Oligomer/Polymer Blend Phase Diagram and Surface Concentration Profiles for Squalane/Polybutadiene: Experimental Measurements and Predictions from SAFT-γ Mie and Molecular Dynamics Simulations.

The compatibility and surface behavior of squalane-polybutadiene mixtures are studied by experimental cloud point and neutron reflectivity measurements, statistical associating fluid theory (SAFT), and molecular dynamics (MD) simulations. A SAFT-γ Mie model is shown to be successful in capturing the cloud point curves of squalane-polybutadiene and squalane--polybutadiene binary mixtures, and the same SAFT-γ Mie model is used to develop a thermodynamically consistent top-down coarse-grained force field to describe squalane-polybutadiene. Coarse-grained molecular dynamics simulations are performed to study surface behavior for different concentrations of squalane, with the system exhibiting surface enrichment and a wetting transition.

Assessing the transferability of common top-down and bottom-up coarse-grained molecular models for molecular mixtures.

The performance of three methods for developing new coarse-grained models for molecular simulation is critically assessed. Two bottom-up approaches are employed: iterative Boltzmann inversion (IBI) and the multiscale coarse-graining method (MS-CG), using an atomistic n-octane-benzene reference system. Results are compared to a top-down coarse-graining approach employing the SAFT-γ Mie equation of state.

Correction: Predicting oligomer/polymer compatibility and the impact on nanoscale segregation in thin films.

Correction for 'Predicting oligomer/polymer compatibility and the impact on nanoscale segregation in thin films' by Elise F. D. Sabattié et al.

Predicting oligomer/polymer compatibility and the impact on nanoscale segregation in thin films.

Compatibility between oligomers and polymers was systematically assessed using differential scanning calorimetry (DSC) and was correlated with similarity in saturation and solubility parameter. These measurements enabled validation of detailed volume of mixing calculations using Statistical Association Fluid Theory (SAFT-γ Mie) and molecular dynamics (MD) simulations, which can be used to predict behaviour beyond the experimentally accessible conditions. These simulations confirmed that squalane is somewhat more compatible with poly(isoprene), "PI" than poly(butadiene), "PB", and further enabled prediction of the temperature dependence of compatibility.

A Green's-Function Approach to Exchange Spin Coupling As a New Tool for Quantum Chemistry.

Exchange spin coupling is usually evaluated in quantum chemistry from the energy difference between a high-spin determinant and a Broken-Symmetry (BS) determinant in combination with Kohn-Sham density functional theory (KS-DFT), based on the work of Noodleman. As an alternative, an efficient approximate approach relying on Green's functions has been developed by one of the authors. This approach stems from solid-state physics and has never been systematically tested for molecular systems.