Rheological Properties Research Articles

Influencing of Cations on the Rheological Properties and Filtration of Iraqi Attapulgite

Influencing of Cations on the Rheological Properties and Filtration of Iraqi Attapulgite

Performance of Various Types of Bacillus Bacteria on the Rheology and Mechanical Properties of Self-Compacting Concrete

Performance of Various Types of Bacillus Bacteria on the Rheology and Mechanical Properties of Self-Compacting Concrete

Enhanced Rheological and Structural Properties of the Exopolysaccharide from Rhizobium leguminosarum VF39 Through NTG Mutagenesis

Microbial exopolysaccharides (EPSs) are biopolymer materials with advantages such as biodegradability, biocompatibility, ease of mass production, and reproducibility. The EPS that was isolated from Rhizobium leguminosarum bv. viciae VF39 is an anionic polysaccharide with a backbone structure consisting of one galactose, five glucose molecules, and two glucuronic acids, along with 3-hydroxybutanoyl, acetyl, and pyruvyl functional groups. Through N-methyl-N′-nitro-N-nitrosoguanidine (NTG) mutagenesis, we isolated and purified a mutant EPS from VF39, VF39 #54, which demonstrated enhanced physicochemical and rheological properties compared to the wild-type VF39. The EPS structure of the VF39 #54 mutant strain showed a loss of glucuronic acid and 3-hydroxybutanoyl groups compared to the wild-type, as confirmed by FT-IR, NMR analysis, and uronic acid assays. The molecular weight of the VF39 #54 EPS was 250% higher than that of the wild-type. It also exhibited improved viscoelasticity and thermal stability. In the DSC and TGA analyses, VF39 #54 had a higher endothermic peak (172 °C) compared to the wild-type (142 °C), and its thermal decomposition point was 260 °C, surpassing the wild-type’s value of 222 °C. Additionally, the VF39 #54 EPS maintained a similar viscosity to the wild-type in various pH, temperature, and metal salt conditions, while also exhibiting a higher overall viscosity. The cytotoxicity test using HEK-293 cells confirmed that the VF39 #54 EPS was non-toxic. Due to its high viscoelastic properties, the VF39 #54 EPS shows potential for use in products such as thickeners, texture enhancers, and stabilizers. Furthermore, its thermal stability and biocompatibility make it a promising candidate for applications in food, pharmaceuticals, and cosmetic formulations. Additionally, its ability to maintain viscosity under varying environmental conditions highlights its suitability for industrial processes that require consistent performance.

Performance Evaluation of Delonix regia Sawdust as Cement Retarder in Oil and Gas Well

Sawdust, a byproduct of wood exploitation and processing, poses environmental pollution risks if not managed appropriately. Its substantial carbon footprint can lead to pollution, habitat disruption, and fire hazards. However, repurposing sawdust as a chemical additive in cement slurry within the oil and gas industry offers an environmentally friendly solution. This practice aligns with sustainability goals, enhances cement slurry properties, promotes wellbore stability, and replaces more hazardous additives, thereby reducing environmental impact. This study is aimed at the production of a retarder (sodium lignin) from sawdust waste obtained from the Delonix regia species, and examining its effect on the thickening time/consistency, compressive strength, and rheological properties on the slurry of a Class G cement At a Bottom Hole Circulating Temperature (BHCT) of 90°C, thickening time tests conducted on the slurry samples revealed that as the concentration of the locally synthesized retarder increases, the thickening time of the concrete also increases, with minimal effect on compressive strength. The optimal thickening time result of 6 hours and 13 minutes was achieved with 0.5% Sodium Lignin (Retarder from Delonix regia sawdust) replacing a portion of the cement. At a bottomhole static temperature (BHST) of 100°C, increasing the concentration of the formulated sample led to higher Plastic Viscosities (PV) and yield points in the slurries. The findings indicate that slurries formulated with sodium lignin maintain viscosities within recommended values, making them suitable for pumping.

Structural response of microtubule and actin cytoskeletons to direct intracellular load.

Microtubule and actin are the two major cytoskeletal polymers that form organized functional structures in the interior of eukaryotic cells. Although the structural mechanics of the cytoskeleton has been extensively studied by direct manipulations in in vitro reconstitution systems, such unambiguous characterizations inside the living cell are sparse. Here, we report a comprehensive analysis of how the microtubule and actin cytoskeletons structurally respond to direct intracellular load. Ferrofluid-based intracellular magnetic tweezers reveal rheological properties of the microtubule complex primarily determined by filamentous actin. The strain fields of the microtubule complex and actin meshwork follow the same scaling, suggesting that the two cytoskeletal systems behave as an integrated elastic body. The structural responses of single microtubules to contact and remote forces further evidence that the individual microtubules are enclosed by the elastic medium of actin. These results, directly characterizing the microtubule and actin cytoskeletons as an interacting continuum throughout the cytoplasm, serve as a cornerstone for the physical understanding of intracellular organization.

Optimization of heat transfer in a double lid-driven cavity with isoperimetric heated blocks using GFEM.

This article is concerned with the examination of flow dynamics and heat transfer characteristics in a 1:4 double lid driven cavity in presence of isoperimetric heated blocks of various shapes. The focus is to identify the optimal shape that enhances the heat transfer in a tall cavity. The parametric settings are chosen in such a way that all the convection regimes including natural, forced and mixed convection could be generated. This cavity has lids positioned at the top and bottom, moving in opposite directions along the x-axis. The physical system is represented as a set of coupled partial differential equations incorporating the rheological properties of the power-law fluids (PL). The governing equations in conjunction with various non-dimensional physical parameters are simulated via Galerkin's Finite Element Method (GFEM) on a very fine hybrid grid. The study includes the computation of the Kinetic Energy and Average Nusselt number to determine the optimal shape. It is concluded that the circular block is superior to the other two in terms of heat transmission efficiency.

Effect of N,N′-Methylenebisacrylamide on properties of porous semi-IPN hydrogels from Acrylamide, Maleic Acid, and its use for Urea absorption

Hydrogel is a three-dimensional polymer that can absorb large amounts of reagents while maintaining structural integrity. This material has been applied in many fields especially in smart agriculture. To improve the economic viability, the reusability of hydrogels in agricultural engineering over multiple cycles of adsorption and desorption is an urgent requirement. This can be solved if the crosslinker is used properly. Therefore, in this work, a series of porous semi-IPN hydrogels based on linear polyacrylamide, acrylamide, maleic acid, and N,N′-methylenebisacrylamide (MBA) were synthesized. The hydrogels were evaluated for the impact of MBA content on the characteristics and applicability as a urea fertilizer carrier. The chemical composition, morphology, mechanical, and rheological properties, swelling behavior, urea absorption and desorption of hydrogels with crosslinker content in the range of 0.5-2.0 % were investigated. The porous structure was confirmed by scanning electron microscopy images. Changing the MBA content significantly affected all characteristics of the hydrogels. In particular, increasing the MBA content decreased the equilibrium swelling ratios in all investigated environments. The maximum amount of urea loaded into the hydrogel was also reduced from 435.88 to 188.50 mg/g. This increase also changed the swelling mechanism from non-Fickian to Fickian, whereas the urea release mechanism changed from Fickian to non-Fickian. Finally, the hydrogels demonstrated stability in soil over multiple cycles of water absorption and release. This study provides valuable insights into designing a semi-IPN hydrogel with desired properties that meet the application requirements of modern farming techniques.

Jammed Pickering Emulsion Gels.

Emulsion gels with specific rheological properties have widespread applications in foods, cosmetics, and biomedicines. However, the constructions of water-in-oil emulsion gels are still challenging, due to the limited interactions available in the continuous oil phase. Here, a versatile strategy is developed to prepare a new type of emulsion gels, called Jammed Pickering emulsion gels (JPEGs). In the JPEG system, SiO2 NPs in the oil phase serve as colloidal surfactants to stabilize water-in-oil Pickering emulsions, while positively-charged NH2-PEG-NH2 molecules in the water phase cross-link negatively-charged SiO2 NPs at the water/oil interface, making NP-stabilized water droplets hard to deform and thus jamming the emulsion system to form emulsion gels. The strategy to prepare JPEGs is versatile and applicable to diverse oil phases. The designed JPEGs possess many advantages, including good biocompatibility for widespread applications, shear-thinning rheological properties for easy processing, good stability Over a wide temperature range and Against centrifugation, good adhesion to wet tissues for tissue engineering, and well-controlled sustained release Under intestinal conditions. The developed JPEGs are demonstrated to be a promising delivery platform and the strategy to achieve JPEGs will trigger more innovations of material design.

Impact of Optimal Silane Concentration on the Rheological Properties and 3D Printing Performance of Al2O3-Acrylate Composite Slurries

In this study, 3-trimethoxy-silylpropane-1-thiol (MPTMS) was used as a surface modifier for Al2O3 powder to systematically analyze the effects of MPTMS concentration on the rheological properties, photocuring characteristics, and 3D printing performance of photocurable composite slurries. MPTMS concentration significantly influenced the rheological behavior of the slurry. Slurries containing 2 wt.% and 5 wt.% MPTMS exhibited a wide linear viscoelastic range (LVR). However, at concentrations of 10 wt.% and 20 wt.%, the LVR range narrowed, which led to reduced dispersion stability. In dispersion stability tests, the slurry with 2 wt.% MPTMS showed the most stable dispersion, while the 5 wt.% MPTMS concentration exhibited the highest photocuring rate. In 3D printing experiments, the 5 wt.% MPTMS concentration resulted in the most stable printed structures, whereas printing failures occurred with the 2 wt.% concentration. At 10 wt.% and 20 wt.%, internal cracking was observed, leading to structural defects. In conclusion, MPTMS forms silane bonds on the Al2O3 surface, significantly impacting the stability, rheological properties, and printing quality of Al2O3-acrylate composite slurries. An MPTMS concentration of 5 wt.% was found to be optimal, contributing to the formation of stable and robust structures.

Egg White-Based Gels with Candelilla Wax: A Study of Rheological, Mechanical, Calorimetric and Microstructural Properties

Bigels (BGs) are innovative composite systems that integrate oleogel and hydrogel structures, and are gaining increasing attention for their unique textural and functional properties in food applications. This study evaluated the rheological and mechanical properties of egg white-based bigels incorporating candelilla wax (CW) as an oleogelator. The results indicate that different egg white protein (EWP) (5–10%) concentrations and hydrogel-to-oleogel ratios (20:80 to 80:20) significantly influenced the structural and functional properties of the bigels. Compression testing revealed no significant differences in strength across the tested range; however, higher EWP concentrations enhanced the stability of the BGs. Furthermore, increased candelilla wax oleogel (CWO) content (60%) markedly improved emulsion stability, resulting in superior strength, as confirmed by dynamic light scattering. Rheological studies demonstrated shear-thinning behavior, particularly at higher hydrogel content related to the oleogel (W/O), which exhibited the highest yield stress. Microstructural investigations confirmed the presence of a continuous oleogel phase within the bigels (W/O) and revealed the formation of a complex structure. These findings suggest that a reduced hydrogel-to-oleogel ratio can be utilized across various food systems, opening new possibilities for creating customized food structures with desirable textural and functional attributes.

Impact of tiger nut milk as a substitute for cow milk on the rheological, physiochemical, and organoleptic properties of functional ice cream

AbstractTiger nuts are an excellent food choice due to their rich mineral, fiber, and antioxidant content. Tiger nut milk was replaced by 25, 50, 75, and 100% of cow’s milk in the ice cream mixture. The impact of substituting cow milk with tiger nut milk on the physicochemical, rheological, and organoleptic properties of ice cream was examined. Adding tiger nut milk in a combination resulted ice cream mixes with more fiber and antioxidants and a lower protein and ash levels compared to the control (100% cow milk). Ice cream with tiger nut milk was higher in Fe and Zn than that of control. Dynamic viscosity values of ice cream mixes with tiger nut milk were decreased with increasing values of the applied shear rate compared to the control. All functional ice cream formulations with tiger nut milk showed higher specific gravity and melting rate with lower overrun percentages than the control. Regarding taste and flavor, structure, texture, and melting in the mouth, there is no appreciable difference between the T25, T50, and control treatments. Therefore, cow’s milk can be replaced with tiger nut milk up to 50% in the ice cream industry to raise the nutritional value and functional properties.

Dry-Cured Ham, ‘Kraški Pršut’, from Heavy Pig Production—A Pilot Study Focusing on the Effect of Ham Weight and Salting

A pilot study was conducted with the aim of adapting the processing of “Kraški pršut”, dry-cured ham, for thighs from heavy pigs. The focus was on the effect of ham weight and salting duration on the quality of dry-cured ham. From a pool of thighs harvested from heavy pigs, a total of 32 green hams were selected (from 16 carcasses) based on weight (two classes; L—lighter, H—heavier) and we used left and right ham for either the standard or a shortened salting phase. Salting duration consisted of phase 1 (7 days for all hams) and phase 2 (7 or 14 days for L, 10 or 17 days for H, in the case of shortened and standard salting, respectively). Equivalent conditions for all hams were maintained during the remaining phases, with a total maturation period of 18 months. The analysis focused on chemical, physical and rheological properties, sensory attributes, and consumer perceptions. The H hams had lower processing losses, resulting in higher moisture and water activity, lower salt content in internal biceps femoris muscle, and a softer texture (instrumental and sensory) than L hams. The salting duration mainly affected weight losses in the salting phase and, consequently, salt content, which was lower in the shortened salting phase, while no effects were observed on texture. The sensory panel perceived weight’s effect on hardness, with L hams being perceived as harder, and salting’s effect on sourness, with hams submitted to longer salting perceived as sourer than H hams. Consumer testing indicated a general preference for softer and less salty hams. Overall, the results show that the applied reduction in salting duration was not substantial, and future trials should explore further optimization in terms of salting and resting phases.

Influence of Ultrasound on the Rheological Properties, Color, Carotenoid Content, and Other Physical Characteristics of Carrot Puree

This study aimed to investigate the effect of ultrasonic frequencies (21 and 35 kHz) on the physical properties of carrot puree at different concentrations (9, 12, and 21 °Brix). The viscosity, total soluble content, density, color, and β-carotene content were tested. It was found that the viscosity of the puree, determined with respect to shear rate, concentration, and the use of ultrasonic treatment, indicates that the purees should be defined as shear thinning fluids. Moreover, a decrease in activation energy was observed with the increase in extract and ultrasonic treatment, which may cause changes in the rate of reactions occurring in the tested material. A significant effect of this may be the observed change in the color of the puree after ultrasonic treatment; the increase in frequency from 21 to 35 kHz caused an increase in redness and yellowness and a decrease in lightness, independently of concentration. The most significant color difference was noted in the puree with a 21 °Brix concentration, where a ΔE value of 21 was recorded. In contrast, the ΔE values for the other purees post-treatment remained below 5. The content of carotenoids did not change after sonication, independently of the concentration of carrot puree.

Synthesis and Mechanism Study of an Environmental Additive Used in Water-Based Drilling Fluids from Bovine Bone Glue

At present, animal bone glue has been widely used in industry, but there are no relevant research reports on its application in the petroleum industry. In this paper, the rheological properties, inhibition, filtration, and temperature resistance performance of modified bone glue (Mbg) were evaluated in water-based drilling fluids, and the results showed that Mbg can significantly affect the performance of water-based muds with minimal dosage, and temperature resistance of Mbg could reach up to 130 °C. The inhibition mechanism of Mbg in drilling fluids was investigated by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), zeta potential, thermogravimetric analysis (TGA), and scanning electron microscope (SEM). Results revealed that when 2% Mbg was added, a three-dimensional network structure was formed in an aqueous solution, which reduced the water content from 4.83% to 4.23%. FT-IR analysis showed that Mbg strongly adsorbed onto clay through hydrogen bonding, which reduced the clay particles in based muds from 1.251 µm to 0.789 µm and effectively controlled the filtration loss of the drilling fluids.

Exploitation of red beet peel powder as a natural food ingredient in whey-fruit based beverage

ABSTRACT Scientists and food producers are studying the potential of utilizing different by-products as highly nutritious food components to meet consumers’ growing demand for healthier and natural goods. Beetroot belongs to the Amaranthaceae family and is highly rich in antioxidants, specifically phenolics and betalains with excellent health properties. The peel of red beetroot, which is generally discarded, has a high concentration of bioactive phytochemicals (betalains, dietary fibers). These compounds are well-known for their strong antioxidant effects, improving cardiovascular health, reducing oxidative stress, and enhancing immunological function. Incorporating red beetroot peel (RBP) powder into whey-fruit-based beverages is a promising method to improve nutritional content and sensory attractiveness. This study investigated the influence of adding RBP to whey-fruit-based beverages, specifically examining its effects on physicochemical and phytochemical characteristics, antioxidant capacity, color, microbiological, and rheological attributes, and consumer preference. The RBP extract exhibited high amounts of total polyphenols (1239.35 ± 0.51 mg GAE/100 g dw) and antioxidant activity (90.02 ± 0.22%). The findings indicated that RBP had a notable impact on the antioxidant capacity (16.38 ± 0.37 μmol TE/g dw for BRBP1, 26.69 ± 0.10 μmol TE/g dw for BRBP3, 36.75 ± 0.31 μmol TE/g dw for BRBP6) of the beverages and enhanced their color without negatively impacting their sensory characteristics. The dynamic oscillatory rheological measurements revealed that beverage supplementation with increasing amounts of RBP obtained stronger networks with solid-like viscoelastic behavior. Using RBP powder as a natural food ingredient in whey-fruit-based beverages enhances their nutritional value and promotes sustainable food processing by making use of by-products from the food industry into innovative food options.

The Influence of the Amount of Technological Waste on the Performance Properties of Fibrous Polymer Composites

The objective of the experimental analysis was to assess the impact of the reuse of technological waste (recyclate) on the selected performance properties of the fibrous polymer composite used to produce components for the automotive industry by injection molding technology. Polyphthalamide (PPA), which belongs to a group of high-tech polymers, was chosen as the analyzed material. In accordance with the set goals, the rheological, mechanical, and structural properties of the material were evaluated using ANOVA analysis in the experimental part of the work, depending on the mass ratio of the recycled material added to the virgin material. The influence of the proportion of recycled material on the lifetime of moldings by the method of their exposure at an elevated temperature for a defined time was also assessed. During the research, it was found that at a concentration of up to 40 wt. % of recyclate, its mechanical properties do not change significantly. At a concentration of 50 wt. %, there is a rapid decrease in mechanical properties. In the long term, it can also be said that the addition of recyclate significantly affects the service life of the components. No significant changes in morphology were observed during the analysis of structural properties.

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.

Study of the rheological properties and nautical depth assessment of fine sediments in Iranian ports

Sediments containing more than 10% clay particles by mass can exhibit cohesive properties. Cohesive sediments are commonly found in coastal areas worldwide, including the southern shore of the Caspian Sea and the northern/northwestern beaches of the Persian Gulf. These cohesive sediments can form a layer of soft to extremely soft mud, known as fluid mud, covering the seabed. The study examined the properties of natural mud samples collected from different depths and locations within three Iranian ports: Anzali Port (Caspian Sea), and Khorramshahr and Bushehr Ports (Persian Gulf). The laboratory analyses included determining the sediment grain-size distribution, density, carbonate content, organic matter content, and rheological properties at different water content ratios. Disregarding the impact of variations in organic matter and carbonate contents in the samples, water content ratio was the main factor affecting the rheological properties of sediments.

Designing invert emulsion drilling fluids for high temperature and high-pressure conditions.

Good and optimal rheology is a primary requisite for a drilling fluid to achieve better hole-cleaning and barite sag resistance. Conventional thickeners like organophilic clay that provide rheology to invert emulsion fluids degrade with time and thereby fail to maintain sufficient rheology of the drilling fluid. Generally, excess amount of organophilic clay or low gravity solids (LGS) is added to the drilling fluid to enhance rheology. However, addition of excess amount of organoclay or low gravity solids not only increases the cost of drilling but also may severely affect other drilling fluid properties, which will require further treatment. In addition, addition of organoclay or low gravity solids increases the plastic viscosity, decreases the rate of penetration thereby ultimately increasing the cost of drilling. Thus, there was a need to develop a drilling fluid with optimal rheology sufficient to give good hole cleaning and barite sag resistance. This paper describes the formulation of 70pcf, 90pcf and 120pcf organoclay-free invert emulsion drilling fluids formulated with a novel rheology modifier combination of RM1 and RM2. The paper describes the synergistic effect of RM1 and RM2 which is a combination of fatty acid and fatty amine respectively. The fluids were hot rolled at 250°F, 250°F and 350°F respectively and the temperature effect on the rheological and filtration properties were studied. The paper also describes the static aging and contamination studies of 90pcf and 120pcf fluids at 250°F and 350°F respectively. Rheology of the 90pcf invert emulsion fluid was measured across high temperature and high pressure (HTHP) conditions to observe their effects on the fluid properties. 70pcf, 90pcf and 120pcf organoclay-free invert emulsion drilling fluids formulated with the novel rheology modifier combination of RM1 and RM2 showed optimal rheology and low HTHP fluid loss. Static aging studies of 90pcf IEFs at 250°F respectively showed that the fluids are sag-resistant with low top-oil separation. Contamination studies of 90pcf fluid showed that the contaminants have minimal effect on the rheology and filtration properties of the invert emulsion fluid. HTHP rheology of the 90pcf invert emulsion fluid shows consistent rheology across high temperatures and pressures. The paper thus demonstrates the superior performance of the rheology modifier combination to achieve good rheological and filtration properties.

Development of a Novel Gluten-Free Cookie Premix Enriched with Natural Flours Using an Extreme Vertices Design: Physical, Sensory, Rheological, and Antioxidant Characteristics

This work aimed to develop novel alternative gluten-free premixes for use in the production of cookies by optimizing the formulation of three different starches (corn, potato, and tapioca starch) in a rice/corn formula and then enriching the optimized formula with various natural flours (acorn, soy, chestnut, chickpea, millet, and quinoa). An extreme vertices mixture design was used to optimize the mixing sub-part consisting of 30% (w/w) of starches. The enriched gluten-free cookies were characterized by physical, rheological, antioxidant, color, and sensory properties. An optimum was obtained by mixing 18.5084 g of corn starch, 6 g of potato starch, and 5.4916 g of tapioca starch. The enrichment results indicated that soy-enriched gluten-free cookies have a high specific volume (2.428 cm3/g) with the highest spread ratio (12.25) compared to other cookies. The rheological properties of enriched gluten-free doughs indicated a higher value of the consistency coefficient (K) of soy-enriched gluten-free cookies. The antioxidant characteristics were enhanced by replacing corn with several types of flours, with higher TPC for acorn (2.83 mg GAE/g dw) and soy-enriched cookies (2.49 mg GAE/g dw) with better antioxidant activities (DPPH, ABTS, and RED). The tasters gave all the cookies favorable ratings for overall acceptability. With an average rating of 7.09, cookies enhanced with chickpea flour have a high acceptability compared to the other cookies. Considering all the tested parameters, PCA analysis clustered millet, corn, quinoa, and chestnut gluten-free enriched cookies into the same group. However, acorn and soy cookies were placed in a separate group, and chickpea-enriched cookies were classified separately.