Conjugated polymers (CPs) are advantageous materials for lower-cost and flexible organic electronic devices, such as organic photovoltaics (OPVs), organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs), bioelectronics, chemical sensors, flexible displays, and wearable electronics. Their pi-conjugated backbones enable charge transport along the chain or through the pi-orbital overlap of neighboring chains. The molecular dynamics and morphology in the crystalline and amorphous phases of both pure and blended CPs have a direct impact on these mechanisms and therefore, the macroscopic performance of the material. A thorough understanding of this relationship is important for the future development of improved materials and devices. In this work, we utilize neutron and X-ray scattering together with molecular dynamics (MD) simulations and density functional theory (DFT) for a powerful combined experimental and theoretical approach to probing the structure and dynamics in poly(3-hexylthiophene) (P3HT) and other polythiophenes. We first utilize quasi-elastic neutron scattering (QENS) to perform a critical assessment of MD simulation force fields for P3HT. Although these models capture system-level dynamics well, they fail to accurately represent characteristic motions along the polymer backbone which play a critical role in charge transport processes. Next, we utilize density functional theory (DFT) to explore the non-bonded, intermolecular interactions of P3HT and use MD simulations to understand their influence on in-silico dynamics. With selective deuteration, characteristic relaxation times are extracted from QENS data for a set of P3HT polymers and oligomers to probe the effect of molecular weight and crystallinity on backbone and side-chain dynamics. Pure CPs are still susceptible to limited environmental stability and low mechanical durability (e.g. cracking), but blending CPs with a commodity polymer, e.g. polystyrene, can improve the lifetime and mechanical robustness of these materials while maintaining electronic performance at low amounts of the conjugated material. In our final study, small-angle neutron scattering (SANS) and wide-angle X-ray scattering (WAXS) are used to characterize phase separation and self-assembly in these polythiophene-polystyrene blends, and correlate phase morphology with macroscopic conductivity.

Scattering is a very powerful tool to study the structure of polymers. Written by highly regarded and respected scientists in the field, this book presents the latest developments in the field of scattering in a uniform, systematic manner. This volume arms readers with both theoretical and experimental aspects of the intended area, offering much simplified theoretical explanations on the physics of scattering. The authors provide discussion on applications of experimental techniques. Han and Akcasu begin with a traditional treatment of light scattering from plane waves, followed by consistent application of density (in both real and Fourier space) correlation functions in both space and time. The authors do not distinguish among light, X-ray, and neutron, excepting their scattering length, q-range, coherence and detection differences. Readers can therefore concentrate on exactly the scattering tools they need to use, while theoretical explanation on the physics of scattering can be made much more simplified and uniform. Presents the latest development in the field of scattering in a uniform, systematic manner Arms readers with both theoretical and experimental aspects Gives a much simpler theoretical explanation on the physics of scattering Demonstrates application of experimental techniques

The 27th Europhysics Conference on Macromolecular Physics focused on applications of scattering methods to the dynamics of polymer dense systems and covered Rayleigh-Brillouin scattering and photon correlation spectroscopy, quasi-elastic neutron scattering, holographic methods, real time X-ray and neutron scattering techniques as well as the treatment of theoretical models and computer simulations of polymer dynamics.

Theoretical and Computational Photochemistry: Fundamentals, Methods, Applications and Synergy with Experimental Approaches provides a comprehensive overview of photoactive systems and photochemical processes. After an introduction to photochemistry, the book discusses the key computational chemistry methods applied to the study of light-induced processes over the past decade, and further outlines recent research topics to which these methods have been applied. By discussing the synergy between experimental and computational data, the book highlights how theoretical studies could facilitate understanding experimental findings. This helpful guide is for both theoretical chemists and experimental photochemistry researchers interested in utilizing computational photochemistry methods for their own work. - Reviews the fundamentals of photochemistry, helping those new to the field in understanding key concepts - Provides detailed guidance and comparison of computational and theoretical methods, highlighting the suitability of each method for different case studies - Outlines current applications to encourage discussion of the synergy between experimental and computational data, and inspiring further application of these methods to other photochemical processes

This book covers properties, processing, and applications of conducting polymers. It discusses properties and characterization, including photophysics and transport. It then moves to processing and morphology of conducting polymers, covering such topics as printing, thermal processing, morphology evolution, conducting polymer composites, thin films