Search Results (425)

This paper presents three realizations of a complete set with a horn antenna and a focusing Gradient Index (GRIN) lens in X-band. The set was specifically designed for advancing additive manufacturing (AM) of polymers with different materials and techniques. The set has three constituent parts: a horn antenna, a support, and a lens. The horn antenna is the active element and must be electrically conductive; it was manufactured with Rigid10K acrylic resin and subsequently metallized using an electroless process. The support needed to be light, robust, and electrically transparent, so that Polyamide 11 (PA11) was used. The lens realization was intended for a dielectric material whose permittivity varies with its density. Therefore, the dielectric permittivity and loss tangent of different polymeric materials used in AM at 2.45, 6.25, and 24.5 GHz were measured. In addition, stochastic and gyroid mesh structures have been studied. These structures allow for printing a volume that presents porosity, enabling control over material density. Measuring the dielectric characteristics of each material with each density enables the establishment of graphs that relate them. The sets were then manufactured, and their frequency response and radiation diagram were measured, showing excellent results when compared with the literature. Full article

Organic solvent nanofiltration (OSN) has emerged as a transformative platform for molecular separation, offering energy-efficient and high-performance alternatives to conventional separation techniques across the food, petrochemical, and pharmaceutical industries. At the core of this advancement lie polyamide membranes, whose exceptional chemical resilience, tunable architecture, and compatibility with a wide range of organic solvents have positioned them as the material of choice for industrial OSN applications. Recent progress encompassing nanostructured additives, controlled interfacial polymerization, and advanced crosslinking strategies has led to significant improvements in membrane selectivity, permeability, and operational stability. As OSN continues to gain traction in sustainable chemical processing, enabling reductions in both energy consumption and environmental waste, ongoing challenges such as membrane fouling, structural degradation, and limited solvent resistance remain critical barriers to broader adoption. This review critically examines the role of polyamide membranes in OSN, emphasizing their structural versatility, physicochemical attributes, and capacity to meet the growing demands of sustainable separation technologies. Full article

Background/Objectives: Effective and targeted delivery of doxorubicin (DOX) remains a significant challenge due to its dose-limiting cardiotoxicity and systemic side effects. Liposomal formulations like Doxil^® have improved tumor targeting and reduced toxicity, but issues such as limited stability, poor release control, and insufficient site-specific delivery persist. As a result, there is a growing interest in advanced drug delivery systems, particularly polymeric nanocarriers, which offer biocompatibility, tunable properties, and ease of fabrication. Methods: This review is organized into two key sections. The first section provides a comprehensive overview of DOX, including its mechanism of action, clinical challenges, and the limitations of current chemotherapy approaches. The second section highlights recent advances in polymeric nanocarriers for DOX delivery, focusing on polymeric micelles as well as other promising systems like hydrogels, dendrimers, polymersomes, and polymer–drug conjugates. Results: Initial discussions explore current strategies enhancing DOX’s clinical translation, including methods to address cardiotoxicity and multidrug resistance. The latter part presents recent studies that report improved drug loading efficiency in polymeric nanocarriers through techniques such as core/shell modifications, enhanced hydrophobic interactions, and polymer–drug conjugation. Conclusions: Despite notable progress in polymeric nanocarrier-based DOX delivery, challenges like limited circulation time, immunogenicity, and manufacturing scalability continue to hinder clinical application. Continued innovation in this field is crucial for the development of safe, effective, and clinically translatable polymeric nanocarriers for cancer therapy. Full article

Thermosensitive Poly(N-isopropylacrylamide) (PNIPAm) films were synthesized via atmospheric pressure dielectric barrier discharge (APDBD) plasma polymerization. In order to control the thickness of the films, a spin coating technique was used during the deposition of N-isopropylacrylamide (NIPAM) monomer solution onto several glass substrates. We used the coefficient of determination (R-square value) in linear regression to investigate the significance and optimize spin coating parameters during the fabrication of NIPAM coatings before exposure to APDBD plasma to ensure reproducible and uniform film properties. The spin coating parameters investigated in this study include spin speed, spin time, and NIPAM solution concentration with R-square values of 0.978, 0.946, and 0.944, respectively. Also, as a result of the thermosensitive nature of NIPAM, the spin coating operating conditions of temperature and humidity were maintained at 39.0 °C and 15%, respectively. During the APDBD plasma polymerization, argon was used as the discharge gas, and the distance between the two parallel electrodes and plasma frequency were maintained at 5.0 mm and 17 kHz, respectively. The plasma exposure time required for polymerization of PNIPAm coatings was optimized to 60 s. Also, the results showed that a coating with minimal defects had an optimal thickness of 5.18 μm, fabricated under conditions of 90 wt.% NIPAM concentration, spin speed of 4000 rpm, and total spin time of 7 s. Full article

The design of suitable chemosensors for environmental pollutants and toxins detection at trace levels remains a critical area of research. Among various chemosensors, Zn(II) coordination polymers have garnered special interest as fluorescent probes for environmental applications. In this article, we report the synthesis of a nitrogen-rich luminescent Zn(II) coordination polymer, TDPAT-Zn-CP, designed for differential fluorescent sensing of antibiotics in an aqueous medium. TDPAT-Zn-CP was synthesized using a star-shaped 2,4,6-tris(di-2-pyridylamino)-1,3,5-triazine (TDPAT) fluorophore, a promising blue-emitting compound. The morphological and structural properties of TDPAT-Zn-CP were thoroughly analyzed using conventional spectroscopic and analytical techniques. The fluorescence titration studies in aqueous medium demonstrated that TDPAT-Zn-CP exhibits remarkable selectivity, sensitivity, and differential fluorescence sensing responses towards various antibiotics. Among the antibiotics tested, TDPAT-Zn-CP displayed a significant fluorescence quenching and high selectivity for sulfamethazine (SMZ), with a Stern–Volmer quenching constant of K_SV = 1.68 × 10⁴ M⁻¹ and an impressive sensitivity of 4.95 ppb. These results highlight the potential of TDPAT-Zn-CP as a practically useful, highly effective polymeric sensor for the differential fluorescence-based detection of antibiotics in water, offering a promising approach for environmental monitoring and contamination control. Full article

Debonding, especially in plastic materials, refers to the separation occurring at the interface within a bonded structure composed of two or more polymeric layers. Due to the great heterogeneity of materials and layering configurations, highly specialized expertise is often required to detect the presence and extent of such defects. This study presents a novel approach that leverages transfer learning techniques to improve the detection of debonding defects across different surface types using PICUS, an acoustic diagnostic device developed at Roma Tre University for the assessment of defects in heritage wall paintings. Our method leverages a pre-trained deep learning model, adapting it to new material conditions. We designed a planar test object embedded with controlled subsurface cavities to simulate the presence of defects of adhesion and air among the layers. This was rigorously evaluated using non-destructive testing using PICUS, augmented by artificial intelligence (AI). A convolutional neural network (CNN), initially trained on this mock-up, was then fine-tuned via transfer learning on a second test object with distinct geometry and material characteristics. This strategic adaptation to varying physical and acoustic properties led to a significant improvement in classification precision of defect class, from 88% to 95%, demonstrating the effectiveness of transfer learning for robust cross-domain defect detection in challenging diagnostic applications. Full article

The electrospinning technique can produce multifunctional polymeric devices by forming solid fibers from polymer solutions under a high-voltage electric field. Variations such as concentric needles yield core/shell fibers. This study evaluates the effects of applied voltage (12.5–20 kV) and tip-to-collector distance (12.5–20 cm) on the morphology and thermochemical behavior of PLGA/PVA fibers made by coaxial electrospinning compared with casting-produced membranes and monolithic fibers. Optimal coaxial fibers (597 ± 90 nm diameter) were produced at 15 cm/12.5 kV, exhibiting a well-defined core/shell structure (PVA core: ~100 nm; PLGA shell: ~50 nm) confirmed by laser scanning confocal (core solution labeled with fluorescein) and TEM. FTIR and TGA demonstrated nearly complete solvent removal in electrospun samples versus ~10% solvent retention in cast films. XRD analysis indicated that cast films (PLGAff) exhibited minimal crystallinity (Xc ≈ 0.1%), while electrospun PLGA (PLGAe) showed cold crystallization and higher crystallinity (Tcc ≈ 90.6 °C; Xc ≈ 2.45%). DSC detected two different Tg (≈43.2 °C and 52.8 °C) in the coaxial fibers, confirming distinct polymer domains with interfacial interactions. These results establish precise processing/structure relationships for defect-free coaxial fibers and provide fundamental design principles for hybrid systems in controlled drug delivery and tissue engineering applications. Full article

In this work, the metal salts were introduced into the resin-solvent gel system to leverage their ortho-substitution effect, thereby accelerating the polymerization-induced phase separation process. Subsequent in-situ carbonization resulted in the preparation of porous carbon materials with three-dimensional interconnected pores. By precisely tuning the parameters of the resin-solvent-metal ion system, control over the pore structure of the porous carbon was achieved, with a porosity range of 16.5% to 66.5% and a pore diameter range of 8 to 248 nm. The addition of metallic salts can simply and effectively increase the pore structure after carbonization, making the infiltration of molten silicon easier. This is beneficial to the joining process of silicon carbide ceramics. Based on these findings, a high-reliability joining technique for large-sized (135 mm × 205 mm) silicon carbide ceramics was developed. The resulting interlayer was dense and defect-free, exhibiting a joining strength of 309 ± 33 MPa and a Weibull modulus of 10.67. These results highlight the critical role of structured porous media in advancing the field of large-sized ceramic joining. Full article

Light-actuated microbots have been studied as a viable tool for interacting with micro/nano environments. Considering their applicability to a wide range of biomedical applications, novel designs, fabrication techniques, and control methodologies are being developed. Especially, micro/nanoscale three-dimensional fabrication techniques have opened many possibilities for developing microbots with complex geometries using resins as materials. Here, we developed microbots that can be actuated with tightly focused laser beams to be used in targeted drug delivery, cell poking, and cell characterization studies. These microbots were fabricated in batches using two-photon polymerization (TPP). Each microbot utilizes a deposited metal layer inside its body to manipulate convective microfluidic flows. Additionally, micro-sized end effectors allow them to make measurable physical contact with biological objects. Their expected performance was evaluated using numerical simulations with the use of multiphysics software. Furthermore, laser-induced loading and unloading of micro-sized cargo show their capability for in vitro applications. Full article

The tumor microenvironment and healing wounds both contain extremely high concentrations of adenosine triphosphate (ATP) compared to normal tissue. The P2Y2 receptor, an ATP-activated purinergic receptor, is typically associated with pulmonary, endothelial, and neurological cell signaling. Here, we examine ATP-dependent signaling in breast epithelial cells and how it is altered in metastatic breast cancer. Using rapid imaging techniques, we show how ATP-activated P2Y2 signaling causes an increase in intracellular Ca²⁺ in non-tumorigenic breast epithelial cells, approximately 3-fold higher than their tumorigenic and metastatic counterparts. The non-tumorigenic cells respond to increased Ca²⁺ with actin polymerization and localization to the cell edges after phalloidin staining, while the metastatic cells remain unaffected. The increase in intracellular Ca²⁺ after ATP stimulation was blunted to control levels using a P2Y2 antagonist, which also prevented actin mobilization and significantly increased cell dissemination from spheroids in non-tumorigenic cells. Furthermore, the lack of Ca²⁺ changes and actin mobilization in metastatic breast cancer cells could be due to the reduced P2Y2 expression, which correlates with poorer overall survival in breast cancer patients. This study elucidates the rapid changes that occur after elevated intracellular Ca²⁺ in breast epithelial cells and how metastatic cancer cells have adapted to evade this cellular response. Full article

Background: Nail gels are decorative fingernail coatings based on (meth)acrylates that are photopolymerized on the nail surface. After polymerization, these coatings typically retain an uncured layer of monomers at the air interface due to oxygen inhibition, which may pose a risk of skin sensitization unless removed. No-wipe topcoats are formulated to address this issue by curing fully; however, no standard test method exists to verify a complete cure. This study presents a method to quantify residual uncured traces of several common nail gel monomers extracted from polymerized commercial no-wipe nail gels. Method: Commercially available no-wipe nail gels were formed into films of controlled thickness and polymerized using a standard UV-curing nail lamp. Solvent extraction was employed to eliminate residual uncured monomers, namely diethylene glycol dimethacrylate (DEGDMA), isobornyl acrylate (IBOA), and 2-hydroxyethyl methacrylate (HEMA). These monomers were quantified utilizing GC-FID and HPLC techniques. Method validation was conducted with samples of known monomer identity and concentration, thereby establishing specificity, linearity, precision, and detection limits. Results: Validated test protocols were established for the analysis of residual uncured traces of three commonly used monomers in nail gel coatings. In all instances, levels of monomer residue in a cured gel coating were found to range from 56 µg/g to 800 µg/g. Tests conducted on commercial products indicated that levels of these monomers fell within the expected normal ranges for such products. Conclusions: Through the utilization of two chromatographic techniques, three analytical methods were established for the simultaneous determination of ingredient concentrations and residual monomer quantities in unreacted bulk formula and cured UV-gel film. These methods and the resultant data facilitate the evaluation of curing completeness, which is essential for product development and safety assessments. Full article

Conductive hydrogels, particularly those incorporating poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), have revolutionized wearable health monitoring by merging tissue-like softness with robust electronic functionality. This review systematically explores design strategies for PEDOT:PSS-based hydrogels, focusing on advanced gelation methods, including polymer crosslinking, ionic interactions, and light-induced polymerization, to engineer hierarchical networks that balance conductivity and mechanical adaptability. Cutting-edge fabrication techniques such as electrochemical patterning, additive manufacturing, and laser-assisted processing further enable precise microstructural control, enhancing interfacial compatibility with biological systems. The applications of these hydrogels in wearable sensors are highlighted through their capabilities in real-time mechanical deformation tracking, dynamic tissue microenvironment analysis, and high-resolution electrophysiological signal acquisition. Environmental stability and long-term durability are critical for ensuring reliable operation under physiological conditions and mitigating performance degradation caused by fatigue, oxidation, or biofouling. By addressing critical challenges in environmental stability and long-term durability, PEDOT:PSS hydrogels demonstrate transformative potential for personalized healthcare, where their unique combination of softness, biocompatibility, and tunable electro-mechanical properties enables seamless integration with human tissues for continuous, patient-specific physiological monitoring. These systems offer scalable solutions for multi-modal diagnostics, empowering tailored therapeutic interventions and chronic disease management. The review concludes with insights into future directions, emphasizing the integration of intelligent responsiveness and energy autonomy to advance next-generation bioelectronic interfaces. Full article

This research explores the potential of green encapsules uploaded with eucalypt essential oil (EEOs) in enhancing their functionality and application in pest control, focusing on suitable ecotype selection from King Abdulaziz University (KAU) campus, Hada Al-Sham (HAS) village, and Briman district as well as optimizing extraction processes. Eucalypt hybrids’ leaves were collected from three different sites, and the EEOs were extracted using microwave-assisted steam distillation (MASD) and electric steam distillation (ESD) techniques. The physical and chemical properties of the EEO were determined. The identification of volatile chemical ingredients in the resulting EEOs was conducted using GC/MS after saponification and methylation procedures, and the ingredients were compared to those obtained from Eucalyptus globulus Labill, the ideal species containing the 1,8-cineol, the principal compound in its essential oil. The 1,8-cineole was found to be the major chemical constituent of the EEOs all over the two extraction methods, regardless of the ecotypes examined, and was interfered with other minor components such as 3-carene, α-pinene, α-myrcene, D-limonene, and α-terpinene. Eucalypt ecotypes grown at Hada Al-Sham village had the highest cineole content (59.29%) among the other sites studied. Compared to the ESD technique, MASD showed much promise because it is simple, facile, more ecofriendly and cost-effective, it kept oils true to their original form, and it allows to warm larger machines and spaces. The polymeric encapsules of either guar gum crosslinked by borax or sodium alginate crosslinked by calcium chloride were fabricated. Moreover, a bioassay screening of the encapsules uploaded with 1,8-cineole was evaluated against termite infection. The encapsules were found to be versatile tools with a wide range of applications; in particular, the alginate encapsules displayed superior characteristics. Furthermore, regardless of the encapsule type and the exposure duration, the mortality (%) of the insects was exceeded significantly for the high cineol concentrations compared to the lower ones for both alginate-based encapsules (ABEs) and guar gum-based encapsules (GGBEs). The higher the cineol concentrations, the higher the mortality percent of the termites. This finding can be attributed to the rapid toxic effect of the cineol compound at higher concentrations. Full article

Addressing hazards from dangerous pollutants requires specialized techniques and risk-control strategies, including detection, neutralization and disposal of contaminants. Smart polymers, designed for specific contaminants, provide powerful solutions for hazardous compound challenges. Their remarkable performance capabilities and potential applications present exciting opportunities for further exploration and development in this field. This editorial aims to provide a comprehensive overview of smart materials with unique features and emerging polymeric technologies that are being developed for isolation, screening, removal, and decontamination of hazardous compounds (e.g., heavy metals, pharmaceutically active contaminants, hormones, endocrine-disrupting chemicals, pathogens, and energetic materials). It highlights recent advancements in synthesis methods, characterization, and the applications of molecularly imprinted polymers (MIPs), along with alternative smart polymeric platforms including hydrogels, ion-imprinted composites, screen-printed electrodes, nanoparticles, and nanofibers. MIPs offer highly selective recognition properties, reusability, long-term stability, and low production costs. Various MIP types, including particles and films, are used in applications like sensing/diagnostic devices for hazardous chemicals, biochemicals, pharmaceuticals, and environmental safety. Full article

This article outlines the method of creating electrodes for electrochemical sensors using hybrid nanostructures composed of graphene and conducting polymers with insertion of gold nanoparticles. The technology employed for graphene dispersion and support stabilization was based on the chemical vapor deposition technique followed by electrochemical delamination. The method used to obtain hybrid nanostructures from graphene and conductive polymers was drop-casting, utilizing solutions of P3HT, PANI-EB, and F8T2. Additionally, the insertion of gold nanoparticles utilized an innovative dip-coating technique, with the graphene-conducting polymer frameworks submerged in a HAuCl₄/2-propanol solution and subsequently subjected to controlled heating. The integration of gold nanoparticles differs notably, with P3HT showing the least adhesion of gold nanoparticles, while PANI-EB exhibits the highest. An inkjet printer was employed to create electrodes with metallization accomplished through the use of commercial silver ink. Notable variations in roughness (grain size) result in unique behaviors of these structures, and therefore, any potential differences in the sensitivity of the generated sensing structures can be more thoroughly understood through this spatial arrangement. The electrochemical experiments utilized a diluted sulfuric acid solution at three different scan rates. The oxidation and reduction potentials of the structures seem fairly alike. Nevertheless, a notable difference is seen in the anodic and cathodic current densities, which appear to be largely influenced by the active surface of gold nanoparticles linked to the polymeric grains. The graphene–PANI-EB structure with Au nanoparticles showed the highest responsiveness and will be further evaluated for biomedical applications. Full article