Viscoelasticity, dynamic solution

Besides kinetic applications, which are still to be fully realized, hydro-dynamic modulation is useful for Schmidt number and diffusion coefficient measurements not only in Newtonian fluids but also in viscoelastic polymer solutions (Ostwald fluids) [291]. 

Multiplicity, bifurcation, stability, and hysteresis in dynamic solutions, nonisothermal viscoelastic model Parameter estimation to characterize convective heat transfer... 

These linear viscoelastic dynamic moduli are functions of frequency. For a suspension or an emulsitm material at low frequency, elastic stresses relax and viscous stresses dominate with the result that the loss modulus, G", is higher than the storage modulus, G. For a dilute solution, G" is larger than G over the entire frequency range, but they approach each other at higher frequencies as shown in Fig. 3. 

Viscoelastic model None Polymer solutions Viscoelasticity Dynamic asymmetry... 

Rheological Properties of Viscoelastic Surfactant Solutions Relationship with Micelle Dynamics... 

The Maxwell model can also be used in order to characterize the dynamic properties of viscoelastic surfactant solutions. The simplicity of comparing rheological data with the theoretical predictions of a Maxwell material is rather attractive. In this way, it is easy to interpret viscoelastic flow processes. 

It is worthwhile to mention that the dynamic properties of these viscoelastic surfactant solutions can evidently be described by monoexponential relaxation properties. This cor-... 

The book first discusses. self-assembling processes taking place in aqueous surfactant solutions and the dynamic character of surfactant self-assemblies. The next chapter reviews methods that permit the. study of the dynamics of self-assemblies. The dynamics of micelles of surfactants and block copolymers,. solubilized systems, microemulsions, vesicles, and lyotropic liquid crystals/mesophases are reviewed. successively. The authors point out the similarities and differences in the behavior of the.se different self-as.semblies. Much emphasis is put on the processes of surfactant exchange and of micelle formation/breakdown that determine the surfactant residence time in micelles, and the micelle lifetime. The la.st three chapters cover topics for which the dynamics of. surfactant self-assemblies can be important for a better understanding of observed behaviors dynamics of surfactant adsorption on surfaces, rheology of viscoelastic surfactant solutions, and kinetics of chemical reactions performed in surfactant self-assemblies used as microreactors. 

Presents the dynamics of surfactant adsorption on surfaces and the rheology of viscoelastic surfactant solutions and their relation to micelle dynamics... 

The purpose of this book is to present an up-to-date picture of the dynamics aspects of self-assemblies of surfactants and amphiphilic block copolymers, from micelles to solubilized systems, microemulsions, vesicles, and lyotropic mesophases. It is organized as follows. The first chapter introduces amphiphiles, surfactants, and self-assembhes of surfactants and examines the importance of dynamics of self-assembhes in surfactant science. Chapter 2 briefly reviews the main techniques that have been used to study the dynamics of self- assembhes. Chapters 3 and 4 deal with the dynamics of micelles of surfactants and of amphiphilic block copolymers, respectively. The dynamics of microemulsions comes next, in Chapter 5. Chapters 6 and 7 review the dynamics of vesicles and of transitions between mesophases. The last three chapters deal with topics for which the dynamics of self-assembhes is important for the understanding of the observed behaviors. The dynamics of surfactant adsorption on surfaces are considered in Chapter 8. The rheology of viscoelastic surfactant solutions and its relation to micelle dynamics are reviewed in Chapter 9. The last chapter deals with the kinetics of chemical reactions performed in surfactant self-assembhes used as microreactors. 

B. Zimm. Dynamics of polymer molecules in dilute solutions viscoelasticity, low birefringence and dielectric loss. J Chem Phys 24 269-278, 1956. 

Zimm, BH, Dynamics of Polymer Molecules in Dilute Solution Viscoelasticity, Flow Birefringence and Dielectric Loss, Journal of Chemical Physics 24, 269, 1956. 

Viscoelastic and transport properties of polymers in the liquid (solution, melt) or liquid-like (rubber) state determine their processing and application to a large extent and are of basic physical interest [1-3]. An understanding of these dynamic properties at a molecular level, therefore, is of great importance. However, this understanding is complicated by the facts that different motional processes may occur on different length scales and that the dynamics are governed by universal chain properties as well as by the special chemical structure of the monomer units [4, 5],... 

Factorizability has also been found to apply to polymer solutions and melts in that both constant rate of shear and dynamic shear results can be analyzed in terms of the linear viscoelastic response and a strain function. The latter has been called a damping function (67,68). 

The above model assumes that both components are dynamically symmetric, that they have same viscosities and densities, and that the deformations of the phase matrix is much slower than the internal rheological time [164], However, for a large class of systems, such as polymer solutions, colloidal suspension, and so on, these assumptions are not valid. To describe the phase separation in dynamically asymmetric mixtures, the model should treat the motion of each component separately ( two-fluid models [98]). Let Vi (r, t) and v2(r, t) be the velocities of components 1 and 2, respectively. Then, the basic equations for a viscoelastic model are [164—166]... 

Tanaka,H., Sakanishi,A., Kaneko,M., Furiuchi,J. Dynamic viscoelastic properties of dilute polymer solutions. J. Polymer Sci. Pt. C15,317-330 (1966). 

Fig. 25 Viscoelastic behavior of a semi-dilute solution of DNA. Elastic modulus (G, filled symbols) and viscous modulus (G", open symbols) are plotted, together with their ratio G"IG = tan 5 (solid curve), for a 93 mg/mL DNA solution subjected to a heating-cooling cycle. The entanglement of DNA helices and, at high temperature, of single strands causes the almost monotonous increase of the dynamic moduli. Reproduced with permission from [110]...

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