Search Results (3,406)

Controlling dimensional fidelity and line-edge roughness is important in chemically amplified negative-tone imaging. In this study, two three-arm random terpolymers containing different acid-labile protecting groups were synthesized via core-first reversible addition–fragmentation chain-transfer (RAFT) polymerization to examine the influence of protecting-group structure within a common star-polymer framework. HTT 334 contained tert-butyl methacrylate (t-BMA), whereas HTM 334 contained 2-methyl-2-adamantyl methacrylate (MAMA). The two polymers exhibited comparable molecular weights and compositions, with narrow dispersities of 1.14 and 1.16. Thermal analysis showed that HTM 334 had a slightly higher glass-transition temperature than HTT 334 (77 and 73 °C, respectively). Fourier transform infrared (FT-IR) spectroscopy revealed spectral changes after exposure and post-exposure baking (PEB) that were consistent with acid-catalyzed deprotection and possible intermolecular reactions involving the hydroxyethyl methacrylate units. Negative-tone patterns were formed using an n-butyl acetate developer under the selected PEB conditions of 70 °C for HTT 334 and 90 °C for HTM 334. Across nominal mask dimensions of 10–80 μm, HTM 334 exhibited printed-to-mask critical-dimension ratios of 0.990–1.039, compared with 0.915–1.003 for HTT 334. HTM 334 also showed lower measured line-edge roughness values of 0.22–0.39 μm than HTT 334, which showed values of 0.52–1.27 μm. At the nominal 10 μm dimension, HTM 334 exhibited a line-edge roughness of 0.27 μm and an LER/CD ratio of 2.60%. These results indicate that an acid-labile protecting-group structure can influence thermal behavior and micrometer-scale pattern fidelity within the investigated three-arm RAFT polymer platform. Full article

The development of sustainable structural materials has driven interest in renewable plant fibers as alternatives to synthetic reinforcements. In this study, the structural, thermal, mechanical, and chemical characteristics of Cyperus papyrus fibers were comprehensively evaluated to assess their potential as reinforcement materials for polymeric composites. The fibers exhibited an average diameter of 164.87 µm, with tensile strength and Young’s modulus values of 141.95 ± 89.33 MPa and 11.15 GPa, respectively. Scanning electron microscopy revealed a rough and irregular surface morphology characteristic of untreated lignocellulosic fibers. X-ray diffraction analysis indicated a crystallinity index of 70.15%, while thermogravimetric analysis demonstrated stability up to 220 °C. Chemical composition analysis revealed high α-cellulose content (63.3%) and moderate lignin levels, contributing to a balance between stiffness and processability. The significant relationship observed between fiber diameter and tensile behavior, together with the structural, chemical, and thermal characteristics of the fibers, provides a broader understanding of the structure–property relationships relevant to their potential use as sustainable reinforcement materials. Overall, C. papyrus fibers represent a promising bio-derived material for environmentally conscious engineering applications. Full article

Infection associated with orthopedic implants and insufficient biological integration remain important clinical challenges. In this study, strontium-substituted hydroxyapatite (SrHA) was prepared by a chemical co-precipitation method, and a SrHA/polydopamine (SrHA@PDA) composite coating was constructed on porous tantalum (Ta) through the self-polymerization of polydopamine (PDA). The coating exhibited a photothermal conversion efficiency of 63.79% under 808 nm near-infrared (NIR) irradiation, with the temperature increasing to 62.7 °C within 10 min. The antibacterial activity was primarily attributed to PDA-mediated photothermal heating. After NIR irradiation, pronounced antibacterial effects were observed against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), while Sr²⁺ release remained controlled during the investigated period. In addition, the SrHA@PDA coating supported MC3T3-E1 osteoblast proliferation, indicating a favorable cellular response. Cross-sectional observations demonstrated the formation of a dense and continuous SrHA-containing coating on the porous Ta scaffold, and biomimetic mineralization further indicated favorable surface bioactivity. Overall, the SrHA@PDA coating integrates controlled Sr²⁺ release, favorable osteoblast response, and PDA-mediated photothermal antibacterial activity within a single surface modification strategy. This multifunctional approach provides a promising platform for improving the biological and antibacterial performance of porous tantalum implants for bone repair applications. Full article

The room-temperature deformation and fracture processes in polymeric (PLA and PA12) samples with an antichiral interior design have been studied through computer simulation and experimental research. The samples were printed by two different methods: FDM and SLS. ANSYS software was utilized to simulate the compression deformation process. The simulation showed that the Poisson ratio of the studied 3D model samples did not depend on the chemical composition and was close to zero under compression. It was found that under the same load, the von Mises stresses in the polylactic acid (PLA) sample were almost twice as high as in the polyamide 12 (PA12) sample structure, which was associated with the different mechanical properties of the initial material. Maximum von Mises stresses were observed in the cylindrical region of the bottom part of the sample. The room-temperature compression experiments revealed that the deformation process of the samples with the antichiral design occurs layer by layer. Room-temperature superelasticity effects associated with both viscoelastic relaxation of the cellular antichiral design and phase transition were found in the 3D-printed PA12 thermoplastic polymeric sample; the sample was deformed up to 49% and recovered its shape after removing the load. The recovery coefficient (Rr) for the PA12 sample was 99 ± 1%. The shape-memory effect in the 3D-printed PLA sample was found when it was immersed in hot water at a temperature of 80 °C. Because the 3D-printed PLA sample was partially destroyed under compressive deformation, the recovery coefficient of the PLA sample for the temperature-induced shape-memory effect was 86%. The microscopy study (SEM) revealed the limitations of the FDM method for printing 3D objects with complex designs, such as antichiral ones. Unlike the SLS method, FDM printing does not provide a strong connection between the cylindrical and ligament parts of the antichiral design structure due to the fibril structure of the PLA filaments and the printing strategy used in FDM. Full article

The development of novel high-performance materials is a key driver of technological progress in biomedicine. To date, polymeric materials have represented one of the most significant advances in addressing a broad range of challenges. Owing to their versatility and tunable properties, polymers have found countless applications, including in highly demanding biomedical fields, particularly when the availability of donor tissue is limited and transplantation is not always a viable option. To overcome these limitations, increasing research efforts have been devoted to the development of tailor-made biocompatible materials capable of restoring physiological functions. Within this context, the present research focuses on the synthesis and characterization of innovative aromatic polyesters containing polar comonomeric units to enhance their hydrophilicity. The reference homopolymer, poly(pentamethylene naphthalate), was chemically modified by incorporating different molar amounts of dimethyl 5-sulfoisophthalate subunits, with the aim of improving surface wettability and biological integration. In addition to high thermal stability and processability, the resulting materials exhibited good optical transparency, with low color saturation and a faint bluish hue, making them potentially suitable for biomedical applications, including the treatment of ocular tissues. Finally, biocompatibility was preliminarily assessed through in vitro cytotoxicity tests. Overall, these findings may lay the foundation for developing a new generation of materials capable of providing advanced solutions for biomedical applications. Full article

Despite the robust mechanical and chemical stability that make hollow flat-sheet ceramic membranes highly attractive for membrane bioreactors (MBRs), the fundamental relationship between their structural design, specifically pore size and structural symmetry, and biological fouling behavior remains elusive. To decouple the effects of membrane architecture on fouling mechanisms, a series of symmetric and asymmetric hollow flat-sheet alumina membranes were systematically engineered. Symmetric architectures with tunable pore sizes were fabricated by controlling aggregate particle sizes, whereas asymmetric counterparts featuring distinct separation layer thicknesses were developed via a tailored dip-coating process. Long-term operational evaluations treating municipal wastewater uncovered a counterintuitive phenomenon. Asymmetric membranes, despite yielding superior retention, experienced markedly accelerated transmembrane pressure evolution and severe cake layer fouling compared to the symmetric supports. Resistance-in-series analysis coupled with classical filtration models demonstrated that thicker separation layers and larger pore sizes were associated with shifts in the dominant fouling mechanism toward rapid and dense cake layer formation, which significantly exacerbated irreversible biological fouling. Furthermore, advanced spectroscopic and high-throughput sequencing techniques revealed that structurally complex asymmetric layers were associated with shifts in extracellular polymeric substances and specific fouling-associated bacterial phyla at the membrane interface. Ultimately, these findings underscore the necessity of architectural optimization to mitigate biofouling and prolong the operational lifespan of ceramic membranes, highlighting the sustainable advantages of symmetric structures. Full article

Polypyrrole (PPy) nanofilms were deposited by in situ chemical oxidative polymerization on polyethylene or polypropylene. The thickness is determined by SEM of the cross-section. Thin thickness nanofilms (180 ± 5 nm) are deposited. The nanofilms are then modified by nucleophilic addition to attach functional groups to the nanofilms. Strong nucleophiles (e.g., thiols) react by conventional heating. Weak nucleophiles (e.g., nitroanilines) only react when applying microwaves. The spectroscopic (UV–visible, FTIR, XPS and XANES) characterization shows the attachment of functional groups and the change in electronic properties upon the reaction. The conductivity of the functionalized PPy nanofilms are lower than unmodified PPy nanofilms, likely due to steric effects on the extended conjugation and disturbance of the electron hopping between chains. While reaction with some nucleophiles (e.g., bisulfite ion) makes nanofilms more hydrophilic, modification with long alkyl chains or fluorinated long chains produces highly hydrophobic nanofilms. No noticeable effect of the reaction on the film thickness is observed, suggesting little or no loss of polymer due to dissolution. Full article

Rice husk (RH) is a renewable siliceous lignocellulosic waste providing a unique, greener and less toxic alternative to conventional synthetic polymeric precursors in the production of carbon-based materials for biomedical applications. In this work we studied the porous structure of RH-lignin-based activated carbon produced in the form of honeycomb carbon monoliths and assessed their potential as hemoadsorbents for blood purification in the treatment of patients with serious medical conditions, such as kidney failure and sepsis. To determine their clinical suitability for such an application, the hemocompatibility and cytotoxicity of the monoliths were investigated using the standard ISO guidelines. The monoliths did not cause any changes in the cell viability or cell lysis. High micro/mesoporosity and surface chemistry of the initial monolith-C, N- and P-doped nanostructured carbon honeycomb monoliths were established by low-temperature nitrogen adsorption (LTNA) studies, mercury porosimetry data (MIP), SEM/EDS analysis and FT-IR spectroscopy. The micro-mesoporous, activated carbon-based filtration/adsorbent prototype devices, in the form of three-dimensional (3D) carbon matrix, functionalized with ion-exchange amino- and phosphate groups and encased in polyolefin heat shrink cable sleeve, have been developed with the capacity to remove protein-bound uremic toxins (PBUTs), such us PCS and IS, as well as inflammatory cytokines (IL-6 and IL-8) from human plasma in a flowing model system. The ammoxidized monolith-N, derived from the monolith-C, had the highest removal efficiency (40.05% for PCS, and 28.4% for IL-6). By contrast, phosphorylated monolith-P demonstrated the highest removal efficiency (54.62% for IS, and 54.4% for IL-8), whilst the monolith-C has the lowest removal efficiency for these adsorbates. These results do not correlate with the LTNA and MIP study results, suggesting that the interaction of surface chemical functional groups with the solutes play key roles in the adsorption mechanism. The ion-exchange mechanism of PBUTs and inflammatory cytokine chemisorption by the monoliths, modified with surface N- and P-containing functional groups, has been proposed. Full article

Polyurethane (PU) is widely used in construction, transportation, automotive products, decorative materials, and related industries because its molecular structure can be tailored to diverse service requirements. This versatility has stimulated growing interest in polyurethane-modified asphalt for pavement engineering. This review examines the chemical structure, reaction mechanisms, and principal synthesis routes of polyurethane-modified asphalt and discusses polyurethane-modified emulsified asphalt, polyurethane composite-modified asphalt, and polyurethane-modified asphalt mixtures. Engineering applications in permeable pavements, bridge and tunnel surfacing, as well as crack and pothole repair are also considered. The review further addresses green in situ polymerization, high-content polyurethane systems, waterborne polyurethane, interfacial adhesion, bio-based formulations, recycled asphalt mixtures, and life-cycle performance. The available evidence indicates that polyurethane can improve high-temperature stability, durability, fatigue resistance, mechanical strength, adhesion, and aging resistance. In suitable formulations, it can also reduce production temperatures and construction-related emissions. Economic feasibility, unresolved technical issues, and future research priorities are discussed at the end of the review. Full article

Resveratrol (RSV) is a naturally occurring polyphenol with well-documented antioxidant, anti-inflammatory, antimicrobial, photoprotective, wound-healing, depigmenting, and anticancer properties, making it an attractive candidate for dermocosmetic and dermatological applications. However, its clinical translation into effective topical products remains limited by poor aqueous solubility, chemical instability, photoisomerization, rapid cutaneous metabolism, and restricted skin penetration, all of which compromise local bioavailability and therapeutic efficacy. This narrative review critically examines the molecular mechanisms underlying the cutaneous effects of RSV and discusses how its physicochemical and pharmacokinetic characteristics influence topical performance. Particular emphasis is placed on advanced delivery strategies developed to overcome these limitations, including lipid-based nanocarriers, polymeric nanoparticles (NPs), nanofibers, inorganic nanocarriers, microneedles, hydrogels, and other emerging delivery platforms. The mechanisms by which these systems improve RSV solubility, stability, controlled release, skin retention, and dermal penetration are critically evaluated together with their reported therapeutic outcomes. Although advanced delivery systems have consistently improved the topical performance of RSV in preclinical studies, clinical evidence remains limited. To date, only one published placebo-controlled clinical trial has specifically evaluated topical RSV as the active ingredient, and none of the advanced RSV-nanocarrier platforms discussed in this review has undergone clinical evaluation. Bridging this substantial translational gap will require not only further optimization of formulation design but also scalable manufacturing, rigorous clinical validation, and regulatory pathways capable of supporting the development of safe, effective and evidence-based next-generation dermocosmetic and dermatological products. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) develops when hepatic lipid acquisition and synthesis exceed the capacity for oxidation and very-low-density lipoprotein export. Flavonoids act on several components of this network, yet their therapeutic development is constrained by poor aqueous solubility, extensive intestinal and first-pass metabolism, variable activity of circulating metabolites, and limited information on hepatic exposure. Experimental studies link representative flavonoids to AMPK–SREBP-1c and PPARα signaling, mitochondrial quality control, Nrf2-dependent redox defense, inflammatory pathways, and the gut–liver axis. By contrast, the available randomized trials of quercetin, hesperidin, anthocyanins, green-tea catechins, EGCG, and soy isoflavones show at most modest changes in liver fat or biochemical markers and do not demonstrate metabolic dysfunction-associated steatohepatitis (MASH) resolution or fibrosis regression. Liposomal, lipid-based, polymeric, and nanocrystal formulations have improved dissolution, systemic exposure, or liver distribution in preclinical models, but comparative pharmacokinetics, chronic safety, manufacturability, and clinical efficacy remain poorly defined. The evidence therefore supports viewing flavonoids as formulation-dependent investigational candidates rather than established MASLD therapies. Progress will depend on chemically standardized products, exposure–response studies, clinically relevant models, and adequately powered trials using validated imaging or histological endpoints. Full article

While limestone calcined clay cement (LC3) can reduce CO₂ emissions by up to 50%, low early-age strength in low-clinker formulations limits its structural adoption. This study investigates practical strategies to accelerate early strength development in low-clinker LC3 mortars (clinker fraction ~42.5%) using sodium carbonate (1–3%) and a commercial chemical accelerator (1.5–3%), evaluated individually and in combination. Eleven mortar mixes were tested for compressive and flexural strength at 3, 7, and 28 days per BS EN 196-1, alongside ATR-FTIR hydration characterization and dry versus wet mixing comparisons. Results show that 2% sodium carbonate is the optimal single dosage, increasing 7-day compressive strength by ~29% (from 6.8 to 8.8 MPa) and flexural strength by 22% (from 2.46 to 3.00 MPa). Combining 1% sodium carbonate with 1.5% accelerator produced a pronounced synergistic effect, boosting 7-day compressive strength by 38% (9.4 MPa) and flexural strength by 34% (3.30 MPa). FTIR spectra confirmed enhanced silicate polymerization and carboaluminate precipitation. These findings provide construction practitioners with a scalable, low-cost chemical activation method to facilitate early demoulding and formwork stripping in sustainable low-carbon construction. Full article

Biofilm-associated infections represent a critical challenge in modern medicine, accounting for approximately 80% of all microbial infections and demonstrating up to 1000-fold higher antimicrobial resistance compared to planktonic bacteria. The extraordinary recalcitrance of biofilms stems from a complex interplay of physical barriers (extracellular polymeric substance matrix), chemical gradients (pH and oxygen heterogeneity), and biological defenses (persister cells and horizontal gene transfer), rendering conventional antibiotics largely ineffective. This comprehensive review highlights the transformative potential of antimicrobial nanoformulations in overcoming these formidable barriers through strategic design principles and diverse mechanisms of action. Evidence demonstrates that rationally engineered nanocarriers achieve improvements in bacterial killing, biofilm biomass reduction, and colony-forming unit reductions compared to free antibiotics. Advanced stimuli-responsive systems exploiting biofilm-specific triggers (acidic pH, bacterial enzymes, elevated ATP) and externally applied stimuli (near-infrared photothermal therapy, ultrasound sonodynamic therapy) enable on-demand therapeutic activation with unprecedented precision, achieving >99.999% bacterial elimination and near-complete biofilm eradication. Despite these remarkable advances, clinical translation remains hindered by challenges in scalability, comprehensive safety evaluation, and regulatory pathway navigation. This review establishes a consolidated evidence base for the design of next-generation antimicrobial nanoformulations, highlights their potential to address biofilm-associated infections, and identifies key knowledge gaps and translation barriers that must be addressed to realize their therapeutic promise. Full article

Linear α-olefins derived from Fischer–Tropsch (FT) synthesis serve as critical feedstocks for high-grade polyolefin production, yet residual oxygenated compounds severely compromise polymerization efficiency and product quality. This study reports the modification of 13X zeolite via Mg/K bimetallic ion exchange to enhance its adsorptive performance for deep oxygenate removal. It is found that Mg/K modification enhances surface polarity and acid sites without destroying the zeolite framework. Adsorption capacity follows the order of Mg/K-13X > Mg-13X > 13X. The process fits the Langmuir isotherm and pseudo-second-order kinetics, indicating monolayer chemical adsorption. Thermodynamic results reveal spontaneous and exothermic adsorption. In fixed-bed tests with 1-hexene and 1-octene, oxygenates are reduced below 5 ppm within 270 min. Breakthrough curves are well-fitted by the Thomas model, with aldehydes breaking through first and alcohols last, owing to polarity-driven adsorption selectivity. After 40 regeneration cycles, the oxygenate removal efficiency remains above 90.72%, confirming exceptional stability and reusability. Mg/K-13X thus represents a highly efficient and robust adsorbent for the deep purification of FT-derived α-olefins. Full article

Hydrolates are aqueous co-products of aromatic-plant distillation whose composition and functionality differ from those of the corresponding essential oils. This critical review links botanical source, distillation conditions, chemical composition, quantitative biological performance, food or agricultural application, and readiness for nano-enabled formulation. Direct hydrolate studies show marked heterogeneity: reported antimicrobial performance ranges from minimum inhibitory concentrations of 5.69–500 μL mL⁻¹ to approximately 1–3.5 log reductions in food models, while antioxidant results depend strongly on the assay and reporting unit. Evidence in foods is most developed for fresh produce, seafood, dairy, meat, and beverages, but direct bakery validation remains a gap. Hydrolates offer aqueous compatibility and generally lower sensory intensity than essential oils, yet low active-compound concentrations, batch variability, microbiological susceptibility, and limited shelf stability restrict reproducible use. Among nano-enabled solutions, one direct lavender-hydrolate nanoemulsion study reported a diameter of 225.4 ± 3.2 nm and a polydispersity index of 0.098 ± 0.011, together with improved antibacterial activity; however, hydrolate-specific encapsulation efficiencies, release kinetics, long-term stability, food validation, and field trials are largely unreported. Liposomes, polymeric nanoparticles, nanogels, and active films therefore remain mostly transferable concepts supported by essential-oil, extract, or isolated-compound studies rather than established hydrolate technologies. Future work should use standardized production and quality markers, free-hydrolate and unloaded-carrier controls, realistic matrices, safety and non-target testing, scale-up analysis, and quantitative sustainability assessment. Hydrolates are promising sustainable phytochemical resources, but claims of nano-enabled advantage require direct comparative evidence. Full article