Rheological Behavior Research Articles

Investigation on the interfacial and emulsion stabilized behavior of dextran/ferritin/resveratrol composite nanoparticles

Glycation of ferritin provides a viable approach to enhance its physicochemical and functional properties. However, there is limited research on the interfacial adsorption properties of glycated ferritin-based colloidal particles. Therefore, this study selected recombinant human H-chain ferritin (rHuHF), rHuHF encapsulated with resveratrol (rHuHF–Res), and rHuHF–dextran glycoconjugates loaded with resveratrol (Dex–rHuHF–Res) as emulsifiers to investigate their interfacial adsorption properties. The results revealed that Dex–rHuHF–Res exhibited superior emulsifying properties and rheological behavior. It also increased the hydrophobicity of the microenvironment around Tyr and Trp residues, while hydrogen bonds, hydrophobic force, and salt bridge were identified as the most important intermolecular interactions. Dex–rHuHF–Res exhibited the biggest contact angle and lowest interface tension, which further reduced the diffusion (Kdiff) from the aqueous phase to the interface but promoted the penetration (Kp) and rearrangement (Kr) rates at the interface. Meanwhile, the emulsion stabilized by Dex–rHuHF–Res displayed excellent freeze-thaw stability, and Dex–rHuHF–Res can be more densely accumulated at the O/W interface to form an interface layer. These findings highlight the promising application of glycated ferritin in stabilizing Pickering emulsions, and deepen our understanding of the interplay among particle interaction, interface adsorption properties, and emulsion stability.

Myosin supramolecular self-assembly: The crucial precursor that manipulates the covalent aggregation, emulsification and rheological properties of myosin

The transformation of molecular conformation and self-assembly properties of myosin during the heating process at different ionic strengths (0.2 M, 0.4 M and 0.6 M NaCl) and its effect on rheological behavior and emulsification properties were investigated. Under incubation temperatures between 40 °C and 50 °C, myosin underwent a supramolecular self-assembly stage dominated by noncovalent forces (hydrogen bonding, ionic bonding and hydrophobic interactions). Higher ionic strength facilitated molecular rearrangement through enhanced swelling of myosin heads and head-to-head assemblies, which contributed to enhanced ordering and homogeneity of myosin covalent aggregates (above 60 °C) and manifested itself macroscopically as enhanced gel viscoelasticity and emulsion stability. In contrast, at lower ionic strength, the tail-to-tail assemblies of myosin led to the preferential formation of covalent cross-links in the tails, which resulted in the inability of molecular rearrangement and the formation of disordered aggregates and finally led to the deterioration of the gel and the destabilization of the emulsion. In conclusion, the supramolecular self-assembly behavior of myosin, as an intermediate process in myosin’s sol–gel transition, is crucial for the orderliness of myosin assemblies, gel network strengthening, and emulsion stability. The obtained insight provides a reference for the precise implementation of quality improvement strategies for meat products.

Computational Intelligence for Modeling the Rheological Properties of the Developed Hydrated Lime-Based Alkali-Activated Materials

The development of alkali-activated materials (AAMs) has gained attention as a sustainable alternative to Portland cement-based concrete. A key factor in AAM performance is its rheological behavior, which influences workability and pumpability. Accurate prediction of these properties is vital for optimizing mix design. This study introduces a computational framework using ensemble and non-ensemble machine learning (ML) techniques to model the yield stress (YS) and plastic viscosity (PV) of AAMs. A comprehensive dataset from previous experiments was used to train models, including artificial neural networks (ANN), gene expression programming (GEP), decision tree, random forest, adaptive boosting, and gradient boosting. The models achieved R² values exceeding 0.95 and correlation coefficients above 0.97. Error metrics, such as MAPE, MAE, MSE, and RMSE, further validated the models’ generalizability. A parametric analysis showed that a 20% increase in hydrated lime (HL) content raised YS by 350Pa, which is similar to the effect of varying fly ash (FA) from 60% to 100%. A 40% increase in FA and HL content increased PV by 4Pa.s and 25Pa.s, respectively. A 3% rise in sodium silicate led to a 400Pa increase in YS, while a similar increase in sodium hydroxide raised YS by 170Pa and PV by 15Pa·s. Overall, this study provides an effective tool for optimizing AAM mix designs by accurately predicting rheological properties and quantifying the impact of key parameters, contributing to the advancement of sustainable cementitious materials in construction.

Avaliação do comportamento reológico de argamassas de revestimento por meio do método do Squeeze-Flow com base no empacotamento de partículas e o teor de água da mistura

Abstract Mortars’ workability results from other properties, such as consistency, plasticity, cohesion, water retention, exudation, initial adhesion and density. A workable mortar distributes itself in application, doesn’t segregate during transport, and remains plastic during the application time. This property depends on several application factors, together with the constituent materials. Therefore, this study aims to assess the influence of the formulation, aggregate type and water content on rheological behavior of rendering mortars, combined with particle packing studies. For this purpose, three usual mortar formulations were chosen. The minimum water content was calculated through the concepts of particle packing and the squeeze flow test. As a result, the influence of each constituent on the workability of the mortar was determined, together with the formulations optimized by the aggregate type. The water content analysis revealed the wet packing density and minimum value required for the formation of the water film around the particles.

Formulation of a novel hot pot dipping sauce enriched with pepper seed press cake: Physical properties and flavor characteristics

Novel hot pot dipping sauces enriched with pepper seed press cake (PSPC) in five proportions were prepared and evaluated in terms of their physical properties and flavor characteristics. The findings indicated that enriching the sauce increased the content of palmitic and linoleic acids, enhanced storage stability, and improved the rheological behavior and textural properties. The maximum concentration of N-heterocyclic compounds was detected when PSPC was added at 5 g/100 g and 10 g/100 g. A suitable amount of PSPC could improve the mouthfeel and intensify the flavors of umami and saltiness. In comparing sauces with different amounts of PSPC added (0–20 g/100 g), the quality, aroma, and taste were better and overall acceptance was highest when PSPC was added in the range of 5 g/100 g to 10 g/100 g. This study provides a possible application of PSPC for improving the flavor, texture, nutritional quality, and storage stability of hot pot dipping sauce.

Co-vulcanization of natural rubber and Eucommia ulmoides gum for mediation of the nonlinear rheology behaviors

Co-vulcanization of natural rubber (NR) and high-moduli Eucommia ulmoides gum (EUG) is promising while the reduction in crystallinity of crosslinked EUG is adverse for developing high-performance materials. Proposed herein is a novel method to prepare high-strength and high-stretchability NR/EUG vulcanizates with rapid vulcanization of EUG into slightly crosslinked particles, followed by further vulcanization of NR to form crosslinked matrix network. Deep eutectic solvents (DESs) are employed to facilitate the vulcanization of EUG during its blending with NR. The two-step vulcanization results in vulcanizates exhibiting superior mechanical properties under shear, tensile, and compressive conditions, significantly exceeding those of vulcanizates prepared by traditional processing methods. The reinforcement mechanism is elucidated by controlling thermomechanical coupling conditions and is supported by comprehensive structural characterizations. It is suggested that the EUG crystalline regions, maintained through the special processing method, work in conjunction with the stress-induced crystallization of the matrix to enhance the vulcanizates, nearly doubling the deformation stress at 800% strain. The crystalline regions can mediate the deformation stress during shear and compression and weaken nonlinear rheological behavior. The established structure-performance relationship is guidable for preparing high-performance NR/EUG blend vulcanizates.

Abelmoschus manihot gum improves the water retention capacity of low-salt myofibrillar protein gels: Perspective on aggregation behaviour and conformational changes during heating

This study aimed to investigate the effect of Abelmoschus manihot gum (AMG) on the water retention capacity of low-salt myofibrillar protein (MP) gel by analysing its aggregation behaviour and conformational changes during heating (30–80 °C). The results revealed that AMG significantly increased the water holding capacity and facilitated the formation of a more uniform gel network structure in low-salt MP gel (P < 0.05). During the heat-induced gelation process, the solubility of low-salt MP significantly decreased, whereas its turbidity evidently increased as the level of added AMG increased (P < 0.05). Furthermore, the dynamic rheological behaviours indicated that low-salt MP-AMG gels underwent early denaturation and unfolded at 58 °C, finally forming an irreversible three-dimensional network at 80 °C. Moreover, adding AMG promoted α-helix-to-β-sheet transition in low-salt MP and decreased its fluorescence intensity during the heating process. Hydrophobic interactions and disulfide bonds were the two dominant forces governing the formation and maintenance of low-salt MP gel. The present study provides theoretical guidance for the production of novel low-salt healthy meat products.

Performance prediction of 304 L stainless steel based on machine learning

With the development of testing technology and data mining methodologies, machine learning (ML) has been widely applied for predicting the performance of materials in various systems including stainless steel with improved performance. To address the limitations of traditional experimental and statistical methods in predicting the thermal deformation of materials, a predictive machine learning model was developed based on the data obtained from thermal simulation compression tests. Specifically, the Arrhenius and the Modified Johnson-Cook (J-C) Constitutive Model were developed utilizing experimental data to initially predict the rheological behavior of 1.52% Cu-304L stainless steel. Then, a physical metallurgy (PM)-guided Back Propagation (BP) model was developed, and Genetic Algorithm (GA), Whale Optimization Algorithm (WOA), and Mind Evolutionary Algorithm (MEA) were incorporated into the model for optimization purposes, respectively. Finally, the results indicate that the PM-MEA-BP model exhibits superior predictive performance, accurately forecasting the texture evolution of 304L stainless steel with random crystal orientation under rolling deformation conditions. Additionally, the present work also clearly demonstrated that the model not only satisfies precision requirement but also has certain guiding significance for optimizing process parameters and forecasting the microstructure and properties of stainless steel.

Electrospinning and Rheological Characterization of Polyethylene Terephthalate and Polyvinyl Alcohol with Different Degrees of Hydrolysis Incorporating Molecularly Imprinted Polymers

This study investigates the electrospinning and rheological properties of polyethylene terephthalate (PET) and polyvinyl alcohol (PVA) with varying degrees of hydrolysis (DH) for molecularly imprinted polymer (MIP) incorporation. The morphology and properties of the electrospun nanofibers were evaluated, revealing that PVA nanofibers exhibited smoother and more uniform structures compared to PET fibers. The rheological behavior of the polymer solutions was also characterized, showing that PVA 99 DH solution exhibited shear-thinning behavior due to the unique structural properties of the polymer chains. The introduction of MIP and NIP additives had no significant impact on the rheological properties, except for PVA 99 MIP and NIP solutions, which showed deviations from Newtonian behavior. The electrospun MIP nanofibers showed a conductivity of 1054 µS/cm for PVA (87–90% DH) and a viscosity of 165.5 mPa·s, leading to optimal fiber formation, while displaying a good adsorption capacity of 0.36 mg for PVA-MIP to effectively target pharmaceuticals such as emtricitabine and tenofovir disoproxil, showing their potential for advanced water treatment applications. The results suggest that the electrospinning process and rheological properties of the polymer solutions are influenced by the molecular structure and interactions within the polymer matrix, which can be exploited to tailor the properties of MIPs for specific applications.

Composite Materials Based on Spent Coffee Grounds and Paper Pulp

The need for biodegradable and environmentally friendly materials is increasing due to resource shortages and rising levels of environmental pollution. Agro-food waste, which includes coffee grounds, is of great interest in the production of composite materials due to its low cost, low density, easy availability, non-abrasive nature, specific properties such as reduced wear on the machinery used, the absence of residues and toxic products, and biodegradable characteristics. The composite materials developed that include coffee grounds exhibit good characteristics. This field is evolving and requires further improvements, but, at this moment, it can be stated that coffee grounds are not just waste but can be transformed into a highly efficient material applicable in various domains. In this study, composite materials were prepared using paper pulp as a matrix, coffee grounds as a filler material, and water as a binding agent. The obtained composite materials were evaluated through thermal analysis, SEM, EDX, ATR-FTIR, and rheological behavior analysis. The composite materials created from paper pulp and coffee grounds proved to be effective for use in the production of seedling pots. The seedling pots created in this study are produced at a low cost, are environmentally friendly, exhibit thermal stability, have good stability over time, and have good resistance to deformation.

Recurrent Neural Network (RNN)-Based Approach to Predict Mean Flow Stress in Industrial Rolling

This study addresses the usage of data from industrial plate mills to calculate the mean flow stress of different steel grades. Accurate flow stress values may optimize rolling technology, but the existing literature often provides coefficients like those in the Hensel–Spittel equation for a limited number of steel grades, whereas in modern production, the chemical composition may vary by thickness, customer requirements, and economic factors, making it necessary to conduct costly and labor-intensive laboratory studies. This research demonstrates that leveraging data from industrial rolling mills and employing machine learning (ML) methods can predict material rheological behavior without extensive laboratory research. Two modeling approaches are employed: Gated Recurrent Unit (GRU) and Long Short-Term Memory (LSTM) architectures. The model comprising one GRU layer and two fully connected layers, each containing 32 neurons, yields the best performance, achieving a Root Mean Squared Error (RMSE) of 7.5 MPa for the predicted flow stress of three steel grades in the validation set.

Deformation Behaviors and Microstructure Evolution of Mg-Zn-Y-Zr Alloys During Hot Compression Process

This study investigated the thermal compression deformability of the low-alloyed Mg-Zn-Y-Zr magnesium alloy temperatures ranging from 300 to 450 °C, and strain rates between 0.01 s−1 and 1 s−1. A hot processing map was established using a novel constitutive model. The results demonstrate that the flow stress of the low-alloyed Mg-Zn-Y-Zr alloy is markedly affected by the deformation temperature and strain rate, predominantly manifesting characteristics of work hardening (WH) and dynamic recrystallization-induced softening. The high-temperature rheological behavior of the alloy is accurately portrayed with a constitutive model, with an activation energy measured at 287 kJ/mol. The mechanism of dynamic recrystallization (DRX) gradually shifts from twinning dynamic recrystallization (TDRX) to continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX). At 400 °C, as the strain rate decreases, the I-phase in the microstructure gradually transforms into the W-phase, weakening the inhibitory effect on DRX grain growth.

Interactions Between Cationic Micellar Solution and Aromatic Hydrotropes with Subtle Structural Variations.

Wormlike micelles (WLMs) with tunable viscoelastic characteristics have emerged as indispensable smart materials with a wide range of applications, which have garnered intense interest over the past few decades. However, quantitatively predicting the effect of various hydrotropes on the rheological behaviors of WLMs remains a challenge. In this article, micelles were formed in a mixture of 3-hexadecyloxy-2-hydroxypropyltrimethylammonium bromide (R16HTAB) and aromatic hydrotropes (e.g., sodium benzoate, sodium cinnamate and their derivatives, respectively) in an aqueous solution. The phase behavior, viscoelasticity and thickening mechanism were systematically studied by macroscopic observation, rheological measurements, electrostatic potential analysis and cryogenic transmission electron microscopy (Cryo-TEM). Rheological measurements were used to probe the remarkable viscoelastic properties of micelles stemming from their lengthening and entanglement under the interaction between R16HTAB and hydrotropes with structural variations. For an equimolar system of R16HTAB and cosolute (40 mM), the relaxation time decreases in the following order: SpMB > SoHB > S4MS > SmMB > S5MS > SB > SmHB > SoMB > SpHB. These results allow us to predict the possible rules for the self-assembly of R16HTAB and aromatic hydrotropes, which is conductive to directionally designing and synthesizing smart wormlike micelles.

Effect of Size-Controlled Nanofluid on Mechanical Properties, Microstructure, and Rheological Behavior of Cement Slurry for Oil Well Cementing

Effect of Size-Controlled Nanofluid on Mechanical Properties, Microstructure, and Rheological Behavior of Cement Slurry for Oil Well Cementing

Investigating the Performance of Self-compacting Concrete Exposed to Hot Weather

This study investigates the behavior of concrete in a real environment with a temperature exceeding 35 °C in the shade. It focuses on the rheological behavior of self-compacting concrete (SCC) and its ability to maintain its self-compacting aspect over time, compared to ordinary concrete (C3). The research also examines the impact of limestone fillers on SCC's fluidity in hot climates. In the hardened state, the study emphasizes concrete durability against sulfate and acid attacks and their effects on its microstructure. Three types of concrete were studied such as SCC without addition (C1), SCC with 15% of limestone fillers (C2), and (C3), were tested in terms of fresh and hardened states, along with durability against acid and sulfate attacks. Results showed that SCC in a hot climate maintained its self-compacting properties up to 25 minutes after mixing. However, over time, the fluidity of SCC with limestone fillers decreased noticeably and faster. The aging of concrete exposed to sulfuric acid in a hot and dry climate for six months was more intense than with sodium sulfate.

Toward Highly Toughened Polylactide/Polycaprolactone‐Based Polyurethane Blends With Shape Memory Property via Reactive Blending

ABSTRACTReactive blending has proven to be a versatile and efficient method for enhancing the impact toughness of polylactide (PLA). PLA/cross‐linked polycaprolactone‐based polyurethane (c‐PCLU) blends are prepared by reactive blending of PLA with PCL triol and hexamethylene diisocyanate (HDI). The reaction mechanism, compatibility, crystallization behavior, rheology behavior, mechanical performance, and shape memory property are thoroughly studied. The FTIR results confirmed that the NCO groups of HDI reacted with the hydroxyl groups of PLA and PCL triol, leading to the in situ formation of c‐PCLU and PLA‐co‐PCLU. The phase morphology exhibits a sea‐island structure, suggesting incompatibility between the two phases. The compatibility of the blends is improved with the increase of the PCL triol feeding ratio. The crystallization ability of PLA is retarded in the reactive blend. Both the elongation at break and the shape recovery ratio increase with c‐PCLU content, reaching up to 94.0% and 92.6%, respectively. These findings show that the formation of c‐PCLU greatly enhanced the toughness and shape memory performance of PLA.

Effect of kefir grain concentration on rheological, microbiological, and physicochemical characteristics of bovine colostrum kefir

Bovine colostrum has high nutrition content such as protein, fat, peptide, micro-nutrients, antimicrobial components and bioactive compounds that benefit the body. Kefir is one way of diversifying food products as fermented beverage products to increase the utilization and functional properties of bovine colostrum, which has a unique taste. Production of colostrum kefir requires the right concentration of kefir grains to obtain high-quality characteristics. Evaluating the effect of kefir grain concentration on the rheological, microbiological, and physicochemical characteristics of bovine colostrum kefir was the purpose of this research. This study used one factorial design with the variation of kefir grain concentrations 10% (T1), 20% (T2), and 30% (T3) (w/v) with seven replications. Rheological analysis was conducted, followed by total lactic acid bacteria, yeast, microbes, protein, fat, ash, water content, carbohydrate, pH, total dissolved solids and alcohol content. Based on the result, different kefir grain concentrations significantly decreased total LAB, yeast, microbes, protein, ash, pH, and total dissolved solids but increased carbohydrate and water content with the addition of kefir grain concentration. Rheology behavior, fats, and alcohol content had no significant difference. Treatment of 10% of kefir grain concentration is the most suitable as it contains the highest total LAB and yeast.

Large Scale Ultrafast Manufacturing of Wireless Soft Bioelectronics Enabled by Autonomous Robot Arm Printing Assisted by a Computer Vision-Enabled Guidance System for Personalized Wound Healing.

A Customized wound patch for Advanced tissue Regeneration with Electric field (CARE), featuring an autonomous robot arm printing system guided by a computer vision-enabled guidance system for fast image recognition is introduced. CARE addresses the growing demand for flexible, stretchable, and wireless adhesive bioelectronics tailored for electrotherapy, which is suitable for rapid adaptation to individual patients and practical implementation in a comfortable design. The visual guidance system integrating a 6-axis robot arm enables scans from multiple angles to provide a 3D map of complex and curved wounds. The size of electrodes and the geometries of power-receiving coil are essential components of the CARE and are determined by a MATLAB simulation, ensuring efficient wireless power transfer. Three heterogeneous inks possessing different rheological behaviors can be extruded and printed sequentially on the flexible substrates, supporting fast manufacturing of large customized bioelectronic patches. CARE can stimulate wounds up to 10 mm in depth with an electric field strength of 88.8 mVmm-1. In vitro studies reveal the ability to accelerate cell migration by a factor of 1.6 and 1.9 for human dermal fibroblasts and human umbilical vein endothelial cells, respectively. This study highlights the potential of CARE as a clinical wound therapy method to accelerate healing.

Description of nonlinear viscous and viscoelastic properties of polyacrylamide solution under loading

Background. Currently, the solution of the problem of describing the rheological behavior of viscoelastic and nonlinear viscous properties of liquid and solid-like materials is far from perfect. For successful application of polymer systems to enhance oil recovery and for preparation of fracturing fluids and drilling fluids, knowledge of their rheological properties is necessary. Objective. To determine the nonlinear viscous and viscoelastic properties of polyacrylamide solution. Material and methods. We made an attempt to describe the rheological behavior of a polyacrylamide solution depending on the shear rate and on the loading time. A binomial rheological model was used to describe steady-state stresses at different shear rates, which showed a high degree of accuracy. To describe the stress from time, we proposed to use a numerical solution of a system of two differential equations representing the well-known Maxwell and Kelvin–Voigt equations. To describe the initial section of the curves for times less than 0.05 s, a model with a variable modulus of elasticity was used. Results. A high degree of correspondence of experimental and design stresses with a time of more than 0.05 s was achieved. The overall solution was achieved by combining two solutions based on shear rate and shear stress. Relationships with high correlation coefficients were found between the elastic modulus, viscosities of Maxwell and Kelvin and the shear stress and shear rate. Conclusions. We show that in addition to the “ordinary” shear rate determined by the rotation of the viscometer cylinder, it is necessary to consider an additional shear rate due to stress changes in time. Due to this approach, a description of the stress maximum and its displacement from the shear rate can be made. We note that the additional shear rate occurred immediately after the start of loading, rather than at the time of stress drop, as commonly believed.

Polyurethanes Made with Blends of Polycarbonates with Different Molecular Weights Showing Adequate Mechanical and Adhesion Properties and Fast Self-Healing at Room Temperature.

Dynamic non-covalent interactions between polycarbonate soft segments have been proposed for explaining the intrinsic self-healing of polyurethanes synthesized with polycarbonate polyols (PUs) at 20 °C. However, these self-healing PUs showed insufficient mechanical properties, and their adhesion properties have not been explored yet. Different PUs with self-healing at 20 °C, acceptable mechanical properties, and high shear strengths (similar to the highest ones reported in the literature) were synthesized by using blends of polycarbonate polyols of molecular weights 1000 and 2000 Da (CD1000 + CD2000). Their structural, thermal, rheological, mechanical, and adhesion (single lap-shear tests) properties were assessed. PUs with higher CD1000 polyol contents exhibited shorter self-healing times and dominant viscous properties due to the higher amount of free carbonate groups, significant carbonate-carbonate interactions, and low micro-phase separation. As the CD2000 polyol content in the PUs increased, slower kinetics and longer self-healing times and higher mechanical and adhesion properties were obtained due to a dominant rheological elastic behavior, soft segments with higher crystallinities, and greater micro-phase separation. All PUs synthesized with CD1000 + CD2000 blends exhibited a mixed phase due to interactions between polycarbonate soft segments of different lengths which favored the self-healing and mobility of the polymer chains, resulting in increased mechanical properties.