vivo, and 6 corresponded to clinical trials. Compared with conventional drug delivery approaches, most of these studies reported improved therapeutic outcomes. These findings highlight the potential of nanosystems as innovative strategies for enhancing OM treatment. Nonetheless, challenges in large-scale manufacturing, including reproducibility and safety, and the limited number of clinical trials warrant careful consideration. Future research with larger clinical trials is essential to validate these findings and effectively guide clinical practice. Full article

Extracellular polymeric substances (EPS) are multifunctional biopolymers that have significant biotechnological potential. In this study, forty-seven strains of Rhodococcus actinomycetes were screened for EPS production and the content of its main components: carbohydrates, lipids, proteins, and nucleic acids. The Rhodococcus strains produced lipid-rich EPS (15.6 mg·L⁻¹ to 71.7 mg·L⁻¹) with carbohydrate concentrations varying from 0.6 mg·L⁻¹ to 58.2 mg·L⁻¹ and low amounts of proteins and nucleic acids. Biofilms of R. ruber IEGM 231 were grown on nitrocellulose filters in the presence of n-hexane, n-hexadecane, or diesel fuel. The distribution of β-polysaccharides, glycoconjugates, and proteins between cells and the extracellular matrix was examined using fluorescence microscopy. The observed release of β-polysaccharides into the biofilm matrix in the presence of n-hexane and diesel fuel was regarded as an adaptation to the assimilation of these toxic hydrocarbons by Rhodococcus cells. Atomic force microscopy of the dried EPS film revealed adhesion forces between 1.0 and 20.0 nN, while some sites were highly adhesive (F_a ≥ 20.0 nN). EPS biosynthetic genes were identified, with two glycosyltransferases correlating with an increase in carbohydrate production. The production of EPS by Rhodococcus cells exhibited strain-specific rather than species-specific patterns, reflecting a high genetic diversity of these bacteria. Full article

Tunable photonic devices are increasingly pivotal in modern optical systems, enabling the dynamic control over light propagation, modulation, and filtering. This review systematically explores two prominent classes of materials, thermo-optic and electro-optic, for their roles in such tunable devices. Thermo-optic materials utilize refractive index changes induced by temperature variations, offering simple implementation and broad material compatibility, although often at the cost of slower response times. In contrast, electro-optic materials, particularly those exhibiting the Pockels and Kerr effects, enable rapid and precise refractive index modulation under electric fields, making them suitable for high-speed applications. The paper discusses the underlying physical mechanisms, material properties, and typical figures of merit for each category, alongside recent advancements in organic, polymeric, and inorganic systems. Furthermore, integrated photonic platforms and emerging hybrid material systems are highlighted for their potential to enhance performance and scalability. By evaluating the tradeoffs in speed, power consumption, and integration complexity, this review identifies key trends and future directions for deploying thermo-optic and electro-optic materials in the next generation tunable photonic devices. Full article

Oil-contaminated wastewater represents a major source of industrial pollution, posing significant risks to both the environment and human health. Traditional oil–water separation methods, including gravity separation, centrifugal separation, and air flotation, are limited by their processing efficiency and scope of applicability. In recent years, innovative oil–water separation technologies have gained considerable attention, particularly those utilizing adsorption, filtration, and membrane separation, owing to their high efficiency and environmental sustainability. Separation materials derived from biomass substrates—such as cellulose, chitosan, and lignin—along with metal-based membranes and polymeric filters, have shown remarkable performance. This is especially true for superhydrophobic/superoleophilic and stimuli-responsive materials, which excel in separating complex emulsified oil systems. This paper provides a comprehensive overview of the strengths and limitations of current separation technologies and explores the potential applications of multifunctional materials in treating oil-contaminated wastewater, offering both theoretical insights and practical guidance for advancing green, efficient oil–water separation solutions. Full article

Accelerated urbanization and industrialization have significantly heightened water contamination risks, posing severe threats to public health and ecological balance. Polymeric membranes stand at the forefront of addressing this challenge, revolutionizing water and wastewater treatment. These membranes adeptly remove a broad spectrum of contaminants, including organic compounds and heavy metals, thereby playing a crucial role in mitigating environmental pollution. This research delves into the sophisticated mechanisms of polymeric membranes in filtering out pollutants, with a spotlight on the enhancements brought about by nanotechnology. This includes a detailed examination of their inherent antibacterial properties, showcasing their innovative design and potential for extensive application. The study further investigates advanced techniques like electrochemical processes and membrane distillation, particularly focusing on desalination. These methods are central to the advancement of water purification, emphasizing efficiency and environmental sustainability. However, challenges such as membrane fouling pose significant hurdles, necessitating ongoing research into surface modifications and antifouling strategies. This paper offers a comparative analysis of various membrane technologies, highlighting their manufacturing complexities and efficiency benchmarks. In summation, the paper underscores the importance of continuous innovation in membrane technology, aiming to develop sustainable and effective water treatment solutions. By bridging the gap between basic science and technological advancements, this review aims to guide practitioners and researchers towards a future where clean water is universally accessible, ensuring the preservation of our ecosystems. Full article

The presence of dissolved sulfides in feed seawater causes severe elemental sulfur fouling in the reverse osmosis (RO) process. However, current pretreatment methods suffer from large footprint, high energy consumption, and limitations in effluent quality. In this study, adsorption and microfiltration are merged into a single process for the pretreatment of sulfide-containing seawater. Powdered activated carbon (PAC) was selected for its superior adsorption capacity (14.6-fold) and faster kinetics (3.9-fold) for sulfide removal compared to granular activated carbon. The high surface area and multiple pore structures of PAC facilitate surface and intraparticle diffusion, as well as anion–π conjugation likely occur between PAC and sulfide. Polypropylene microporous membranes, capable of tolerating high PAC dosages, were used in the hybrid process. Long-term pilot tests demonstrated that the effluent (turbidity < 1 NTU and SDI₁₅ ≈ 2.50) met the quality requirements for RO unit feedwater, achieving 100% sulfide removal efficiency over 101 h, with no risk of PAC leakage throughout the entire operation process. The formation of a loose, porous PAC cake layer alleviates membrane fouling and enhances the retention and adsorption of metal(loid)s and sulfide. Moreover, the low permeate flux of the polymeric membranes significantly mitigates filter cake formation. The hybrid system adapts to variations in feedwater quality, making it highly suitable for desalination plants with limited space and budget. These findings offer valuable insights and practical guidance for advancing seawater desalination pretreatment. Full article

A multifunctional paper-based composite of paper coated with a polypyrrole@lignocellulosic slurry (PPy@LS) and carboxymethyl cellulose (CMC) was developed. PPy@LS was prepared via the polymerization of pyrrole onto a lignocellulosic slurry derived from hemp stalks prepared using deep eutectic solvents. The PPy@LS slurry was mixed with the required amount of CMC and vacuum-filtered onto filter paper to fabricate the composite (PPy@LS/CMC). The resulting composite paper exhibited excellent multifunctional properties, including electrical conductivity, photothermal conversion, and antibacterial properties. These properties are stable against external environments, such as water and abrasion, due to the addition of CMC. The electrical conductivity of PPy@LS/CMC varied in the dry (1.6 × 10⁻⁴ S/cm) and wet (4.8 × 10⁻⁶ S/cm) states, suggesting its potential application in humidity sensing. Notably, the PPy@LS/CMC paper achieved significant photothermal activity under light irradiation, as demonstrated by the measured surface temperature exceeding 80 °C in 10 min. Moreover, the composite paper exhibited > 99.9% antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The combination of the inherent characteristics of filter paper along with the photothermal property of PPy enable the PPy@LS/CMC composite appropriate for solar interfacial evaporation application. These multifunctional composite papers with innovative combinations of properties have great potential for applications in smart packaging, humidity sensing, biomedicine, and solar-driven water purifications. Full article

To enhance oil and gas recovery, a novel hydrophobic terpolymer was synthesized via free radical polymerization. The terpolymer consists of acrylamide, acrylic acid, and hydrophobic monomers, and is used as a hydraulic fracturing fluid thickener for freshwater environments. Hydrophobic groups were introduced into terpolymer to improve its tackiness and temperature resistance. The conformation and key parameters of hydrophobic monomers at different temperatures were investigated through a combination of experiments and molecular dynamics simulations. These methods were employed to elucidate the mechanism behind its high-temperature resistance. The experiment results show that, at concentrations between 0.2% and 0.4%, significant intermolecular aggregation occurs, leading to a substantial increase in solution viscosity. Configuring the base fluid of synthetic polymer fracturing fluid with 1% doping, the apparent viscosities of the base fluid were 129.23 mPa·s and 133.11 mPa·s, respectively. The viscosity increase rate was 97%. The base fluid was crosslinked with 1.5% organozirconium crosslinker to form a gel. The controlled loss coefficient and loss velocity of the filter cake were C₃ = 0.84 × 10⁻³ m/min^1/2 and v_c = 1.40 × 10⁻⁴ m/min at 90 °C, meeting the technical requirements for water-based fracturing fluid. Molecular dynamics simulations revealed that the radius of gyration of the hydrophobically linked polymer chain segments decreases as the temperature increases. This is due to the increased thermal motion of the polymer chain segments, resulting in less stretching and intertwining of the chains. As a result, the polymer chains move more freely, which decreases the viscosity of the solution. In conclusion, the proposed fracturing fluid thickener system demonstrates excellent overall performance and shows significant potential for application in oil and gas recovery. Full article

The rapid developments in conductive polymers with flexible electronics over the past years have generated noteworthy attention among researchers and entrepreneurs. Conductive polymers have the distinctive capacity to conduct electricity while still maintaining the lightweight, flexible, and versatile characteristics of polymers. They are crucial for the creation of flexible electronics or gadgets that can stretch, bend, and adapt to different surfaces have sparked momentous interest in electronics, energy storage, sensors, smart textiles, and biomedical applications. This review article offers a comprehensive overview of recent advancements in conductive polymers over the last 15 years, including a bibliometric analysis. The properties of conductive polymers are summarized. Additionally, the fabrication processes of conductive polymer-based materials are discussed, including vacuum filtering, hydrothermal synthesis, spray coating, electrospinning, in situ polymerization, and electrochemical polymerization. The techniques have been presented along with their advantages and limitations. The multifunctional applications of conductive polymers are also discussed, including their roles in energy storage and conversion (e.g., supercapacitors, lithium-ion batteries (LIBs), and sodium-ion batteries (SIBs)), as well as in organic light-emitting diodes (OLEDs), organic solar cells (OSCs), conductive textiles, healthcare monitoring, and sensors. Future scope and associated challenges have also been mentioned for further development in this field. Full article

The idea supporting the investigation of the current manuscript was to develop customized filters for air conditioners with different pore percentages and geometry with the additional advantage of presenting antibacterial performance. This property was expected due to the reinforcement of Cu nanoparticles in the polymeric matrix of poly(lactic acid) (PLA) and polyurethane (TPU). The filaments were characterized by their chemical composition, thermal and mechanical properties, and antibacterial behavior before and after processing by fused filament fabrication. An X-ray photoelectron spectroscopy showed that the nanocomposite filaments presented Cu particles at their surface in different valence states, including Cu⁰, Cu⁺, and Cu²⁺. After processing, the metallic particles are almost absent from the surface, a result confirmed by micro-computer tomography (μ-CT) characterization. Antibacterial tests were made using solid-state diffusion tests to mimic the dry environment in air conditioner filters. The tests with the nanocomposite filaments showed that bacteria proliferation was hindered. However, no antibacterial performance could be observed after processing due to the absence of the metallic element on the surface. Nevertheless, antimicrobial performance was observed when evaluated in liquid tests. Therefore, the obtained results provide valuable indications for developing new nanocomposites that must maintain their antimicrobial activity after being processed and tested in the dry conditions of solid-state diffusion. Full article

Face masks are essential pieces of personal protective equipment for preventing inhalation of airborne pathogens and aerosols. Various face masks are used to prevent the spread of virus contamination, including blue surgical and N95 filtering masks intended for single use. Traditional face masks with self-sanitisation features have an average filtration efficiency of 50% against airborne viruses. Incorporating nanomaterials in face masks can enhance their filtration efficiency; however, using nanomaterials combined with thermal heaters can offer up to 99% efficiency. Bacterial contamination is reduced through a self-sterilisation method that employs nanomaterials with antimicrobial properties and thermoregulation as a sanitisation process. By combining functional nanomaterials with conductive and functional polymeric materials, smart textiles can sense and act on airborne viruses. This research evaluates the evidence behind the effectiveness of nanomaterials and thermoregulation-based smart textiles used in self-sanitising face masks, as well as their potential, as they overcome the shortcomings of conventional face masks. It also highlights the challenges associated with embedding textiles within nanomaterials. Finally, it makes recommendations regarding safety, reusability, and enhancing the protection of the wearer from the environment and underscores the benefits of reusable masks, which would otherwise pollute the environment. These self-sanitising face masks are environmentally sustainable and ideal for healthcare, the food industry, packaging, and manufacturing. Full article

Electro-conductive membranes coupled with a low-voltage electric field can enhance pollutant removal and mitigate membrane fouling, demonstrating significant potential for electrified wastewater treatment. However, efficient fabrication of conductive membranes poses challenges. An in situ oxidative polymerization approach was applied to prepare PVDF-based conductive membranes (PVDF-CMs) and response surface methodology (RSM) was adopted to optimize modification conditions enhancing membrane performance. The anti-fouling property of the conductive membranes was analyzed using model pollutants. The results indicate that when the concentrations of the pyrrole, BVIMBF₄, and FeCl₃·6H₂O are 0.9 mol/L, 4.8 mmol, and 0.8 mol/L, respectively, the electrical resistance of the PVDF-CM is 93 Ω/sq with the water contact angle of 31°, demonstrating good conductivity and hydrophilicity. Batch membrane filtration experiments coupled with negative voltage indicated that when an external voltage of 2.0 V is applied, membrane fouling rates for the conductive membrane filtering BSA and SA solutions are reduced by 17.7% and 17.2%, respectively, compared to the control (0 V). When an external voltage of 0.5 V is applied, the membrane fouling rate for the conductive membrane filtering HA solution is reduced by 72.6%. This study provides a valuable reference for the efficient preparation of conductive membranes for cost-effective wastewater treatment. Full article

Intraocular lenses (IOLs) play a pivotal role in restoring vision following cataract surgery. The evolution of polymeric biomaterials has been central to addressing challenges such as biocompatibility, optical clarity, mechanical stability, and resistance to opacification. This review explores essential requirements for IOL biomaterials, emphasizing their ability to mitigate complications like posterior capsule opacification (PCO) and dysphotopsias while maintaining long-term durability and visual quality. Traditional polymeric materials, including polymethyl methacrylate (PMMA), silicone, and acrylic polymers, are critically analyzed alongside cutting-edge innovations such as hydrogels, shape memory polymers, and light-adjustable lenses (LALs). Advances in polymer engineering have enabled these materials to achieve enhanced flexibility, transparency, and biocompatibility, driving their adoption in modern IOL design. Functionalization strategies, including surface modifications and drug-eluting designs, highlight advancements in preventing inflammation, infection, and other complications. The incorporation of UV-blocking and blue-light-filtering agents is also examined for their potential in reducing retinal damage. Furthermore, emerging technologies like nanotechnology and smart polymer-based biomaterials offer promising avenues for personalized, biocompatible IOLs with enhanced performance. Clinical outcomes, including visual acuity, contrast sensitivity, and patient satisfaction, are evaluated to provide an understanding of the current advancements and limitations in IOL development. We also discuss the current challenges and future directions, underscoring the need for cost-effective, innovative polymer-based solutions to optimize surgical outcomes and improve patients’ quality of life. Full article

Damage in composite laminates evolves through complex interactions of different failure modes, influenced by load type, environment, and initial damage, such as from transverse impact. This paper investigates damage growth in cross-ply polymeric matrix laminates under tensile load, focusing on three primary failure modes: transverse matrix cracks, delaminations, and fiber breaks in the primary loadbearing 0-degree laminae. Acoustic emission (AE) techniques can monitor and quantify damage in real time, provided the signals from these failure modes can be distinguished. However, directly observing crack growth and related AE signals is challenging, making numerical simulations a useful alternative. AE signals generated by the three failure modes were simulated using modified step impulses of appropriate durations based on incremental crack growth. Linear elastic finite element analysis (FEA) was applied to model the AE signal propagating as Lamb waves. Experimental attenuation data were used to modify the simulated AE waveforms by designing arbitrary magnitude response filters. The propagating waves can be detected as surface displacements or surface strains depending upon the type of sensor employed. This paper presents the signals corresponding to surface strains measured by surface-bonded piezoelectric sensors. Fiber break events showed higher-order Lamb wave modes with frequencies over 2 MHz, while matrix cracks primarily exhibited the fundamental S₀ and A₀ modes with frequencies ranging up to 650 kHz, with delaminations having a dominant A₀ mode and frequency content less than 250 kHz. The amplitude and frequency content of signals from these failure modes are seen to change significantly with source–sensor distance, hence requiring an array of dense sensors to acquire the signals effectively. Furthermore, the reasonable correlation between the simulated waveforms and experimental acoustic emission signals obtained during quasi-static tensile test highlights the effectiveness of FEA in accurately modeling these failure modes in composite materials. Full article