Rotational Viscometer Research Articles

Paper-based radial chromatographic assay for rapid in situ measurement of gelatinized starch concentration

Starch gelatinization is pivotal in food processing, impacting viscosity, texture, and functionality. However, current methods for determining concentration and viscosity of gelatinized starch (GS), such as falling ball and rotational viscometers, are impractical for in situ measurements due to bulky equipment. Here, we introduce a paper-based radial chromatographic assay (PRCA) method for rapidly measuring the concentration of gelatinized starch (GS). We utilized Evans Blue (EB) as a chromatic agent to label GS and generate color-ring patterns on a nitrocellulose membrane based on the “Coffee-ring” effect. The resulting PRCA patterns varied depending on the GS concentrations, yielding a good linear correlation (R2 > 0.967) between grayscale value and viscosity. This method enables rapid measurement of GS concentration within 10 s, even with varying ratios of amylose to amylopectin. PRCA demonstrates a detection limit for GS concentration between 0.027% and 0.051%, which is 10-20 fold lower than that of traditional rotational-viscometer. The intensity of PRCA patterns at pH 3 (45.8) was significantly lower than those at higher pH levels (5 to 9), consistent with the decreased viscosity measured by the viscosimeter. The intensity of PRCA patterns did not change with increasing temperature from 25°C to 90°C, despite the significant decrease in viscosity from 345 mPa•s to 195 mPa•s. Additionally, PRCA can monitor changes in starch viscosity during the hydrolysis process, which decreases from 744 mPa•s to 6 mPa•s. This capability provides an efficient means of measuring the concentration and viscosity of GS during food processing.

Viscosity of Wheat Starch Paste Used in Traditional Chinese Conservation Techniques

Abstract In traditional Chinese conservation of historic books and mounted scrolls, the preparation and use of paste is an important process step. The viscosity of the paste is a key factor to consider, taking into account various parameters such as conservation technique, paper condition, or paper thickness. This study aims to determine the viscosity variation of diluted and thick pastes used in traditional Chinese conservation techniques with a rotary viscometer. During conservation treatment, as the number of restored leaves increases, the viscosity of diluted paste tends to increase significantly. The study highlights the different requirements for viscosity depending on its use either in Chinese books or Chinese hanging scrolls and emphasizes the importance of monitoring and adjusting paste viscosity during the conservation process. The use of a rotary viscometer, along with the traditional finger test method, is a significant step forward in improving the accuracy and efficiency of determining paste viscosity.

Secondary degradation of bio-oil degraded crumb rubber and preparation of stable degraded crumb rubber modified asphalt

Using bio-oil to desulfurize and degrade crumb rubber (CR) significantly enhances the compatibility between CR and asphalt, improving the workability of CR-modified asphalt and providing environmental and economic benefits. However, the secondary degradation of bio-oil degraded crumb rubber (ODR) in asphalt hinders the stability of ODR-modified asphalt. To optimize the mechanical performance of ODR-modified asphalt, the secondary degradation behaviors of ODR were investigated. The degree of CR degradation was determined by solubility testing, while the rheological properties and chemical structures of ODR-modified asphalt were characterized through rotational viscometer, dynamic shear rheometer, bending beam rheometer, and Fourier transform infrared spectrometer. The processes for preparing stable ODR modifier and ODR-modified asphalt were proposed to mitigate the damage caused by bio-oil and degraded CR to the high temperature mechanical properties of asphalt. The results show that at lower processing temperatures for ODR-modified asphalt, the volatilization of light components is predominant, while higher processing temperatures prompt secondary degradation of ODR. By stirring at 280°C for 2 hours to acquire moderately degraded CR, and then concentrating it at 220°C for 2 hours, a stable ODR less susceptible to secondary degradation can be obtained. The workability, temperature sensitivity, and low temperature cracking resistance of stable ODR-modified asphalt improve significantly. The reduction of ester group and increase in aromaticity restore the high temperature deformation resistance of ODR-modified asphalt. Further, the inclusion of composite SBS extends the range of rheological properties in ODR-modified asphalt, bolstering the application potential of ODR in asphalt pavement.

Effect of fluorine on the viscosity and structure of non-reactive mold fluxes for high-Mn high-Al steel

The impact of varying F content from 4 wt% to 10 wt% on the structure and properties of non-reactive mold slag for high-Mn high-Al steel was investigated in this study. Employing a combination of techniques including a rotary viscometer, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy, the viscosity and structure of mold slag were analyzed. The findings revealed that increasing F content led to a gradual reduction in viscosity, activation energy for viscous flow, and the internal friction within the mold fluxes, consequently enhancing its fluidity. The Al–O–Al structure remained stable throughout the experimental range. The decrease in QAl2 content indicated a continuous depolymerization process, leading to the formation of free [Al2OF6] and [AlO6] structures as F content increased. At the same time, the replaced O2− ions were assimilated by [AlO4] tetrahedron, facilitating the formation [AlO6] octahedron. Consequently, the slag structure was simplified, resulting in a reduction in the degree of polymerization and viscosity.

EXPERIMENTAL STUDY OF NON-EQUILIBRIUM RHEOLOGICAL EFFECTS DURING THE FLOW OF PARAFFINIC OILS OF TIMAN-PECHORA BASIN. THIXOTROPY, SUPER ANOMALOUS VISCOSITY, OSCILLATIONS OF SHEAR STRESS

Laboratory experiments were carried out to study the non-stationary and non-equilibrium flow regimes of some paraffinic and high paraffinic crude oils of the Timan-Pechora Basin in a rotational viscometer. The presence of thixotropic properties (shear thinnig and hy steresis loops on the flow curves) is shown. The threshold character of the dependence of the area of the hysteresis loop on the oil tempera ture is demonstrated. Experiments have shown that under certain conditions on the flow curves of the studied oils, there are areas of a decrease in shear stress with an increase in shear rate, similar to areas of a «super anomalous» viscosity (SAV) in plastic lubricants. The shape and size of these areas, i.e. the intensity of the «superanomality» manifestation strongly depends on the experiment conditions and are poorly reproducible from experiment to experiment. In experiments, the SAV phenomenon at temperatures below the gelation temperature was always observed when the sample of paraffinic oil was at rest for a sufficiently long time before deformation. If, however, it was in the gap between the viscometer cylinders after the end of the next measurement cycle for a short time (no more than a few minutes), then at the next cycle of recording the flow curve, the SAV phenomenon can be practically imperceptible, although the hysteresis remains. Experiments show that if a sample of high paraffinic oil is deformed at a constant low shear rate, i.e. constant angular velocity of rotation of the device cylinder, and a temperature below the temperature of gelation, then on the falling curve of the dependence of shear stress on time («shear thinning»), oscillations in shear stress with a period equal to the period of rotation of the viscometer cylinder can be observed.

HIIT serves as an efficient training strategy for basketball players by improving blood fluidity and decreasing oxidative stress.

A challenge for coaches and athletes is to find the best combination of exercises during training. Considering its favorable effects, HIIT has been very popular recently. The goal of this study was to investigate anthropometric features, performance, erythrocyte deformability, plasma viscosity (PV) and oxidative stress in response to acute and long-term (6 weeks) HIIT in adolescent basketball players. 22 sportsmen between the ages of 14-16 were included. Tabata protocol was applied to the HIIT group in addition to their routine training program 3 days/week, for 6 weeks. Erythrocyte deformability was determined using an ectacytometer (LORCA), PV with a rotational viscometer. Total oxidant status (TOS), total antioxidant status (TAS) were measured by kits. HIIT for 6 weeks induced an improvement in performance tests and waist circumference. 6 weeks of HIIT resulted in a decrement, while the last exercise session yielded an increment in RBC deformability. PV and TOS of HIIT groups were decreased on the 6th week. Our results demonstrate that, HIIT in addition to the routine exercise program is beneficial for improving performance and blood fluidity as well as decreasing oxidative stress in basketball players. Therefore, HIIT seems as an efficient training strategy for highly-trained individuals.

The substantiation of the composition and technology of obtaining a microemulsion in laboratory conditions for pediatric use

Aim. To substantiate the composition and parameters of the technological process of obtaining a microemulsion with the essential oil of common fennel fruit for pediatric use. Materials and methods. The study objects were experimental samples of an emulsion with fennel essential oil (active pharmaceutical ingredient), acacia, xanthan and guar gums, soy lecithin, PEG-40 hydrogenated castor oil, PEG-100 stearate, glycerin monostearate, polysorbate-80 (emulsifiers) and purified water. Information-search, information-analytical, organoleptic, physicochemical, rheological and pharmacotechnological research methods were used. The rheological parameters were determined on a “Reotest-2” rotary viscometer (Germany) with coaxial cylinders, pH was measured potentiometrically on a pH‒150 MI pH-meter (Khimtest Ukraine+), thermal stability was determined in a SP50 drying cabinet. The microscopic studies of experimental emulsion samples were carried out using a Granum microscope with a Toupcam UCMOS video camera. The statistical processing of the data obtained was performed using Microsoft Excel 2007 spreadsheets. Results and discussion. The composition and technology of obtaining a microemulsion with the essential oil of fennel fruit in the conditions of a pharmacy for pediatric use were experimentally substantiated. The technological process consisted of the following stages: preparatory work, weighing of ingredients, mixing of ingredients, packaging, and registration of the drug for dispensing. The drug was manufactured in aseptic conditions. Standardization of the drug obtained was carried out: description, thermal and colloidal stability, pH value, viscosity, uniformity of the mass of doses extracted from multi-dose containers, mass of the contents of the container. The presence of anethole and terpenoids was proven by TLC method. Conclusions. At the current level of development of the pharmaceutical industry, the improvement of providing consumers with high-quality medicines is implemented by choosing the optimal dosage form, the composition of excipients, rational technology, and the use of modern equipment.

Purification and use of crude green glycerol from the transesterification of triglycerides in the formulation of an alcohol gel hand sanitizer

The aim of this study was to produce an alcohol gel hand sanitizer containing green glycerol. Crude glycerol was purified using chemical and physical treatments. The sanitizer was prepared using 71.100 g of 99.3° GL ethanol, 28.0 g H2O, 0.5 g of Carboxypolymethylene [Carbopol 940® or Carbomer], 5 drops of triethanolamine (pH 5–7), and glycerol (1.5% w/w). The thermal behavior of the ethanol, carbopol, triethanolamine, glycerol, and alcohol gels were evaluated using Thermogravimetry and Differential Thermal Analysis. The apparent viscosity was obtained using a rotary viscometer. The determination of in vitro spreadability was achieved by an adaptation of the Knorst method. The ethanol content was measured by headspace gas chromatography using a flame ionization detector. The thermal behavior of the gels was influenced by the presence of glycerol, which confirms the possible network interactions formed. The relative densities of the samples were between 0.887 and 0.890 g/cm3. No alteration of the pH of the formulation resulted from the incorporation of glycerol. The apparent viscosities of the alcohol gels were greater than 20,000 cP. No alteration in the in vitro spreadability of the gel alcohol (530.6 mm2) resulted from the addition of glycerol. Hand sanitizer was produced using glycerol from a transesterification reaction. It represents an alternative use for the glycerol being produced in biodiesel processes. The product satisfied the requirements of WHO that preconize a formulation containing 1.45% glycerol as an humectant to protect skin against dryness and dermatitis.

Two-Level Self-Thickening Mechanism of a Novel Acid Thickener with a Hydrophobic-Associated Structure during High-Temperature Acidification Processes.

Two acid thickeners, ADMC and ADOM, were prepared by aqueous solution polymerization using acrylamide (AM) and methacryloyloxyethyl trimethyl ammonium chloride (DMC) as raw materials, with or without the introduction of octadecyl polyoxyethylene ether methacrylate (OEMA). It was characterized by FTIR, 1H NMR, and the fluorescence spectra of pyrene. The double-layer thickening mechanism of ADOM was proved by comparing the thickening and rheological properties of ADMC and ADOM tested by a six-speed rotary viscometer and a HAKKE MARSIV rheometer during the acidification process. The results showed that the synthetic product was the target product; the first stage of the self-thickening ADOM fresh acid solution during high-temperature acidification was mainly affected by Ca2+ concentration, and the second stage of self-thickening was mainly affected by temperature. The residual viscosity of the 0.8 wt% ADOM residual acid solution was 250, 201.5, and 61.3 mPa·s, respectively, after shearing at 90, 120, and 150 °C for 60 min at a shear rate of 170 s-1. The thickening acid ADOM with a hydrophobic association structure has good temperature resistance and shear resistance, which can be used for high-temperature deep-well acid fracturing. In addition, no metal crosslinking agent was introduced in the system to avoid damage to its formation, and ADOM exhibited good resistance to Ca2+, which could provide ideas for the reinjection of the acidizing flowback fluid. It also has certain advantages for environmental protection.

Development of antifungal gel, composition and technology based on pomiferin metabolite isolated from fruits of Maclura aurantiaca growing in Kazakhstan

The aim. The purpose of this study is to develop the optimal composition and rational gel technology under the conventional name "Kaz-P7" based on the antifungal pomiferin.
 Materials and methods. The object of the study is the substance pomiferin.
 Based on the physicochemical properties of the gel (poorly soluble in water) and technological properties structurant - Carbopol Ultrez 20 (swelling) chosen optimal solvent system: DMSO-PG-water (1:4:1) corresponding to the maximum solubility of drug and polymer provides swelling.
 Following the requirements of GF RK I, vol. 1, 2.2.8, 2.2.10 was determined by rotational viscometric method. Rheological properties of the sample are determined using rotational viscometer "Rheolab QC" (firm "Anton Paar", Austria) with coaxial cylinders CC27/S-SN29766 determined. The rheological parameters were studied at a temperature of 20 °C – 35 °C using the MLM U15c thermostat included in the rheostat.
 Results. Gel dosage forms provide better bioavailability of the drug substance. In addition, gels are a more modern dosage form, pleasant in terms of organoleptic characteristics.
 The technology of gel manufacturing consists of two parallel processes: preparation of the drug substance solution and its introduction into the base. From the point of view of biopharmacy, which studies the biological effect of drugs depending on their physical properties, dosage form and preparation technology, the greatest release of the drug substance occurs when it is introduced into the dosage form in dissolved form.
 Pomiferin administered in the dissolved state has the most therapeutic effect on the gel base. At the same time, active pharmaceutical ingredients (APIs) were dissolved in different solvents with gradual heating. The ratio of solvents DMSO-PG-water (1:4:1) at which the developed dosage form will be more structured, stable, and thixotropic gel is established.
 Conclusions. Fungal skin diseases are among the most frequently discussed problems in the literature. The relevance of this topic is determined by the high prevalence of pathogens, which account for 37-42 % of all skin diseases. It was experimentally established that for the complete neutralization of one gm of carbopol Ultraz 20 in the DMSO-PG-water solvent system (1:4:1), one gm of triethanolamine (pH 7.0) is consumed. The optimal diluent consisting of DMSO-PG- water in the ratio (1:4:1) was selected by physico-chemical analysis methods, and one gm of triethanolamine (pH 7.0) was selected as the neutralizing agent. The following composition was chosen as the optimal gel model: API-3.0, DMSO-3.0, PG-50.0, Carbopol Ultrez 20-1.0, and Triethanolamine-1.0. The optimal composition and technology of the gel codenamed "Kaz-P7" based on the substance obtained by pomiferin was developed

Investigated on hot mix epoxy resin used in steel bridge deck pavement affected by collaborative toughen

The hot-mix epoxy resin commonly used in the market has insufficient toughness, resulting in cracking of steel bridge deck pavement. To obtain the excellent toughness of hot mix epoxy resin, the collaborative toughen is put forward to overcome the shortcoming. In order to character epoxy resins and epoxy asphalts affected by toughening agent, standard test method of tensile properties for plastics is used. The synergistic toughening mechanism and lyotropy of 1# rubber additive and 2# rubber additive are approved by analyzing scanning electron microscope. Synchronous thermal analyzer is applied to study reactivity of epoxy resin. The viscosity, reactivity and rheological performance of epoxy asphalt, which affected by toughen agent, are investigated by Brinell rotary viscometer and Dynamic shear rheometer respectively. According to the results, the excellent epoxy resin is obtained, when the dosage of toughen agent is 15 %. The activation energy of epoxy resin before and after toughen are 48.6 KJ/mol and 42.4 KJ/mol, respectively. Besides the toughen agent can reduce the viscosity of epoxy asphalt. Finally, R1 and R2 can enhance the elastic of epoxy asphalt and reduce the glass transition temperature of epoxy asphalt. In summary, with R1 and R2 added, the toughen of epoxy resin improved obviously. The application of toughened epoxy resin to the pavement of orthotropic steel bridge deck will has a very broad prospect.

Justification of the composition of the base of the emulsion ointment for the fungal diseases skin treatment

The relevance and socio-economic significance of the problem is determined by the prevalence of fungal diseases, which are affected by every fifth inhabitant of the planet (according to the World Health Organization). Among fungal diseases, dermatomycoses, which are complicated by infection and keratization of the skin, are of particular importance.
 In the treatment of dermatomycoses, a significant place belongs to external therapy (soft and liquid medicinal products). Dermatological medicinal products in Ukraine are mainly represented by drugs of foreign production – 58.2%.The range of multicomponent drugs affecting all links of the pathological process is 21%. Therefore, the development of a scientifically based composition and technology of a multicomponent soft medicine for the treatment of dermatomycoses is an urgent problem of our time.
 The goal of our research was to develop the optimal composition of the emulsion ointment base for the treatment of fungal skin diseases.
 The objects of the study were combinations in different ratios of surface-active substances, hydrophilic non-aqueous substances and emulsifiers. The osmotic properties of the experimental bases were studied using dialysis through a semipermeable membrane. The study of the rheological properties of the samples was carried out on a rotary viscometer Reotest-2 (USA) with a water circulation heater. Determination of colloidal stability (for emulsion systems) was carried out according to DSTU 4765:2007 «Cosmetic creams. General technical conditions». Determination of thermal stability was carried out according to DSTU 4765:2007 «Cosmetic creams. General technical conditions».
 Based on the conducted experimental studies, the composition of the base of the emulsion ointment was substantiated. Rheological studies have established the optimal concentration of surface-active substances in emulsions. The study of the osmotic activity of model emulsions made it possible to establish the optimal ratio of hydrophilic-non-aqueous solvents in the composition of model samples.
 On the basis of the conducted structural-mechanical and pharmacological studies, the composition of the emulsion base of the o/w type emulsion ointment was substantiated for treatment of fungal skin lesions: petroleum jelly (20.0 g), emulsifier No. 1 (5.0 g), PEO-400 (5.0 g), glycerin (5.0 g), Na-KMC (1.0 g), purified water up to 100.0 g.

Physical-chemical and biopharmaceutical research of ointments with cyminal

Local wound treatment remains one of the most pressing problems of modern medicine. The effectiveness of local drug therapy with the use of various medications depends on the differentiated use of drugs depending on the phase of the wound process.
 Taking into account modern wound treatment technologies, it is important to develop the composition and technology of an application drug (cream, ointment, gel) taking into account not only the phase of the wound process, but also the Time-concept component, in particular the ability of the drug to create an optimal moist environment and have antimicrobial properties, since the absence of infection in the wound is the basis for successful healing.
 The aim of our study was to develop an optimal composition of ointment for wound treatment based on technological and physicochemical studies.
 The rheological properties of the samples were studied using a Reotest-2 rotational viscometer (USA) with a water circulating heater. The structural viscosity was determined at a temperature of 20 ± 0,2 °C. Thermostatization was performed in the ITZH-0-03 thermostat.
 The temperature was determined by a laboratory thermometer with a division price of 0,1 °C. The acid-base balance was determined potentiometrically according to the State Standard Form I. The pharmacokinetic parameters of the drug were determined by dialysis through a semipermeable membrane.
 The experimental ointment is a non-Newtonian fluid. Its fluidity begins after a certain mechanical stress is applied, i.e., after the kinetic energy of the particles of the structural frame increases, which leads to the breakdown of bonds between its elements. The maximum destruction of the system occurs at a temperature of 40 °С. The experimental data showed that the pH of the ciminal ointment is in the range from 5,5 to 7.5, which is optimal for the treatment of infected wounds. The pharmacokinetic parameters of the drug were determined: reaction rate of release of active substances; reaction rate constants, half-life. The kinetic processes of ciminals release from the drug are described by the first-order equation.
 The composition and technology of the ointment have been substantiated on the basis of experimental studies.

Effect of nano-TiO2 on physical and rheological properties of asphalt cement

Abstract In recent years, nano-modified asphalt has gained significant attraction from researchers in the design of asphalt pavement fields. The recently discovered Titanium dioxide nanoparticles (TiO2) are among the most exciting and promising nanomaterials. This study examines the effect of 1, 3, 5, and 7% of nano-TiO2 by weight of asphalt on some of its rheological and hardened properties. The experimental study included physical and rheological properties. The asphalt penetration, softening point, ductility, and rotational viscometer tests indicate that 5% nano-TiO2 is the ideal amount to be added to bitumen as a modifier. The study of the rotating viscosity test showed that the addition of nano-TiO2 helped to increase viscosity and lessen bituminous sensitivity. Rutting factor in terms of G*/sin δ indicated the addition of 3 to 7% of nano-TiO2 increased the rutting resistance of asphalt against higher temperatures and promoted performance grade by about one grade at 3% and two grades at a range of 5–7% this suggests that nano-TiO2 increased the stiffness of the asphalt and leading to enhance the rutting performance of asphalt. While fatigue parameter, G*.sin δ shows that as nanocontent increases, higher stiffness at 5 and 7% of TiO2 content leads to an increase in complex modulus and a decrease in fatigue parameter. Higher creep stiffness and higher m-values were noted at low temperatures as nano increases in asphalt binder, increasing stiffness and decreasing the m-value at −6 and 12°C. As a result, using 5% nano-TiO2 will improve asphalt’s physical properties and enhance asphalt anit-rutting and fatigue resistance.

Viscosity of Cohesive Sediment‐Laden Flows: Experimental and Empirical Methods

AbstractThe rheological behaviors of suspended sediments are crucial for investigating near‐bed particle dynamics; for these investigations, the viscosity of a highly concentrated suspension is primarily focused on quantifying its resistance to deformation. By using a rotational viscometer, the relationships between relative viscosities (ηr) for different sediment types and their volumetric concentrations (ϕ) are studied for low‐to high‐concentration slurries. The results show that the conventional Einstein formula for diluted sand severely underestimates ηr. In the case of pure silts and non‐cohesive quartz, ηr demonstrates a gradual linear increase, reaching values around order of 101 as ϕ increases within the range of 0.2–0.4. Meanwhile, the ηr values of clays exhibit an exponential rise before leveling off at a plateau. Specifically, the ηr values of kaolinite, montmorillonite, and bentonite rise with ϕ lower than 0.3 and reach to plateau of values of thousands, which rise more rapidly than chlorite and illite. The modified viscosity model based on Costa (2005, https://doi.org/10.1029/2005GL024303) agrees reasonably well with observations and produces similar ηr ∼ ϕ relationships. In addition, the model is coupled with a hydrodynamic model to simulate the deposition of a thickened tailings slurry and a one‐dimensional dam break. The proposed model performs well in predicting the quasi‐equilibrium profiles of the non‐Newtonian fluid, which are validated by available analytical solutions. The results suggest that future models should be focused on the effects of flow properties, especially for non‐Newtonian fluids, and on large‐scale modeling applications, which can increase the accuracy of predictions of the transport characteristics of sediments and pollutants in rivers, lakes, and coastal areas.

Preparation of sodium alginate encapsulated anionic polyacrylamide microcapsules with delayed thickening performance

Polyacrylamide (PAM) is a polymer compound that is widely used in oil extraction, wastewater treatment, food processing and other fields. As a typical polymer flooding agent, PAM has received much attention in the field of oil extraction due to its unique of viscoelastic properties. However, polymer flooding faces several challenges in oil reservoirs, including high injection pressure, high shear loss and crossflow. In an effort to overcome this challenge, we designed a method of coating Ca2+ cross-linked sodium alginate onto the core structure of polyacrylamide, providing shear resistance and sustained release performance for the polymer. The important role of the shell material was indirectly demonstrated by measuring its apparent viscosity using digital rotary viscometer. Moreover, the swelling behavior of microcapsules in water was observed using an optical microscope. The protective shell made the slow release of anionic PAM into water under stirring at 500 rpm, maintaining the viscosity of the fluid below 10 mPa·s within 2 h, and the viscosity increased from 1.8 mPa·s to 30 mPa·s after 35 h. In addition, this work revealed the importance of effective encapsulation by emulsification/external gelation method and a facile shell modification by the layer-by-layer self-assembly method.

Viscosity Anomalies of Magnetic Fluid Stabilized by a Double Layer of Surfactant in Water

Purpose to study the temperature dependence of the viscosity of a water-based magnetic fluid.Method. Consists of measuring the dynamic viscosity of a magnetic fluid based on cobalt ferrite particles stabilized in water by a double layer of surfactant. Lauric acid (first layer) and a mixture of lauric acid and sodium dodecyl sulfate (second layer) were used as a stabilizer. Measurements were performed using a Brookfield DV-II+Pro rotational viscometer equipped with a coaxial cylinder system. The measuring system of the viscometer was thermostated using a KRIO-VT-12-1 thermostat.Results. The temperature dependences of dynamic viscosity were measured for three samples of magnetic fluid based on cobalt ferrite particles of various concentrations in the temperature range 0–90C°. The obtained temperature dependences of viscosity are radically different from the temperature dependences both predicted by known theories and experimentally observed for kerosene-based magnetic fluids. According to well-known theoretical models, the ratio of the viscosity of the magnetic fluid to the viscosity of the base medium is a certain universal function of particle concentration. Different models offer different types of this feature. But it clearly follows from them that the viscosity ratio should not depend on temperature. For magnetic fluids based on kerosene, it has been experimentally established that its relative viscosity decreases with increasing temperature. However, according to the results obtained, the relative viscosity of a water-based magnetic fluid does not decrease with increasing temperature, but increases significantly. That is, the viscosity of a water-based magnetic fluid decreases more slowly with increasing temperature than the viscosity of water.Conclusion. The observed dependencies completely contradict the known patterns, both theoretical and experimentally established for kerosene-based magnetic fluids. The results obtained may be useful for the further development of the theory of aqueous colloidal solutions with particle stabilization by a double layer of surfactants.

Investigations on the optical, dielectric, electrical, and rheological properties of PEG200/ZnO semiconducting nanofluids for soft matter based technological innovations

Semiconducting nanofluids (SNFs) consisting of poly (ethylene glycol) (PEG200) as a green biocompatible base fluid with homogeneous dispersion of eco-friendly zinc oxide (ZnO) nanomaterial, concentrations ranging from 0.01 to 0.20 wt%, are prepared by state-of-the-art ultrasonic cavitation homogenized process. These PEG200/ZnO SNFs are characterized by employing an ultraviolet-visible (UV-Vis) spectrophotometer, precision inductance-capacitance-resistance (LCR) meter, and rotational viscometer. A detailed analysis of 200–800 nm range UV–Vis absorbance spectra of these SNFs revealed longer stability of suspended ZnO nanoparticles in PEG200 fluid, and their nanomaterial concentrations dependent absorbance and extinction coefficient with tunable dual energy band gaps ranging from 3 to 5 eV. Optical performance recognized the potential applications of these SNFs in the advances of soft matter based optoelectronic and photosensitive devices and also as an excellent UV radiation shielding material. The study of 20 Hz – 1 MHz range dielectric and electrical spectra explained that the ZnO concentrations have a significant impact on the electrical conductivity of these SNFs, while the dielectric permittivity and electrode polarization relaxation process are marginally altered. High static dielectric permittivity (∼ 22) and low electrical conductivity of about μS/cm order, at 303.15 K, evidence the suitability of these SNFs in advances of energy storage devices. The rheological behaviour of PEG200/ZnO materials is carried out at different temperatures ranging from 303.15 to 323.15 K, which illustrates the Newtonian characteristics of these nanofluids with moderate dynamic viscosity and activation energy, and therefore, they could be utilized as effective heat transfer materials in photovoltaic/thermal devices and systems.

ВЛИЯНИЕ ГИПЕРРАЗВЕТВЛЕННОГО ПОЛИМЕРА НА ЗНАЧЕНИЯ ВЯЗКОСТИ ДЛЯ ТРУБОПРОВОДНОЙ ПЕРЕКАЧКИ ЖИДКИХ УГЛЕВОДОРОДОВ

The article presents the results of studies of the industrial hyperbranched polymer Boltorn W300 on the values of the dynamic viscosity of oil from Yakut fields in various concentrations and in different temperature ranges from 5 to 25 ° C in increments of 5 ° C, which can positively influence the processes of pipeline transportation of oils in conditions of complex rheological parameters of pipeline operation networks. A preliminary analysis of oil for physical and chemical properties was carried out and the rheological characteristics of the base oil were studied. It has been established that, according to the results of structural group analysis, the chemical composition of the oil is paraffinic. Using a rotational viscometer, the dynamic viscosity of the shear rate of an oil system containing an additive component in concentrations of 10, 30, 50, 80 and 100 ppm. It was revealed that the effectiveness of the hyperbranched polymer Boltorn W300 is observed only at low temperatures (below 10 0C); an increase in the effectiveness of the hyperbranched polymer Boltorn W300 from an increase in the concentration of the polymer additive in the oil system was also revealed. The most effective additive concentration in this study is 100 ppm, where the viscosity index is reduced by 40,7 %. The greatest effectiveness of the hyperbranched polymer Boltorn W300 in reducing dynamic viscosity and improving rheological properties is observed in the region of low shear rates - up to 3 s-1, which can be preliminarily assessed as a positive quality for use on pipelines for pumping oil media during the pipeline commissioning period, at which low shear rates are observed. shear rates and low oil flow rates.

ОЦЕНКА СООТВЕТСТВИЯ БУРОВЫХ РЕАГЕНТОВ, ПОСТАВЛЯЕМЫХ ИЗ СЕВЕРНЫХ РАЙОНОВ КИТАЯ

The article presents the results of conformity assessment of reagents for oil well drilling, produced and supplied to Russia from China. The current state of Russian-Chinese co-operation in the field of supply of oilfield chemicals and reagents for drilling oil and gas wells is presented. It is shown that the import of xanthan gum and guar gum is necessary and alternative-free due to the lack of raw materials for the production of these types of drilling reagents in Russia. The relevance of the study is due to the current situation of sanctions pressure and trade and economic blockade by Western countries, which gives cooperation with China in various industrial areas a strategic nature. After the withdrawal of Western companies it was China that replaced huge volumes of chemical reagents for oil production, in this connection it is necessary to control Chinese chemistry in terms of efficiency and safety of application at oil and gas production facilities. The methods of viscometry, gravimetry, sieve analysis were used in this work. Two samples of xanthan resin and one sample of low viscosity polyanionic cellulose were tested. As a result of the tests it was shown that the quality of Chinese-made drilling reagents meets the requirements of Russian and international standards. In addition, new technical possibilities for viscosity determination on the rotational viscometer have been revealed, which consist in the possibility of using a rotational viscometer equipped with a torsion spring f1, instead of a rotational viscometer equipped with a torsion spring f0.2, specified in the international standard ISO 13500. The work also shows the unlikelihood of organochlorine compounds in the composition of polyanionic cellulose and xanthan gum.