ALEXANDROS CHREMOS SERIES
These findings are also closely related to relative simple case of electrolyte solutions, where the strength of solvent interaction with ionic species dictates the location of the ion along the Hofmeister series and modulating the solution properties of these solutions such as viscosity, density, and surface tension. Our findings demonstrate that the solvent is responsible for heterogeneous structure formation in salt-free polyelectrolyte solutions, revealing the essential role of the solvent interactions with the charged species in the description of the polyelectrolyte solutions. Vasiliki Falara, H B Wilson, and two other persons are also associated with this address. To probe this effect, we perform molecular dynamics simulations based on a coarse-grained model of polyelectrolyte solutions with an explicit solvent. Alexandros is a resident of 305 Ashley Rd, Newark, DE. This effect has significant implications for the function of proteins and other natural occurring polyelectrolytes (e.g., DNA), as emphasized long ago by Kirkwood and coworkers. The theoretical difficulties are especially great for flexible polyelectrolytes due to the additional complex coupling between the polyelectrolyte chain configurations and a diffuse 'polarizable' cloud of counter-ions around these polymers. While, it is widely appreciated that highly charged particles having the same charge to form dynamic clusters in solution, an accepted theoretical framework which accounts for this ubiquitous phenomenon, has been slow to develop. Most polymers encountered in living systems are polyelectrolytes because of their solubility in water, and this broad class of polymers is also ubiquitous in commercial materials in which water solubility is required examples include hydrogels in diapers and gene delivery, thickeners in food industries, drug delivery, water purification agents, and cosmetics. Title: Solvation effects in (poly)electrolyte solutions These observations are qualitatively consistent with the interpretation of recent X-ray photon correlation spectroscopy on supported star polymer films.ChBE Seminar Series: Alexandros Chremos, NISTĪmy Alexandros Chremos, Postdoctoral Researcher at NIST In particular, the width of the substrate interfacial layer grows with increasing f, saturating in value around f = 12, while the width of the interfacial zone near the “free” boundary, where the polymer dynamics is greatly accelerated compared to the film interior, is less influenced by changes in polymer topology. The mobility gradients in the film, quantified by the relaxation time obtained from the intermediate scattering function on a layer-by-layer basis, are also significantly altered by f. AI Papadopoulos, S Badr, A Chremos, E Forte, T Zarogiannis, P. In particular, we observe a general slowing down in the rate of relaxation of the entire film with an increasing functionality f, a general trend attributed mainly to an alteration of the effective cohesive interaction strength when f is increased. Chremos A, 0000-0002-1254-3972, NIST Materials Science and Engineering Laboratory The Journal of Chemical Physics, , 147(24): 241103 DOI: 10.1063/1. Douglas, A comparative study of thermodynamic, conformational, and structural properties of bottlebrush with star and ring polymer melts, The Journal of Chemical Physics, 10.1063/1.5034794, 149, 4, (044904), (2018). National Institute of Standards and Technology. correspondence should be addressed: Electronic. While the spatial variation of segmental density profile is only weakly dependent on star polymer topology, the polymer topology significantly affects both the average rate of relaxation and the spatial variation of the average segmental relaxation time τ α as a function of depth from the film substrate, z. March 2022 Alexandros Chremos, Ferenc Horkay and Jack F. We simulate the structure and dynamics of star polymer films of varying arm mass M a and number of star arms f on a supporting solid substrate with an attractive interaction and compare to the corresponding properties of thin films of linear polymers.
0 kommentar(er)
