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The oil phase obtained by blending and oleogel methods has potential for the production of non‑hydrogenated and low-saturated puff pastry margarine, thereby reducing intakes of both types of dietary fat. The crystal form, microstructure, rheology, and baking applications of puff pastry margarines prepared with anhydrous milk fat (AMF)/palm stearin (POs), POs/palm oil (PO), beef tallow (BT)/PO, or AMF/POs/diacetyl tartaric acid ester of mono(di)glycerides (DATEM) oleogels were investigated using X-ray scattering, polarized light microscope, and rheometer, respectively. All margarines exhibited β'-form crystal and strongly viscoelastic at low strain. With the addition of DATEM oleogel, their crystal microstructure became more uniform and finer, and the croissants were less hard (1690) and chewiness (160). The chewiness of croissants produced using the margarines was significantly improved with POs content. The theoretical basis for preparation and application in non‑hydrogenated and low-saturated puff pastry margarine was provided in the present study., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In the context of soft matter and cellular mechanics, microrheology - the use of micron-sized particles to probe the frequency-dependent viscoelastic response of materials - is widely used to shed light onto the mechanics and dynamics of molecular structures. Here we present the implementation of active microrheology in an Acoustic Force Spectroscopy setup (AFMR), which combines multiplexing with the possibility of probing a wide range of forces ( ~ pN to ~nN) and frequencies (0.01-100 Hz). To demonstrate the potential of this approach, we perform active microrheology on biological samples of increasing complexity and stiffness: collagen gels, red blood cells (RBCs), and human fibroblasts, spanning a viscoelastic modulus range of five orders of magnitude. We show that AFMR can successfully quantify viscoelastic properties by probing many beads with high single-particle precision and reproducibility. Finally, we demonstrate that AFMR to map local sample heterogeneities as well as detect cellular responses to drugs., (© 2024. The Author(s).)

AbstractNanomaterials were widely employed to improve the physicochemical properties of various chemicals in enhanced oil recovery (EOR). In the present study, the novel Janus amphiphilic silica nanoparticle (JNS) was successfully prepared, whose structure and property were confirmed via Fourier transform infrared spectroscopy, Zeta potential measurement, transmission electron microscopy, interfacial tension and contact angle measurements. Then the effects of JNS, hydrophilic silica nanoparticles (HLS) and hydrophobic silica nanoparticles (HBS) on the viscosity of the hydrophobic modified HPAM (HOA101) solution were studied. It was found that JNS exhibited a greater ability to enhance the viscosity, temperature resistance and salt resistance of HOA101 solution in comparison to the other two polymer nanofluids. The interaction mechanisms between nanoparticles and HOA101 were proposed, which were verified by the viscoelasticity measurements and control experiments. Core flooding experiments and micromodel flooding tests demonstrated that the JNS/HOA101 dispersion could effectively expand the sweep efficiency to highly increase the oil recovery from 8.4% to 14.3%. [ABSTRACT FROM AUTHOR]

Inertial effects caused by perturbations of dynamical equilibrium during the flow of soft matter constitute a hallmark of turbulence. Such perturbations are attributable to an imbalance between energy storage and energy dissipation. During the flow of Newtonian fluids, kinetic energy can be both stored and dissipated, while the flow of viscoelastic soft matter systems, such as polymer fluids, induces the accumulation of both kinetic and elastic energies. The accumulation of elastic energy causes local stiffening of stretched polymer chains, which can destabilise the flow. Migrating multicellular systems are hugely complex and are capable of self-regulating their viscoelasticity and mechanical stress generation, as well as controlling their energy storage and energy dissipation. Since the flow perturbation of viscoelastic systems is caused by the inhomogeneous accumulation of elastic energy, rather than of kinetic energy, turbulence can occur at low Reynolds numbers. This theoretical review is focused on clarifying the role of viscoelasticity in the appearance of low-Reynolds turbulence. Three types of system are considered and compared: (1) high-Reynolds turbulent flow of Newtonian fluids, (2) low and moderate-Reynolds flow of polymer solutions, and (3) migration of epithelial collectives, discussed in terms of two model systems. The models considered involve the fusion of two epithelial aggregates, and the free expansion of epithelial monolayers on a substrate matrix. [ABSTRACT FROM AUTHOR]

We present a numerical analysis of the rheology of a suspension of red blood cells (RBCs) for different volume fractions in a wall-bounded, effectively inertialess, small amplitude oscillatory shear (SAOS) flow for a wide range of applied frequencies. The RBCs are modeled as biconcave capsules, whose membrane is an isotropic and hyperelastic material following the Skalak constitutive law. The frequency-dependent viscoelasticity in the bulk suspension is quantified by the complex viscosity, defined by the amplitude of the particle shear stress and the phase difference between the stress and shear. SAOS flow basically impedes the deformation of individual RBCs as well as the magnitude of fluid-membrane interactions, resulting in a lower specific viscosity and first and second normal stress differences than in steady shear flow. Although it is known that the RBC deformation alone is sufficient to give rise to shear-thinning, our results show that the complex viscosity weakly depends on the frequency-modulated deformations or orientations of individual RBCs but rather depends on combinations of the frequency-dependent amplitude and phase difference. The effect of the viscosity ratio between the cytoplasm and plasma and of the capillary number is also assessed. [ABSTRACT FROM AUTHOR]

The molecular network of natural rubber (NR) gum is determined by the interparticle diffusion when NR latex coagulates. However, the roles played by the non-rubber components (NRC) species on the heterogeneous network structure and on the viscoelasticity of NR gum have not been throughly investigated. Here, the molecular relaxation was studied by linear rheology. In addition, the inter- and intra-cycle nonlinearities under large amplitude oscillatory shear (LAOS) were studied for gums with extracted and added NRC. It was found that the high molecular weight free protein restricts the interdiffusion and improves the entanglement density, while the added lipid induces homogeneous distribution of NRC. The physical associations coming from free proteins increase the segment friction and retard the terminal relaxation. Onset of the strain softening was found to be induced by entangled network density. Both the elastic and viscous LAOS nonlinearities can be regulated by adjusting the NRC species. This work sheds light on the contributions of major NRC species on the network structure and nonlinear viscoelasticity of NR gum. [Display omitted] • The non-rubber components of NR influence latex coagulation and entanglement density. • Roles of non-rubber components on the NR gum relaxations were investigated. • The nonlinear viscoelasticity of NR gum can be regulated by non-rubber components. [ABSTRACT FROM AUTHOR]

[Display omitted] Hetero-aggregation of oppositely charged colloidal particles with controlled architectural and interactional asymmetry allows modifying gel nanostructure and properties. We hypothesize the relative size ratio between cationic nanospheres and varied-size anionic two-dimensional nanoclays will influence the gel formation mechanisms and resulting rheological performance. Hybrid colloidal gels formed via hetero-aggregation of cationic gelatin nanospheres (∼400 nm diameter) and five types of nanoclays with similar 1 nm thickness but different lateral sizes ranging from ∼ 30 nm to ∼ 3000 nm. Structure-property relationships were elucidated using a suite of techniques. Microscopy and scattering probed gel nanostructure and particle configuration. Rheology quantified linear and non-linear viscoelastic properties and yielding behavior. Birefringence and polarized imaging assessed size-dependent nanoclay alignment during shear flow. Nanoclay size ratio relative to nanospheres affected the gelation process, network structure, elasticity, yielding, and shear response. Gels with comparably sized components showed maximum elasticity, while yield stress depended on nanoclay rotational mobility. Shear-induced nanoclay alignment was quantified by birefringence, which is more pronounced for larger nanoclay. Varying nanoclay size and interactions with nanospheres controlled dispersion, aggregation, and nematic ordering. These findings indicate that architectural and interactional asymmetry enables more control over gel properties through controlled assembly of anisotropic building blocks. [ABSTRACT FROM AUTHOR]

Due to cyclic loading, clays composed of different mineral compositions exhibit non-linear viscoelastic characteristics. This study quantified the effect of the mineral composition on the non-linear viscoelastic properties of clays. Large-amplitude oscillatory shear rheological tests and cryo-electron microscopy tests were conducted on clays containing quartz, feldspar, montmorillonite, and kaolinite (Q, F, Mt., and Kaol). The results indicated that as the clay content in the soil sample increased, so did the value of relative intensity(I 3 / 1), the Lissajous curves shifted from elliptical to rectangular, and the absolute values of the overall non-linear viscoelasticity parameters (N E and N V) were also larger. In addition, its non-linear viscoelasticity was more prominent, supported by the cryo-electron microscopy test outcomes. Montmorillonite played a more significant role than kaolinite in increasing the nonlinear viscoelasticity of the soil samples. The study findings have significant academic and practical value, facilitating an in-depth understanding of the viscoelastic behavior of clays, rheological studies of other types of clay soils, and geotechnical engineering applications. • Studying clay non-linear viscoelastic behavior (NLVEB) using rheology. • Quantifying NLVEB of clay using overall characterization parameters (N E and N V). • Clay mineral composition and content have a great influence on the NLVEB in clays. • Montmorillonite is extremely important for the NLVEB in clays. [ABSTRACT FROM AUTHOR]

In this research, the effects of modifiers on the high-temperature rheological and fatigue properties of asphalt were investigated by utilizing montmorillonite (MMT) and organic montmorillonite (OMMT) as modifiers for 70# and styrene butadiene styrene (SBS) asphalt, respectively. Temperature scanning tests and linear amplitude scanning (LAS) tests were performed using a dynamic shear rheometer (DSR) to evaluate the viscoelasticity, rutting resistance, and fatigue properties of the asphalt binder. The rheological properties under high-temperature and high-frequency conditions were also characterized by the Black curve and Cole–Cole transformation. Additionally, the elastic properties of the asphalt were examined using nanoindentation (NI). The results of the DSR tests indicate that the incorporation of MMT/OMMT into asphalt enhances its elastic properties and reduces its viscous properties, leading to improved resistance to shear deformation, rutting, and fatigue. Moreover, the NI tests show that the addition of MMT or OMMT improves the elastic properties of the asphalt, while also validating the effectiveness of nanoindentation in assessing the viscoelasticity of asphalt. [ABSTRACT FROM AUTHOR]

Background: Protein-polysaccharide complexes have been successfully used for emulsion stabilization. However, it is unclear how the complex's surface charge influences aggregation stability and coalescence stability of emulsions, and whether a low charged interfacial film can still maintain the coalescence stability of oil droplets. In the present study, the effects of pH (around the pI of protein) on the aggregation and coalescence stability of emulsions were investigated., Results: Whey protein isolate (WPI) and peach gum polysaccharides (PGP) complexes (WPI-PGP complexes) were synthesized at pH 3, 4 and 5. Their sizes were 598, 274 and 183 nm, respectively, and their ζ-potentials were +2.9, -8.6 and -22.8 mV, respectively. Interface rheological experiments showed that WPI-PGP complex at pH 3 had the lowest interfacial tension, and formed the softest film compared to the complexes at pH 4 and 5. Microfluidic experiments showed that all WPI-PGP complexes were able to stabilize droplets against coalescence within short timescales (milliseconds). At pH 3, no coalescence was observed even under conditions where the continuous phase flow influenced the shape of oil droplets (from spheres to ellipsoids). At pH 4 and 5, the model emulsions were stable over 16 days of storage, extensive aggregation and creaming occurred at pH 3 after 8 days. Importantly, no coalescence took place., Conclusion: The present study confirmed that the aggregation stability of the emulsions was mainly determined by the surface charge of the complex, whereas the coalescence stability of emulsions is expectedly determined by steric repulsion, providing new insights into how to prepare stable food emulsions. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: Dispersion presents both a challenge and a diagnostic opportunity in shear wave elastography (SWE). Shear Wave Rheometry (SWR) is an inversion technique for processing SWE data acquired using an acoustic radiation force impulse (ARFI) excitation. The main advantage of SWR is that it can characterize the shear properties of homogeneous soft media over a wide frequency range. Assumptions associated with SWR include tissue homogeneity, tissue isotropy, and axisymmetry of the ARFI excitation). Objective: Evaluate the validity of the SWR assumptions in ex vivo bovine liver. Approach: SWR was used to measure the shear properties of bovine liver tissue as function of frequency over a large frequency range. Assumptions associated with SWR (tissue homogeneity, tissue isotropy, and axisymmetry of the ARFI excitation) were evaluated through measurements performed at multiple locations and probe orientations. Measurements focused on quantities that would reveal violations of the assumptions. Main results: Measurements of shear properties were obtained over the 25-250 Hz range, and showed a 4-fold increase in shear storage modulus (from 1 to 4 kPa) and over a 10-fold increase in the loss modulus (from 0.2 to 3 kPa) over that decade-wide frequency range. Measurements under different conditions were highly repeatable, and model error was low in all cases. Significance and Conclusion: SWR depends on modeling the ARFI-induced shear wave as a full vector viscoelastic shear wave resulting from an axisymmetric source; it is agnostic to any specific rheological model. Despite this generality, the model makes three main simplifying assumptions. These results show that the modeling assumptions used in SWR are valid in bovine liver over a wide frequency band., (© 2024 IOP Publishing Ltd.)

Rheological properties of gastric contents depend on the food ingested, and on the volume and composition of secretions from the host, which may vary. This study investigates the impact of saliva regular incorporation in the stomach after a meal on the rheological properties of gastric contents, considering two levels of salivary flow (low = 0.5 and high = 1.5 mL/min). In vitro chymes were obtained by mixing sour cream, simulated gastric fluid, two different volumes of oral fluid (at-rest human saliva, SSF for Simulated Salivary Fluid or water) and adjusting pH at 3. Chymes samples were characterized at 37°C for their particle size and rheological properties. Overall, particle size distribution was not different between samples: incorporating a larger volume of saliva resulted in more heterogeneity, but the surface area moment D[3,2] and volume moment D[4,3] did not differ significantly with the oral fluid type. Shear viscosity of chyme samples was higher when saliva was incorporated, in comparison with water or SSF. In addition, as shown from data extracted at γ ̇ $$ \dot{\gamma} $$  = 20 s -1 the higher the fluid volume the lower the shear viscosity, which is attributed to a dilution effect. However, this dilution effect was attenuated in the case of saliva, most likely due to its composition in organic compounds (e.g., mucins) contributing to the rheological properties of this biological fluid. In these in vitro conditions, both saliva and the salivation rate had a significant but slight impact on the rheological properties of gastric contents (of the order of 1-5 mPa s at γ ̇ $$ \dot{\gamma} $$  = 20 s -1 )., (© 2024 Wiley Periodicals LLC.)

Texture and sensory studies at various temperatures are important in evaluating and improving the functionality of butter. While literature is scarce, we evaluated and compared the effect of temperature (5-25°C) on the texture, rheological and sensory properties of commercial butter samples (salted, unsalted, cultured, and spreadable) from the New Zealand market. In addition, the instrumental analyses were compared with the sensory evaluation, to understand the possibility of using instrumental analysis to evaluate consumer liking for different butters. Butter type, temperature, and their type-temperature interaction exhibited significant differences for all instrumental textural parameters. As expected, higher temperature produced softer butter that was more spreadable, liquid-like, less adhesive, less cohesive, had lower storage modulus (G') and lower loss modulus (G″) with the melting of milk fat crystals; however, the rate of change varied for the different butter samples. We have established meltability as the parameter for evaluating butter selection for different applications. The spreadable butter sample exhibited the lowest hardness and G', and highest spreadability (p < .05) at all temperatures, owing to its low solid fat content and the abundance of low-melting triglycerides. The cultured butter sample had the highest melting point, owing to compositional differences. The instrumental and sensory texture analyses were highly correlated, indicating the comparative effectiveness of both approaches for studying the effects of different temperatures on butter textural properties. Overall, our findings provide detailed reference to the dairy industry for butter manufacture, considering variation in fatty acid composition, texture analysis, rheology, and sensory analysis, over the range of storage/usage temperatures., (© 2024 Wiley Periodicals LLC.)

Oleogels are of high interest as promising substitutes for trans fats in foods. An emulsion-templated method was used to trap olive oil in the chitosan crosslinked with vanillin matrix. Oil in water emulsions (50:50 w / w ) with different chitosan content (0.7 and 0.8% w / w ) with a constant vanillin/chitosan ratio (1.3) were air-dried at different temperatures (50, 60, 70, and 80 °C) and freeze-dried (-26 °C and 0.1 mbar) to produce oleogels. Only falling rate periods were determined during air-drying kinetics and were successfully modeled with empirical and diffusional models. At a drying temperature of 70 °C, the drying kinetics were the fastest. The viscoelasticity of oleogels showed that the elastic modulus significantly increased after drying at 60 and 70 °C, and those dried at 50 °C and freeze-dried were weaker. All oleogels showed high oil binding capacity (>91%), but the highest values (>97%) were obtained in oleogels with a threshold elastic modulus (50,000 Pa). The oleogels' color depended on the drying temperature and chitosan content (independent of the drying method). Significant differences were observed between air-dried and freeze-dried oleogels with respect to oxidative stability. Oxidation increased with the air-drying time regardless of chitosan content. The found results indicated that drying conditions must be carefully selected to produce oleogels with specific features.

Vertebroplasty is a minimally invasive surgical procedure used to treat vertebral fractures, which conventionally involves injecting poly(methyl methacrylate) (PMMA) bone cement into the fractured vertebra. A common risk associated with vertebroplasty is cement leaking out of the vertebra during the injection, which may occur due to a lack of understanding of the complex flow behavior. Therefore, experiments to quantify the cement's flow properties are necessary for understanding and proper handling of the bone cement. In this study, we aimed to characterize the behavior of PMMA bone cement in its curing stages to obtain parameters that govern the flow behavior during injection. We used rotational and oscillatory rheometry for our measurements, as well as a custom-made injector setup that replicated a typical vertebroplasty setting. Our results showed that the complex viscoelastic behavior of bone cement is significantly affected by deformations and temperature. We found that the results from rotational tests, often used for characterizing the bone cement, are susceptible to measurement artifacts caused by wall slip and "ridge"-like formations in the test sample. We also found the Cox-Merz rule to be conditionally valid, which affects the use of oscillatory tests to obtain the shear-thinning characteristics of bone cement. Our findings identify important differences in the measured flow behavior of PMMA bone cement when assessed by different rheological methods, an understanding that is crucial for its risk-free usage in downstream medical applications.

Background: Methylcellulose has been applied as a primary binding agent to control the quality attributes of plant-based meat analogues. H owever, a great deal of effort has been made to search for hydrocolloids to replace methylcellulose because of increasing awareness of clean labels. In this study, a machine learning framework was proposed in order to describe and predict the flow behavior of six hydrocolloid solutions, and the predicted viscosities were correlated with the textural features of their corresponding plant-based meat analogues., Results: Different shear-thinning and Newtonian behaviors were observed depending on the type of hydrocolloid and the shear rate. Methylcellulose exhibited an increasing viscosity pattern with increasing temperature, compared to the other hydrocolloids. The machine learning algorithms (random forest and multilayer perceptron models) showed a better viscosity fitting performance than the constitutive equations (power law and Cross models). In addition, three hyperparameters of the multilayer perceptron model (optimizer, learning rate, and the number of hidden layers) were tuned using the Bayesian optimization algorithm., Conclusion: The optimized multilayer perceptron model exhibited superior performance in viscosity prediction (R 2  = 0.9944-0.9961/RMSE = 0.0545-0.0708). Furthermore, the machine learning-predicted viscosities overall showed similar patterns to the textural parameters of the meat analogues. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Biodegradable green composites of poly(butylene succinate) (PBS) and poly(L-lactide) (PLA) fibers were initially melt-blended aiming to obtain balanced comprehensive properties. According to the morphological observations, the PLA fibers were uniformly embedded in the PBS matrix. Rheology measurements suggested that the incorporation of PLA fibers improved the viscoelasticity of PBS melt. The percolation network of PLA fibers was formed at content of 20 wt%. The presence of PLA fibers inhibited the crystallization and reduced the isothermal crystallization rate of PBS in the composites. Moreover, the reinforcing effect of PLA fibers on the PBS matrix was found to be very significant. The storage modulus and tensile modulus of the composite with 30 wt% PLA fibers were 74% and 94% higher than those of neat PBS, respectively. PBS/PLA fiber composites prepared by simple melt blending method displayed the combination of enhanced melt strength and modulus, while maintaining the biodegradability of PBS matrix, which is of great potential for the wider practical application of environmentally friendly polymers. [ABSTRACT FROM AUTHOR]

In this study, compound regeneration of SBS-modified bitumen (SMB) was carried out by a composite rejuvenator composed of furfural extraction oil (FEO) and 1,6-hexanediol diglycidyl ether (HDDGE) in the presence of catalyst triethanolamine (TEOA). SMB was subjected to three aging-regeneration cycles, and the physical and rheological properties, toughness and tenacity, and chemical structures of the SMB after each aging-regeneration cycle were tested to investigate the regeneration effect of the composite rejuvenator on SMB at different numbers of cycles. The ductility decreases and low-temperature properties deteriorate as the number of cycles increased, but the high-temperature properties of the SMB are improved. The complex modulus aging index and phase angle aging index indicate that the viscous behavior of SMB weakens after the second and third aging. The degree of viscoelasticity and toughness recovery decreases with the increase in the number of cycles, and the tenacity of SMB after the third aging-regeneration cycle is basically lost. The results of the Fourier transform infrared (FTIR) spectra tests prove that with the increase in the aging–regeneration cycles of SMB, the intensity of FTIR peaks of oxygen-containing functional groups is greater, and the recovery of aged SMB is gradually weakened. [ABSTRACT FROM AUTHOR]

Slip on clay fault planes at shallow depths in the seismogenic zone could be controlled by their rheology as well as their frictional properties; however, the rheological nature of clay faults is still an open question. Investigating the rheological properties of clay minerals is essential for understanding and modeling shallow earthquake faulting. Here, we perform dynamic viscoelasticity measurements on three clay minerals, namely kaolinite, illite, and smectite, wetted with water using a custom-made high pressure, high temperature rheometer. Our results confirm that the rheological properties resulting from the microstructure of clay minerals depend on the oscillation frequency, oscillation amplitude, temperature, and amount of water contained. In addition, the rheological properties vary systematically with the type of clay mineral. This suggests that the viscoelastic behavior of earthquake faults varies with the type of clay minerals present. • Dynamic viscoelasticity measurements are performed on clay minerals under high temperature and high pressure. • Dynamic viscoelasticity of clay minerals depends on oscillation frequency, oscillation amplitude, temperature and the type of mineral. [ABSTRACT FROM AUTHOR]

An analysis and modeling of the linear viscoelastic behavior of maltenes (M) blended with styrene–butadiene–styrene block copolymer (SBS) are presented in this study. M were mixed with different amounts of SBS (Elastomer, E) (0.25–80 wt%) to investigate the effect of polymer concentration on linear viscoelastic response of the blends; storage and loss moduli were obtained from small amplitude oscillatory shear tests (SAOS). Time–temperature superposition master curves were analyzed by a Maxwell multi-modal model with up to nine relaxation times. Han, Cole–Cole and Van Gurp-Palmen diagrams were prepared from the rheological data. Two different responses were observed: At low E contents, a dispersed system rheological response was observed and verified by microscopy with elastomer as the dispersed phase and maltenes as the matrix, while at high E content the response was that of a co-continuous system. Mixtures with E > 2 wt% exhibited change in their thermomechanical properties with a phase inversion at E > 50 wt%. Furthermore, at low E concentration resins stabilize the dispersed phase by diminishing the magnitude of the viscoelastic moduli, conversely, at high E concentration a swelled polymer-rich phase creates a network that significantly influences of the viscoelastic properties. [ABSTRACT FROM AUTHOR]

Lubrication by hydrogels is an emerging area in surface science. Although oil‐driven friction reduction is predominant in literature, emulsion gel‐based lubrication has attracted very little attention to date. We hypothesize that an interplay of viscoelasticity and oil volume fraction may modulate the lubricity of emulsion‐filled gels. Herein, phase‐change gelatin‐based emulsion‐filled gels with different sugar alcohols and oil droplet concentrations (0–30 wt%) are tested for their lubrication performance. The rheological and tribological tests are analyzed in conjunction with spectroscopic and structural characterizations to reveal structure–function relationship. Structural characterizations demonstrate that hydrogen bonding is enhanced in pure gelatin gels with the increase of sugar alcohol (glycerol)‐replacement time, which enhance the storage modulus (G′) of the gel networks. Emulsified droplets serve as active fillers further strengthening the G′ and strikingly the presence of glycerol reduced the thermoresponsiveness of the emulsion‐filled gels. Emulsion‐filled gels containing sugar alcohols, irrespective of their type, can greatly reduce the friction coefficients (μ) between hydrophobic surfaces in the boundary and mixed regimes versus the systems without sugar alcohols. In the hydrodynamic regime, the friction coefficient of the system is proportional to the second plateau shear viscosity, regulated by the oil content. [ABSTRACT FROM AUTHOR]

Vitrimers are a class of dynamic polymer networks that perform bond-exchange reactions (BERs) under environmental stimuli while preserving network connectivity. The viscoelastic properties of vitrimers are not only dependent on the kinetics of BERs, but also the architectures of polymer matrix. Here, we investigate the influence of polymer architectures on the dynamics and linear viscoelasticity of vitrimers through varying the sticker (reactive bead) distribution in the precursor chain and the BERs energy barrier (U b) by performing hybrid molecular dynamics-Monte Carlo simulations. Increasing U b , vitrimers with block and gradient distributions exhibit considerably faster relaxations of chain ends, Rouse mode, and stress and lower zero-shear viscosity than the analogs with random and uniform distributions, in qualitative agreement with the predictions of the sticky Rouse model. In contrast, the distribution of stickers has a small influence on the relaxation of dynamic bonds regardless of the U b value. By comparing the molecular structures of vitrimers with different distributions of stickers, we find that the molecular defects, especially the relatively longer dangling end in block and gradient distributions, impair the effect of dynamic bonds on the dynamics and viscoelasticity of vitrimers. This suggests that the dangling defects can be leveraged for further development of recyclable and healable materials with fast stress relaxation and improved flowability. [Display omitted] • The molecular defects impair the effect of dynamic bonds on the dynamics and viscoelasticity of vitrimers. • The distribution of stickers has a small influence on the relaxation of dynamic bonds in vitrimers. • The variation of the linear rheological behaviors with the distribution types of stickers is consistent with the predictions of the sticky Rouse model for unentangled vitrimers. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vitro study was to evaluate the changes the rheological properties of some soft lining materials, to compare the rheological properties and viscoelastic behaviour at different temperatures., Materials and Methods: Five soft lining materials (acrylic and silicone based) were used. the storage modulus (G'), loss modulus (G"), tan delta (tan δ) and complex viscosity (η') were chosen and for each material, measurements were repeated at 23, 33 and 37  °C, using an oscillating rheometer. All data were statistically analyzed using the Mann Whitney U test, Kruskal Wallis test and Conover's Multiple Comparison test at the significance level of 0.05., Results: Soft lining materials had different viscoelastic properties and most of the materials showed different rheological behavior at 23, 33 and 37  °C. At the end of the test (t¹5), at all the temperatures, Sofreliner Tough M had the highest storage modulus values while Visco Gel had the highest loss Tan delta values., Conclusions: There were significant changes in the rheological parameters of all the materials. Also temperature affected the initial rheological properties, and polymerization reaction of all the materials, depending on temperature increase., Clinical Implications: Temperature affected the initial rheological properties, and polymerization reaction of soft denture liner materials, and clinical inferences should be drawn from such studies conducted. It can be recommended to utilize viscoelastic acrylic-based temporary soft lining materials with lower storage modulus, higher tan delta value, and high viscosity in situations where pain complaint persists and tissue stress is extremely significant, provided that they are replaced often., (© 2024. The Author(s).)

A recent strategy for controlling saturated fat intake consists on the design of vegetable oil-based emulsions. The aim was to characterize the linear and nonlinear viscoelastic properties of o/w emulsions formulated with two types of cellulose: MX (methylcellulose, MC) and F4M (hydroxypropyl methylcellulose, HPMC). The emulsions were characterized by steady flow curves and frequency sweeps in SAOS (Small Amplitude Oscillatory Shear) regime. In order to evaluate linear and non-linear response, strain sweeps were performed from 0.01 to 1000% strain amplitude at different frequencies (0.1, 1 and 5 Hz). Fourier Transform rheology and orthogonal stress decomposition were applied and LAOS (Large Amplitude Oscillatory Shear) parameters (G' M , G' L , η M ' , η L ' , S and T) were analysed. The type of cellulose ether significantly affected both flow behaviour and internal structure of the samples. MX emulsion presented greater consistency at rest and higher gel strength in SAOS regime with a lower frequency dependence than F4M emulsion. However, both emulsions presented similar properties at large deformations, showing shear thinning and strain stiffening behaviour. Nonlinear viscoelastic analysis allows to improve the textural characterization of emulsions, providing complementary useful information for establishing the most suitable formulation in experimental conditions closer to real applications and processes. • Consistency and internal structure of the emulsions depended on the cellulose type. • Similar viscosity at high rates resulted from the different shear thinning character. • Both emulsions showed a similar strain stiffening behaviour for large deformations. • Characteristics in nonlinear regime were not in accordance with linear behaviour. [ABSTRACT FROM AUTHOR]

Nonlinear rheology of Pickering emulsions is used to further investigate the nonlinear and unrecoverable transformation of inner structures, which is beyond the linear viscoelastic regime of tiny structural disturbances. Exploring various rheological methods plays a vital role in emulsion applications, such as simulating the macroscopic structural transformation between static and liquidlike flow states, strain overshoot, and regeneration for broken structures. According to our previous studies, cellulose nanofibers (CNFs) Pickering emulsions are a typical system for investigating polymer-based emulsions with the auxiliary surfactant [didodecyldimethylammonium bromide (DDAB)] for enhancing CNF absorption. To further study different rheological properties by varying CNF or DDAB contents, multiple interval thixotropic test, large amplitude oscillatory shear, and concentration-time-dependent superposition are employed to study the linear viscoelasticity and structural transformation of nonlinear range. This research was conducted based on the previous published works [Cui et al., Materials 15, 8285 (2022)] as a further characterization for the same sample series. [ABSTRACT FROM AUTHOR]

In the present study, a systematic literature review (SLR) is conducted to collect, compile, and summarize the findings of previous studies in a meaningful and systematic way. This review focuses on the ideal blending ratios, mixing parameters, and the physical, thermal, and rheological performance of waste plastic-modified asphalt. It highlights the most significant research results about the challenges like phase separation, low-temperature performance, and workability for waste plastic-modified asphalt and progress in this domain. The results point out that the use of chemical and physical additives can help in the reduction of phase separation. Furthermore, this paper debates the aging characteristics and it was seen that the integration of waste plastic in asphalt has shown to slow down the aging process of the binder. The review article put forward details of various field projects across the globe utilizing waste plastic. The review concludes by presenting key findings, identifying research gaps, and suggesting future directions to advance the knowledge and to fully comprehend the possible application of waste plastic-modified bitumen in sustainable road construction., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In the last decade, hydrogels for hydraulic fracturing based on viscoelastic surfactants have been actively studied. Interest in these systems is justified by their unique qualities: good viscoelasticity and the ability to form stable suspensions of proppant or sand, destruction without the formation of bridging agents, hydrophobization of the rock surface and metal of technological equipment, as well as oil-cleaning properties. These qualities are most often provided by a minimum set of components—a surfactant and an electrolyte. However, the absence of a polymer limits the use of these gels in formations where fluid leakoff is possible. In this article, a liquid was studied, based on a pseudo gemini surfactant (PGVES) with the addition of a water-soluble polysaccharide. The objects of study were selected based on the assumption of interactions between PGVES and the polymer; interactions which favorably influence the technological characteristics of the fracturing fluid. To confirm the hypothesis, rheological studies were carried out. These included rotational viscometry and oscillatory studies at various temperatures. The settling velocity of particles of various proppant fractions was studied and tests were carried out to assess fluid leakoff. The performed experiments show an improvement in the characteristics of the PGVES-based gel under the influence of the polysaccharide. In particular, the rheological properties increase significantly, the stability of proppant suspensions improves, and the fluid leakoff of systems decreases, all of which expands the possibility of using these fracturing fluids and makes this area of experimentation promising. [ABSTRACT FROM AUTHOR]

The polycaprolactone-polydimethylsiloxane-polycaprolactone (PCL-PDMSPCL) triblock copolymer films of variable PCL chain are analyzed for rheological characteristics in this paper. The dynamics of viscoelastic behavior of photocrosslinked films above their crystal melting temperature (Tcm) is measured using oscillatory shear rheology experiments. The frequency sweep tests are analyzed at 0.1% strain as obtained from linear viscoelastic region. Shear thinning is observed in the study of complex viscosity. It has been noted that viscosity rises with increase in crosslink density and decrease in with PCL chain length. Time-dependent effect on the copolymer films has been analyzed by creep recovery behavior. The Burgers model is fitted in creep compliance data to analyze its viscoelastic and viscous region. An examination of structure recovery revealed that recovery increased as PCL chain length decreased. Tensile strength and percentage elongation are studied at ambient conditions with a universal testing machine, while storage modulus and tan δ are analyzed by a dynamic mechanical analyzer at varying temperatures. [ABSTRACT FROM AUTHOR]

Objective: The aggregation behavior of silk fibroin under specific conditions can influence its kinetic behavior and viscoelastic properties, thereby affecting biological properties of silk fibroin materials. Therefore, this study systematically investigated the self-assembly aggregation behavior of silk fibroin and explored the conditions for enhancing its mechanical performance and biological properties. Methods: Regenerated silk fibroin was extracted and prepared from domestic silkworm cocoons, and the optimal assembly conditions were determined through turbidity experiments. Rheological experiments were conducted to study the influence of Na+ on the kinetic behavior and viscoelastic properties of silk fibroin solutions. Cell proliferation experiments were carried out to investigate the biological properties of silk fibroin. Results: The extracted regenerated silk fibroin primarily exhibited a random coiled structure. The optimal in vitro self-assembly conditions involved assembly of a 4 mg/mL solution at 70 ℃ for 6 hours. The addition of Ca2+ to the silk fibroin solution inhibited in vitro self-assembly, while the addition of Na+ accelerated the assembly rate and increased the degree of assembly. Furthermore, with increasing Na+ concentration, the gel strength of silk fibroin gradually increased, leading to a more stable gel network. Cell proliferation experiments demonstrated that the solution of regenerated silk fibroin was more conducive to cell growth and proliferation than its self-assembled fibers. Conclusion: The concentration, temperature, assembly time, and ions all have an impact on the in vitro self-assembly aggregation behavior of silk fibroin. This study provides preliminary research on the self-assembly aggregation conditions and biological properties of silk fibroin, offering experimental basis for improving the performance of silk fibroin as a food packaging material.

Hyaluronic acid (HA) hydrogels are commonly used for facial dermal filling and for alternative medical aesthetic purposes. High diversity exists in commercial formulations, notably for the optimization of finished product stability, functionality, and performance. Polyvalent ingredients such as calcium hydroxylapatite (CaHA) or vitamin B3 (niacinamide) are notably used as bio-stimulants to improve skin quality attributes at the administration site. The aim of the present study was to perform multi-parametric characterization of two novel cross-linked dermal filler formulas (HAR-1 "Instant Refine" and HAR-3 "Maxi Lift") for elucidation of the various functional impacts of vitamin B3 incorporation. Therefore, the HAR products were firstly comparatively characterized in terms of in vitro rheology, cohesivity, injectability, and resistance to chemical or enzymatic degradation (exposition to H2O2, AAPH, hyaluronidases, or xanthine oxidase). Then, the HAR products were assessed for cytocompatibility and in vitro bio-stimulation attributes in a primary dermal fibroblast model. The results showed enhanced resilience of the cohesive HAR hydrogels as compared to JUVÉDERM® VOLBELLA® and VOLUMA® reference products in a controlled degradation assay panel. Furthermore, significant induction of total collagen synthesis in primary dermal fibroblast cultures was recorded for HAR-1 and HAR-3, denoting intrinsic bio-stimulatory effects comparable or superior to those of the Radiesse® and Sculptra™ reference products. Original results of high translational relevance were generated herein using robust and orthogonal experimental methodologies (hydrogel degradation, functional benchmarking) and study designs. Overall, the reported results confirmed the dual functionalization role of vitamin B3 in cross-linked HA dermal fillers, with a significant enhancement of hydrogel system stability attributes and the deployment of potent bio-stimulatory capacities. [ABSTRACT FROM AUTHOR]

Carbohydrate polymers have broad application prospects, especially in food and cosmetic fields, and rheology is very important for controlling the quality and functions of their final products. Therefore, the steady and transient rheological behaviors of polysaccharides with different chain conformations of triple helix, double helix, and random coils were studied systematically. In our findings, the extraordinary low‐shear thickening phenomena of polysaccharides (lentinan, curdlan, and xanthan) with helix conformation were observed at a certain concentration depending on the stiffness and molecular weight, different from the steady‐shear rheological property of pullulan, which was attributable to the arrangement from order to disorder of stiff chains at the shear rate of < 0.1 s−1. Lentinan, curdlan, and xanthan in solution showed obvious viscoelasticity and thixotropic behavior with significant concentration and stiffness dependence, while the flexible pullulan only exhibited Newtonian viscous fluid even at high concentration of 20%. Stress overshoot for the four polysaccharides occurred after shearing, and the higher stiffness and molecular weight delayed the occurrence of stress overshoot. Obviously, chain conformation plays a key role on controlling the rheology of polysaccharides. This work provides scientific basis for the application of these polysaccharides in food and cosmetics field. [ABSTRACT FROM AUTHOR]

The effects of using a hard (artisanal) margarine (which has a higher lipidic and lower aqueous contents) and using a soft (commercial) margarine (which has a lower lipidic and higher aqueous contents), along with a casein hydrolysate, on the rheological properties of different biscuit short doughs were examined. The characteristic parameters in the linear viscoelastic range (LVER) were analysed by stress sweep at 6.3 rad/s and 25 °C. The two margarines showed similar values of strain amplitude (γmax), but the hard margarine exhibited a significantly higher firmness in the LVER, as expected. An analogous result was found for the biscuit doughs made with hard margarine and soft margarine. The addition of a casein hydrolysate (CH) to both biscuit doughs produced an increase in the loss factor, indicating a loss of the solid-like character in the dough networks. Nevertheless, a different trend in the consistency of the dough, which depended on the type of margarine, was found. While, after adding CH, the dough made with soft margarine showed a significant reduction in rigidity, the dough with hard margarine exhibited an increased firmness upon CH addition. Yield stress tests showed that CH facilitates the transition from elastic to plastic deformation at the yield point more intensely in the dough with soft margarine.

Abstract Purpose The aim of this in vitro study was to evaluate the changes the rheological properties of some soft lining materials, to compare the rheological properties and viscoelastic behaviour at different temperatures. Materials and methods Five soft lining materials (acrylic and silicone based) were used. the storage modulus (G’), loss modulus (G”), tan delta (tan δ) and complex viscosity (η’) were chosen and for each material, measurements were repeated at 23, 33 and 37 °C, using an oscillating rheometer. All data were statistically analyzed using the Mann Whitney U test, Kruskal Wallis test and Conover’s Multiple Comparison test at the significance level of 0.05. Results Soft lining materials had different viscoelastic properties and most of the materials showed different rheological behavior at 23, 33 and 37 °C. At the end of the test (t¹5), at all the temperatures, Sofreliner Tough M had the highest storage modulus values while Visco Gel had the highest loss Tan delta values. Conclusions There were significant changes in the rheological parameters of all the materials. Also temperature affected the initial rheological properties, and polymerization reaction of all the materials, depending on temperature increase. Clinical implications Temperature affected the initial rheological properties, and polymerization reaction of soft denture liner materials, and clinical inferences should be drawn from such studies conducted. It can be recommended to utilize viscoelastic acrylic-based temporary soft lining materials with lower storage modulus, higher tan delta value, and high viscosity in situations where pain complaint persists and tissue stress is extremely significant, provided that they are replaced often.

As a soluble fiber, inulin is present in many plants and has many applications in food and non-food products. In this work, we investigated the rheological properties of inulin dispersions at seven concentrations. The linear viscoelastic properties of inulin were determined using a conventional mechanical rheometer. At 25 wt%, inulin exhibited fluid-like viscoelastic liquid behavior. However, when concentrations were ≥27.5 wt%, inulin exhibited gel-like viscoelastic properties. The viscoelastic properties (moduli and viscosities) increased with increasing inulin concentration. The high-frequency linear rheological properties of inulin were also investigated using the modern light scattering technique, diffusion wave spectroscopy (DWS). The diffusion wave spectroscopy (DWS) measurements showed the amplitude of complex moduli (|G*(ω)|) of inulin gels (≥27.5 wt%) to be proportional to ½ power law of the frequency, which suggests inulin gels behave similarly to flexible polymers. The non-linear steady shear experiments demonstrated that inulin exhibited shear-thinning behavior that was well fitted by a power law constitutive model. The trend of the power law exponent from the experiments indicated that the shear-thinning extent for inulin was greater as the inulin concentration increased. The results of this work indicated that the properties of inulin gel can be manipulated by altering its concentration. Therefore, the desired inulin product can be designed accordingly. These results can be used to direct further food and non-food applications, such as wound healing materials for inulin gels. [ABSTRACT FROM AUTHOR]

Electrothermal pumping is a recently trending method to force highly conductive fluids in a wide range of microfluidics applications with biological processes. Although most polymer fluids (biological and synthetic) are highly conductive exhibiting viscoelastic rheological properties that are relevant to biomedical applications, their behavior under the effect of electrothermal force has not yet been studied. To this aim, the PTT model (non-linear rheological constitutive equation) and electrothermal equations are implemented in the developed OpenFOAM solver. The effect of rheological characteristics of the fluids on the physical parameters such as velocity, elastic behavior, and vortices strength of electrothermal flow are investigated through the viscoelastic non-dimensional numbers. According to the results, electrothermal outlet velocity decreases by 726% as the retardation ratio (β number) increases from 0.2 to 0.9 and increases by 107% as the Weissenberg number raises from 0.001 to 10. Investigating all non-dimensional numbers simultaneously leads to the conclusion that higher electrothermal velocity is achieved by viscoelastic fluids with lower viscosity and higher relaxation time. This fact is useful for choosing the proper fluid for a particular application. As a practical example, 3000 ppm polyethylene oxide solution results in higher velocity in electrothermal flow compared to the 5% polyvinylpyrrolidone and 2000 ppm xanthan gum solution. [ABSTRACT FROM AUTHOR]

The rheological properties of porcine heart, kidney, liver and brain were measured using dynamic oscillatory shear tests over a range of frequencies and shear strains. Frequency sweep tests were performed from 0.1 Hz to a maximum of 9.5 Hz at a shear strain of 0.1%, and strain sweep tests were carried out from 0.01% to 10% at 1 Hz. The effect of pre-compression of samples up to 10% axial strain was considered. The experimental measurements were fit to a Semi-Fractional Kelvin Voight (S-FKV) model. The model was then used to predict the stress relaxation in response to a step strain of 0.1%. The prediction was compared to experimental relaxation data for the porcine organ samples, and the results agreed to within 30%. In conclusion, this study measured the rheological properties of porcine organs and used a fractional viscoelastic model to describe the response in frequency and time domain.

Yam (Dioscorea. sp.) is an edible starchy tuber with potential for being a commercial source of starch for industrial purposes, but yam starch is underutilized. The dynamic oscillatory and thermal properties of yam starches from sixteen varieties each of Dioscorea. rotundata, Dioscora. alata, Dioscorea. bulbifera and one variety of Dioscorea. dumetorum from Nigeria were studied to determine their potential for industrial utilization. The storage modulus, loss modulus, damping factor and complex viscosity as a function of frequency (ω) of the dioscorea gels, as well as the onset temperature (To), peak gelatinization temperature (Tp), end of gelatinization (TC), and gelatinization enthalpy of the starches were determined by standard procedures. Results showed that all the dioscorea starches showed a typical elastic behavior with the magnitude of G′ greater than G″ while tan δ < 1 in all varieties. Thus, the starch gels were more elastic than viscous. All the starch gels exhibited shear thinning characteristics and showed frequency (ω) independence characteristics of weak gels. D. rotundata varieties had the lowest ∆Hgel, while D. bulbifera varieties had the highest. The diversity of the visco-elastic and thermal properties of the yam starch gels from different varieties and species can be an advantage in their utilization in both food and non-food industries. [ABSTRACT FROM AUTHOR]

A well-known method for reducing or swapping out undesirable and controversial fats in food is oleogelation. To quantify the effects of droplets-particle inclusion on the textural aspects of gelled systems, a thorough understanding of rheological behavior of oleogels (OGs) is necessary. Otherwise stated, a rational grasp of rheological characterization is essential for food development, optimization, and processing (when touching or putting food into the mouth, rheological flow qualities influence our perception). This narrative review primarily intends to investigate rheological and textural characteristics of various oleogelator-based OGs, such as operative connection between hardness, distortion, stresses, and rheological parameters like viscosity, elasticity, and viscoelasticity, as well as flow behavior and recovery. Expanding oleogelators concentration and synergistic interactions between them increase robustness and moduli values, as compared to single oleogelators. However, given the lack of information on the connection between the OGs' macroscopic rheological characteristics and their microstructural characteristics, this review presents state-of-the-art overview of various oleogelator-based OGs, highlighting the importance of structure–rheology relationships of OGs to provide advanced knowledge on the development of innovative OGs. [ABSTRACT FROM AUTHOR]

In this study, the viscoelastic properties of porcine kidney in the upper, middle and lower poles were investigated using oscillatory shear tests. The viscoelastic properties were extracted in the form of the storage modulus and loss modulus in the frequency and time domain. Measurements were taken as a function of frequency from 0.1 Hz to 6.5 Hz at a shear strain amplitude of 0.01 and as function of strain amplitude from 0.001 to 0.1 at a frequency of 1 Hz. Measurements were also taken in the time domain in response to a step shear strain. Both the frequency and time domain data were fitted to a conventional Standard Linear Solid (SLS) model and a semi-fractional Kelvin–Voigt (SFKV) model with a comparable number of parameters. The SFKV model fitted the frequency and time domain data with a correlation coefficient of 0.99. Although the SLS model well fitted the time domain data and the storage modulus data in the frequency domain, it was not able to capture the variation in loss modulus with frequency with a correlation coefficient of 0.53. A five parameter Maxwell–Wiechert model was able to capture the frequency dependence in storage modulus and loss modulus better than the SLS model with a correlation of 0.85.

A few experiments have reported that the time development of shear stress under fast-startup shear deformations exhibits double peaks before reaching a steady state for bimodal blends of entangled linear polymers under specific conditions. To understand this phenomenon, multi-chain slip-link simulations, based on the primitive chain network model, were conducted on the literature data of a bimodal polystyrene solution. Owing to reasonable agreement between their data and our simulation results, the stress was decomposed into contributions from long- and short-chain components and decoupled into segment number, stretch, and orientation. The analysis revealed that the first and second peaks correspond to the short-chain orientation and the long-chain stretch, respectively. The results also implied that the peak positions are not affected by the mixing of short and long chains, although the intensity of the second peak depends on mixing conditions in a complicated manner.

The aims of this work are to study the rheological behaviors of a microemulsion of Glucopone–water–hydrocarbon systems and to use a fractional model to describe several experimental results of these systems. Four different types of hydrocarbons were considered. The frequency dependent storage, G′, and loss modulus, G″, were investigated below the critical strain. The critical strain was found to decrease as the alkane chain lengths increased, while the opposite behavior was observed for zero shear viscosity, η0. Most of the microemulsions exhibited stable elastic fluid behavior (G′ > G″) below 10 rad s−1 angular frequency. For all systems, elastic modulus values were found to be greater than loss modulus in the frequency range studied, indicating more elastic behaviors. Shear-thinning behaviors were observed, and the complex viscosity decreased with an increase in hydrocarbon chain lengths. The effects of hydrocarbon types on the rheological behaviors were more profound in the dodecane systems which showed maximum values of G′ and η0. The Friedrich–Braun model was introduced and was used to describe several experimental results on Alkyl polyglocoside solutions. Fractional rheology successfully described the viscoelastic phenomena in Glucopone surfactant solutions and the comparisons between the experimental results and the theoretical predictions were found to be satisfactory.

Simple Summary: Blood clots are formed when blood vessels are injured. They help stop bleeding and heal wounds, but can also cause serious problems if they block blood flow or break off and travel to other organs. This study investigates how blood clots differ in people with cancer compared to healthy or non-cancerous individuals. This study found that cancer patients have higher levels of histones in their blood, which make their clots stiffer and resistant to lysis. Further, clots formed in cancer patients have higher viscoelastic properties, and hence are harder to break down. These findings suggest that cancer patients have abnormal clotting properties that may increase their risk of developing thrombosis, and evaluating these properties can be helpful in detecting cancer. Background: Blood viscoelasticity and plasma protein levels can play an important role in the diagnosis and prognosis of cancer. However, the role of histones and DNA in modulating blood clot properties remains to be investigated. This study investigates the differences in blood viscoelasticity and plasma protein levels among cancer patients, individuals with other diseases, and healthy individuals. Methods: Blood samples were collected from 101 participants, including 45 cancer patients, 22 healthy individuals, and 34 individuals with other diseases. Rheological properties of clots formed in vitro by reconstituted elements of fibrinogen or plasma were analyzed with an Anton Paar Rheometer, USA. Plasma protein levels of D-dimer, TPA, EPCR, fibrinogen, and histone H3 were measured through ELISA. Blood clots were formed with or without DNA and histones (H3) by adding thrombin and calcium to plasma samples, and were evaluated for viscoelasticity, permeability, and degradation. Results: Cancer patients show higher blood viscoelasticity and plasma D-dimer levels compared to healthy individuals and individuals with other diseases. Our in vitro analysis showed that the addition of histone to the plasma results in a significant decrease in viscoelasticity and mean fiber thickness of the clot formed thereafter. In parallel studies, using plasma from patients, DNA and histones were detected in fibrin clots and were associated with less degradation by t-PA. Moreover, our results show that the presence of DNA and histones not only increases clots' permeability, but also makes them more prone to degradation. Conclusions: Plasma histones and DNA affect the structure of the clot formed and induce defective fibrinolysis. Moreover, the increased viscoelastic properties of plasma from cancer patients can be used as potential biomarkers in cancer prognosis. [ABSTRACT FROM AUTHOR]

• PLA/PHBH/PVAc ternary blends were prepared by simply melt mixing. • PVAc was electively located in PLA matrix and refined phase morphology. • Addition of PHBH and PVAc increased the flexibility and toughness of PLA. • Melt viscoelasticity of PLA was improved by incorporation of PHBH and PVAc. To toughen brittle poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate- co -3-hydroxyhexanoate) (PHBH) and poly(vinyl acetate) (PVAc) were introduced into PLA matrix to prepared PLA/PHBH/PVAc ternary blends. PVAc was electively located in PLA matrix and refined phase morphology owing to better miscibility of PVAc with PLA than with PHBH. Increase in PVAc content decreased the crystallization rate and the crystallinity of PLA due to the dilution effect. More importantly, prominent enhancement of flexibility and toughness of PLA was obtained by the addition of PHBH and PVAc. Elongation at the break and impact strength of ternary blend with 10 wt% PVAc were 277 % and 326 % higher than that of neat PLA. Melt viscoelasticity of PLA was improved by incorporation of PHBH and PVAc. The combination of increased toughness and high melt viscoelasticity established in PLA biodegradable blends represent properties required in a wider range of applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Oscillatory shear tests are frequently used to determine viscoelastic properties of complex fluids. Both the amplitude and frequency of the input signal can be independently varied, allowing rheologists to probe a wide range of material responses. Historically, most oscillatory tests have focused on the measurement and application of the total strain. However, the total strain is a composite parameter consisting of recoverable and unrecoverable components. Use of only the total strain therefore provides an incomplete description of the rheology. In this work, we provide a mathematical derivation for the determination of the recoverable and unrecoverable components in steady-state linear viscoelastic oscillatory flows via a simple experimental procedure. The relationship between the total strain and its components is fully explored and challenged in the context of how rheologists define moduli and common rheological models. These relations are demonstrated via experimental measurements on model viscoelastic and viscoplastic materials: wormlike micelles and Carbopol 980. Additionally, we show how the derived mathematics fully details the conditions where the Cox-Merz rules are valid in terms of recovery rheology. Finally, we demonstrate how a thorough understanding of the strain components can be used to create a simple nonlinear model that reproduces all common amplitude sweep behaviors. [ABSTRACT FROM AUTHOR]

The multiple regeneration of aging asphalt pavements has emerged as a pavement maintenance approach. However, the micromechanisms and performance deterioration patterns associated with multiple regenerations remain unclear. The present work aims to investigate the rheological and physicochemical properties of styrenic block copolymers (SBS)-modified asphalt during multiple recycling processes. The rheological properties, nanostructure, and functional group evolution of SBS-modified asphalt during multiple recyclings were evaluated using rotational viscosity, frequency scanning, multistress creep recovery (MSCR), atomic force microscopy (AFM), and Fourier transform infrared (FTIR) tests. The key findings demonstrated that the viscoelasticity of asphalt is affected by both SBS degradation and asphalt aging. During the initial aging phase, SBS degradation mainly affects the asphalt properties, whereas the subsequent aging process becomes the dominant factor. Moreover, the viscoelasticity of the asphalt binder is primarily influenced by aging rather than the SBS degradation. Importantly, the SBS-modified asphalt continues to meet specification requirements even after multiple recycling rounds, demonstrating the feasibility of aging SBS-modified asphalt binder through multiple regeneration techniques. [ABSTRACT FROM AUTHOR]