Download or read book An Improved Form for the Electrostatic Interactions of Polyelectrolytes in Solution and Its Implications for the Analysis of QELSS Experiments in Sodium Dodecyl Sulfate and Cetyl Trimethyl Ammonium Bromide written by Nicholas V. Sushkin and published by Universal-Publishers. This book was released on 1997-11 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: The electrostatic interaction between two charged spheres in the presence of a screening electrolyte is calculated at the level of the linearized Debye-Hückel theory. The calculation is performed analytically as a multipole expansion by applying two-center spherical harmonic expansions and symbolic manipulation methods. I focus on charge-charge and charge-induced dipole interactions, calculated for two spheres of possibly unequal size. The former interaction is given to good approximation by the familiar Debye-Hückel form q1q2exp[-k(R-2a)]/[(epsilon*r(1]ka)^2]. The new results are the charge-induced dipole interactions. Physically, these terms arise from two sources: (i) surface polarization charge at the surface of each sphere, and (ii) exclusion of the counterion cloud of each sphere from the volume occupied by the other sphere. With parameters appropriate for micelles, the charge-induced dipole interactions dominate the charge-charge interaction at small separations. Quasi-elastic light scattering measurements of the diffusion of sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) micelles in aqueous solutions, and the diffusion of mesoscopic optical probes through the same solutions, were carried out at 35°C and multiple solvent ionic strengths. Assuming a spherical micelle, I deduced the micelle radius, aggregation number, charge, and hydration from nonlinear least-squares fits to both probe and mutual diffusion data. For SDS micelles the charge that I find is lower than reported in the literature [Hayter, J. B.; Penfold, J. Colloid & Polymer Science 1983, 261, 1022; Triolo, R.; Caponetti, E.; Graziano, V. J. Phys. Chem. 1985, 89, 5743.] because I used an improved functional form of the micellar electrostatic interaction. I find a smaller aggregation number and a larger micellar hydration than literature values. My analysis of CTAB data implies extensive micellar growth, and failure of the spherical micelle assumption.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polyelectrolytes written by Visakh P. M. and published by Springer. This book was released on 2014-09-03 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a valuable reference source to graduate and post graduate students, engineering students, research scholars polymer engineers from industry. The book provides the reader with current developments of theoretical models describing the thermodynamics polyelectrolytes as well as experimental findings. A particular emphasis is put on the rheological description of polyelectrolyte solutions and hydrogels.
Download or read book Polyelectrolyte Solutions written by Stuart Alan Rice and published by . This book was released on 1961 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamics of Polyelectrolyte Solutions and Polymer Crystallization written by Sabin Adhikari and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymeric systems exhibit interesting macroscopic properties under different thermodynamic conditions and are prevalent in both biology and synthetic world. How a system of polymers behaves under different thermodynamic conditions is determined by the interplay of different possible interactions such as short-ranged Van der Waals and long-ranged electrostatic interactions and the entropy of individual components present in the system. This work is mostly focused on the theoretical study of the thermodynamic phase behaviors of charged polymers in solutions. We use the methods of both analytical theory and numerical computations in order to find the free energies and then the thermodynamically most stable states of systems under consideration. Our topics of interest in this work include phase separation of solutions of oppositely charged polyelectrolytes (also known as complex coacervation), interfacial tension in polyelectrolyte complex coacervates, orientations of rigid polyelectrolytes in solutions and the statistics of amorphous chains in polymer semi-crystals. We develop a new free energy expression to study the phase behaviors of polyelectrolyte complex coacervates, complementing numerous existing theories and construct phase diagrams to predict the effect of experimental variables in the phase behavior. We explore in detail on both the upper critical solution (UCST) and the lower critical solution (LCST) behavior and compare the theoretical predictions with experiments. The constructed phase diagrams predict that salt and asymmetry in polycation-polyanion content suppress complex coacervation. We also show that a solution can exhibit UCST or LCST depending upon the temperature dependencies of the solvent{polymer interaction parameter and the solvent dielectric constant. These predictions are in qualitative agreements with experiments. Further, by using this new free energy, we numerically compute the interfacial tension between the interface of a polyelectrolyte complex coacervate phase and a coexisting aqueous dilute phase. We predict that the interfacial tension decreases with increasing the salt concentration and it increases with increasing the polyelectrolyte chain length. Next, we study the thermodynamics of charged rods in solution, focusing on the effect of electrostatic interactions among the rods in determining their relative orientations. We show that electrostatic repulsion among the rods tends to stabilize the solution against the isotropic-nematic phase transition/separation. Finally, we study the statistics of ties and loops in the amorphous regions of polymer crystals. Here the focus is on determining the fraction of ties, it is because of their relevance in determining the mechanical properties of semicrystalline polymers. We calculate the fraction of ties and loops by calculating the partition sum of the amorphous region by using the field-theoretic techniques in statistical mechanics. We show that the fraction of ties increases with increasing the chain length and it decreases with increasing the thickness of the amorphous region.
Download or read book Physical Chemistry of Polyelectrolyte Solutions Volume 158 written by Mitsuru Nagasawa and published by John Wiley & Sons. This book was released on 2015-09-09 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Advances in Chemical Physics series provides the chemical physics field with a forum for critical, authoritative evaluations of advances in every area of the discipline. This volume explores topics from Thermodynamic Properties of Polyelectrolyte Solutions to ion-binding of polyelectrolytes. The book features: The only series of volumes available that presents the cutting edge of research in chemical physics Contributions from experts in this field of research Representative cross-section of research that questions established thinking on chemical solutions An editorial framework that makes the book an excellent supplement to an advanced graduate class in physical chemistry or chemical physics
Download or read book Physical Chemistry of Polyelectrolytes written by Tsetska Radeva and published by CRC Press. This book was released on 2001-02-21 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt: An examination of the fundamental nature of polyelectrolytes, static and dynamic properties of salt-free and salt-added solutions, and interactions with other charged and neutral species at interfaces with applications to industry and medicine. It applies the Metropolis Monte Carlo simulation to calculate counterion distributions, electric potentials, and fluctuation of counterion polarization for model DNA fragments.
