Rheological Properties Research Articles

Rheological properties and excellent thermal shock stability of Al2O3-SiC-C castables containing continuous TiC coated graphite

High-flux molten iron and intermittent circulation accelerated the damage process of Al2O3-SiC-C castables under alternating thermal stress. A continuous TiC coated graphite was prepared using sol-gel combined with carbothermal reduction to investigate its influence on the flow properties, microstructure, mechanical properties and thermal shock resistance of Al2O3-SiC-C castables. The results show that a lower Ti/C molar ratio and higher heat treatment temperature are more favorable for the synthesis of TiC and the formation of a continuous and complete TiC coated graphite layer on the graphite surface. The introduction of TiC coated graphite significantly enhance the mechanical properties and thermal shock stability of Al2O3-SiC-C castables, with a remarkable 227% increase in residual strength after thermal shock. In addition, during the oxidation process of the samples with TiC coated graphite, TiO2 generated from the oxidation of TiC fills the pores and facilitates the growth of Al6Si2O13, which enhances the tightness of the bonding of the castable matrix, thus contributing to the improvement of the overall performance.

Environmentally friendly high-content polyurethane modified asphalt: Workability evaluation and early performance evolution

High-content polyurethane modified asphalt (HPMA) has ignited the enthusiasm of researchers due to its low-carbon characteristics and excellent performance. The workability and service performance of HPMA are both affected by complex curing reaction. The viscosity of HPMA changes over time at simulated construction temperature, and the evolution of the chemical structure and rheological properties at different environmental temperatures at the early stage were systematically investigated in this work. After thorough exploration, the construction tolerance time for HPMA-50 % (with isocyanate pre-polymer content of 50 %) and HPMA-30 % (with isocyanate pre-polymer content of 30 %) at a construction temperature of 130 ℃ are 46 minutes and 72 minutes, respectively, which can basically meet the construction time requirements. The complex modulus of HPMA gradually increases with the increasing curing time, and the phase angle temperature dependence of HPMA-50 % is significantly weakened compared to HPMA-30 %, its viscoelasticity gradually transforms to thermoset. Meanwhile, the high-temperature rutting factor improvement rate of HPMA-50 % reaches 142.1 % after curing for 14 days, indicating a tremendously improved rutting resistance. The high-temperature creep recovery rates of HPMA-50 % and HPMA-30 % increased from 65.9 % and 3.6–96.1 % and 7.6 %, respectively, after 14 days of curing. This reveals that increasing the isocyanate pre-polymer content and extending the curing time all can significantly improve the entropy-elastic properties and creep recovery ability of HPMA. Fluorescence microscopy analysis showed that the polyurethane particles in HPMA changed from a granular structure to a network structure during the curing process, and gradually transitioned to a continuous phase as the pre-polymer content increased. Further research also revealed a good correlation between the conversion rate of isocyanates and the rheological performance index of HPMA. Additionally, a functional model between the rheological performance index of HPMA and curing times was successfully established, which accurately predicted the evolution law of the rheological performance of HPMA under different ambient temperatures. The evolution mechanism of the early performance of environmentally friendly HPMA was investigated in this work, which laid the methodological foundation and theoretical basis for determining the construction tolerance time of HPMA and accurately evaluating its performance at the early stage.

Isolation of ice structuring proteins from winter wheat in frigid region (Dongnongdongmai1) and the effect on freeze–thaw stability of dough

In this study, ice structuring proteins (WISPs) extracted from winter wheat in a frigid region were prepared and added to frozen-thawed dough. The WISPs were characterized, revealing that they contained a higher proportion of hydrophilic amino acids and had a molecular weight of approximately 15 kDa. The highest thermal hysteresis activity (THA) observed was 0.62 °C. The secondary structure of WISPs was determined to be as follows: β-sheet: 49.33 %, random coil: 13.87 %, α-helix: 16.35 %, β-turn: 20.45 %. The study investigated the effects of different additions of WISPs on the water mobility, glass transition temperature, microstructure, rheological properties, and texture analysis of frozen-thawed dough. The results demonstrated that the inclusion of WISPs reduced the fluidity of water and water migration in the dough during the frozen-thawed cycle. This protective effect preserved the internal structure and gluten network of the dough, leading to increased viscosity, elasticity, and improved texture properties of the frozen-thawed dough. Furthermore, the addition of WISPs at concentrations ranging from 0 % to 0.7 % resulted in a 1.8 °C increase in the glass transition temperature (Tg). Overall, these findings suggest that WISPs can serve as a beneficial additive for enhancing the freeze–thaw stability of dough.

Influence of micromorphology and water content on the rheological properties and performance evaluation model of loess mudflow

Evaluation of the rheological characteristics of loess mudflow is of great significance to ecological environment protection (by loess, we mean a wind-blown Quaternary silt deposit), and geological disaster assessment in the Loess Plateau of China. Rheological characteristics of rheology for loess mudflow are highly variable due to heterogeneity in particle micromorphology and water content, and current rheological models struggle to reconcile the structural dynamics with the equilibrium behavior of soil at different concentrations and microstructures. A rheological study of loess mudflow for five regions on the Loess Plateau was carried out in this investigation, and the results showed that loess transformed from a solid-like stage to a liquid-like stage under steady loads and exhibited significant shear thinning characteristics and shear rate dependence, in which the shear rate less than 2 s−1 was the main region of loess strength attenuation and the maximum yield stress is about 1411 Pa. A smaller water content and more complex particle micromorphology led to a higher yield stress, but there was no significant correlation between flow index and particle shape and water content. Additional structural dynamics and particle fractal theory were then introduced, providing an improved model that could reconcile the structural dynamics and particle micromorphology of loess with its equilibrium behavior at different water contents and shear stresses. All the test data were distributed around a dimensionless master curve. Considering the difficulty of obtaining rheological parameters, an evaluation criterion containing three levels (clay-rich, silt-rich, and sand-rich) for the evaluation of the rheological properties of loess mudflow was proposed, which can reconcile the test results and models under different working conditions. Such an evaluation criterion can also be applied to soils of other textures, providing a straightforward manner to determine the relevant rheological parameters. The research results provide a theoretical basis for ecological environmental protection and geological disaster assessment in the Loess Plateau region based on rheological characteristics.

Improvement on gel properties of chicken myofibrillar protein with electron beam irradiation: Based on protein structure, gel quality, water state

This study aimed to investigate the effects of electron beam (E-beam) irradiation at different doses (0–15 kGy) on the solubility, rheological properties, emulsification characteristics, and moisture distribution of chicken myofibrillar proteins (MPs). Irradiation treatment notably increased the solubility, surface hydrophobicity, emulsification properties, and apparent viscosity of MPs, based on conformational changes caused by irradiation-induced oxidative denaturation of proteins. However, high doses of irradiation (15 kGy) induced in excessive cross-linking and aggregation of proteins, reducing the solubility, emulsification properties, and shear stress. Degradation of myosin heavy and light chains in irradiated MPs increased the content of β-turns and random coils. Additionally, the initial relaxation times of T21 and T22 in irradiated protein gels were reduced, and the peak value of P21 was increased, which improved the water-capturing ability of protein gels. Altogether, these results findings suggest that electron beam irradiation can be applied as a potential technique for modifying muscle proteins.

Synergistic sun protection via glucosylrutin-enhanced multiple emulsions

A sunscreen multiple emulsion with a “two films and three phases” structure was prepared using a two-step emulsification method. In this system, the inner aqueous phase contained dissolved Glucosylrutin, while the oil phase included a triazine-based chemical UV absorber. The composition and morphology of the emulsion were optimized, and its rheological properties and physical stability were analyzed. This study demonstrates the application of multiple emulsions in sun protection, highlighting their synergistic behavior in UV defense and their capacity to enhance the antioxidant properties derived from Glucosylrutin.

Improving the processability and mechanical strength of self-hardening robocasted hydroxyapatite scaffolds with silane coupling agents

Bone cements are the subject of intensive research, primarily due to their versatility and the increasing importance for personalized medicine. In this study, novel hybrid self-setting scaffolds, based on calcium phosphates and natural polymers, were fabricated using the robocasting technique. Additionally, the influence of two different silane coupling agents, tetraethyl orthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS), on the physicochemical and biological properties of the obtained materials was thoroughly investigated. The chemical and phase compositions (XRF, XRD, FTIR), setting process, rheological properties, mechanical strength, microstructure (SEM), and chemical stability in vitro were comprehensively examined. The use of silane coupling agents improved compressive strength of the scaffolds from 5.20 to 9.26 MPa. The incorporation of citrus pectin into the liquid phase of the materials, along with the use of a hybrid hydroxyapatite-chitosan powder, not only facilitated the development of printable pastes suitable for robocasting but also enhanced the physicochemical properties of the robocasted scaffolds. The results presented in this study underscore the beneficial influence of silane coupling agents on the characteristics of calcium phosphate-based bone scaffolds. Developed robocasted scaffolds hold great potential for applications in the field of bone tissue engineering and personalized medicine. Further in vitro and in vivo studies are necessary to validate their suitability for clinical applications.

FRESH 3D printing of zoledronic acid-loaded chitosan/alginate/hydroxyapatite composite thermosensitive hydrogel for promoting bone regeneration

The aim of this study was to develop a composite thermosensitive hydrogel for bone regeneration applications. This hydrogel consisted of chitosan, alginate and hydroxyapatite, and was loaded with zoledronic acid as a model drug. The feasibility of three-dimensional (3D) printing of the thermosensitive hydrogel using the extrusion technique was investigated. The 3D printing technique called Freeform Reversible Embedded Suspended Hydrogel (FRESH) printing was employed for this purpose. To characterize the composite hydrogels, several tests were conducted. The gelation time, rheological properties, and in vitro drug release were analyzed. Additionally, the cell viability test on human osteosarcoma MG-63 cells for the composite hydrogel was assessed using an MTT assay. The results of the study showed that the zoledronic acid-loaded composite thermosensitive hydrogel was successfully printed using the FRESH 3D printing technique which was not possible otherwise i.e., by using traditional 3D printing techniques. Further examination of the printed constructs using a Scanning Electron Microscope revealed the presence of porous and layered structures. The gelation times of the composite thermosensitive hydrogel was determined to be 10 and 20 min, respectively for scaffolds with and without HA, indicating the successful formation of the gel within a reasonable time to the FRESH technique. The flow behavior of the hydrogel was found to be pseudoplastic, following a non-Newtonian flow pattern with Farrow’s constant (N) values of 1.708 and 1.853 for scaffolds with and without hydroxyapatite, respectively. In terms of drug release, scaffolds prepared with and without hydroxyapatite reached nearly 100% of zoledronic acid release in 360 h and 48 h, respectively. The cell viability test on human osteosarcoma MG-63 cells using MTT assay has shown increased cell viability % in the case of the composite hydrogel, indicating a biocompatible scaffold. Overall, this study successfully developed a composite thermosensitive hydrogel loaded with zoledronic acid for bone regeneration applications and 3D printed using the FRESH 3D printing technique. The results of this study provide valuable insights into the potential use of this composite hydrogel for future biomedical applications.

Functional, structural, and rheological properties of the complexes containing sunflower petal extract with dairy and plant-based proteins

This study aims to investigate the impact of sunflower petal extract (SFE) on the functional and structural properties of sodium caseinate and chickpea proteins. For this purpose, 3.5 % of sodium caseinate solution and 3.5 % of protein extracted from chickpea powder were prepared in phosphate buffer (pH = 7). SFE was used at different concentrations, from 1 to 3 % in different protein solutions and functional, structural and rheological properties were measured. The results revealed that complexation of SFE with different proteins can enhance the antioxidant, foaming properties, solubility, emulsion activity, emulsion stability, viscoelastic behavior, and can decrease surface hydrophobicity. FTIR and docking results showed that the most bonding type was non-covalent bonds. Major phenolic compounds containing heliannone A, B, and kaempferol had strong affinity with sodium caseinate, and then chickpea protein. Therefore, the results demonstrated that SFE and its complexes had appropriate emulsifying properties that reduces interfacial tension in the water/oil interface.

Enhancing the viscoelastic properties of bacterial cellulose hydrogels through ultrasonic and enzymatic modification of xyloglucan

Bacterial cellulose (BC) hydrogels exhibit nanofibril porous network with good viscoelasticity for use as food ingredients and medical materials. Xyloglucan (XG), a hemicellulose with branching residues, can hybridize with BC to improve the hydrogel's extensibility. Thus, modifying the molecular structure of XG can fine-tune the viscoelastic properties of BC hydrogels. In this study, tamarind seed XG subjected to ultrasonic and enzymatic treatment was hybridized with BC to form composite materials. The results indicated that incorporating modified XG reduced the modulus and enhanced the viscous behaviour of BC to varying degrees. XG modified via ultrasonic treatment demonstrated a higher binding efficiency (19–22 %) with cellulose compared to enzymatically treated XG (11–13 %). The enzymatically treated XG improved the maximum elongation ratio to 57 %, but reduced the storage modulus to 30 kPa. Although ultrasonic-treated XG had a similar effect on the shear modulus, it had less impact on the extensibility of BC, with an elongation ratio of 38 %. Additionally, the incorporation of modified XG also regulated the nonlinear viscoelasticity of BC. These findings advance our understanding of the application of XG as a regulator of mechanical and rheological properties, broadening its utility in BC hydrogel formulations for the food industry and medical material development.

Preparation and characterization of dressing-type emulsions formulated with hydrocolloids from the mango (Mangifera indica) peel

Mango is a popular tropical fruit known worldwide and mango peel is a waste product worthy of valorization. This study explores the stabilizing effect of hydrocolloids extracted from mango peel in dressing-type emulsions (DE). Emulsions stabilized with different ratios of mango (Mangifera indica) peel-derived hydrocolloids (PE) and guar gum (1% wt. total concentration) were prepared and characterized: DE1 (0.25/075), DE2 (0.5/0.5), DE3 (0.75/0.25) and DE4 (1/0). Particle size distribution, ζ-potential, proximal composition, color, microstructure, and rheological properties were evaluated. All the samples showed similar proximal compositions. However, PE/guar gum ratio influences color parameters. For the microstructural analysis, Sauter's mean droplet size ranged from 6.41 to 11.11 µm. The ζ- potential values ranged from -18.03±0.21 to -16.97 mV. Emulsions exhibited shear thinning responses that can be well described by the Williamson model, and gel-like viscoelastic character with G’ higher than G”. The activation energy values (Eα) deduced from the application of an Arrhenius model to the viscous flow behaviour of the emulsions ranged from 108.46 to 143.44 Kj/mol. From the microstructural analysis and the rheological characterization, it can be inferred that PE favors the flocculation of the emulsion droplet in high concentrations. Overall, this research contributes to the sustainable exploitation of a mango waste material, such as the peel, in food emulsions.

Preparation of cod protein composite gels for dysphagia by high-pressure homogenization: Egg white microgels-based high-phase emulsion as a texture modifier

The rising prevalence of dysphagia among the aging population presents significant challenges in developing specialized diets that combine soft textures with high nutritional value. This study investigates the formulation of cod protein composite gels (CPCGs) using high internal phase emulsions (HIPEs, 5–25 %) derived from cooked cod protein and egg white microgels. The CPCGs were prepared via high-pressure homogenization at 400 bar for 10 min. The texture, water retention, rheological properties, and network structure of the CPCGs were analyzed. Results demonstrated that incorporating HIPEs increased the hardness and whiteness of CPCGs. The water holding capacity peaked at 98.52 % with 15 % HIPEs. Additionally, as the concentration of HIPEs increased, the apparent viscosity, support properties, and thermal stability of CPCGs improved, although the critical strain point decreased from 475.33 % (control) to 199.33 % (25 % HIPEs). The network structure of CPCGs became denser and more uniform with higher HIPE concentrations, with noticeable changes in the gel skeleton when HIPEs exceeded 15 %. According to the International Dysphagia Diet Standardization Initiative (IDDSI) tests, all CPCG formulations met Level 6 - soft and bite-sized criteria. This study offers valuable insights into the development of fish protein-based dysphagia diets that are both nutritious and safe for swallowing.

Green and synergistic effects of buton rock asphalt and styrene-butadiene-styrene on asphalt performance: Focus on resistance to thermal oxygen aging

The enhancement of asphalt properties was investigated through utilizing the Buton rock asphalt (BRA) and styrene–butadiene–styrene (SBS) in this study. Despite of the splendid high-temperature resistance of the BRA-modified asphalt, it could be liable to low-temperature cracking. Hence, a composite BRA/SBS-modified asphalt was explored. The rheological tests, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) were employed for analyzing the rheological, thermal, and chemical stability properties of the samples. The findings demonstrated that SBS promoted the low-temperature crack resistance of the BRA-modified asphalt, and BRA improved the thermal stability and thermal oxygen aging resistance of the SBS-modified asphalt. Considering the overall anti-aging and anti-fatigue effectiveness, 2 % SBS and 10 % BRA were proposed as the appropriate dosages for the modified asphalt. The analysis of correlation revealed that the BRA could be introduced to mitigate the influence of aging on the performance of SBS-modified asphalt to resist the irreversible deformation. This study could address the limitations of the BRA-modified asphalt and promote its application in road constructions.

Physicochemical and processing properties and in vitro fecal fermentation characteristics of Prunus cerasifera Ehrhart polysaccharide

Prunus cerasifera Ehrhart fruit polysaccharide (PCP) was obtained after determining the optimal extraction conditions for complex enzyme-assisted hot buffer extraction based on single-factor experiments and response surface methodology, followed by characterization of its physicochemical, processing, rheological, and biological properties. PCP was a thermally stable carbohydrate with acidic functional groups and a molecular weight of 1398.69 kDa, exhibiting smooth, dense flake and honeycomb network microstructures. PCP had favorable hygroscopicity, moisturizing properties, water and oil-holding capacity, proemulsification capability, and in vitro antioxidant activity. The apparent viscosity of PCP in an aqueous system was dependent on concentration and temperature and was altered by the variety and amount of metal ions added; its aqueous solutions exhibited strong viscosity and hydrogel-forming tendencies at suitable concentrations, along with excellent hydrogel properties after gelation. Furthermore, PCP favored the growth of beneficial gut microbiota and associated microbes responsible for producing essential short-chain fatty acids. Overall, PCP displayed high potential as a multifunctional additive for applications in the food, pharmaceutical, and cosmetic industries.

Influence of Microwave Hydrodiffusion and Gravity (MHG) drying process on Ulva sp: Ulvan, Molecular weight, Rheology, and film development

Ulva sp green seaweed was dehydrated using the proposed Microwave hydrodiffusion and gravity (MHG) approach and the traditional convective air oven drying method (CO). The impact of MHG at the tested irradiation powers (50−250 W) was evaluated on the drying kinetics, energy requirements, microstructural aspects, proximate chemical composition, and colour features of the dried algal material. Furthermore, its influence was ascertained on the extractability, molecular weight, and structural and rheological characteristics of ulvan. The polymer obtained after drying under the selected MHG conditions was used to generate ulvan biobased film. Findings revealed that high irradiation powers required lower pre-treatment time: MHG at 200, 250 W-15 min, 100 W-45 min, 150 W-25 min, 50 W-240 min with moisture content around 10g/100 g. MHG has no detrimental influence on colour and preserves the nutritional quality of the dried Ulva sp. Samples pre-treated at 150 W for 25 min displayed the highest ulvan yield (26.8 g/100 g). MHG does not affect the rheological and structural properties of ulvan and allows the recovery of high molecular ulvan weight, comparable to the commercial ones. The formed film produced from ulvan demonstrated strong mechanical behaviours that could be employed as a prospective biodegradable material.

Influence of Salt and Temperature on the Rheological and Filtration Properties of Cellulose Nanofiber/Bentonite Water-Based Drilling Fluids

Influence of Salt and Temperature on the Rheological and Filtration Properties of Cellulose Nanofiber/Bentonite Water-Based Drilling Fluids

Effect of steel slag on rheological and mechanical properties of sulfoaluminate cement-based sustainable 3D printing concrete

Effect of steel slag on rheological and mechanical properties of sulfoaluminate cement-based sustainable 3D printing concrete

White cabbage waste powder improves gluten-free rice-based breadsticks functional and nutritional characteristics

Fruit and vegetable industrialization generates large amounts of organic residues abundant in bioactive compounds. In the present work, white cabbage powders (WCP) were used to partially replace rice flour (5, 10, 20 and 30% w/w) in the formulation of gluten-free breadsticks. Physicochemical (moisture content, water and oil absorption capacity), pasting, and antioxidant properties (reducing sugars, total phenols and DPPH scavenge ability) were evaluated in flour blends. Breadsticks quality was evaluated by analysing dough rheology, physicochemical (aw, colour, texture) and antioxidant properties. Water and oil absorption capacities improved with WCP addition, whereas pasting properties worsened. Dynamic oscillatory tests revealed that WCP incorporation increased G’ and G’’ values. Colour attributes were also significantly modified with WCP addition, whereas breadsticks hardness reduced compared to control formulation. Nutritional properties of breadsticks improved with WCP addition, as deduced from the better antioxidant characteristics obtained for both blends and breadsticks, when vegetable powders were added. In conclusion, this study reveals that WCP can be suggested as functional food ingredient to increase the nutritional properties of new, rice-based gluten-free breadsticks.

Enhanced characterization and utilization of cowpea protein isolate: rheological and textural properties of heat-induced gels for plant-based egg omelet formulation

This study aimed to evaluate the potential of cowpea isolate (CPI) as an effective plant-based egg substitute by comparing its composition and physicochemical properties with those of commercial isolates, including mung bean, soy, and pea proteins. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis identified a distinctive vicilin-like globulin in CPI that is critical for the unique functional properties of CPI. CPI has a smaller particle size, resulting in superior gelation capacity and water retention, which are essential for egg substitute applications. Thermal analysis revealed the high stability of CPI, which is advantageous for food processing. Notably, the unique heat-induced gelation behavior of CPI, characterized by a smooth transition from solid- to liquid-like states, provided a strength not observed in its commercial counterparts. Microstructural analysis showed that the CPI gel closely resembled the egg gel, underscoring the potential of CPI to mimic the texture of eggs, particularly in omelets.

Carbon microspheres prepared from soluble starch hydrothermal carbonization for extending thermal stability of water-based drilling fluid

This study employed hydrothermal carbon microspheres (HCMs) as high-temperature stabilizers in drilling fluids. The HCMs were synthesized through a green hydrothermal carbonization method, using soluble starch as the precursor. The impact of HCMs on the thermal stability of xanthan, polyanionic cellulose and synthetic polymer solutions was assessed by comparing their rheological changes before and after thermal aging. The rheology and filtration properties of a polymer-based drilling fluid in the presence of HCMs were recorded before and after dynamic thermal aging at various temperatures for 16 h and static thermal aging at 200 °C for 96 h. The results demonstrated that HCMs effectively maintained stable rheology and low filtration loss following dynamic hot rolling at various temperatures and prolonged static thermal aging, surpassing the performance of conventional Na2SO3 and nano-SiO2 stabilizers. Mechanistic studies, including dissolved oxygen measurements, free radical detection, and cryo-scanning electron microscopy observations, revealed that HCMs can consume dissolved oxygen, scavenge free radicals, and physically crosslink polymers. This process prevents polymer thermo-oxidative degradation and ensures the stability of the drilling fluid. HCMs are novel, stable, sustainable, and highly effective high-temperature stabilizers for water-based drilling fluids. This study introduces a new application of biomass-derived hydrothermal carbonaceous materials for high-temperature drilling.