Search Results (436)

Methylcellulose is a thermoresponsive polymer that undergoes thermally induced association and gelation upon heating, with behavior strongly influenced by thermal history, concentration, and ionic environment. In this work, dynamic light scattering (DLS) was used beyond conventional particle size analysis to monitor the temperature-dependent mobility of methylcellulose solutions through the apparent diffusion coefficient, complemented by transmittance and oscillatory rheology. For a 0.1 wt.% methylcellulose solution, rheology showed a sol–gel transition during heating between approximately 50 and 60 °C, but no complete gel–sol transition during cooling, indicating pronounced thermal hysteresis. Transmittance and DLS confirmed this path dependence while revealing different recovery behavior: optical turbidity recovered near 38–40 °C, whereas apparent mobility recovered at slightly lower temperatures, around 30–35 °C. A simple Arrhenius-type model described sol-state mobility but not the full heating cycle. Therefore, a two-state phenomenological model was introduced, representing DLS-derived mobility as weighted sol-like and gel-like contributions. The model captured mobility loss, recovery, and a hysteresis window of about 22 °C. Overall, DLS-derived apparent mobility provides a useful descriptor of methylcellulose association, dissociation, and hysteresis, complementing rheology and turbidity measurements. Full article

Binder bonding strength (BBS) is critical to aggregate retention and friction performance in high-friction surface treatment (HFST). Although epoxy resin is traditionally used, asphalt-based binders offer a sustainable alternative; however, their bonding behavior and influence on polishing performance remain insufficiently understood. This study investigated the evolution and optimization of BBS in crumb rubber-modified (CRM) asphalt for rhyolite-based HFSTs. BBS was measured under dry and wet-conditioned states for two CR contents (10% and 15%), two CR types (cryogenic and ambient), two interaction temperatures (170 and 200 °C), and interaction times from 10 to 240 min. HFST performance was assessed using the British pendulum tester (BPT), dynamic friction tester (DFT), and circular track meter (CTM) under accelerated polishing. CR modification reduced dry BBS relative to the base binder but substantially improved moisture resistance: wet conditioning reduced base-binder BBS by 23.8%, versus 5.8–9.8% for CRM binders. BBS evolution was temperature-dependent. At 170 °C, BBS decreased and gradually recovered through 240 min, while binders prepared at 200 °C peaked at 120 min before declining. Type III factorial ANOVA identified CR content as the dominant factor affecting BBS, with interaction temperature, interaction time, and their combined effects also being significant. Despite lower BBS, 15% CRM binders generally retained higher HFST friction performance than 10% binders after accelerated polishing. The moderate relationship between dry BBS and coefficient of friction (COF) loss (R² = 0.68) confirmed that BBS alone could not predict HFST durability, while a stronger BPN-COF loss correlation (R² = 0.79) confirmed consistent rankings across friction test methods. Cryogenic CRM prepared at 200 °C for 120 min provided the best balance among bonding development, rheology, and friction retention. These findings demonstrate that while bonding strength alone does not govern HFST durability across interactions, its evolution with interaction time exerts a significant effect on friction retention within a given interaction condition, highlighting interaction-time optimization as a critical parameter for developing sustainable CRM-based HFSTs. Full article

Two warm-mix modification routes were examined to determine how additive chemistry affects the service-temperature rheology of rubber-modified asphalt. Wax-based and bio-oil-based additives were incorporated at 1–3%, and the resulting binders were characterized by FTIR, dynamic shear rheology, MSCR, LAS, and BBR testing. These measurements respectively provided physicochemical evidence and quantified the phase-related response, deformation recovery, fatigue-related damage tolerance, and low-temperature relaxation. The wax-based system developed a stiffness-oriented response: an intermediate dosage produced comparatively lower J_nr and higher R, but further addition impaired relaxation, with m(60) decreasing to 0.285 at −18 °C for the 3% formulation. In contrast, the bio-oil-based system favored relaxation; at a 3% dosage, the LAS-predicted N_f at 2% strain was 15,200 cycles, while m(60) reached 0.460 at −12 °C and 0.384 at −18 °C. The binder-level evidence therefore identifies different selection priorities: an intermediate wax dosage is advantageous when deformation recovery is emphasized, whereas the bio-oil-based route is more favorable for relaxation and low-temperature response. Additional mixture and workability testing is required before these binder findings are translated into construction-temperature or field-performance recommendations. Full article

Spray cosmetics couple formulation composition with actuator design and biological targets, so their performance is governed by rapid, nonequilibrium interfacial processes that cannot be predicted from in-bottle stability or equilibrium surface tension alone. This targeted narrative review integrates evidence across storage stability, atomization, droplet flight and evaporation, deposition, film formation, active delivery, inhalation safety and environmental fate. It examines how surfactant molecular structure, micellar replenishment, dynamic surface tension, interfacial viscoelasticity and extensional rheology influence droplet-size distributions, wetting, spreading and deposition. Particular attention is given to competing effects: enhanced breakup may increase airborne fine fractions; stronger interfacial films may impair sprayability; enhanced penetration may reduce barrier tolerance; and bio-based origin does not necessarily imply a lower life-cycle burden. Across moisturizing, sunscreen, hair- and scalp-care, makeup-setting, cleansing-foam and emerging functional sprays, this review develops an interface-to-outcome framework and a multiobjective operating-window concept linking formulation and device variables to efficacy, manufacturability, safety and sustainability. The available evidence supports product-specific, whole-process validation rather than optimization against any single equilibrium property, while highlighting the need for spray-relevant dynamic measurements, realistic exposure assessment and validated formulation–device co-design. Full article

Background/Objectives: Erythrocyte sedimentation rate (ESR) is one of the most widely used tests for assessing inflammatory conditions. Current guidelines require that Erythrocyte Sedimentation Rate (ESR) testing be performed within four hours of collection for samples stored at RT or within 24 h if refrigerated; this is challenging with dispersed collection sites. Thus, we investigated whether testing technology affects sample stability by comparing results obtained using iSED^®, based on photometric rheology, with the classical Westergren method. Methods: Samples were evaluated at multiple time intervals. ESR values from each timepoint were plotted against their Time 0 values, and correlation statistics were analyzed using Passing-Bablok regression analysis and a Stability Drift analysis. Samples were considered stable if the correlation statistics of the Passing-Bablok analysis were statistically indistinct from the identity line. Results: Samples in the iSED/RT cohort were stable for up to 28 h after collection, while those in the iSED/4–8 °C cohort were stable for up to 48 h. Samples in the Westergren/RT cohort were stable for up to 10 h after collection, but significantly deteriorated at 12 h and beyond. Conclusions: The iSED methodology provides accurate ESR results for samples stored up to 28 h at RT and 48 h at 4–8 °C, which was significantly superior to the Westergren method for which samples were stable at RT for only 10 h. Full article

Cell-laden hydrogel bioinks for extrusion bioprinting are commonly evaluated by precursor rheology, extrusion behavior, and immediate shape fidelity, yet these measures do not establish whether printed constructs remain stable and functional during culture or tissue maturation. This review examines the post-printing evolution of cell-laden extrusion-printed hydrogel constructs, prioritizing direct evidence from cell-laden prints and using acellular prints and bulk hydrogels only to clarify mechanisms. Maturation is organized into immediate stabilization, network evolution and environmental equilibration, and long-term remodeling. Crosslinking, hydration, ion exchange, stress relaxation, degradation, cellular contraction, and matrix deposition may support maturation or cause structural, mechanical, interfacial, transport, and biofunctional failure. We propose a conceptual, research-oriented use-point assessment framework that compares each construct with relevant reference states and application-specific requirements after stabilization, during culture, and before intended use. The framework links the earliest observed critical deviation to relevant measurements, targeted redesign, and reassessment under the same conditions. A cartilage construct illustrates sequential evaluation of geometry, wet-state mechanics, cell distribution, and matrix formation. Current evidence is limited by inconsistent assessment times, incomplete reporting, and few integrated longitudinal studies. Future work should standardize maturation histories, model construct trajectories, and prospectively validate product-specific criteria. Evaluation should focus on the complete cell-laden extrusion-printed construct at its intended use point rather than on the freshly printed filament. Full article

Additive manufacturing provides a fabrication route for electrode components with controlled macrostructure; however, printable carbon inks that also incorporate oxygen reduction reaction active precursors remain underdeveloped. Here, XC-72 carbon was combined with selected metal precursors to prepare N–C, Fe–N–C, and Pt-containing carbon ink formulations for direct ink writing. The precursor mixtures were incorporated into a polyurethane-based matrix, pyrolyzed at 900 °C, and characterized using X-ray diffraction, oscillatory rheology, rotating ring-disk electrode measurements, Brunauer–Emmett–Teller surface-area analysis, and scanning electron microscopy. XRD confirmed retention of carbon diffraction features and the formation of metal-containing crystalline phases after pyrolysis. Oscillatory rheology showed storage moduli exceeding loss moduli for the tested formulations, indicating elastic-dominant behavior suitable for shape retention during printing. For the PGM-free formulations, incorporation of nitrogen and iron precursors improved ORR onset potential, half-wave potential, limiting current density, and electron-transfer selectivity relative to the carbon control. BET analysis showed a decrease in accessible surface area after precursor incorporation, consistent with partial pore blocking or structural modification during pyrolysis. These results establish a printable formulation platform for ORR-active carbon-based inks, while future work is required to isolate the effects of printed architecture, pore hierarchy, and durability under fuel-cell operating conditions. Full article

The continuous joining of aluminum alloys to engineering thermoplastics has emerged as a promising manufacturing path for lightweight hybrid structures, yet the influence of polymers’ mechanical behavior on friction stir joining remains poorly understood. This work investigates the role of melt rheology on the morphology, joining interface, and mechanical strength of dissimilar joints that combine AA6082-T6 with two engineering-grade thermoplastics, Noryl^® GFN2 and SustaPEEK^®. Two joining strategies were assessed under identical processing conditions: conventional friction stir joining (FSJ) and through-slot friction stir joining (TS-FSJ), the latter incorporating thin titanium strips intended to reduce heat transfer to the polymer. Joint morphology was assessed by optical and scanning electron microscopy, mechanical performance was evaluated through quasi-static tensile-shear testing, and the rheological behavior of both polymers was characterized by steady shear and oscillatory measurements. Conventional FSJ produced defect-free aluminum–Noryl joints, with a mechanical strength of 111.3 ± 8.4 kN/m, whereas aluminum–PEEK joints exhibited localized polymer overflow, poor surface finish and scattered strength performance of 116.7 ± 77.2 kN/m. Rheological measurements showed that PEEK exhibited higher melt viscosity and viscoelastic moduli, restricting polymer flow and promoting unstable interface formation. Although titanium inserts reduced heat transfer in TS-FSJ, their deformation reduced the effective joining area, resulting in lower tensile strength. Polymer rheology was identified as one of the key factors governing material flow, defect formation, process stability, and the joints’ mechanical performance, emphasizing the importance of tailoring the processing parameters reflecting the rheological characteristics of each polymeric base material. Full article

JP-10 is a pivotal high-density hydrocarbon fuel for advanced aerospace propulsion systems. Doping aluminum nanoparticles to prepare nanofluid fuels is a promising route to enhance its energy density and combustion performance, yet the droplet formation mechanism of such multiphase fuels remains poorly understood, hindering single-droplet combustion research and atomization system optimization. This work constructed a piezoelectric drop-on-demand (DOD) monodisperse droplet generation platform integrated with phase Doppler anemometry (PDA) and high-speed imaging. Using Al/JP-10/OA nanofluids with aluminum mass fractions of 0.1 wt. %, 0.5 wt. % and 1.0 wt. %, we systematically explored the effects of liquid flow rate, driving frequency and particle concentration on droplet size, size uniformity and ejection velocity. In this work, Al/JP-10/OA nanofluids with aluminum mass fractions of 0.1 wt. %, 0.5 wt. % and 1.0 wt. % were tested under liquid flow rates of 1.1–1.5 mL/min and driving frequencies of 10–50 kHz, with measured droplet diameter ranging from 241.04 μm to 292.26 μm and ejection velocity ranging from 1.65 m/s to 2.45 m/s. The results demonstrate that average droplet diameter increases linearly with flow rate and decreases monotonically with driving frequency. Compared with the 0.1 wt. % nanofluid, the 1.0 wt. % nanofluid shows a 4.4% larger droplet diameter and 12.1% lower ejection velocity, while the 0.1 wt. % sample retains excellent monodispersity with a size Span below 0.098. The multi-scale regulation mechanisms involving viscous variation, shear-thinning rheology and particle agglomeration are further clarified. This study provides fundamental data and theoretical support for atomization design of nanofluid aviation fuels. Full article

Accurate wellbore-pressure prediction is essential for safe drilling and pressure management in ultra-deep wells, where high temperature and pressure strongly alter drilling-fluid rheology. Existing rheological-parameter models are often calibrated for specific fluids and narrow temperature–pressure ranges, limiting their use in ultra-deep-well hydraulics. We measured three water-based drilling fluids at temperatures and pressures up to 210 °C and 206.5 MPa, compared seven rheological models, and developed a multidimensional evaluation method considering global fitting accuracy, extreme-condition performance, low-shear-rate representation, absolute shear-stress deviation, and model complexity. Using ambient-condition Herschel–Bulkley (H-B) parameters as baselines, we proposed a temperature–pressure (T-P)-coupled correction model requiring fluid-specific calibration to predict H-B parameters over the tested range. The fluids exhibited temperature-induced thinning, pressure-induced thickening, and shear-thinning behavior. The H-B model showed the best overall performance, with mean R² values above 0.997 and mean absolute percentage errors below 2.5% for all fluids. Substituting the corrected parameters into the H-B equation yielded mean shear-stress errors no greater than 4.04%. Field validation showed that the T-P-coupled model reduced the mean circulating-pressure-loss error from 2.72% to 0.78%. This approach provides practical inputs for rheology estimation and circulating-pressure calculation in ultra-deep wells under wide temperature and pressure conditions. Full article

Rubber extrusion has evolved through overlapping advances in equip design, rheological characterization, numerical modeling, sensing, and control. This structured critical narrative review synthesizes 180 sources published from 1972 to 2026, assembled through iterative keyword searching and backward and forward citation tracing. The conventional three-zone theory of solid conveying, compression, and metering is used as a bounded analytical framework, while the literature is organized into four overlapping analytical periods spanning empirical design, constitutive and numerical modeling, engineering-scale simulation, and multiphysics and data-enabled methods. Evidence is distinguished among direct rubber-extrusion validation, rubber-material or rheological studies, transferable general polymer extrusion studies, and enabling computational, sensing, or control research. Five persistent challenges are identified: formulation-dependent nonlinear rheology; incomplete representation of filler-network evolution and wall slip; limited cross-machine and cross-formulation validation; high computational cost; and the lack of standardized datasets and reporting protocols. Digital twins, physics-informed neural networks, and neural operators are promising but remain insufficiently validated for industrial rubber extrusion. Priorities include transparent benchmark datasets, evidence-graded, uncertainty- and latency-aware validation, multimodal sensing, transferable reduced-order and learned models, and measurable sustainability indicators. Together, these priorities define a validation-oriented roadmap for more reliable, transferable, and sustainable rubber-extrusion modeling and control. Full article

Mayonnaise is a high-viscosity food emulsion whose consistency evolves during shearing due to structural rearrangement and possible emulsion destabilization. This study presents a laboratory-scale proof-of-concept for adapting an established motor current-derived accumulated entropy generation (AEG) framework as a thermodynamic descriptor for monitoring mayonnaise structure changes. First, eight reference fluids were tested using a rotating-bob viscometer at shear rates of 600, 800, and 1000 s⁻¹ to establish the relationship between viscosity and motor current. The corrected current response showed a strong linear correlation with viscosity. The approach was then extended to commercially available mayonnaise samples. Due to the higher viscosity and structured nature of mayonnaise, testing was performed at 1000 s⁻¹, where stable shearing could be achieved. A modified impeller-based viscometer setup was used to continuously shear the mayonnaise and monitor the motor current in situ, while rheometer measurements were performed independently to validate the corresponding viscosity changes during shearing. The motor current decreased with shearing time, consistent with the reduction in measured viscosity. The calculated AEG increased continuously and distinguished the shear stability of different mayonnaise formulations. The viscosity degradation rates of two different mayonnaises are characterized using the degradation coefficient B introduced in the degradation–entropy generation (DEG) theorem. A higher B value indicates greater structural breakdown. These results suggest that current-derived entropic parameters (B coefficient and AEG) may serve as practical, sensor-accessible descriptors for monitoring mayonnaise consistency evolution when direct torque measurement or in-line rheology is unavailable. Full article

Supramolecular hydrogels are usually prepared in aqueous media containing diverse ions, for instance, buffer solutions, yet the influences of ions, especially the Hofmeister effect, on their self-assembly are often overlooked. Here, we systematically investigate the impacts of different anions in the Hofmeister series on the self-assembly of supramolecular hydrogels. On the basis of a hydrazone formation-mediated supramolecular gelation system, we found that the addition of kosmotropic anions can accelerate the self-assembly of gelators as determined by rheology and critical gelation concentration tests. Confocal microscopy observations and rheological measurements demonstrate that the resultant hydrogels have denser fibrous networks and higher stiffness relative to the samples without additional kosmotropic anions. In contrast, chaotropic anions effectively impede the self-assembly process. These impacts of ions on the self-assembly of supramolecular hydrogels are in line with the specific ion effect. This work suggests that the Hofmeister effect can serve as an effective approach to control the self-assembly and the properties of supramolecular hydrogels, and the effects of ions should be considered in the studies of supramolecular hydrogels. Full article

Background: Patients with type 2 diabetes (T2D) frequently exhibit impaired erythrocyte deformability, which contributes to microvascular dysfunction. We previously reported that imeglimin, a mitochondrial-targeted antidiabetic agent, prolongs erythrocyte lifespan. This study investigated the effects of imeglimin on whole-blood fluidity and its clinical implications in patients with T2D. Methods: This post hoc analysis of the INFINITY study included 25 patients with T2D who completed 6 months of imeglimin treatment (2000 mg/day) followed by a 3-month follow-up. Whole-blood fluidity was assessed by measuring whole-blood passage time using a microchannel array flow analyzer (MC-FAN). Hematological parameters, glycemic markers, and vascular indices, including brachial-ankle pulse wave velocity (baPWV) and toe-brachial index (TBI), were also assessed. Results: Whole-blood fluidity, assessed by 3-month averages of whole-blood passage time, showed an improvement trend at Months 1–3 (p = 0.058) and a significant improvement at Months 4–6 (p = 0.016) compared with baseline; this effect was reversed after discontinuation. Erythrocyte lifespan significantly increased by 10–20% during treatment and remained prolonged after discontinuation. Conversely, red blood cell count, hemoglobin, and hematocrit decreased during treatment and returned toward baseline post-discontinuation. At Month 6, baPWV increased, and TBI decreased, both showing reversibility after treatment cessation. Conclusions: In this exploratory post hoc analysis, imeglimin treatment was associated with reduced whole-blood passage time measured using the MC-FAN system, suggesting improved whole-blood fluidity in patients with T2D. The clinical and mechanistic significance of this observation requires confirmation in future controlled prospective studies incorporating direct assessments of erythrocyte rheology and microvascular function. Full article

Controlling the interfacial behavior is essential for understanding the efficiency of surfactant–nanoparticle systems in practice. In this study, we investigate how silica (SiO₂) nanoparticles alter the surface and interfacial properties of sodium dodecyl sulfate (SDS) solutions at water–air and water–hexane interfaces, as well as their impact on the formation and stabilization of foams. While the negatively charged SiO₂ nanoparticles alone exhibit negligible surface activity, their combination with SDS leads to the formation of composite interfacial layers with enhanced surface pressure and dilational viscoelasticity. The increase in interfacial pressure reflects a high surface concentration and denser packing of SDS–SiO₂ associates. Interfacial rheology measurements show that SDS–SiO₂ nanofluids form more elastic interfacial films compared to pure SDS, with a maximum dilational elasticity at intermediate surfactant concentrations. This indicates the formation of mechanically stronger interfacial layers capable of resisting deformation. Foam experiments demonstrate that silica nanoparticles significantly improve foam formation and foam stability. These improvements correlate with increased surface pressure and interfacial elasticity, demonstrating that foam stability is primarily determined by the formation of robust interfacial layers and not solely by a reduction in surface tension. Overall, this study demonstrates how the presence of silica nanoparticles can affect the adsorption of SDS via hydrophobic interaction, leading to the formation of stronger interfacial films, improved foam stability, and expanded potential for applications in industrial processes, such as foam flooding based on nanoparticle/surfactant solutions to enhance oil–gas recovery. Full article