Molecular weight concentration

Hashimoto T., Shibayama M., and Kawai H., Ordered structure in block copolymer solution. 4. Scaling rules on size of fluctuations with block molecular weight, concentration temperature in segregation and homogeneous regimes. Macromolecules, 16, 1093, 1983. 

The paraffins in diesel fuel can vary in molecular weight, concentration, and crystallization temperature. For this reason, fuels with similar physical properties may behave differently at low temperatures. This difference in behavior can be related to the low-temperature properties of the fuel paraffins present. 

The simple solubility model is not adequate to explain the variation of observed effects with molecular weight, concentration and ionic strength. However, its simplicity and relative ease of use warrant further modification. 

Frederick, J.E., Tschoegl,N.W., Ferry.J.D. Dynamic mechanical properties of dilute polystyrene solutions dependence on molecular weight, concentration, and solvent. J. Phys. Chem. 68,1974-1982 (1964). 

Compound Formula Molecular weight Concentration Density (kg/L) Boiling point (°C) Comments... 

A number of factors influence the magnitude of the second virial coefficient. These include the nature of the polymer and solvent, the molecular weight distribution of the polymer and its mean molecular weight, concentration and temperature of the solution, and the presence or absence of branching in the polymer chain. 

Avogadro s constant (6.023 x 10 - per mole) molecular weight concentration (moles/liter) symbol for a monomer unit (Chapter 6)... 

Acid or Base Molecular Weight Concentration % by (Moles/1) Weight Specific Gravity... 

Weinbauer, M. G., and Peduzzi, P. (1995). Effect of virus-rich high molecular weight concentrates of seawater on the dynamics of dissolved amino acids and carbohydrates. Mar. Ecol. Prog. Ser. 127, 245-253. 

In the presence of solutes with small molecular weights, concentration polarization is likely to occur but with much less effect than in the case of ultrafiltration as explained in Section 12.2.1. A theoretical model concerning separation of sucrose and raffinose by ultrafiltration membranes has been proposed by Baker et al. [53] which assumes transport of solvent and solute exclusively through pores. This model can apply to ceramic nanofilters as they exhibit a porous structure with a pore size distribution. The retention characteristics of a given membrane for a given solute is basically determined by its pore-size distribution. The partial volume flux jy through the pores which show no rejection to the solute can be expressed as a fraction of the total volume flux fy. 

Properties of the solute Type of analyte (volatility, polarity, molecular weight) Concentration... 

Kikuchi K, Yoshioka K. Electric birefringence of potassium polystyrenesulfo-nate in aqueous solution as a function of molecular weight, concentration and field strength. J Phys Chem 1973 77 2101-2107. 

By definition, miscible polymer blends are singlephase mixtures. Miscibility depends on the molecular weight, concentration, temperature, pressure, deformation rate, etc. Flow of these systems can be compared to that of solutions of low molecular weight, miscible components, or to flow of mixtures of polymeric fractions. Both models are far from perfect, but they serve to illustrate the basic behavior of miscible systems. 

Decades of research in polymer drag reduction have shown that the effects of variables such as polymer molecular structure, flexibility, molecular weight, concentration, and solvency are important. They are described below along with polymer mechanical degradation. 

An overview of company information in terms of current commercially-marketed viscoelastic properties is presented in the Appendix Table. It is significant to take into account molecular weight, concentration and chemical composition when comparing these substances, especially with those manufactured by different companies. 

Correlations of the scaling parameters with polymer molecular weight, concentration, and size are examined, a increases markedly with polymer molecular weight, namely a for r 1. r/ is 0.5 for large polymers (M larger than 400 kDa or so), but increases toward 1.0 or so at smaller M. Scaling parameters for the diffusion of star polymers do not differ markedly from scaling parameters for the diffusion of linear chains of equal size. 

The relaxation time 1 and the pol3mer contribution to the viscosity rjp depend strongly on the polymer molecular weight, concentration, and equihbrium conformation. Kinetic theory can be used to obtain scaling behavior for these quantities. At dilute concentrations, for example, the Zimm bead-spring model predicts the relaxation time as a function of the drag on polymer chain segments. 

Viscosity is the resistance to flow of material under an applied external force at a specified temperature and pressure. It depends on the nature of polymers, that is their physical and chemical structures, molecular weight, concentration of solution (for solution viscosity), temperature and pressure of the test medium and the applied external shear force. 

By establishing structure property relationships one should be able to select polymers for specific technical applications. To give an example, we established a zero-shear-viscosity molecular weight - concentration relationship which is valid... 

The viscoelastic properties of polymers are quite important in polymer technology. A great deal of experimental work has been done, and at the same time phenomenological theories have been developed to a highly sophisticated level. These are summarized in various monographs. An overview of this field can be obtained in the excellent textbook by Bird et al Here we shall limit ourselves to the molecular aspects of the problem, i.e., how the viscoelastic properties are related to the molecular dynamics and how they depend on molecular parameters such as molecular weight, concentration, and molecular structure. 

A review of the mentioned published papers shows that the germination stimulating activity of chitosan and their derivatives is strongly dependent on molecular weight, concentration, soaking time, and various plants. Therefore, to apply the technique of seed coating, we have to test carefully all the mentioned conditions. 

A poly(3-HB)/calcium polyphosphate complex has been isolated from E. coli and other species. This complex, whose structure is thought to consist of two high molecular weight concentric helices, is believed to form ion channels (Chapter 11.1) in natural membranes. 

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