Rheological Properties Research Articles

Effect of heat treatment on the structural and emulsifying properties of copra meal protein: Improving interfacial properties to enhance performance of its Pickering emulsion

This study investigated the impact of different temperatures and durations on the structural and emulsifying properties of copra meal protein. Additionally, the stability of copra meal protein Pickering emulsions was assessed through rheological and interfacial characteristics. Findings revealed a positive correlation between emulsification properties and heating temperature and duration. Thermal aggregates, facilitated by hydrogen bonds, hydrophobic interactions, and disulfide bonds, significantly enhanced surface hydrophobicity. Heat-treated copra meal protein-based Pickering emulsions demonstrate enhanced adsorption at the oil-water interface and resistance to diffusion. The three-phase contact angle increases from 57.7° to 79.8° following heating at 95 °C for 30 min. The addition of NaCl and heating treatment did not affect emulsion particle size or interface adsorption ability. But it improved the rheological properties to varying degrees. These results offer valuable insights for optimizing the physicochemical and functional attributes of copra meal protein in the food industry.

3D printing of rice starch incorporated peanut protein isolate paste: Rheological characterization and simulation of flow properties

This study investigates the viscosity and creep behavior of peanut protein isolate (PPI) paste incorporated with rice starch (RS) for potential applications in 3D printing. The change in flow properties during the 3D printing was also studied by numerical simulation. The paste exhibited shear-thinning behavior with yield stress. The pressure predicted from the Herschel-Bulkley model showed higher values than those derived from the Power-Law model. The PPI and RS levels had negligible influence on velocity and shear rate; however, they showed greater dependence on the inflow rate. The fractional element model described the creep data well (R2 > 0.9). The addition of PPI resulted in increased viscosity, simulated pressure, and mean extrusion force, with similar effects observed for RS, except at higher PPI levels. Furthermore, the 3D-printed objects revealed that deformations were pronounced at low concentrations of PPI and RS, while resolution suffered when employing higher concentrations of PPI and RS. Industrial relevanceUsing peanut protein isolate, a plant-based high protein ingredient in 3D printing, reduces energy consumption, thereby reducing carbon footprints, offers improved functional properties, and diversifies dietary options by offering an alternative protein source from peanuts. The printing is influenced by the rheological properties of food ink. Thus, knowing the rheological properties of food ink can help researchers and industries to prepare food inks with desired properties. The observations of numerical simulation of this work have the potential to offer practical insights for designing 3D printing systems. In summary, this work has the potential to aid in improving and developing food ink for 3D printing, hence enhancing the performance of extrusion-based 3D food printers.

The effect of anti-agglomerant tween on the thermal and rheological properties of TBAF semi-clathrate hydrate slurry used for cold storage systems

Hydrate, as a phase change cold storage material, can form the slurry with certain fluidity, enabling convective heat transfer during both the heat absorption and heat release stages (cold storage or refrigeration), with high heat transfer efficiency. However, high viscosity and significant flow pressure losses are the principal challenges limiting its advancement. The paper selected four non-ionic surfactants as hydrate anti-agglomerants (Tween 20, 40, 60, 80) and utilized DSC to examine their effects on the thermal properties of TBAF semi-clathrate hydrate slurry at three theoretical hydrate concentrations (with mass fraction of 0.60, 0.70, and 0.80). Additionally, it measured the viscosity variation during the endothermic dissociation stage of the TBAF hydrate slurry and calculated the flow pressure losses in hydrate slurries within various pipe diameters. The results revealed that the presence of Tween increased the hydrate growth within the slurry, resulting in a higher available phase change enthalpy. Tween 80 demonstrated the most significant increase in enthalpy increasing effect, with an available phase change enthalpy ranging from 128.08 to 170.03 kJ/(kg·slurry) and an increase in enthalpy of 52.14 % to 91.62 %. For TBAF hydrate slurries with the theoretical hydrate mass fraction of 0.60, the addition of Tween 20 or Tween 80 significantly reduced viscosity, dropping to between 57.6 mPa·s and 116 mPa·s, and reducing viscosity by 43.4 % to 71.9 %. Furthermore, most flows with anti-agglomerants were in the laminar regime. The addition of Tween 20 and Tween 80 achieved the maximum reduction in flow pressure loss per unit length, with the highest reduction being 80.2 % (0.11 kPa/m) and 71.1 % (0.15 kPa/m), respectively. Both the phase change enthalpy of the hydrate and the viscosity of the hydrate slurry impacted the flow pressure drop within pipes. Increasing phase change enthalpy and reducing viscosity are effective strategies for mitigating flow pressure drop.

Formulation and evaluation of Dorzolamide hydrochloride microsponges loaded in situ gel for ocular administration

Due to the unique structure of the eye, which inhibits the entry of drug molecules into the desired site, the ophthalmic delivery of the drug has been one of the most challenging tasks for a pharmaceutical scientist. For this reason, in this investigation a novel microsponge for an anti-glaucoma drug, Dorzolamide hydrochloride, was formulated as in situ gel for ocular administration with an aim to improve its therapeutic efficacy and reduce the systemic adverse effects. The microsponges were prepared by the quasi emulsion solvent diffusion method and was incorporated into 20% pluronic F-127 which led to consistent in situ gel at 35°C. They were evaluated for physicochemical properties like pH, gelling capacity, gelation time, rheological properties and release profile and ocular irritancy test. The prepared Dorzolamide hydrochloride microsponges showed high entrapment efficiency of 85% and mean particle size of 2 μm with polydispersity index (PDI) of 0.77 which are ideal for ocular delivery. These microsponges is formulated into in situ gel which showed higher therapeutic efficacy compared to free drug in gel. It was found to be non-irritant to the rabbit’s eye. These results confirms that Dorzolamide hydrochloride microsponges in situ gels have promising features, benefits and advantages for a novel ophthalmic drug delivery to treat glaucoma.

Evaluation of rheological properties of soft lining materials with different composition under various temperatures

PurposeThe 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 methodsFive 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.ResultsSoft 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.ConclusionsThere 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 implicationsTemperature 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.

Improvement of Surimi Gel from Frozen-Stored Silver Carp

Silver Carp (SC) is an under-utilized, invasive species in North American river systems. In this study, the synergistic effects of manufactured Microfiber (MMF), Transglutaminase (TG), and chicken skin collagen (CLG)) to enhance surimi gel quality from frozen SC were studied. The gel strength, textural properties, rheological properties, water-holding capacity (WHC), water mobility, microstructure, and protein composition of the gel samples were determined to assess the impact of the additives individually and synergistically. The results suggested that TG had the most pronounced effect on the surimi gel properties by promoting protein cross-linking. Synergistic effects between TG, MMF, and CLG can bring effective gel property enhancement larger than the individual effect of each additive alone. With the established response-surface models, the combination of CLG and MMF can be optimized to produce surimi gels with less TG but comparable in properties to that of the optimal result with high TG usage. The findings of this study provided a technical foundation for making high-quality surimi gel products out of frozen-stored SC with synergistic utilization of additives, which could serve as guidelines for the industrial development of new surimi products.

Interaction of polysaccharides on gel characteristics and protein microstructure of threadfin bream surimi gel

SummaryPolysaccharide is widely used to improve gel characteristics of surimi gel. The impacts of the polysaccharides tamarind kernel powder (TKP) and tapioca starch (TS) at concentrations of 0%, 2.5% and 5% by weight were investigated on protein conformation [Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM)] and textural characteristics (rheological property, gel strength, solubility, SH contents) of threadfin bream surimi gel. Higher G′ and G″ values were observed in surimi paste added with TKP. Hydrogen bonding increased at higher concentrations of polysaccharides. Addition of TS increased hydrophobic interaction and promoted alteration of the α‐helix to the β‐sheet in the gel structure, while adding TKP to surimi gel had the opposite effect. FTIR images indicated that higher concentrations of polysaccharides resulted in abundant specific polysaccharide functional groups. Microstructures of surimi gel with TKP exhibited an irregular network, with large voids leading to decreased gel strength, while addition of TS increased network density, promoting higher gel strength.

Rheology and physical properties of sonicated chickpea concentrate with fructans in aqueous media and stable emulsions

Based on the rheological and other physical properties of chickpea concentrate (CPC)/fructan aqueous mixtures containing 0.2% carboxymethyl cellulose (CMC) and their respective emulsions, the macrostructure of the system was elucidated, and its effect on the stability of the proposed emulsions was evaluated. The zeta potential and particle size of the CPC dispersions subjected to ultrasonic treatment were analyzed. Neither agave (AGF) nor chicory fructans (CHF) affected the rheological behavior (Newtonian) of aqueous systems containing only CPC. A Carreau behavior was observed when CMC was added. A synergistic effect occurred when 6% CHF was mixed with CMC. Furthermore, CHF led to a higher overall viscosity than AGF in the systems studied. Fructans changed the total charge of the protein dispersion and increased the particle size. The viscoelastic properties confirmed the liquid-like behavior of the aqueous mixtures. Emulsions containing CPC/CMC mixtures and fructans exhibited thixotropic behavior; emulsions containing 30% oil followed the Carreau model, while emulsions containing 60% oil were fitted to the Hershel-Bulkley model for upward and downward shear rate curves. The latter behavior corresponded to the formation of a weak gel structure and a flocculated oil droplet network, as confirmed by the mechanical spectra. The droplet size in the emulsions decreased in the presence of fructans, particularly for 3% CHF and 6% AGF. However, 6% CHF led to the formation of the most kinetically stable emulsions. These results confirm the possibility of incorporating CPC and fructans as oil-in-water emulsions stabilized with CMC into healthy plant-based products.

Synthesis and Characterization of Multiple Stimuli-Responsive Fluorescent Polymer Hydrogels Based on Terpyridine and N-isopropylacrylamide

A series of stimuli-responsive fluorescent hydrogels were successfully synthesized via micelle radical copolymerization of hydrophilic acrylamide (AM), hydrophobic chromophore terpyridine-based monomer (TPY), and N-isopropylacrylamide (NIPAM). These hydrogels presented blue emissions (423–440 nm) under room temperature, which is caused by the π-π* transition of the conjugated structures. Once the ambient temperature was increased to 55 °C, the fluorescence color changed from blue (430 nm) to pink (575 nm) within 10 min, subsequently to yellow (535 nm), and eventually back to pink. The thermal-responsive properties are attributed to the transition of the TPY units from unimer to dimer aggregation via the intermolecular charge transfer complex at high temperatures. The hydrogels showed pH-responsive properties. The emission peak of the hydrogel exhibited a blue shift of ~54 nm from neuter conditions to acidic conditions, while a 6 nm red shift to an alkaline environment was observed. The hydrogels demonstrated an obvious change in fluorescence intensity and wavelength upon adding different metal ions, which is caused by the coordination between the terpyridine units incorporated on the backbones and the metal ions. As a consequence, the hydrogels presented a sharp quenching fluorescence interaction with Fe2+, Fe3+, Cu2+, Hg2+, Ni2+, and Co2+, while it exhibited an enhanced fluorescence intensity interaction with Sn2+, Cd2+, and Zn2+. The microstructural, mechanical, and rheological properties of these luminescent hydrogels have been systematically investigated.

Suppression of Segmental Chain Dynamics on a Particle's Surface in Well-Dispersed Polymer Nanocomposites.

The Rouse dynamics of polymer chains in model nanocomposite polyethylene oxide/silica nanoparticles (NPs) was investigated using quasielastic neutron scattering. The apparent Rouse rate of the polymer chains decreases as the particle loading increases. However, there is no evidence of an immobile segment population on the probed time scale of tens of ps. The slowing down of the dynamics is interpreted in terms of modified Rouse models for the chains in the NP interphase region. Thus, two chain populations, one bulk-like and the other characterized by a suppression of Rouse modes, are identified. The spatial extent of the interphase region is estimated to be about twice the adsorbed layer thickness, or ≈2 nm. These findings provide a detailed description of the suppression of the chain dynamics on the surface of NPs. These results are relevant insights on surface effects and confinement and provide a foundation for the understanding of the rheological properties of polymer nanocomposites with well-dispersed NPs.

Effect of storage on the physicochemical, rheological, antioxidant activity, and sensory properties of soy whey‐fortified pineapple juice beverages

AbstractIncorporating soy whey into pineapple juice can enhance nutritional and nutraceutical potential. The present study was conducted to develop soy whey‐fortified pineapple juice beverage and impact of ambient storage conditions on physicochemical, antioxidant, rheological, and sensory properties of functional beverage. Increasing the storage period decreased pH from 4.1 to 3.7 for control and 4.0 to 3.8 for soy whey‐treated samples. TSS increased from 8.3 to 10.6 on 0th day for control and soy whey‐treated beverage samples while on the 30th day, the TSS ranged from 8.9 to 11.1°B. Up to 30% soy whey incorporation, the DPPH, reducing power, and ABTS of beverages increased from 5.58%–57.01%, 56.35%–56.90%, and 4.84%–47.01%, respectively. The flow index (n) of the beverage formulations ranged between 0.4758 and 0.6521, and the yield stress between 0.018 and 0.025 Pa, hence showing Herschel–Bulkley character. With the increase in concentration and storage period, both G′ and G″ values decreased considerably (p < .05). The standard plate and yeast and mold count decreased considerably with an increase in soy whey and increased with an increase in storage. The sensory score of the beverages up to 30% soy whey exhibited best sensory score results compared to control and samples with 30% above soy whey content.

A Novel Fracturing Fluid Based on Functionally Modified Nano-Silica-Enhanced Hydroxypropyl Guar Gel

Considering the damage caused by conventional fracturing fluid in low-permeability reservoirs, a novel fracturing fluid (FNG) combining hydroxypropyl guar (HPG) and functionally modified nano-silica (FMNS) was prepared. The properties of heat/shear resistance, rheological property, proppant transportation, and formation damage were evaluated with systematic experiments. The results showed that the viscosities of FNG before and after the heat/resistance were 1323 mPa·s and 463 mPa·s, respectively, while that of conventional HPG gel was 350 mPa·s. FNG is a pseudoplastic strong gel with a yield stress of 12.9 Pa, a flow behavior index of 0.54, an elastic modulus of 16.2 Pa, and a viscous modulus of 6.2 Pa. As the proportions of proppant mass in further sections transported with FNG were higher than those transported with HPG gel, FNG could transport the proppant better than HPG gel at high temperatures. Because of the amphiphilic characteristics of FMNS, the surface/interface properties were improved by the FNG filtrate, resulting in a lower oil permeability loss rate of 10 percentage points in the matrix than with the filtrated HPG gel. Due to the considerable residual gel in broken HPG gel, the retained conductivity damaged with broken FNG was 9.5 percentage points higher than that damaged with broken HPG gel. FNG shows good potential for reducing formation damage during fracturing in low-permeability reservoirs in China.

The Effects of Aging on Microstructures and Rheological Properties of Modified Asphalt with GO/SBS Composite

The Effects of Aging on Microstructures and Rheological Properties of Modified Asphalt with GO/SBS Composite

Effects of fly ash and silica fume on the rheological properties of magnesium phosphate cement-emulsified asphalt (MPC-EA) composite repair materials

Effects of fly ash and silica fume on the rheological properties of magnesium phosphate cement-emulsified asphalt (MPC-EA) composite repair materials

Workability Tests and Rheological Properties of Manufactured Sand

Workability Tests and Rheological Properties of Manufactured Sand

Integrated analysis of electroosmotic and magnetohydrodynamic peristaltic pumping in physiological systems: Implications for biomedical applications

AbstractThe study of rheological properties in biological fluids, influenced by electroosmosis and magnetohydrodynamic (MHD) peristaltic mechanisms, plays a vital role in designing micro‐scale biomimetic pumping systems for targeted drug delivery. Considering these significant applications, the current study focuses on the integrated analysis of electroosmotic and magnetohydrodynamic peristaltic pumping of Williamson fluid within physiological systems with variable viscosity and thermal conductivity. The dimensional momentum equations are linearized under the approximation of lubrication theory. The current study deals with the impact of various physical parameters on flow, heat transfer, and pumping characteristics. These parameters include the magnetic parameter, variable viscosity, variable thermal conductivity, Helmholtz‐Smoluchowski velocity, and so on. It is noted from the current analysis that, Helmholtz‐Smoluchowski velocity and velocity slip parameters have decreasing effect on skin friction and Sherwood number. The electroosmotic and magnetic parameters contribute to larger trapped bolus sizes. These findings contribute significantly to advancing the development of efficient micro‐scale biomimetic pumping systems tailored for precise target drug delivery applications.

Research on Low-Cost High-Viscosity Asphalt and Its Performance for Porous Asphalt Pavement

To develop a cost-effective, high-viscosity asphalt for porous asphalt pavement, we utilized SBS, tackifier, and solubilizer as the main raw materials, identified the optimal composition through an orthogonal experiment of three factors and three levels, and prepared a low-cost high-viscosity asphalt. We compared its conventional and rheological properties against those of rubber asphalt, SBS modified asphalt, and matrix asphalt, employing fluorescence microscopy and Fourier transform infrared spectroscopy for microstructural analysis. The results indicate that the optimal formula composition for high-viscosity asphalt was 4–5% styrene-butadiene-styrene (SBS) + 1–2% tackifier +0–3% solubilizer +0.15% stabilizer. The components evenly dispersed and the performances were enhanced with chemical and physical modification. Compared with SBS modified asphalt, rubber asphalt, and matrix asphalt, the softening point, 5 °C ductility, and 60 °C dynamic viscosity of high-viscosity asphalt were significantly improved, while the 175 °C Brookfield viscosity was equivalent to SBS modified asphalt. In particular, the 60 °C dynamic viscosity reaches 383,180 Pa·s. Rheological tests indicate that the high- and low-temperature grade of high-viscosity asphalt reaches 88–18 °C, and that high-viscosity asphalt has the best high-temperature resistance to permanent deformation and low-temperature resistance to cracking. It can save about 30% cost compared to commercially available high-viscosity asphalt, which is conducive to the promotion and application of porous asphalt pavement.

Synthesis and study of organo-modified silica based hydrogels: Rheological properties and drug release kinetics.

The method of synthesis of unmodified and organo-modified silica hydrogels and their composites with orotic acid as a model drug was developed. The hydrogels had a pH of 6.5-7.8. The particulate nature and highly porous structures of the hydrogel materials were revealed using scanning electron and optical microscopy methods. The content of aqueous phase in the hydrogels was 99% or more. In order to evaluate the possibility of their application as a basis for development of novel soft drug formulations and cosmetic compositions, rheological properties of the hydrogels and in vitro release kinetics of the drug were studied. The effects of synthesis conditions (increasing concentration of catalyst of silica sol formation, drug loading) and the silica matrix modification with various organic groups on the indicated properties were investigated. It was found that all synthesized hydrogels exhibited pseudoplasticity, thixotropy and controlled release of the drug, which are important for their potential application. However, in general, the indicated effects led to worsening the properties of the hydrogel materials in comparison with the unmodified silica hydrogels.

Elasticity Modification of Biomaterials Used in 3D Printing with an Elastin–Silk-like Recombinant Protein

The recombinant structural protein described in this study was designed based on sequences derived from elastin and silk. Silk–elastin hybrid copolymers are characterized by high solubility while maintaining high product flexibility. The phase transition temperature from aqueous solution to hydrogel, as well as other physicochemical and mechanical properties of such particles, can differ significantly depending on the number of sequence repeats. We present a preliminary characterization of the EJ17zipR protein obtained in high yield in a prokaryotic expression system and efficiently purified via a multistep process. Its addition significantly improves biomaterial’s rheological and mechanical properties, especially elasticity. As a result, EJ17zipR appears to be a promising component for bioinks designed to print spatially complex structures that positively influence both shape retention and the internal transport of body fluids. The results of biological studies indicate that the addition of the studied protein creates a favorable microenvironment for cell adhesion, growth, and migration.

Rheological Behavior Features of Feedstocks with a Two-Component Wax–Polyolefin Binder Compared to Analogs Based on Polyoxymethylene

Despite the large number of studies devoted to different compositions of polymer binders for PIM technology, the actual task is still a comparative analysis of the properties of different types of binders to determine their advantages and disadvantages and optimize the compositions used. In this regard, this study aims at the identification and comparative analysis of the rheological properties of the most demanded feedstocks with binders based on polyoxymethylene and a wax–polyolefin mixture under the condition of using identical steel powder filler. The rate of change in the volume fraction of the liquid phase of the binder in the compared feedstocks with temperature change was determined by the calculation–experimental method. As shown, the temperature dependence of the viscosity of feedstocks with a binder based on a polymer blend depends on factors with variable power, i.e., the viscosity change with temperature occurs by different mechanisms with their relaxation spectra. Thus, the principle of temperature–time superposition for feedstocks with multicomponent binders is not applicable, and the study of the viscosity of such materials should involve a wide range of shear rates and temperatures using experimental methods. Capillary rheometry was used to measure the flow curves of feedstocks based on polyoxymethylene and wax–polyolefin binders. The analysis of flow curves of feedstocks showed that feedstocks with a binder of solution–thermal type of debinding have significantly lower viscosity, which is an advantage for molding thin-walled products. However, their difference of 1.5 times sensitivity to the shear rate gradient leads to their lower resistance to “jets” and liquation of components because of shear rate gradients when molding products with elements of different cross-sectional areas.