The Terminology of Intrinsic Viscosity and Related Functions

1946 ◽  
Vol 19 (4) ◽  
pp. 1092-1098
Author(s):  
L. H. Cragg
Keyword(s):  
Intrinsic Viscosity ◽  
Kinematic Viscosity ◽  
Relative Viscosity ◽  
Flow Time ◽  
Inherent Viscosity ◽  
Routine Practice ◽  
Concentration Coefficient ◽  
Specific Viscosity ◽  
Reduced Viscosity ◽  
Relative Flow

Abstract The confusion existing in the use of symbols and names for Kraemer's “intrinsic viscosity” and other functions related to it is illustrated and deplored. The reasonable plea is made that one name be adopted for each function and that it be used with no other meaning. To stimulate discussion and ultimate action, the following names are proposed: “specific viscosity” for ηsp; “reduced viscosity” for ηsp/c, “inherent viscosity” for (ln ηr)/c; and “intrinsic viscosity” for [η], whether determined as “limiting reduced viscosity” limc→0 (ηsp/c), or as “limiting inherent viscosity” limc→0 (ηr/c), or as “limiting viscosity concentration coefficient” limc→0 (dηr/dc). Often, especially in routine practice, it is the relative kinematic viscosity νr, that is determined ; unless this is shown to be numerically equal to the relative viscosity ηr, the symbols and names of the derived functions should be modified accordingly: thus, (ln νr)/c inherent kinematic viscosity, [ν] intrinsic kinematic viscosity. Frequently, also, kinetic energy corrections are neglected; under these circumstances the suggested usage is tr, relative flow time, tsp/c reduced flow time, [t] intrinsic flow time, etc.

THE EVALUATION OF THE INTRINSIC VISCOSITY (AS INTRINSIC FLOW TIME) OF GR-S IN BENZENE

1947 ◽  
Vol 25b (4) ◽  
pp. 333-350
Author(s):  
L. H. Cragg ◽  
T. M. Rogers ◽  
D. A. Henderson
Keyword(s):  
Intrinsic Viscosity ◽  
Relative Viscosity ◽  
Flow Time ◽  
Routine Work ◽  
Relative Flow

From careful measurements of the relative flow times of solutions of GR-S in benzene, it has been established that the intrinsic flow time (and hence the intrinsic viscosity) of GR-S in benzene may be most precisely determined by the use of a function [Formula: see text], based on the Baker equation relating ηr, the relative viscosity, and c, the concentration; for the GR-S–benzene system the value of n may be taken as 8. For the greatest precision [t] is determined by linear (horizontal) extrapolation, to zero concentration, of the [Formula: see text] vs. c plot; in rapid routine work [t] may be evaluated as [Formula: see text] by measurements on only one solution of a concentration such that tr = 1.8 ± 0.4.

Viscosity studies of polyvinyl alcohol (PVA, Mw = 1,25,000) in solvent distilled water and aqueous solution of urea

2010 ◽  
Vol 7 (2) ◽  
pp. 443-448
Author(s):  
S. Panda ◽  
G. C. Mohanty ◽  
R.N. Samal ◽  
G. S. Roy
Keyword(s):  
Aqueous Solution ◽  
Polyvinyl Alcohol ◽  
Polymer Solution ◽  
Flow Time ◽  
Inherent Viscosity ◽  
Distilled Water ◽  
Reduced Viscosity ◽  
Aqueous Urea ◽  
C 30

Reduced viscosity (ηsp/C) and inherent viscosity ln (ηrel/C) of PVA (Mw = 1,25,000) has been calculated by measuring the flow time of polymer solution in solvents like distilled water and 4M Urea at six different tempratures 25° C, 30° C, 35° C, 40° C, 45° C, and 50° C. From exptrapolation of curve (/C) versus C and (ln /C) versus C, thermoviscosity parameters like Huggins’ Constrant (KHl), Kraemer's constant (KHll) and viscosity concentration co-efficient (a2) have been estimated. In aqueous solution (PVA in distilled water), Huggins' relation does not hold good. So a2 = .201[h]2.28 is used; but in aqueous Urea (PVA in 4M Urea), Huggins' relation holds good. Also η =KMα and value of a more for 4M Urea i.e aqueous Urea is better solvent for PVA than distilled water.

A viscometric study of the breakdown of casein in milk by rennin and rennet

1961 ◽  
Vol 28 (2) ◽  
pp. 165-173 ◽  
Author(s):  
G. W. Scott Blair ◽  
J. C. Oosthuizen
Keyword(s):  
Intrinsic Viscosity ◽  
Order Term ◽  
Specific Viscosity ◽  
Reduced Viscosity ◽  
Reaction Constant ◽  
Zero Order Reaction ◽  
Straight Lines ◽  
Viscometric Study ◽  
Considerable Range ◽  
Ostwald Viscometer

SummaryIn the later stages of the reaction between rennin and casein drastic viscometric methods are undesirable, but in the first stages there is a fall in viscosity which may be satisfactorily measured in an Ostwald viscometer. Using fat-free milk, the viscosity at first falls linearly with time. At low rennet concentrations (Ce) this may be said to constitute a zero-order reaction (constant k0). At higher rennet concentrations and after longer times, the reaction passes to first order (constant k1). After very long times it doubtless becomes more complex.The values of k0 are proportional, over a considerable range, to the milk concentration (Cm), those of k1 being independent of Cm.For pure rennin k0 and k1 are proportional to Ce, but for commercial rennets they vary as a power (N) of Ce and the value of N appears to measure the rennin purity. The potentialities of the method for assessing rennet activities are also discussed.If the reduced viscosity (specific viscosity÷Cm) of fat-free milks is plotted against Cm, good straight lines are obtained which may be extrapolated to zero concentration to give a reliable value of intrinsic viscosity. The intrinsic viscosity falls progressively during the protein breakdown process but the slope of the curves (‘second order term’) remains unchanged.

scholarly journals Shear viscosity dependence on concentration of (polyethylene oxide - xanthan) pseudo plasticity polymer collide

2018 ◽  
Vol 6 (2) ◽  
pp. 1-7
Author(s):  
Obaid K. A. ◽  
Rassol S. R. ◽  
Hussain A. J. ◽  
Musa A. O.
Keyword(s):  
Shear Viscosity ◽  
Polyethylene Oxide ◽  
Relative Viscosity ◽  
Physical Property ◽  
Specific Viscosity ◽  
Oil Drilling ◽  
Average Mass ◽  
Reduced Viscosity ◽  
Molecular Radius ◽  
Viscosity Dependence

Introduction: Its necessary to bear in mind that we life in theword increase industrialization, therefore we make many modifications to material to getting on best characterizations. The aim ofthis research is to Prepare new Pseudo Plasticity Polymer Collide.Materials and Methods: In the present paper effects of xanthancellulose gum (X) on rheological properties of polyethylene oxidepolymer (PEO, 3000 Daltons) included different type of viscosityhas been investigated by using the following parameters: (Spindle:no.1, Speed: 60 rpm and Temperature: RT), different sort of viscosity is computed for a PEO that dissolved in distilled cold waterwith completely different various concentrations (0.1, 0.2 to 0.8)%g/mL once and before adding (0.25 and 0.5) g X for every concentration. Results and Discussion: The results show that all properties of density, shear viscosity, relative viscosity, specific viscosity,reduced viscosity, intrinsic viscosity, viscosity average mass and theeffective molecular radius have been enhanced after the addition ofxanthan. Conclusions: Addition of xanthan are often applied asthicker mixture in coating, oil drilling and pumping of fluids attributable related pseudo physical property

A NOTE ON THE VARIATION WITH TEMPERATURE OF THE INTRINSIC VISCOSITY OF GR-S IN BENZENE

1947 ◽  
Vol 25b (4) ◽  
pp. 351-356
Author(s):  
T. M. Rogers ◽  
D. A. Henderson ◽  
L. H. Cragg
Keyword(s):  
Intrinsic Viscosity ◽  
Kinematic Viscosity ◽  
Flow Time ◽  
Point Determination ◽  
The One

The intrinsic viscosity, [η], (as well as the intrinsic flow time, [t], and the intrinsic kinematic viscosity, [ν]) of normal GR-S in benzene has been shown to be independent of temperature, over the range 10° to 55 °C, within the experimental precision [Formula: see text]. In this range of temperatures, also, the functions [Formula: see text] and [Formula: see text] are independent of concentration (up to at least 0.3%), and may therefore be used in the one-point determination of [t] and [ν].

scholarly journals Calculation and Corrections of Kinematic Viscosity and Intrinsic Viscosity

1991 ◽  
Vol 7 (05) ◽  
pp. 524-530
Author(s):  
Chen Li-Ban ◽  
◽  
Yang Shu-Ying
Keyword(s):  
Intrinsic Viscosity ◽  
Kinematic Viscosity

scholarly journals Haemorheology in dilute, semi-dilute and dense suspensions of red blood cells

2019 ◽  
Vol 872 ◽  
pp. 818-848 ◽  
Author(s):  
Naoki Takeishi ◽  
Marco E. Rosti ◽  
Yohsuke Imai ◽  
Shigeo Wada ◽  
Luca Brandt
Keyword(s):  
Red Blood Cells ◽  
Intrinsic Viscosity ◽  
Blood Cells ◽  
Volume Fraction ◽  
Relative Viscosity ◽  
Shear Plane ◽  
Constitutive Law ◽  
Stable Mode ◽  
Volume Fractions ◽  
Wide Range

We present a numerical analysis of the rheology of a suspension of red blood cells (RBCs) in a wall-bounded shear flow. The flow is assumed as almost inertialess. The suspension of RBCs, modelled as biconcave capsules whose membrane follows the Skalak constitutive law, is simulated for a wide range of viscosity ratios between the cytoplasm and plasma,$\unicode[STIX]{x1D706}=0.1$–10, for volume fractions up to$\unicode[STIX]{x1D719}=0.41$and for different capillary numbers ($Ca$). Our numerical results show that an RBC at low$Ca$tends to orient to the shear plane and exhibits so-called rolling motion, a stable mode with higher intrinsic viscosity than the so-called tumbling motion. As$Ca$increases, the mode shifts from the rolling to the swinging motion. Hydrodynamic interactions (higher volume fraction) also allow RBCs to exhibit tumbling or swinging motions resulting in a drop of the intrinsic viscosity for dilute and semi-dilute suspensions. Because of this mode change, conventional ways of modelling the relative viscosity as a polynomial function of$\unicode[STIX]{x1D719}$cannot be simply applied in suspensions of RBCs at low volume fractions. The relative viscosity for high volume fractions, however, can be well described as a function of an effective volume fraction, defined by the volume of spheres of radius equal to the semi-middle axis of a deformed RBC. We find that the relative viscosity successfully collapses on a single nonlinear curve independently of$\unicode[STIX]{x1D706}$except for the case with$Ca\geqslant 0.4$, where the fit works only in the case of low/moderate volume fraction, and fails in the case of a fully dense suspension.

Mechanochemical Transformation and Synthesis of Polymers

1961 ◽  
Vol 34 (1) ◽  
pp. 215-227 ◽  
Author(s):  
A. A. Berlin
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
High Speed ◽  
Rotation Speed ◽  
Mechanical Energy ◽  
Average Molecular Weight ◽  
Internal Stresses ◽  
Natural Polymers ◽  
Specific Viscosity ◽  
Mechanical Breakdown

Abstract The mechanical grinding, milling, mixing, homogenization, freezing and other processes of the physico-mechanical processing of high polymers are widely used in the industries of plastics, rubbers, synthetic fibers, food products, silicates and many other branches of technology. Some of these processes have a great significance in biochemistry, medicine and biology. An analysis of the available experimental data permits one to reach the conclusion that in the intensive grinding of natural polymers (cellulose, starch, proteins or synthetics (polystyrene, rubber, polyisobutylene, etc.) a mechanical scission (cracking) of the macromolecules is observed. The possibility of macromoleeular scission under the grinding of high molecular weight substances is due to the high probability of a localization of mechanical energy at different sections of the polymer chain, which under certain conditions causes internal stresses exceeding the strength of covalent or ionic bonds. Mechanical breakdown of macromolecules is possible not only with dry or wet grinding, but also by mechanical action on polymer solutions. Thus, for instance, Staudinger has shown that the high speeds and forces of friction developed in forcing a 0.005 molar tetralin solution of polystyrene, average molecular weight = Mave=6⋅106, through a platinum capillary bring about a scission of the macromolecules which is revealed in a decrease of about 30% in the specific viscosity of the solution. Forcing a solution of polyisobutylene (Mave=3.9×104–23×104) in dichlorobenzene through a capillary with a diameter of 0.2 mm causes a decrease in the intrinsic viscosity and an increase in the constant of the Huggins equation. An increase in the Mave of the polymer structure formation (cross-linking) and a repeated forcing through is conducive to the mechanical breakdown of the macromolecules. It has been established that in mixing together solutions of polymeric substances (starch, gelatine, polyvinyl alcohol, etc.) with high-speed mixers having a rotation speed of over 4000 rpm, a sharp decrease in the intrinsic viscosity [ν] is observed, while the degree of scission increases, with an increase in the rotation speed of the mixer, and also with a decrease in the concentration of the solution.

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