Relevant bibliographies by topics / Viscometric measurements

Journal articles
Dissertations / Theses
Books
Book chapters
Conference papers

Academic literature on the topic 'Viscometric measurements'

Author: Grafiati

Published: 5 June 2025

Last updated: 15 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Viscometric measurements.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Viscometric measurements"

K., G. Ojha, C. Heda L., Pareek C., and R. Mosalpuri S. "Viscometric investigations and molecular interactions of triphenodioxazine dyes in mixed organic solvents." Journal of Indian Chemical Society Vol. 86, May 2009 (2009): 458–64. https://doi.org/10.5281/zenodo.5810095.

Full text

Abstract:

Department of Pure and Applied Chemistry, M. D. S. University, Ajmer-305 009, Rajasthan, India Department of Chemistry, S. D. Govt. ·college, Beawar-305 901, Rajasthan, India E-mail : lal57heda@yahoo.com, msonraj@yahoo.com, pareekcd@yahoo.com Manuscript received 5 March 2008, revised 31 December 2008, accepted 1 January 2009 Colloid chemical behaviour of 6,13-dichloro-3,10-dimethyl trlphenodioxazine (TPDO-1) aod 6,13-dibromo-3,10- dimethyl triphenodioxazine (TPDO-II) in non-aqueous solvent mixture benzene-methanol or varying composition has been Investigated by viscometrlc measurements at 303 ± 0.1 K. The viscosity or the system Increases with the increase in triphenodioxazine concentration. The Trend Change Point (TCP) values have been determined by intersection or two straight lines which are found to be dependent on the composition of solvent mixtures. The study confirms that the nature of triphenodloxazine agglomerate formed below and above 50., benzene concentration is quite different. The viscometric data have been analysed in terms or Einstein, Vand, Moulik and Jones-Dole equations. These well known equations have been successfully applied to explain the results of vicosity measurements and the viscometric parameters show that the behaviour of triphenodloxazine dyes changes in the proximity or 50'10 benzene concentration.

APA, Harvard, Vancouver, ISO, and other styles

Heda, L. C., Rashmi Sharma, S. R. Mosalpuri, and Pramod B. Chaudhari. "Viscometric investigations and molecular interactions of some derivatives of 5-Substituted indole dihydropyrimidines in mixed organic solvents." Eclética Química Journal 35, no. 2 (2018): 23. http://dx.doi.org/10.26850/1678-4618eqj.v35.2.2010.p23-32.

Full text

Abstract:

Colloid chemical behavior of indole dihydropyrimidines in non-aqueous solvent mixture benzene-methanol of varying composition has been investigated by viscometric measurements at 303K± 0.1. The viscosity of the system increases with the increase in concentration. The Trend Change Point (TCP) values have been determined by intersection of two straightlines, which are found to be dependent on the composition of solvent mixtures. The study confirms that the nature of synthesized compounds agglomerate formed below and above 50% benzene concentration is quite different. The viscometric data have been analyzed in terms of Einstein, Vand, Moulik and Jones-Dole equations. These well known equations have been successfully applied to explain the results of viscosity measurements and the viscometric parameters show that the behavior of compound changes in the proximity of 50% benzene concentration.

APA, Harvard, Vancouver, ISO, and other styles

Lewandowska, Katarzyna, and Marta Szulc. "Characterisation of Hyaluronic Acid Blends Modified by Poly(N-Vinylpyrrolidone)." Molecules 26, no. 17 (2021): 5233. http://dx.doi.org/10.3390/molecules26175233.

Full text

Abstract:

The viscosity behaviour and physical properties of blends containing hyaluronic acid (HA) and poly(N-vinylpyrrolidone) (PVP) were studied by the viscometric technique, steady shear tests, tensile tests and infrared spectroscopy. Viscometric and rheological measurements were carried out using blends of HA/PVP with different HA weight fractions (0, 0.2, 0.5, 0.8 and 1). The polymer films and HA/PVP blend films were prepared using the solution casting method. The study of HA blends by viscometry showed that HA/PVP was miscible with the exception of the blend with high HA content. HA and its blends showed a shear-thinning flow behaviour. The non-Newtonian indices (n) of HA/PVP blends were calculated by the Ostwald–de Waele equation, indicating a shear-thinning effect in which pseudoplasticity increased with increasing HA contents. Mechanical properties, such as tensile strength and elongation at the break, were higher for HA/PVP films with wHA = 0.5 compared to those with higher HA contents. The elongation at the break of HA/PVP blend films displayed a pronounced increase compared to HA films. Moreover, infrared analysis confirmed the existence of interactions between HA and PVP. The blending of HA with PVP generated films with elasticity and better properties than homopolymer films.

APA, Harvard, Vancouver, ISO, and other styles

Brunchi, C. E., and L. Ghimici. "AQUEOUS SOLUTIONS OF CHITOSAN: VISCOMETRIC AND FLOCCULATION PROPERTIES." TEXTEH Proceedings 2021 (October 22, 2021): 123–30. http://dx.doi.org/10.35530/tt.2021.21.

Full text

Abstract:

The hydrodynamic and flocculation properties of aqueous solution of chitosan (CS) were investigated at room temperature. The viscometric data of dilute CS solutions were discussed in terms of Wolf method as a function of polymer concentration, salt nature (NaCl, NaNO3, and CaCl2) and concentration. The flocculation properties in emulsions of some commercial pyrethroid insecticides (Fastac 10 EC (F), Decis (Dc) and Karate Zeon (KZ)) were evaluated. The viscosity measurements reveal that the experimental data fit well with the Wolf model and the [η] values decrease in salt aqueous solutions. For the same insecticide concentration (0.02%, v/v), UV-Vis spectroscopy measurements show maximum removal efficiency around 90% for Fastac 10EC and Decis and 80% for Karate Zeon. The residual KZ absorbance decreased with the increase of insecticide concentration in the initial emulsion, from 80% for the lowest concentration (0.02%, v/v) to around 90% for the highest one (0.06%, v/v). The supernatant zeta potential dependence on the chitosan dose pleads for the charge neutralization as the main mechanism for the flocculation of pyrethroid insecticide particles.

APA, Harvard, Vancouver, ISO, and other styles

Kim, Mahn Won, and D. G. Peiffer. "Quasielastic light scattering and viscometric measurements on dilute ionomer solutions." Journal of Chemical Physics 83, no. 8 (1985): 4159–65. http://dx.doi.org/10.1063/1.449081.

Full text

APA, Harvard, Vancouver, ISO, and other styles

D., A. Pund, J. Meshram N., and T. Tayade D. "The viscometric measurements of S-substituted triazinothiocarbamides at various compositions." Journal of Indian Chemical Society Vol. 92, Jun 2015 (2015): 1038–42. https://doi.org/10.5281/zenodo.5674754.

Full text

Abstract:

Department of Chemistry, J. D. Institute of Engineering and Technology, Yavatmal-444 001, Maharashtra, India Department of Chemistry, S. R. R. L. Science College, Morshi-444 905, Maharashtra, India Department of Chemistry, Government Vidharbha Institute of Science and Humanities, Amravati-444 604, Maharashtra, India E-mail : skdtayade@gmail.com S-Triazino and thiocarbamido nucleus containing drugs have their own importance, significance and identity in the organic, drug, pharmaceutical and medicinal chemistry since from last four decades. Therefore, viscometric measurements of newly synthesized drugs viz. 1-(4-hydroxy)-S-triazino-3-o-tolylthiocarbamide (L1 ), 1-(4-hydroxy)-S-triazino– 3-m-tolylthiocarbamide (L2 ) and 1-(4-hydroxy)-S-triazino-3-p-tolylthiocarbamide (L3 ), were carried out at various percentage compositions of solvent to investigate effect of structure, group on S-triazinothiocarbamides. The data and result obtained during this investigation gave detail information regarding drug absorption, transmission, activity and effect of these drugs. Taking all these things into consideration this research work was carried out.

APA, Harvard, Vancouver, ISO, and other styles

Barkhudaryan, Vigen G., Gayane V. Ananyan, Yeva B. Dalyan, and Samvel G. Haroutiunian. "Development of viscometric methods for studying the interaction of various porphyrins with DNA. Part I: meso-tetra-(4N-hydroxyethylpyridyl) porphyrin and its Ni-, Cu-, Co- and Zn- containing derivatives." Journal of Porphyrins and Phthalocyanines 18, no. 07 (2014): 594–99. http://dx.doi.org/10.1142/s1088424614500357.

Full text

Abstract:

The influence of water soluble cationic meso-tetra(4N-hydroxyethyl)pyridyl porphyrin ( H 2 THOEtPyP 4) and it's metal complexes with Ni ( II ), Cu ( II ), Co ( II ) and Zn ( II ) on hydrodynamic and spectral behavior of DNA solutions has been studied by viscometry and UV-vis absorption methods. It was shown that the presence of planar porphyrins, such as H 2 THOEtPyP 4, NiTHOEtPyP 4 and CuTHOEtPyP 4 leads to an increase in viscosity at relatively small concentrations, and then decreases to stable values. Such behavior corresponds to intercalation of these porphyrins in DNA structure, which results in a decrease of helical twist and lengthening of the DNA molecule. In the case of porphyrins with axial ligands, such as ZnTHOEtPyP 4 and CoTHOEtPyP 4, the relative viscosity decreases, which is explained by self-stacking of these porphyrins on DNA surface. Calculation and interpretation of binding parameters (Kb and n) demonstrated good agreement of viscometric and spectrophotometric measurements.

APA, Harvard, Vancouver, ISO, and other styles

K., N. MEHROTRA, TANDON KIRTI, and K. RAWAT M. "Ultrasonic and Viscometric Studies of Yttrium Soap; in Mixed Organic Solvents." Journal of Indian Chemical Society Vol. 69, Apr 1992 (1992): 193–98. https://doi.org/10.5281/zenodo.5994683.

Full text

Abstract:

Department, of Chemistry, Institute of Basic Sciences (Agra University). Kintudari Rona, Agra-282-002 Manuscript received 4 June 1990. revised 29 October 1991, accepted 19 March 1992 The ultrasonic and viscosity measurements or yttrium soaps (caprylate, caprate and innate) in a mixture or ben ene and dimethyl formamide (3 : 2) have been carried out with a view to determine the critical mieellar c-mcentratio, soap-solvent interaction and other allied parameters. The various acoustic parameters (intermolecular free-length adiabatic compressibility. apparent molar compressibility. specific acoustic impedance, molar sound velocity solvation number available volume and relative association) have been evaluated by ultrasonic velocity measurements. The results of viscosity measurements have been explained in terms of well known equations.

APA, Harvard, Vancouver, ISO, and other styles

Katime, I., R. Valenciano, and M. Anasagasti. "Thermal, viscometric and light scattering measurements from PMMA/polystyrene/toluene systems." Thermochimica Acta 88, no. 2 (1985): 379–85. http://dx.doi.org/10.1016/0040-6031(85)85458-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Haidekker, Mark A., Amy G. Tsai, Thomas Brady, et al. "A novel approach to blood plasma viscosity measurement using fluorescent molecular rotors." American Journal of Physiology-Heart and Circulatory Physiology 282, no. 5 (2002): H1609—H1614. http://dx.doi.org/10.1152/ajpheart.00712.2001.

Full text

Abstract:

Molecular rotors, a group of fluorescent molecules with viscosity-dependent quantum yield, were tested for their suitability to act as fluorescence-based plasma viscometers. The viscosity of samples of human plasma was modified by the addition of pentastarch (molecular mass 260 kDa, 10% solution in saline) and measured with a Brookfield viscometer. Plasma viscosity was 1.6 mPa · s, and the mixtures ranged up to 4.5 mPa · s (21°C). The stimulated light emission of the molecular rotors mixed in the plasma samples yielded light intensity that was nonoverlapping and of significantly different intensity for viscosity steps down to 0.3 mPa · s ( n = 5, P < 0.0001). The mathematical relationship between intensity ( I) and viscosity (η) was found to be η = (κ I)ν. After calibration and scaling the fluorescence based measurement had an average deviation versus the conventional viscometric measurements that was <1.8%. These results show the suitability of molecular rotors for fast, low-volume biofluid viscosity measurements achieving accuracy and precision comparable to mechanical viscometers.

APA, Harvard, Vancouver, ISO, and other styles

More sources

Dissertations / Theses on the topic "Viscometric measurements"

黃柏林 and Pat-lam Patrick Wong. "An investigation of the rheological behaviour of lubricants using the optical impact viscometry technique." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1990. http://hub.hku.hk/bib/B31232036.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Williams, R. H. "A laboratory viscometry system for the measurement of the rheological properties of silicate melts." Thesis, Lancaster University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.371951.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Lin, Chih-Jung, and 林志榮. "Investigation of aggregation properties of dilute poly[2-methoxy-5-(2’-ethylhexyloxy)-1,4- phenylenevinylene] solutions in shearing flow by in situ viscometric/flow turbidity measurements." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/24570253140295689813.

Full text

Abstract:

碩士 國立中正大學 化學工程所 96 Semiconducting conjugated polymers play an important role in both PLED displays and polymer solar cells. In practical processing, it is essential to control the state of polymer aggregation in the precursor solution as well as in the dried film. In this work, we conducted in-situ viscometric/flow turbidity measurements to study the aggregation properties of dilute MEH-PPV solutions under static or shearing-flow conditions. At various polymer concentrations, consistency was generally noted between the reduced viscosity and the Mie radius obtained from in-situ viscometric/flow turbidity measurements and the hydrodynamic radius estimated from dynamic light scattering measurement. The experimental results suggested that the average aggregate size increases and the stability decreases with decreasing polymer concentration. Overall, the present study suggested that in-situ viscometric/flow turbidity measurements are an ideal means to investigate the aggregation properties of MEH-PPV solutions.

APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Viscometric measurements"

International, Strategic Directions, ed. Physical properties measurement: Thermal analysis, particle characterizaiton, rheology, viscometry, and physical testing. Strategic direcitons International, 1997.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Viscometric measurements"

Powell, Robert L. "Rotational Viscometry." In Rheological Measurement. Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-017-2898-0_9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Powell, R. L. "Rotational viscometry." In Rheological Measurement. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-4934-1_9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Walton, David J., and J. Phillip Lorimer. "Polymer properties and characterization." In Polymers. Oxford University Press, 2000. http://dx.doi.org/10.1093/hesc/9780198503897.003.0002.

Full text

Abstract:

This chapter discusses the properties and characterization of polymers. The techniques most commonly used to determine polymer molar mass include end-group analysis, osmometry, light scattering, ultracentrifugation, sedimentation, viscometry, and chromatography. However, most of these involve rather lengthy procedures and in practice molar masses are obtained from high performance gel permeation chromatography (HPGPC) or viscosity measurements. It is important to recognize that the fundamental measurements of molar mass must be performed on dilute solutions so that intermolecular interactions can be ignored. The chapter then looks at polymer stereochemistry; structure-property relationships; and polymer processing. It also considers the thermal methods of polymer analysis, in which some physical property of a substance is measured as a function of temperature or time while the substance is subject to a controlled temperature programme. The most common techniques are differential scanning calorimetry, thermal gravimetry, dynamic mechanical analysis, dilatometry, heat-deflection temperature, and melt index.

APA, Harvard, Vancouver, ISO, and other styles

"The Relationship Between High-Temperature Oil Rheology and Engine Operation." In The Relationship Between High-Temperature Oil Rheology and Engine Operation. ASTM International100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, 1985. http://dx.doi.org/10.1520/mnl11957d.

Full text

Abstract:

PURPOSE. The ASTM High-Temperature Rheology/Engine Correlation Task Force (ASTM D02.07.0B TF/EC) has written this status report in partial response to a Society of Automotive Engineers (SAE) request to “develop a test method which incorporates high-temperature, high-shear rate viscometrics or other rheological characteristics to predict the performance of both single and multigrade (i.e., both Newtonian and VI-improved) engine oils in engine bearings and/or the ring and cylinder area (1). “Although this report does not deal with the development of particular viscosity measurement techniques, it does have two specific objectives which relate to this SAE request: (1) to summarize, and interpret, as necessary, all pertinent published studies relating high-temperature oil rheology to selected measures of engine performance and durability, and (2) to suggest areas for possible future research needed to resolve any uncertainties which remain regarding the effects of oil rheological properties on these same engine operating factors.

APA, Harvard, Vancouver, ISO, and other styles

"Table of Contents." In The Relationship Between High-Temperature Oil Rheology and Engine Operation. ASTM International100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, 1985. http://dx.doi.org/10.1520/mnl11956d.

Full text

Abstract:

APA, Harvard, Vancouver, ISO, and other styles

Harding, Stephen E. "Hydrodynamic properties of proteins." In Protein Structure. Oxford University PressOxford, 1997. http://dx.doi.org/10.1093/oso/9780199636198.003.0009.

Full text

Abstract:

Abstract Since the first edition of this book, there has been something of a renaissance of hydrodynamic methods for the determination of the mass, quaternary structure, gross conformation, and interaction properties of proteins and other macromolecules in solution. By ‘hydrodynamic’ (Greek for ‘watermovement’) techniques, we mean any technique involving motion of a macromolecule with or relative to the aqueous solvent in which it is dissolved or suspended. This therefore includes not only gel filtration, viscometry, sedimentation (velocity and equilibrium), and rotational diffusion probes (fluorescence anisotropy depolarization and electric-optical methods), but also ‘classical’ and ‘dynamic’ light scattering, which both derive from the relative motions of the macromolecular solute in relation to the solvent. This definition also includes electrophoretic methods (considered in Chapter 8 and not covered here), which are powerful tools for separation, purification, and identification of proteins, but also, with ‘SDS’ methodology, provide an estimate of polypeptide molecular weight (see Chapter I). The present chapter therefore considers the hydrodynamic determination of ‘molar mass’ or molecular weight and quaternary structure (subunit composition and arrangement, self-association phenomena. and polydispersity). It will also consider the measurement of protein conformation in dilute solution with particular reference to the use of the analytical ultracentrifuge, a technique although of considerable antiquity (70th birthday in 1993) that has been the centre of the revival of hydrodynamic methodology.

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Viscometric measurements"

Vraneš, Milan B., Snežana M. Papović, Jovana Panić, et al. "Antifreeze with coffee taste." In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.120v.

Full text

Abstract:

This study presents the results of volumetric and viscometric measurements of caffeine solutions in an equimolar mixture of ethylene glycol – water, known as antifreeze. Measurements were made in the temperature range T = (283.15 – 313.15) K and up to a caffeine molality of 0.12 mol∙kg-1. Experimental results are supported by molecular dynamics (MD) computer simulations. The obtained results indicate that water molecules have a dominant role in the solvation of caffeine. At the same time, ethylene glycol acts as a dehydrating agent and promotes the self-aggregation of caffeine and the investigated mixture.

APA, Harvard, Vancouver, ISO, and other styles

Hong, Sung-Ryong, Shaju John, and Norman M. Wereley. "Quasi-Steady Herschel-Bulkley Analysis of Magnetorheological Dampers With Preyield Viscosity." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82593.

Full text

Abstract:

A magnetorheological (MR) fluid, modeled as a Bingham-plastic material, is characterized by a field dependent yield stress, and a (nearly constant) postyield plastic viscosity. Based on viscometric measurements, such a Bingham-plastic model is an idealization to physical magnetorheological behavior, albeit a useful one. A better approximation involves modifying both the preyield and postyield constitutive behavior as follows: (1) assume a high viscosity preyield behavior over a low shear rate range below the yield stress, and (2) assume a power law fluid (i.e., variable viscosity) above the yield stress that accounts for the shear thinning behavior exhibited by MR fluids above the yield stress. Such an idealization to the MR fluid’s constitutive behavior is called a viscous-power law model, or a Herschel-Bulkley model with preyield viscosity. This study develops analytical quasi-steady analysis for such a constitutive MR fluid behavior applied to a flow mode MR damper. Closed form solutions for the fluid velocity, as well as key performance metrics such as damping capacity and dynamic range (ratio of field on to field off force). Also, specializations to existing models such as the Herschel-Bulkley, the Biviscous, and the Bingham-plastic models, are shown to be easily captured by this model when physical constraints (idealizations) are placed on the rheological behavior of the MR fluid.

APA, Harvard, Vancouver, ISO, and other styles

Kirby, Glen H., Kevin M. Cooley, and Beth L. Armstrong. "Tailored Rheological Behavior of Mullite and BSAS Suspensions Using a Cationic Polyelectrolyte." In ASME Turbo Expo 2005: Power for Land, Sea, and Air. ASMEDC, 2005. http://dx.doi.org/10.1115/gt2005-68491.

Full text

Abstract:

The effects of a cationic polyelectrolyte, polyethylenimine, on the rheological behavior of aqueous mullite and celsian phase, barium strontium aluminosilicate (BSAS) suspensions have been studied to optimize a dip-coating process. The surface of the ceramic particles was characterized in aqueous media using zeta potential measurements. The ionization behavior and hydrodynamic radius of polyethylenimine in aqueous media was characterized by potentiometric titration and dynamic light scattering measurements, respectively. The rheological behavior of concentrated ceramic suspensions containing polyethylenimine was characterized by stress viscometry and elastic modulus measurements. Polyethylenimine imparts repulsive, electrosteric interactions between mullite and BSAS particles in aqueous suspension, resulting in shear thinning flow behavior, linear elastic moduli, and yield stress values that are minimized for suspensions with a critical PEI concentration of 0.2 mg PEI per m2 of mullite and 0.4 mg PEI per m2 of BSAS, respectively. The elastic moduli and yield stress of mullite and BSAS suspensions were nearly identical at equivalent fractions of their critical PEI concentration. Uniform coatings were obtained upon dipping SiC, Si3N4, and Si-metal substrates into shear-thinning suspensions containing PEI at 81–88% of the critical concentration. Dense mullite coatings were demonstrated on SiC substrates after sintering at 1400°C.

APA, Harvard, Vancouver, ISO, and other styles

Pereira, Américo S., and Fernando T. Pinho. "Rheology and Bulk Flow Characteristics of a Thixotropic Fluid in Turbulent Pipe Flow." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-1161.

Full text

Abstract:

Abstract In this work, aqueous suspensions of 1% and 1.5% by weight Laponite and a blend of 0.5%/ 0.07% Laponite/ CMC are investigated in terms of their rheology and their hydrodynamic behaviour in a pipe flow. The viscometric viscosity was measured for all fluids, but due to the fluid thixotropy a flow-equilibrium procedure was adopted. All fluids were viscoplastic and the measurement of the yield stress was carried out by direct and indirect methods. The yield stress values were of 0.93, 2.13 and 3.4 Pa for the 1% Laponite, 0.5/0.07% Laponite/CMC blend and 1.5% Laponite suspensions, respectively. The oscillatory tests shows that the 1% Laponite suspension is inelastic but the other two suspensions exhibit some elasticity. All solutions exhibited drag reduction with the difference between the total and shear-thinning drag reductions (DR – DRv) of the order of 10% to 20% for both pure laponite suspensions but increasing to 25 to 30% for the laponite-polymer blend. For the pure clay suspensions, and based also on evidence from the literature, it was speculated that DR – DRv, could be due to a strong decrease of the viscosity associated with a turbulence-induced destruction of the internal structure plus a second mechanism more akin to that found with drag reducing polymer solutions.

APA, Harvard, Vancouver, ISO, and other styles

Davidson, Drew A., and Gary L. Lehmann. "Squeeze Flow Study of a Colloidal Paste." In ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73394.

Full text

Abstract:

Crucial to the development and characterization of thermal interface materials (TIMs) is an understanding of the squeeze flow process that is commonly used to form thin bond layers in micro-electronic assemblies. A single model TIM, a dense, fairly monomodal suspension of submicron alumina particles suspended in a silicone-based resin, is first characterized as a Bingham fluid using a parallel disk rotational viscometer. Next, the model TIM is squeezed from ∼1 mm initial thickness to ∼.01 mm limiting thickness under nominally constant applied load (68 to 345 kPa) between 20 mm diameter aluminum plates in an axial compression test apparatus (the type commonly used for materials testing). The test plates are flat (∼10 μm flatness deviation over the plate) and smooth (Ra ∼ 20 nm), and are fixed in the test column with epoxy for optimum parallelism. Bond layer thickness is estimated using the LVDT built into the compression tester. The thickness measurement resolution is limited by LVDT noise of 10–20 microns. Squeezing forces are well above the ∼.02 N noise level of the 100 N load cell. Of the test system compliance, inertia, and friction, only the compliance is significant to our testing, and is corrected for. Squeeze flow tests of Newtonian standards are used to qualify the test process. In the case of the model paste, Bingham fluid model parameters from rotational viscometry are used in a lubrication model of squeeze flow that shows good agreement with the measured gap vs. time behavior during squeezing. Improved agreement is obtained by including plate flatness deviation and time-dependent force in the lubrication model. Parallel disk viscometry and squeeze flow testing of the base resin of the model TIM shows Newtonian behavior.

APA, Harvard, Vancouver, ISO, and other styles

Knight, R., X. Fang, and T. E. Twardowski. "Structure and Properties of HVOF Sprayed Amorphous Polymer Matrix Nanocomposite Coatings." In ITSC2001, edited by Christopher C. Berndt, Khiam A. Khor, and Erich F. Lugscheider. ASM International, 2001. http://dx.doi.org/10.31399/asm.cp.itsc2001p0361.

Full text

Abstract:

Abstract The high velocity oxy-fuel [HVOF] combustion spray technique has previously been shown to be an excellent solution for depositing crystalline matrix nano-reinforced polymer coatings. Dense polymer coatings can be produced by controlling both the particle dwell time in the HVOF jet and through substrate thermal management. Use of an amorphous matrix material, polycarbonate, will enable the role of matrix crystallinity on the structure and properties of thermally sprayed polymer matrix nanocomposite coatings to be separated from effects resulting from the reinforcing phase. An amorphous, commercial polycarbonate powder with a broad particle size distribution and irregular particle morphology has been successfully deposited by HVOF spraying using hydrogen as fuel gas. Polycarbonate matrix coatings up to 18 mils thick with zero to 10 vol. % loadings of nano-sized hydrophobic and hydrophilic silica, and carbon-black have been sprayed onto Al substrates. Results from optical microscopy. X-ray diffraction, scratch, density, microhardness and dilute-solution viscometry measurements will be presented. These indicate that incorporation of the nanosized filers improved the scratch resistance and microhardness of the coatings by 50 % and 23 %, respectively, relative to sprayed pure polymer. Some degradation of the polymer matrix was also detected, with molecular weight being reduced from 17,000 in the feedstock to ~5,000 in the sprayed deposits. The influence of variations in process parameters such as fuel:oxygen ratio, total gas flow, spray distance, nozzle length, total travel distance, and spray distance/nozzle length ratio on coating structure will also be addressed. The threshold loading of silica in the polycarbonate matrix for which dense coatings can be obtained has also been determined.

APA, Harvard, Vancouver, ISO, and other styles

Steindl, Johannes, Rafael Eduardo Hincapie, Ante Borovina, et al. "Improved EOR Polymer Selection Using Field-Flow Fractionation." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/207700-ms.

Full text

Abstract:

Abstract Various polyacrylamide polymers have been successfully applied in chemical EOR projects. These polymers are characterised by high molecular weights (MW) to achieve high viscosifying power. The molecular weight distribution (MWD) of the polymers has a major impact on polymer properties and performance. Measuring the molecular weight distribution is challenging using conventional methods. Field-Flow Fractionation (FFF) enables the determination of the distribution to select and quality check various polymers. Polymers with high molar masses (&gt; 1 MDa) are used for EOR to obtain highly viscous aqueous solutions. The MWD of the polymers is crucial for the solution characteristics. Conventional analysis of polymers is performed using either viscometry – which is able to determine the average MW but does not give information on MWD, or size-exclusion chromatography – which is restricted to molecular weights of &lt; 20 MDa. FFF is based on the analytes flowing at different speeds in a channel dependent on their size and mass. This effect leads to separation, which is then used to determine the MWD. FFF allows to determine the MW and MWD of various ultra-high molecular weight polyacrylamides (HPAAMs). The FFF measurements showed, that despite similar MWs are claimed, substantial differences in MWD are observed. This technology offered the quantification the MWD of HPAAMs up to a MW of 5 GDa. Furthermore, gyration radii of the HPAAM molecules were determined. Selecting polymers on viscosifying power only is not addressing issues related to different MW and MWDs such as selective polymer retention and degradation of the high molar mass part of the distribution. The results were used to improve the polymer selection for chemical EOR projects. Overall, this work presents a new technique for analysis of ultra-high molecular weight EOR polymers, which enables the possibility to determine the full range of polymer MWD. This available information enhances the EOR polymer selection process addressing selective polymer retention and mechanical degradation in addition to the viscosifying power of polymers.

APA, Harvard, Vancouver, ISO, and other styles

Alhajeri, Mubarak Muhammad, Jenn-Tai Liang, and Reza Barati Ghahfarokhi. "Polyelectrolyte Multilayered Nanoparticles as Nanocontainers for Enzyme Breakers During Hydraulic Fracturing Process." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205981-ms.

Full text

Abstract:

Abstract In this study, Layer-by-Layer (LbL) assembled polyelectrolyte multilayered nanoparticles were developed as a technique for targeted and controlled release of enzyme breakers. Polyelectrolyte multilayers (PEMs) were assembled by means of alternate electrostatic adsorption of polyanions and polycations using colloidal structure of polyelectrolyte complexes (PECs) as LbL building blocks. High enzyme concentrations were introduced into polyethyleneimine (PEI), a positively charged polyelectrolyte solution, to form an electrostatic PECs with dextran sulfate (DS), a negatively charged polyelectrolyte solution. Under the right concentrations and pH conditions, PEMs were assembled by alternating deposition of PEI with DS solutions at the colloidal structure of PEI-DS complexes. Stability and reproducibility of PEMs were tested over time. This work demonstrates the significance of PEMs as a technique for the targeted and controlled release of enzymes based on their high loading capacity, high capsulation efficiency, and extreme control over enzyme concentration. Entrapment efficiency (EE%) of polyelectrolyte multilayered nanoparticles were evaluated using concentration measurement methods as enzyme viscometric assays. Controlled release of enzyme entrapped within PEMs was sustained over longer time periods (&gt; 18 hours) through reduction in viscosity, and elastic modulus of borate-crosslinked hydroxypropyl guar (HPG). Long-term fracture conductivity tests at 40℃ under closure stresses of 1,000, 2,000, and 4,000 psi revealed high fracture clean-up efficiency for fracturing fluid mixed with enzyme-loaded PEMs nanoparticles. The retained fracture conductivity improvement from 25% to 60% indicates the impact of controlled distribution of nanoparticles in the filter cake and along the entire fracture face as opposed to the randomly dispersed unentrapped enzyme. Retained fracture conductivity was found to be 34% for fluid systems containing conventional enzyme-loaded PECs. Additionally, enzyme-loaded PEMs demonstrated enhanced nanoparticle distribution, high loading and entrapment efficiency, and sustained release of the enzyme. This allows for the addition of higher enzyme concentrations without compromising the fluid properties during a treatment, thereby effectively degrading the concentrated residual gel to a greater extent. Fluid loss properties of polyelectrolyte multilayered nanoparticles were also studied under static conditions using a high-pressure fluid loss cell. A borate-crosslinked HPG mixed with nanoparticles was filtered against core plugs with similar permeabilities. The addition of multilayered nanoparticles into the fracturing fluid was observed to significantly improve the fluid- loss prevention effect. The spurt-loss coefficient values were also determined to cause lower filtrate volume than those with crosslinked base solutions. The PEI-DS complex bridging effects revealed a denser, colored filter cake indicating a relatively homogenous dispersion and properly sized particles in the filter cake.

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!