Capillary Viscometer Research Articles

Method of Detecting Liquid Meniscus in Capillary Using Ultraviolet Sensor

The accuracy of determining the physical and chemical properties of a liquid, in particular, assessing the viscosity of the liquid used, is considered an important technical problem in medicine, food, oil, chemical industries, as well as in other areas that determine the quality and safety of human life and activity. For example, assessing the viscosity of the liquid used is a key stage in the design of hydraulic systems. Today, the improvement of methods for determining the viscosity of a liquid is on the path to automation (digitalization) of measurement instruments and methods. In this area, the activities of metrologists and engineers are consistent with the national program «Digital Economy of the Russian Federation» adopted in 2017. The article discusses the capillary method for determining the kinematic viscosity of a liquid as the most accurate of all possible methods at present. The method is based on determining the time of liquid flow between two marks, which are applied to the walls of a glass capillary viscometer forming a measuring tank. One of the main problems of this method is that all stages of measurement are performed by a person, even recording the moment when the liquid meniscus crosses the mark, which is a violation of one of the key principles of process automation – independence of execution, which only implies monitoring the operation of the system. Since ready-made solutions do not fit the laboratory’s measurement tasks, the management decided to develop and conduct a study of an information and measuring system that will carry out the process of detecting the liquid meniscus at the mark level, as well as recalculate the measured time interval into the kinematic viscosity value. The key decision in this development is the choice of a sensor for detecting the liquid meniscus. Based on the literature review, it was decided to use a photoelectric sensor. A study of the transmission spectra of liquids used in this method was conducted to select the wavelength at which the sensor will operate. Thus, a type of photoelectric sensor designed to operate in the UV range has been selected to automate the method of detecting the liquid meniscus when it crosses a mark applied to a capillary tube. The article is addressed to metrologists who perform verification and calibration of glass capillary viscometers, specialists in the field of experimental and theoretical viscometry. The method proposed by the authors can become the basis for further improvement of the method for measuring the kinematic viscosity of a liquid.

Density, thermal expansion, dynamic viscosity of halogenated arenes

Purpose. Experimental study of the density, thermal expansion and dynamic viscosity of halogenated arenes at temperatures from 293.15 to 343.15 K and atmospheric pressure 97.992 kPa.Methods. Density was determined by the pycnometric method, viscosity by the capillary method. A quartz pycnometer type PZh2 with a nominal capacity of 10 ml and a glass capillary viscometer type VPZh-2 with a nominal capillary diameter of 0.34 mm were used. The mass of liquids was measured using an electronic scale VSL-200/0.1A with a division value of 0.0001 g. Numerical methods were used to process the experimental results.Results. Experimental data were obtained on the density, coefficient of volumetric thermal expansion and dynamic viscosity of liquid o-xylene, ethylbenzene, fluorobenzene, chlorobenzene, bromobenzene, toluene, o-fluorotoluene, mfluorotoluene, p-fluorotoluene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, 2,4-dichlorotoluene, 2,6-dichlorotoluene. Density and dynamic viscosity data are approximated by a third-degree polynomial. Data on the coefficient of volumetric thermal expansion are obtained from approximated measured density data. The maximum estimate of the measurement error for density was 0.13 %, for dynamic viscosity – 3.5 %. The maximum calculation error for the coefficient of thermal expansion is estimated at 3 %.Conclusion. Mathematical processing of the obtained experimental data on density and dynamic viscosity made it possible to obtain analytical relations in the form of power polynomials that allow calculating the values of these quantities at any temperature from the studied temperature range and atmospheric pressure with an error not exceeding the error of experimental determination. The calculated values are in good agreement with the data provided in the reference and scientific literature. The experimental data obtained complement the information on the properties of some of the liquids under consideration, for which the dependences of density and viscosity on temperature are poorly understood. The substances under study are used in various sectors of the economy and are therefore technically important liquids. The measurement results can be used in condensed matter physics, for the analysis of liquid hydrocarbons, and can be useful in the chemical industry.

Note on the Kinetic Energy Correction for Capillary Viscometers

Note on the Kinetic Energy Correction for Capillary Viscometers

A Review of Viscosity Measurement Techniques for Semi-Solid Metal Fluids in Thixoforming Processes

This paper critically reviews two viscometry techniques: capillary viscometers and parallel plate compression (PPC) viscometers, which are used in the viscosity measurement of semi-solid metal (SSM) fluids for thixo routes. Capillary and PPC viscometers have emerged as valuable viscometers in the study of thixo routes of SSM, with insights into their unique flow behavior being explored. Thixoprocessing of SSM is particularly suitable for specific alloys, especially those with specific solidification properties such as eutectics. It is a method of thixoforming that uses a material's non-dendritic microstructure. The thixo method's viscosity measurement is challenging, requiring sample preparation, sophisticated equipment, precise temperature, and pressure control. Previous studies have lacked sufficient information on measurement methods, viscometers, and limitations to measuring viscosity for the thixo route of SSM. Hence, this study thoroughly examines the principles, advantages, limitations, and application areas of viscometry methods. Several factors influencing viscosity measurements, such as temperature, shear rate, and sample preparation, are discussed in detail. A comparative analysis is conducted to evaluate the performance and accuracy of capillary viscometers and parallel plate compression viscometers. This review will provide a comprehensive understanding of SSM's viscometry techniques and assist researchers and practitioners in selecting the most appropriate method for their specific applications in semi-solid metal processing and characterization.

Anticancer drug delivery: Investigating the impacts of viscosity on lipid-based formulations for pulmonary targeting

Pulmonary drug delivery via aerosolization is a non-intrusive method for achieving localized and systemic effects. The aim of this study was to establish the impact of viscosity as a novel aspect (i.e., low, medium and high) using various lipid-based formulations (including liposomes (F1-F3), transfersomes (F4-F6), micelles (F7-F9) and nanostructured lipid carriers (NLCs; F10-F12)) as well as to investigate their impact on in-vitro nebulization performance using Trans-resveratrol (TRES) as a model anticancer drug. Based on the physicochemical properties, micelles (F7-F9) elicited the smallest particle size (12–174 nm); additionally, all formulations tested exhibited high entrapment efficiency (>89 %). Through measurement using capillary viscometers, NLC formulations exhibited the highest viscosity (3.35–10.04 m2/sec). Upon using a rotational rheometer, formulations exhibited shear-thinning (non-Newtonian) behaviour. Air jet and vibrating mesh nebulizers were subsequently employed to assess nebulization performance using an in-vitro model. Higher viscosity formulations elicited a prolonged nebulization time. The vibrating mesh nebulizer exhibited significantly higher emitted dose (ED), fine particle fraction (FPF) and fine particle dose (FPD) (up to 97 %, 90 % and 64 µg). Moreover, the in-vitro release of TRES was higher at pH 5, demonstrating an alignment of the release profile with the Korsmeyer-Peppas model. Thus, formulations with higher viscosity paired with a vibrating mesh nebulizer were an ideal combination for delivering and targeting peripheral lungs.

Impact of Systolic Blood Viscosity on Deep White Matter Hyperintensities in Patients With Acute Ischemic Stroke.

Elevated blood viscosity (BV), a critical determinant in blood rheology, is a contributing factor in cerebrovascular diseases. The specific influence of BV on small vessel disease burden remains unexplored. This study aims to examine the relationship between BV and regional white matter hyperintensity (WMH) volume in patients with acute ischemic stroke. We enrolled a cohort of 302 patients with acute ischemic stroke or transient ischemic attack who were admitted to a hospital within 7 days of symptom onset in this study. We measured whole BV using a scanning capillary-tube viscometer and categorized systolic blood viscosity into 3 groups based on established references. We quantified and normalized WMH volumes using automated localization and segmentation software by NEUROPHET Inc. We performed multivariable logistic regression analysis to assess the correlation between systolic BV and WMH. The mean subject age was 66.7±13.4 years, and 38.7% (n=117) of the participants were female. Among a total of 302 patients, patients with higher deep WMH volume (T3) were typically older and had an atrial fibrillation, strokes of cardioembolic or undetermined cause, elevated levels of C-reactive protein, diastolic blood viscosity and systolic BV. A multivariable adjustment revealed a significant association between high systolic BV and increased deep-WMH volume (odds ratio [OR], 2.636 [95% CI, 1.225-5.673]). Elevated systolic BV is more likely to be associated with deep WMH volume in patients with acute ischemic stroke or transient ischemic attack. These findings reveal novel therapeutic strategies focusing on blood rheology to enhance cerebral microcirculation in stroke management.

Performance analysis and degradation mechanism of acrylamide co-polymer as rheology and filtrate reducers in different salt aqueous-based drilling mud systems at high-temperature conditions

To maintain performance of an aqueous-based drilling muds (ABDMs), it was imperative to understand the decay mechanism of the incorporated synthetic polymers, when exposed to the elevated temperatures. The understanding of the decay mechanism could provide a polymer replenishment strategy for the fluid to retain a specific rheology and filtrate control performance. In this context, thermal-degradation of various acrylamide co-polymers was investigated in different monovalent brines. The acrylamide co-polymers were custom synthesized, and their molecular weight and % sulfonic substitution was verified using the capillary viscometer and nuclear magnetic resonance spectroscopy techniques respectively. The co-polymer thermal degradation mechanism (i.e., polymer hydrolysis) in various monovalent brines (KCl, NaCl and NaBr) was quantified by novel titration for temperature range {121 °C, 177 °C}. The degradation response of the co-polymers was then correlated with their rheology and HPHT (high-pressure-high-temperature) filtrate performance; for instance, the titration studies showed that co-polymer degradation was 12–15% and 44–47% after sixteen hours aging at 121 °C and 177 °C respectively; correspondingly the co-polymer performance in ABDM, exhibited HPHT filtrate of 12–18 mL and 38–40 mL at those respective temperatures after sixteen hours of aging. The quantified understanding of the co-polymer thermal degradation was used to device a new approach for co-polymer replenishment strategy; it was illustrated that a 7% replenishment of the co-polymer for every eight hours, at 121 °C, enabled sustained HPHT filtrate of 12–18 mL for the studied evaluation period of thirty-two hours. The replenishment approach presented in the study would provide a valuable tool for drilling automation to ensure sustained fluid performance.

Viscosity of Hydrogen and Methane Blends: Experimental and Modelling Investigations

Understanding of thermophysical and transport properties of H2-NG blends are needed for the gradual introduction of hydrogen into the national gas grid. A capillary tube viscometer was used to measure the viscosity of hydrogen + methane blends (with hydrogen mole fraction = 0, 0.1000, 0.1997, 0.5019, and 1) at temperatures from 213 to 324 K and pressures up to 31 MPa. A total 147 experimental viscosity measurements were made for the three H2 + CH4 blends and compared against the predictions of five different viscosity models: a one-reference corresponding states (Pedersen) model, a two-reference corresponding states (CS2) model, an extended corresponding states (ECS) model, a corresponding states model derived from molecular dynamic simulations of Lennard Jones (LJ) fluids, and a residual entropy scaling (SRES) method. All the model predictions showed a relatively low deviation compared to the measured viscosities. The density required for viscosity model predictions were computed using Multi-Fluid Helmholtz Energy Approximation (MFHEA) equations of state (EoS). To check the experimental procedure and applicability of the viscometer equipment, viscosity validation measurements were carried out for propane, hydrogen, and methane. The measured viscosities of the pure components were in good agreement with the respective viscosity models with AARD of 0.24%, 0.25%, and 0.58% for propane, hydrogen, and methane, respectively.Graphical

Association of Cerebral Artery Stenosis with Blood Viscosity in Patients with Transient Ischemic Attack

Background: Blood viscosity (BV) reflects blood thickness and stickiness, crucial for vascular health. Elevated BV is linked to stroke risk factors, suggesting a role in transient ischemic attacks (TIA).Methods: This retrospective observational study investigated BV levels in TIA patients with and without cerebral artery stenosis. Patients admitted within 24 hours of symptom onset between March 2017 and December 2021 were included. Baseline characteristics, including demographics and vascular risk factors, were assessed. BV measurements were obtained within 24 hours of symptom onset using a scanning capillary-tube viscometer. Patients were categorized into TIA groups based on the presence or absence of cerebral artery stenosis.Results: Of the 153 TIA patients screened, 86 were included for analysis. The mean age was 62.6 years, with a predominance of hypertension (59%) and dyslipidemia (45%). Patients with cerebral artery stenosis (TIA-AT group, n=56) exhibited significantly higher BV levels within 24 hours of symptom onset compared to those without stenosis (TIA-E group, n=30). This finding suggests a potential link between underlying pathophysiological mechanisms of TIA and BV levels.Conclusion: Despite the limitations of a single-center, retrospective study, this research suggests that there is evidence of increased blood viscosity in patients with TIA who have cerebral artery stenosis, implying that blood viscosity may play a role in the pathophysiology of TIA. Further research involving larger cohorts is warranted to elucidate the precise mechanisms linking BV to TIA and to validate its utility as a prognostic marker and therapeutic target in TIA management.

Two-capillary viscometer for temperatures and pressures relevant to CO2 capture, transport, and storage—operation and improved analysis at high pressure

High-pressure viscosity measurements are crucial for understanding CO2 transport and storage because CO2 is often transported as a supercritical fluid, at a high pressure and temperature above its critical point. In this study, we extended the operational range of our new two-capillary viscometer to handle pressures up to 20 MPa, focusing on the behaviour of CO2 at temperatures around 300 K. The analysis model is based on the low-pressure principle, which relied on virial descriptions of density and viscosity, proved inadequate under these conditions. Therefore, we introduced a modified hydrodynamic model as a function of density that is suitable for viscosity measurements at high pressure and liquid states. The modified model bypasses the need for a density virial correction. We conducted initial viscosity tests on pure CO2 at five isotherms: 280.01 K, 298.15 K, 300.01 K, 323.15 K, and 348.15 K to validate the performance of the new two capillary viscometer and the modified model at high pressures. The experimental viscosities agreed with the model predictions and comparable within the estimated uncertainty of the data. In addition, we thoroughly explained the calibrations and the analysis of uncertainty estimation. The uncertainty analysis showed a maximum extended combined uncertainty of 1.3% (k = 2) within all thermodynamic states—gas, liquid, and close to the critical region.

Investigation of Zinc on hemorheological parameters in a rat model of diabetes

Diabetes mellitus (DM) is a complex, chronic metabolic disorder characterized by impaired regulation of blood glucose levels. Zinc (Zn) is an essential trace elements that plays a role in various physiological processes within the body, including those related to diabetes. The current study was investigated the effect of Zn supplementation on hemorheological parameters in a rat model of DM. After induction of DM, 32 male Wistar albino rats were divided into four groups: control, Zn, DM, and Zn+DM. Whole blood viscosity (WBV) was determined by using digital cone and plate viscometer and plasma viscosity (PV) was determined by a Coulter Harkness capillary viscometer. The rats in the DM Group showed a decrease in both Zn levels and body weight, as well as an increase in glucose levels when compared to the control group. Diabetic rats supplemented with Zn displayed lower blood glucose levels and higher concentrations of Zn compared to the DM Group. The higher PV and lower hematocrit level were measured in DM Group than control group and lower PV, higher hematocrit level were measured in Zn+DM group than DM Group. The WBV was measured at four different shear rates (57.6–115.2 - 172.8–230.4 s −1). A statistically significant increase was observed in the DM group compared to the control group. Additionally, a statistically significant decrease was observed in the Zn+DM Group compared to the DM Group at a shear rate of 230.4 s−1. Erythrocyte rigidity index (Tk) and oxygen delivery index (ODI) were computed under conditions of high shear rate. The rats in the DM group exhibited a reduction in ODI and an elevation in Tk in comparison to the control group. Conversely, the diabetic rats supplemented with Zn exhibited decreased Tk and increased ODI compared to the DM Group. Zn supplementation seems to have a potential beneficial effect for protecting adverse affect of diabetes on hemorheogical parameters and for maintaining vascular health.

A Study of Blood Viscosity and Inflammatory Biomarkers’ Levels in Bilateral Primary Varicose Veins/Reticular Veins as Predictive Markers

Objectives Cross-sectional data was collected for a period of 1 year to assess the biomarkers of inflammation, and blood viscosity as predictive markers in patients with primary bilateral varicose veins or reticular veins that might progress to varicose veins. Material and Methods A sample of 40 participants, 20 controls and 20 patients aged 18–65 years falling under the reticular veins and symptomatic varicose veins (C1, 2s), primary etiology (Ep), superficial veins (As), reflux pathology (Pr) categories of Clinical, etiologic, anatomic, Pathophysiologic (CEAP) classification with the exception of telangiectatic veins, were included in the study. Blood viscosity was measured using a Capillary Viscometer. Evaluated inflammatory markers were tissue Plasminogen Activator (tPA), Plasminogen Activator Inhibitor-1 (PAI-1), and fibrinogen. Analysis was done using Statistical Package for the Social Sciences (SPSS) software and Chi-square, Fisher’s, Bonferroni, and Analysis of Variance (ANOVA) tests were applied. Results There was a statistically insignificant relationship between occupation and different study groups. Standing hours and serum fibrinogen levels had a significant difference in different study groups. Serum tPA, Serum PAI-1, and blood viscosity had an insignificant difference between different study groups. It was revealed that the pairwise group comparisons of study group C2 vs. control group C0, study group C1 vs. control group C0 and study group C2 vs. study group C1, and study group C2 vs. control group C0 each were significantly different pairwise. Conclusion Blood viscosity, tPA and PAI-1 cannot be used as predictive markers in patients with bilateral (B/L) primary varicose veins/reticular veins. Serum fibrinogen levels can be used as predictive markers for the development of B/L primary varicose veins and in our particular study with a predictive range of 189.4–327.9 mg/dL but not for B/L reticular veins. Prolonged standing, irrespective of the occupation of the patient, is associated with the development of B/L reticular veins and B/L varicose veins.

Hexagonal Boron Nitride as Filler for Silica-Based Elastomer Nanocomposites.

Two-dimensional hexagonal boron nitride (hBN) has attracted tremendous attention over the last few years, thanks to its stable structure and its outstanding properties, such as mechanical strength, thermal conductivity, electrical insulation, and lubricant behavior. This work demonstrates that hBN can also improve the rheological and mechanical properties of elastomer composites when used to partially replace silica. In this work, commercially available pristine hBN (hBN-p) was exfoliated and ball-mill treated in air for different durations (2.5, 5, and 10 h milling). Functionalization occurred with the -NH and -OH groups (hBN-OH). The functional groups were detected using Fourier-Transform Infrared pectroscopy (FT-IR) and were estimated to be up to about 7% through thermogravimetric analysis. The presence of an increased amount of oxygen in hBN-OH was confirmed using Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy. (SEM-EDS). The number of stacked layers, estimated using WAXD analysis, decreased to 8-9 in hBN-OH (10 h milling) from about 130 in hBN-p. High-resolution transmission electron microscopy (HR-TEM) and SEM-EDS revealed the increase in disorder in hBN-OH. hBN-p and hBN-OH were used to partially replace silica by 15% and 30%, respectively, by volume, in elastomer composites based on poly(styrene-co-butadiene) from solution anionic polymerization (S-SBR) and poly(1,4-cis-isoprene) from Hevea Brasiliensis (natural rubber, NR) as the elastomers (volume (mm3) of composites released by the instrument). The use of both hBNs in substitution of 30% of silica led to a lower Payne effect, a higher dynamic rigidity, and an increase in E' of up to about 15% at 70 °C, with similar/lower hysteresis. Indeed, the composites with hBN-OH revealed a better balance of tan delta (higher at low temperatures and lower at high temperatures) and better ultimate properties. The functional groups reasonably promote the interaction of hBN with silica and with the silica's coupling agent, sulfur-based silane, and thus promoted the interaction with the elastomer chains. The volume of the composite, measured using a high-pressure capillary viscometer, increased by about 500% and 400% after one week of storage in the presence of hBN-p and hBN-OH. Hence, both hBNs improved the processability and the shelf life of the composites. Composites obtained using hBN-OH had even filler dispersion without the detachments of the filler from the elastomer matrix, as shown through TEM micrographs. These results pave the way for substantial improvements in the important properties of silica-based composites for tire compounds, used to reduce rolling resistance and thus the improve environmental impacts.

Measurement and control of extensional viscosity in barrier coating dispersions

This study aimed to understand the effect of various rheological additives on the extensional viscosity of barrier coating dispersions, as well as to understand the role extensional viscosity plays in stabilizing a liquid curtain. The apparent extensional viscosity was measured using two devices that create accelerating flows: a capillary viscometer and an orifice rheometer. Additives tested include several polyvinyl alcohols, a high molecular weight polyethylene oxide, and carboxymethylcellulose. Extensional viscosity plays a significant role in stabilizing a liquid curtain, as it slows down hole expansion and prevents impurities and disturbances from causing holes in the first place. Some of the additives could substantially increase the extensional viscosity of the dispersions without increasing the shear viscosity outside the typical range of processability for a curtain coater. Some of the additives exhibited coil-stretch transition, meaning they start increasing extensional viscosity above a certain extension rate. Polymers with low chain lengths exhibited finite extensibility, which indicates the polymer chain has fully extended and cannot provide further extensional viscosity, even though the extending force is increased. Polymeric additives with stiff or branched chains significantly raised shear viscosity without increasing extensional viscosity. Both methods could reliably measure extensional viscosity in curtain coating barrier dispersions.

The history of the development of the capillary method of measuring kinematic viscosity: from the Lomonosov viscometer to the information measuring system

The history of the development of the capillary method of viscosity measurements is described and the tasks of automation and improvement of this method are considered. A comparative analysis of the currently relevant vibrational, rotational, capillary methods of measuring the viscosity of a liquid and the measuring instruments implementing them is given. The State verifi cation scheme for viscosity measuring instruments to represent the role of the capillary method in general and glass capillary viscometers in particular in this structure is briefl y described. The reasons why the capillary method is used in many countries as the main high-precision method for measuring the viscosity of liquids are considered. A detailed derivation of the formula for calculating the kinematic viscosity of the liquid under study is given. As one of the possible ways to further develop the capillary method of measuring kinematic viscosity, it is proposed to create an information-measuring system for measuring the kinematic viscosity of the liquid under study. The principle of operation of this system is described and plans for its implementation are formulated. It is shown that it is possible to increase the accuracy of measurements of the viscosity of liquid media by the capillary method by automating measurements and installing detectors of a certain type. The results of the performed analysis are relevant to ensure the uniformity of viscosity measurements in the Russian Federation.

Experimental Evaluation of Kinetic Behavior of Asphaltene Particles: Effect of Temperature, Shear Stress, and Inhibitors

Summary Asphaltene deposits under a variety of temperatures and shear stresses in reservoirs, wells, and crude oil transmission pipelines, and it is currently one of the most serious problems in the oil industry. The size of asphaltene particles strongly affects the deposition rate. The particle size is mainly determined by aggregation rate that depends on shear rate and temperature. Therefore, different shear rates of 127 s–1 and 254 s−1 were applied within Couette flow at 25°C, 45°C, and 65°C, and the particle size was analyzed by using an optical microscope. Crude oil viscosity and asphaltene solubility were determined using a capillary tube viscometer and IP143 procedure, respectively. In this work, the effects of four additives, namely, dodecyl benzene sulfonic acid (DBSA), nonyl phenol (NP), salicylic acid (SA), and benzoic acid (BA), were studied on the aggregation of asphaltene particles in a light crude oil. The additives were chosen based on their functional groups. Moreover, asphaltene functional groups were determined using a Fourier transform infrared (FTIR) analyzer to better understand the behavior of inhibitors in preventing the aggregation of asphaltene particles at different conditions. DBSA, BA, and SA were inhibitors, and NP behaved as a promoter. According to the results, the presence of acidic groups, SO3H in DBSA and COOH in SA and BA, increases the interaction of inhibitor with asphaltene and so reduces the aggregation of asphaltene particles. The stronger acidic group of DBSA improved its performance compared to other inhibitors. Both increasing temperature and increasing shear stress resulted in higher collisions of asphaltene particles and thus lowered the efficiency of inhibitors at a constant concentration.

Droplet Based Estimation of Viscosity of Water–PVP Solutions Using Convolutional Neural Networks

The viscosity of a liquid is the property that measures the liquid’s internal resistance to flow. Monitoring viscosity is a vital component of quality control in several industrial fields, including chemical, pharmaceutical, food, and energy-related industries. In many industries, the most commonly used instrument for measuring viscosity is capillary viscometers, but their cost and complexity pose challenges for these industries where accurate and real-time viscosity information is vital. In this work, we prepared fourteen solutions with different water and PVP (Polyvinylpyrrolidone) ratios, measured their different viscosity values, and produced videos of their droplets. We extracted the images of the fully developed droplets from the videos and we used the images to train a convolutional neural network model to estimate the viscosity values of the water–PVP solutions. The proposed model was able to accurately estimate the viscosity values of samples of unseen chemical formulations with the same composition with a low MSE score of 0.0243 and R2 score of 0.9576. The proposed method has potential applications in scenarios where real-time monitoring of liquid viscosity is required.

INVESTIGATION OF MODIFIED POLYACRYLAMIDE FOR OIL DISPLACEMENT

At present, the use of surfactants and water-soluble polyelectrolytes, which act as stabilizing and selective agents, is inextricably linked with the successful solution of the technological issues in the world of chemical, oil and other industries. The purpose of the work is to synthesize and study the physicochemical properties of modified polyacrylamide with gossypol resin and further crosslinking in the presence of potassium persulfate and sodium sulphate to displace oil. Methods. To establish the spectral characteristics of the modified PAA, IR spectra have been taken on an IR-Fourier spectrometer. For the structural-elemental composition (SEM), a Jeol JSM-6490l V electron microscope has been used. The viscosity of modified PAA solutions has been measured in a Ubellode capillary viscometer with a hanging level. Results and discussion. The studies, carried out by the authors of the study of the colloid-chemical properties of polymer composites, allow us to conclude that the reagents obtained during the hydrolysis of vat residues of fatty acids distillation with sodium hydroxide with further cross-linking in the presence of potassium persulfate and sodium sulphate have good surfaceactive and emulsifying properties, which is important when displacing oil from layers. The surface tension of polymer compositions has been studied. With an increase in the concentration of the solution, the surface tension decreases, i.e., the surface activity increases. Conclusion. The research results show that the injection of a polymer reagent solution can increase the oil displacement efficiency by 6-7%.

Effect of ethanol on the density and viscosity of choline chloride/urea eutectic system

The densities and viscosities of choline chloride/urea deep eutectic solvents (DESs) at molar ratios of 1:1.5, 1:2, and 1:2.5 (abbreviated as [ChCl][Urea]1.5, [ChCl][Urea]2 and [ChCl][Urea]2.5) were measured in this work. In addition, the effects of ethanol on the density and viscosity of choline choloride/urea DESs were also investigated. The experimental density and viscosity data were obtained from 303.15 K to 323.15 K at atmospheric pressure. The measurements were carried out using digital vibrating U-tube densimeter and Ubbelohde capillary viscometer. The Jouyban-Acree model was used to correlate the experimental density and viscosity data. In addition, for comparison purpose, the viscosity model based on the preferential solution theory was also used for the viscosity correlation. The excess molar volumes and viscosity deviations of the studied mixtures were calculated from the experimental data, and the results were analyzed. The Redlich–Kister equation was used to correlate the excess molar volumes and viscosity deviations of the ethanol/[ChCl][Urea]x mixtures.

Rheological properties of CO2 hydrate slurries in presence of Dioctyl sodium sulfosuccinate (AOT) in a dynamic loop for refrigeration application

Recent studies have shown real potential for using hydrate slurries as a secondary fluid in indirect refrigeration systems. However, pipeline clogging problems can appear due to hydrate agglomeration. Additives are generally used to counteract these problems. In this study, rheological properties of CO2 hydrate slurries in the presence of an additive Dioctyl sodium sulfosuccinate (AOT) are investigated. The capillary viscometer method is used to determine the fluid behaviour and the AOT impact on the slurry rheology. A dynamic loop is set up to collect experimental pressure drop and volume flow rate data. Based on the Rabinowitch and Mooney approach and Herschel-Bulkley model to determine the rheological properties, a shear-thinning behaviour was observed. The importance of the behaviour index choice in the procedure is discussed. Finally, the results obtained with AOT are compared with pre-existing studies. The present study highlights the AOT potential to significantly improve the CO2 hydrate slurries properties.