Polymer/matrix nanocomposites (PNCs) are materials with exceptional properties. They offer a plethora of promising applications in key industrial sectors. In most cases, it is preferable to disperse the nanoparticles (NPs)...

We investigate single and opposing silica plates, either bare of grafted, in contact with vacuum or melt phases, using self-consistent field theory. Solid–polymer and solid–solid nonbonded interactions are described by means of a Hamaker potential, in conjunction with a ramp potential. The cohesive nonbonded interactions are described by the Sanchez-Lacombe or the Helfand free energy densities. We first build our thermodynamic reference by examining single surfaces, either bare or grafted, under various wetting conditions in terms of the corresponding contact angles, the macroscopic wetting functions (i.e., the work of cohesion, adhesion, spreading and immersion), the interfacial free energies and brush thickness. Subsequently, we derive the potential of mean force (PMF) of two approaching bare plates with melt between them, each time varying the wetting conditions. We then determine the PMF between two grafted silica plates separated by a molten polystyrene film. Allowing the grafting density and the molecular weight of grafted chains to vary between the two plates, we test how asymmetries existing in a real system could affect steric stabilization induced by the grafted chains. Additionally, we derive the PMF between two grafted surfaces in vacuum and determine how the equilibrium distance between the two grafted plates is influenced by their grafting density and the molecular weight of grafted chains. Finally, we provide design rules for the steric stabilization of opposing grafted surfaces (or fine nanoparticles) by taking account of the grafting density, the chain length of the grafted and matrix chains, and the asymmetry among the opposing surfaces.

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Phenol hydrodeoxygenation over a commercial NiMo/γ-Al2O3 catalyst in a reduced and sulfided form was investigated. Crushed particles (0.165–0.315 mm) were employed to determine the intrinsic reaction kinetics in either case. The internal diffusion phenomena within the catalytic particle of commercial dimensions and forms were also studied, and the phenol effective diffusion coefficient and effectiveness factor for both forms of the catalyst were determined. The sulfided form was active to phenol conversion at higher temperatures in comparison to the reduced form. As indicated from the data acquired by phenol, cyclohexanol, and benzene hydrotreatment experiments, phenol hydrodeoxygenation over the reduced and sulfided NiMo/γ-Al2O3 catalyst follows both parallel pathways: the direct deoxygenation (DDO) and the stepwise hydrogenation (HYD). The stepwise hydrogenation (HYD) pathway is favored under the tested conditions. In the presence of the reduced catalyst, cyclohexanol and cyclohexane are the main products and the selectivity toward cyclohexanol is high at low temperatures. In the presence of the sulfided catalyst, cyclohexane was the main hydrotreatment product together with a small amount of benzene.

In this article, we publish the one-dimensional version of our in-house code, RuSseL, which has been developed to address polymeric interfaces through Self-Consistent Field calculations. RuSseL can be used for a wide variety of systems in planar and spherical geometries, such as free films, cavities, adsorbed polymer films, polymer-grafted surfaces, and nanoparticles in melt and vacuum phases. The code includes a wide variety of functional potentials for the description of solid–polymer interactions, allowing the user to tune the density profiles and the degree of wetting by the polymer melt. Based on the solution of the Edwards diffusion equation, the equilibrium structural properties and thermodynamics of polymer melts in contact with solid or gas surfaces can be described. We have extended the formulation of Schmid to investigate systems comprising polymer chains, which are chemically grafted on the solid surfaces. We present important details concerning the iterative scheme required to equilibrate the self-consistent field and provide a thorough description of the code. This article will serve as a technical reference for our works addressing one-dimensional polymer interphases with Self-Consistent Field theory. It has been prepared as a guide to anyone who wishes to reproduce our calculations. To this end, we discuss the current possibilities of the code, its performance, and some thoughts for future extensions.