Authors: Jenny Mahoney | Ying Jia
Source: Journal of Polymer Science Part B Polymer Physics (article, 2019-09-15)
Field: Chemistry — Physical and Theoretical Chemistry

Recent advances in the physics of polymer systems The beauty of polymer physics lies in its practicality and its pervasiveness. It can explain why some batteries work better than others, why thin films have different properties than their bulk counterparts, and how conductivity can be improved by proper stacking of polymer chains. As we approach the end of the first century of modern polymer science, we continue to witness remarkable progress and important developments in the field. With this in mind, we present a special issue of the Journal of Polymer Science, Part B: Polymer Physics highlighting recent advances in the physics of polymer systems. The issue consists of a collection of papers from some of the best minds in polymer physics – our Editorial Advisory Board. The Review by Loo and Balsara provides a comprehensive overview of literature data on the thermodynamic properties of salt-containing polymer blends and copolymers. Adding salt to a polyelectrolyte solution has significant effects on diffusion behaviors. Muthukumar shows that coupled dynamics of polymer segments, counterions, and coions from added salt lead to an intermediate diffusive mode in between the classical ordinary and extraordinary diffusive modes in polyelectrolyte solutions. Two-dimensional (2D) conducting polymers have been widely applied in flexible electronics, ion-exchange membranes, biotechnology and energy devices. In a forward-looking Perspective, Park and co-workers highlight most recent synthetic advances in 2D polymers with large lateral sizes and outline potential challenges and future avenues related to their commercialization. With progress in computational modeling techniques comes better methods to design and manufacture polymeric materials. As DNA and RNA are increasingly used in bio- and nano-technology applications, it is crucial to understand how polymer-solvent interactions impact their melting temperature when they are conjugated with polymers. Prhashanna and Jayaraman investigate these systems using coarse-grained molecular simulations, comparing melting behavior of charged/stiff oligonucleic acids with neutral/flexible ones. Dutcher and co-workers use principal component analysis and machine learning concepts to distinguish polyethylene pipe formulations by examining the contribution of individual IR bands, which will ultimately allow for better optimization of pipe performance and durability. Predicting the behavior and experimental features of complex polymer systems requires a deep understanding of the underlying theory. Polymer blends are well-studied but are known to exhibit anomalies in their dynamics at different length and time scales. Colmenero presents a memory function formalism to explain this behavior, which considers the effect of the collective dynamics on the chain dynamics of a tagged polymer chain. With an appropriate contact mechanics model, atomic force microscopy (AFM) enables quantitative evaluation of surface interactions and elasticity. Nishi and co-workers present new easy-to-use methods to derive the elastic modulus of a soft and adhesive material from an AFM force curve. Experimental insight into crystallization and phase behavior, the glass transition, and polymer chain dynamics provides new opportunities to precisely tune material properties. Choudhary and Crosby use evaporative self-assembly based on stop-and-go flow-coating to form mesoscale nanoribbons. Different control parameters influence the final size, geometry, and mechanical properties of the nanoribbon helices. Shull and co-workers present the optimization of the quartz crystal microbalance as a high frequency direct measurement technique. A high frequency shear wave is excited through a deposited thin film, and the viscoelastic properties of the film are obtained in excellent agreement with values obtained by traditional techniques. When hydrogenated polynorbornene (hPN) is synthesized through ring-opening metathesis polymerization, the hydrogenation route employed can significantly influence the chain microstructure, and thereby its crystal structure and stability. Klein and Register show that the content of trans units influences both the low-temperature crystal structure and the polymorphic transition temperature of hPN, presenting another tool to control phase behavior. Physical aging represents the slow structural evolution of the nonequilibrium glassy material toward equilibrium. Traditionally, physical aging in bulk polymers is associated with local segmental motions and is independent of molecular weight. The physical aging rate of thin films has been found to be reduced from that of the bulk due to the presence of the free surface and the enhanced mobility it imparts. Thees and Roth discover an unexpected molecular weight dependence exhibited by the physical aging response of thin polystyrene films, indicating that chain connectivity and entropy modify the gradient in dynamics near interfaces in polymer glasses. Supramolecular associative polymer networks consist of (macro)molecular building blocks associated by physical transient bonds. The dynamic mechanical properties of supramolecular associative polymer networks depend on interchain entanglements, chemical structures and the content of associative groups. Seiffert and co-workers study the interplay of interchain entanglement, interchain transient association, and aggregation of the associative groups into clusters and their effects on the dynamic mechanics of a library of supramolecular associative polymer networks. The results enrich the assortment of available approaches to stimuli-responsive materials. We hope you will enjoy reading this diverse lineup of papers showcasing the vibrant polymer physics research from our editorial advisory board. We are grateful to all those who contribute to the success of JPSB: our authors, our reviewers, our board members, and of course, our readers. Thank you for your continued support! Polymer physics ; Polymer science ; Polymer ; Physics ; Nanotechnology ; Materials science ; Nuclear magnetic resonance Advanced Physical and Chemical Molecular Interactions