Experimental Results Of Viscosity Research Articles

Prediction of glass phase viscosity in firing traditional ceramics and porcelain tiles with waste glass powder

The theoretical calculation of the viscosity of traditional ceramic materials is complex and models based on glass processing are generally used to estimate the viscosity of the glass phase according to its chemical composition. FactSage model considers structural information from silicate melts (glass phase), which is a different approach compared to other models. The viscosity of the melt fraction was calculated for different traditional ceramics, such as hard porcelain, technical porcelain, sanitary ware and porcelain tiles, including formulations with partial replacement of the fluxing raw material by soda-lime glass waste. FactSage model consistently indicated an increase in viscosity with higher levels of silica and a decrease in viscosity with the utilization of soda-lime glass waste in the formulations. Different responses and a nonlinear behavior were presented when varying the Na2O/K2O contents in the glass phase. The tested models presented reliable results for the processing of molten glass, but depending on the chemical composition and temperature, significant differences were observed among the values. Despite this, models that simulate the viscosity of the glass phase can help to optimize production conditions, but more investigations are needed to improve the relationship between theoretical and experimental results of viscosity.

Theoretical Development in the Viscosity of Ferrofluid

Abstract The viscosity of ferrofluid has a vital role in liquid sealing of the hard disk drives, biomedical applications as drug delivery, hyperthermia, and magnetic resonance imaging. The theoretical expressions for ferrofluid viscosity and its limitation are presented in detail in this article. A qualitative comparison of the theoretical and experimental viscosity results is also shown. In the absence of a magnetic field, the viscosity of ferrofluid depends on the volume concentration of magnetic nanoparticles, including surfactant layers. However, the viscosity of ferrofluid due to stationary magnetic field depends on the angle between the applied magnetic field and vorticity in the flow. If this angle is 90 deg, then there is a maximum increase in the viscosity. When field frequency matches with the relaxation time, known as resonance condition, then there is no impact of an alternating magnetic field in the viscosity of ferrofluid. If the frequency of an alternating magnetic field is less than resonance frequency, then an alternating magnetic field increases the viscosity of ferrofluid. For diluted ferrofluid, present theoretical results of viscosity have good agreement with the experimental data.

A novel empirical equation for the effective viscosity of nanofluids based on theoretical and empirical results

In practice, nanofluids' thermal conductivity and viscosity are the most important parameters in engineering applications. Viscosity affects pumping performance. Theoretical viscosity correlations are widely used in numerical studies. However, existing correlations show an underestimation of the actual viscosity compared to the measurement results. Although many nanofluid viscosity correlations have been developed, there is no generally accepted correlation. This paper reviews the theoretical, numerical, and experimental viscosity correlations and proposes a new correlation based on an analysis of approximately 1200 experimental and 4000 theoretical data tested for about 50 types of nanofluids in the temperature range 273–333 K and particle diameters 2–300 nm. The studied volume fraction range for the nanofluids was up to 10%. Existing correlations take into account the impact of up to two to three parameters The new viscosity correlation is proposed to predict the effective viscosity of nanofluids based on regression analysis of theoretical and experimental viscosity results, and it considers several factors that significantly affect the effective viscosity of nanofluids, such as nanoparticle diameter, density, temperature, types of nanoparticles, and base fluid.

Acoustic and viscometric studies of ternary liquid mixtures of aqueous sodium methyl p-hydroxybenzoate with polyethylene glycols at 250C

The various ultrasonic parameters like acoustic impedance, adiabatic compressibility, intermolecular free length, relaxation time, relative association, attenuation and Gibb’s free energy of polyethylene glycols with molecular weight 200 and 600 in aqueous sodium methyl para-hydroxybenzoate is evaluated at 250C from the density, speed of sound and viscosity. Jone-Dole’s equation has been employed to analyze the experimental results of viscosity. The existence of interaction among the fragments of ternary liquid mixtures has been determined from viscosity coefficients. The polyethylene glycols act as the structure builder in water. The viscosity coefficient B surges with escalation in molecular mass of polyethylene glycols. The structure builder property of polyethylene glycols follows the order PEG-600 > PEG-200.

Experimental analysis on stability and rheological behaviour of TiO2/canola oil nanolubricants

Present experimental study investigates the stability evaluation of TiO2/canola oil nanolubricant using Triton X-100 as a surfactant. In order to examine the better dispersion stability of three different mass ratios of TiO2: Triton X-100 (i.e. 1:2, 1:3 and 1:4) were added in canola oil. Zeta potential method was used to examine the stability of prepared samples. Furthermore, the influence of particles loading on rheological behaviour of TiO2/canola oil nanolubricant has also been investigated for the temperature of 40 °C and 100 °C at a constant shear rate (500 s−1). The results revealed that the highest stability was observed for TiO2: Triton X-100 mass ratio of 1:3. Viscosity of TiO2/canola oil nanolubricant was increased with the increase of particle loading while it decreased with temperature. Experimental viscosity results was also correlated with the available viscosity models and large deviation was to be observed. Hence, a regression model has been proposed with a function of particle concentration and temperature.

Interactions of Cetyltrimethylammonium Bromide with 1,3-Dioxolane in Water: A Study of Viscosity and Volumetric Properties

Densities and viscosities of ternary mixtures containing cetyltrimethyl ammonium bromide (CTAB) in aqueous solution of 1,3-dioxolane have been measured at 5 K intervals from 298.15 to 313.15 K and at atmospheric pressure. The experimental results of viscosity and density have been analyzed by using Jones-Dole equation and Masson equation. The values of constants A and B of Jones-Dole equation have been interpreted in terms of solute-solute and solute-solvent interactions. The standard partial molar volume,Vφ 0 at infinite dilution were determined from Masson equations. The structure making/breaking capacity of solute is interpreted with the help of Helper equation. The positive value of Helper′s constant (∂2Vφ 0/∂T2)p and the negative value of dB/dT shows that CTAB in studied organic solvent predominantly acts as a structure-maker.

Effects of interphase regions and filler networks on the viscosity of PLA/PEO/carbon nanotubes biosensor

The present work suggests a simple model for viscosity of polymer carbon nanotubes (CNT) biosensor assuming CNT concentration, CNT dimensions, interphase thickness, and network size. CNT concentration, CNT size, and interphase thickness express the effective filler concentration and the percolation threshold, which determine the fraction of networked CNT in nanocomposite biosensors. The experimental results of viscosity for the prepared samples containing poly(lactic acid) (PLA), poly(ethylene oxide) (PEO), and carbon nanotubes (CNT) are measured to approve the suggested model. Moreover, the developed model presents the roles of all parameters in the viscosity to confirm the predictions. The predictions properly agree with the experimental data of samples demonstrating the predictability of the developed model. Thin and large CNT (high aspect ratio) mainly increase the viscosity, while thick or short CNT produce very low viscosity. A high CNT concentration and thick interphase significantly enhance the viscosity, while a low content of CNT or a thin interphase cause an extremely low viscosity. In addition, the percentage of CNT in the networks directly manipulates the viscosity. POLYM. COMPOS., 40:4135–4141, 2019. © 2019 Society of Plastics Engineers

Optimization of the rheological properties of epoxy resins for glass and carbon reinforced plastics

Vacuum assisted resin transfer moulding (VARTM) offers advantages such as simplicity, low cost of consumables, and the ability to carry out the impregnation process and curing without using expensive equipment and tooling. In the VARTM process, rheological properties of resin have a critical impact on the impregnation and curing process. In this article, the experimental results of viscosity are presented, including the glass transition temperature, and the tensile and bending strength of the epoxy binders with the amine hardener, which depend on the quantity of its active solvent composition. The active solvent used is diethylene glycol. It shows that for an increase in the content of the active solvent, a reduction in the viscosity and a reduction of the glass transition temperature and strength occurs. The optimum composition of the binder is selected by using the Pareto optimization criteria and the Cayley - Smorodinskaya method. By using the epoxy binder, the active solvent should not exceed 10-15% by weight. This approach helps to optimize the amount of active solvent added to the epoxy resins for the criterion of viscosity, strength, and heat resistance.

Measurements and Comparison to Predictions of Viscosity of Heavily Filled HDPE with Natural Fibers

AbstractComposites of rice hulls at various levels of loadings in recycled HDPE were characterized rheologically using a conical extrusion die and small amplitude oscillatory shear (SAOS) measurements. Although the results do not match, due to the invalidity of the Cox–Merz rule for such composites, both types of measurements indicate that increasing the filler concentration results in significantly higher viscosities and increased shear thinning. The errors associated with the use of a conical die due to viscous dissipation are assessed through computer simulations. They are small for relatively small throughputs (small pressure drops). The experimental results for viscosity are compared to predictions of the Einstein–Batchelor equation for suspensions of spherical particles, the Guth–Simha equation, and the empirical Krieger–Dougherty correlation, for filler loadings of up to 70% by weight. The comparison indicates that reasonable approximations of the consistency index of the power law viscosity model are possible through using the above expressions for loadings up to perhaps 40–50% by weight.

Possibility of using Tragacanth gum and whey powder as an egg substitute in mayonnaise.

در این پژوهش امکان استفاده از پودر آب پنیر و صمغ کتیرا بعنوان جایگزین تخم مرغ در سس مایونز مورد مطالعه قرار گرفت. بمنظور بهینه‌یابی فرمولاسیون سس مایونز کم کلسترول، از طرح آماری مخلوط استفاده شد. تیمارها با ترکیب تخم مرغ (0-10 گرم)، پودر آب پنیر (0-10 گرم) و ژل صمغ کتیرا (0-10 گرم) با استفاده از نرم افزار مینی تب تعیین شد و پایداری، ویسکوزیته، ویژگی های حسی و بافتی سس مایونز کم کلسترول مورد بررسی قرار گرفت. نتایج آزمون پایداری نشان داد که به استثنای نمونه های M5 (تخم مرغ صفر، صمغ کتیرا صفر و 10 گرم پودر آب پنیر)، M8 (تخم مرغ صفر، 10 گرم صمغ کتیرا و پودر آب پنیر صفر) و M10 (تخم مرغ صفر، 5 گرم صمغ کتیرا و 5 گرم پودر آب پنیر) سایر نمونه ها صد در صد پایدار بودند. به لحاظ ویسکوزیته بیشترین و کمترین مقدار به ترتیب در نمونه های M6 (33/3 گرم تخم مرغ ، 33/3 گرم صمغ کتیرا و 33/3 گرم پودر آب پنیر) و M5 (تخم مرغ صفر، صمغ کتیرا صفر و 10 گرم پودر آب پنیر) مشاهده شد. از نظر سفتی و چسبندگی بیشترین مقدار متعلق به نمونه M6 (33/3 گرم تخم مرغ ، 33/3 گرم صمغ کتیرا و 33/3 گرم پودر آب پنیر) و کمترین مقدار در نمونه M5 (تخم مرغ صفر ، صمغ کتیرا صفر و 10 گرم پودر آب پنیر) بود. بیشترین میزان روشنی نیز در نمونه M1 (5 گرم تخم مرغ ، 5 گرم صمغ کتیرا و پودر آب پنیر صفر) مشاهده شد. در نهایت نتایج حاصل از بهینه یابی فرمولاسیون نشان داد که مقادیر 17/2 گرم تخم مرغ، 28/5 گرم صمغ کتیرا و 74/2 گرم پودر آب پنیر ، ترکیب مناسبی جهت جایگزینی تخم مرغ در سس مایونز و تولید فرآورده کم کلسترول می باشد.

Does the ethanolammonium acetate ionic liquid mix homogeneously with molecular solvents?

In order to study micro-structural heterogeneities in the solutions of ionic liquids (ILs), ethanolammonium acetate (EOAA) IL has been synthesized and (1) H NMR spectra of its binary solutions, namely EOAA/DMSO and EOAA/n-butanol, have been measured at 298.15 K. Then the concentration-dependent chemical shifts δ (-CH3 , EOAA), δ (-CH3 , DMSO) and δ (-CH3 , n-butanol) have been correlated separately using the local composition (LC) model. The results indicated that self-association of EOAA played the leading role within EOAA-rich region in mixtures. However with the molecular solvents increasing, the interactions between EOAA and solvents gradually predominated. Moreover the comparisons between DMSO and n-butanol have demonstrated that DMSO could break the network of IL more easily, indicating that the influence of DMSO on the properties of EOAA should be more obvious, which was consistent with experimental results of viscosity and conductivity. Furthermore the maximum difference between the local and the bulk appeared at x(EOAA) ≈ 0.5 for both systems, which reflected remarkable nonideality of mixtures at this concentration. Copyright © 2015 John Wiley & Sons, Ltd.

Modeling the Rheological Characteristics of Flexible High-Yield Pulp-Fibre-Reinforced Bio-Based Nylon 11 Bio-Composite

The aim of this work was to develop a mathematical model to investigate the rheological characteristics of viscoelastic pulp-fibre composite materials. The rheological properties of High-Yield Pulp (HYP) reinforced bio-based Nylon 11 (Polyamide 11) (PA11) composite (HYP/PA11) were investigated using a capillary rheometer. Novel predicted multiphase rheological-model-based polymer, fibre, and interphasial phases were developed. Rheological characteristics of the compo-site components influence the development of resultant microstructures; this in turn affects mechanical characteristics of a multiphase composite. The main rheological characteristics of polymer materials are viscosity and shear rate. Experimental and theoretical test results of HYP/PA11 show a steep decrease in apparent viscosity with increasing shear rate, and this melt-flow characteristic corresponds to shear-thinning behavior in HYP/PA11. The non-linear mathematical model to predict the rheological behavior of HYP/PA11 was validated experimentally at 200°C and 5000 S-1 shear rate. Finally, predicted and experimental viscosity results were compared and found to be in a strong agreement.

Influence of Waste Water used in Irrigation on the Physical Properties of Olive Oil in Palestine

In this study, olive oil samples of different irrigation system of different regions in Palestine were studied. The density, refractive index, acidity and viscosity of the samples were measured. The acidity of olive oil samples from different location and different irrigation system was measured. The overall results indicate that acidity increase for samples their trees were irrigated by waste water and classified to Lampante oil, and most of the olive oil samples are classified to be ordinary virgin oil. The viscosity of olive oil samples of 2014 crop from different regions was studied. The experimental results of viscosity showed that the viscosity increased for samples were irrigated by waste water. The concentration of some metals in olive oil samples irrigated by waste water was found to be highly concentrated compared with literature values of metals.

Influence of thickeners on cement paste structure and performance of engineered cementitious composites

Hydroxypropyl methylcellulose (HPMC) and amphoteric polyacrylamide (ACPAM) were respectively used to prepare engineered cementitious composite (ECC) which exhibits strain-hardening behavior under uniaxial tension. The connections between cement paste structure and the performance of the composite in fresh and hardened state were investigated, aiming at achieving the desirable workability at a given solids concentration. The experimental results of viscosity and microstructure of cement pastes show that the intimate connections between flocculation groups lead to the growing increase in viscosity. The results of deformability and fiber dispersion demonstrate that fiber dispersion coefficient is a comprehensive index which can reflect the performance of deformability as well as uniformity. And the desirable fresh mixture can be achieved by optimizing the viscosity of cement paste. At last, the ductile strain-hardening performance of the ECC prepared with HPMC or ACPAM was investigated through uniaxial tensile test.

Viscosity of Prehydrolysis Liquor of a Hardwood Kraft-Based Dissolving Pulp Production Process

In this study, experimental viscosity results of hardwood prehydrolysis liquor (PHL) from the kraft-based dissolving pulp production process were obtained and used to develop empirical models describing the effect of temperature, solid content, the interaction between solute and solvent, and the concentration of lignin and hemicelluloses. The concentration, molar mass, and molecular weight of lignin and polysaccharide of PHL, all are the factors that affect the rheological behavior of the PHL. The results showed that, on the one side, Zaman and Fricke’s model gave better fitting when the viscosity is lower, on the other hand, a much better fitting of the Moosavifar’s model could be obtained by taking interaction between solute and solvent, solids content, concentration of lignin and hemicelluloses into account when the viscosity is higher, because of the interaction between solute lignin/hemicelluloses and solvent water, and the aggregation of lignin with itself, hemicelluloses with itself, and lignin with hemicelluloses. Consequently, using two different correlations in covering different viscosity value regions (η > 2 mPa s or η < 2 mPa s) of PHL led to better fitting of the data than those using just one single correlation.

Viscosity and Density Measurements of Diisopropyl Ether and Dibutyl Ether at Different Temperatures and Pressures

Experimental results of viscosity and density of diisopropyl ether and dibutyl ether are reported over the temperature range from (243.15 to 373.15) K. The measurements were performed at pressures from atmospheric pressure or above saturation up to the maximum pressure, which were approximately 21.7 MPa for diisopropyl ether and 21.1 MPa for dibutyl ether. The measurements were performed simultaneously using a vibrating-wire instrument operated in the forced mode of oscillation. The present results for both properties are compared with values from the literature when possible. The overall uncertainties of these results are ± 2.0 % in viscosity and ± 0.2 % in density. The measurements were correlated with the Tait-type equation for density and hard-sphere scheme for viscosity. For diisopropyl ether, the average absolute deviations of measurements from the correlations of viscosity and density are 0.39 % and 0.008 %, respectively. With regard to dibutyl ether, the average absolute deviations of the present results from the correlations are 0.21 % for viscosity and 0.009 % for density.

Viscometric and volumetric behaviour of binary mixtures of sulfolane and N-methylpyrrolidone with monoethanolamine and diethanolamine in the range 303–373 K

Capillary viscometry was used to determine the kinematic viscosity of the binary systems composed of N-methylpyrrolidone + monoethanolamine and N-methylpyrrolidone + diethanolamine throughout the concentration range, at eight different temperatures in the range 303.15–373.15 K. Pure component values of viscosity were also determined in the temperature range 303.15–423.15 K. Using a rolling ball viscometer the absolute viscosity was obtained for the binary systems composed of tetramethylene sulfone (sulfolane) + monoethanolamine and tetramethylene sulfone + diethanolamine, throughout the concentration range, at three different temperatures in the range 303.15–373.15 K. Density results were obtained using a vibrating-tube densimeter for the four pure components and the four binary systems studied, in the same temperature range and the whole concentration range for the binary systems as the viscosity measurements. The experimental viscosity results for the four pure solvents cover a broader temperature range than previously reported by other workers. The experimental results of viscosity for both pure and binary systems show a decrease with increasing temperature as expected. In the case of the binary systems the change of viscosity with concentration for the two sets of mixtures with N-methylpyrrolidone is very large in the range of 303.15–353.15 K, whereas it is small in the range 363.15–373.15 K. The observed behaviour of the change of viscosity with concentration for sulfolane with monoethanolamine is different from that shown by sulfolane with diethanolamine, at 303.15 and 323.15 K; the first system shows a minimum viscosity point in the sulfolane-rich region whereas at 373.15 K it shows values of viscosity greater than that of the pure components in the whole range of concentration; and the second system shows large variations of viscosity at low sulfolane concentration, at 303.15 and 323.15 K; whereas at 373.15 K the viscosity values change smoothly between those for the two pure components. From the density results, molar excess volumes were derived, which were correlated using the Redlich–Kister equation; the final expression includes the functionality with both concentration and temperature.

Compatibility of polyvinyl alcohol and poly(methyl vinyl ether- co-maleic acid) blends estimated by molecular dynamics

The CSIR has developed a novel oxygen barrier technology for plastics packaging based on interpolymer complex formation between PVOH (polyvinyl alcohol) and PMVE-MA (poly(methyl vinyl ether- co-maleic acid)). As interpolymer complexation interactions are strongly dependent on stoichiometric ratios, the estimation of the optimum blend ratio is an important component of blend design. This study used molecular dynamics modelling to predict the ratio of optimum interaction for PVOH:PMVE-MA blends. Amorphous cells were constructed containing blends of short-chain repeat units of PVOH and PMVE-MA. The oligomers were equilibrated using both NVT and NPT dynamics and the cohesive energy densities (CED's) of the models were computed. From the CED's, energies of mixing and Flory–Huggins Chi Parameter ( χ) values were estimated. The χ-values were negative for all blends, indicating favorable interaction between the two polymers. The minimum χ-values were found around 0.6–0.7 mass fraction of PMVE-MA, which agrees well with experimental viscosity results (this work), which indicated optimum interaction around 0.7 mass fraction PMVE-MA. These results confirm that molecular dynamics can be used as a tool for investigating interpolymer complexation phenomena.

Viscosity and density of mixtures of methane and n-decane from 298 to 393 K and up to 75 MPa

Experimental results of viscosity and density of mixtures of methane and n-decane are reported at temperatures from 303 to 393 K and pressures up to 75 MPa, at five compositions. This binary mixture is considered as a model for gas–condensate fluids since it presents dew-point and bubble point lines extending up to 35 MPa at room temperature. Viscosity and density were measured simultaneously using a vibrating-wire sensor, in an apparatus specifically built to study gas–liquid mixtures. The present results for both properties are compared with values from the literature when possible and present overall uncertainties of ±0.2% for density and ±3% for viscosity. Precisions are of about one third of the uncertainties for both properties. The excess volume of the mixture reaches −20 cm 3 mol −1 at 393 K and 40 MPa. Viscosity has a marked non linear behaviour with composition, that is nonetheless well represented by a predictive scheme based on the theory of transport properties of the hard-sphere fluid.

Flow birefringence of temporary polymer networks

The statistical theory of temporary polymer networks is an effort of describing the macroscopic behavior of such networks based on molecular behavior analysis. The calculation of the stress tensor of a network and the satisfactory comparison with experimental viscosity results was shown before [Rheol. Acta 28 (1989) 193]. Here we present the foresights of the theory as regards flow birefringence. The polarizability tensor is calculated first and then the birefringence of a four-functional temporary polymer network is estimated for a stationary simple shear flow. The dependence of the calculated quantities on shear rate is in line with existing experimental evidence.