Chain Conformation and Exciton Delocalization in a Push-Pull Conjugated Polymer.

Linear and nonlinear optical line shapes reveal details of excitonic structure in polymer semiconductors. We implement absorption, photoluminescence, and transient absorption spectroscopies in DPP-DTT, an electron push-pull copolymer, to explore the relationship between their spectral line shapes and chain conformation, deduced from resonance Raman spectroscopy and from calculations. The viscosity of precursor polymer solutions before film casting displays a transition that suggests gel formation above a critical concentration.

Computational Approaches for Organic Semiconductors: From Chemical and Physical Understanding to Predicting New Materials.

While a complete understanding of organic semiconductor (OSC) design principles remains elusive, computational methods─ranging from techniques based in classical and quantum mechanics to more recent data-enabled models─can complement experimental observations and provide deep physicochemical insights into OSC structure-processing-property relationships, offering new capabilities for in silico OSC discovery and design. In this Review, we trace the evolution of these computational methods and their application to OSCs, beginning with early quantum-chemical methods to investigate resonance in benzene and building to recent machine-learning (ML) techniques and their application to ever more sophisticated OSC scientific and engineering challenges. Along the way, we highlight the limitations of the methods and how sophisticated physical and mathematical frameworks have been created to overcome those limitations.

The Solution is the Solution: Data-Driven Elucidation of Solution-to-Device Feature Transfer for π-Conjugated Polymer Semiconductors.

The advent of data analytics techniques and materials informatics provides opportunities to accelerate the discovery and development of organic semiconductors for electronic devices. However, the development of engineering solutions is limited by the ability to control thin-film morphology in an immense parameter space. The combination of high-throughput experimentation (HTE) laboratory techniques and data analytics offers tremendous avenues to traverse the expansive domains of tunable variables offered by organic semiconductor thin films.

Effect of Block Length and Side Chain Length Ratios on Determining a Multicompartment Micelle Structure.

Previous work has identified the importance of the lipophilic-fluorophilic block length ratio in predicting the morphology of linear lipophilic-hydrophilic-fluorophilic (hereafter referred to as BAC) micelle systems. Here, a generalized form of this structural parameter is developed that makes no assumption of BAC triblock co-polymer linearity, while still providing accurate predictions of the micelle morphology. The morphologies of BAC micelles formed by triblock co-polymers with or have similar features, with the only notable difference being an inversion of the lipophilic and fluorophilic regions.

Structural Tunability of Multicompartment Micelles as a Function of Lipophilic-Fluorophilic Block Length Ratio.

Structural variation in multicompartment micelles consisting of lipophilic-hydrophilic-fluorophilic (hereafter referred to as BAC) triblock copolymers is investigated using the dissipative particle dynamics simulation method. It is demonstrated from our results that the structure of BAC multicompartment micelles is effectively tuned as a function of the lipophilic-fluorophilic ratio parameter, here termed [Formula: see text], of the constituent linear triblock copolymers. In particular, a morphological deviation from onion-like ABC micelles arises in BAC micelle systems as [Formula: see text] increases.

Molecular Modeling Approach to Determine the Flory-Huggins Interaction Parameter for Polymer Miscibility Analysis.

In this work, we present a thorough procedure for estimating the Flory-Huggins χ-parameter for use in atomistic and mesoscale molecular simulations in computational materials science. In particular, we propose improvements upon traditional Flory-Huggins theory by implementing a Connolly volume normalization (CVN). We apply this technique to several test systems, including a blend of poly (epichlorohydrin) and poly (methyl acrylate), a blend of polyethylene glycol and poly (methyl methacrylate), a blend of polystyrene and deuterated polystyrene, and three molecular-weight variants (monomer, dimer, and trimer) of a triblock copolymer for use in multicompartment micelle applications.