Taylor & Francis makes every effort to ensure the accuracy of all the information (the "Content") contained in the publications on our platform. Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Versions of published Taylor & Francis and Routledge Open articles and Taylor & Francis and Routledge Open Select articles posted to institutional or subject repositories or any other third-party website are without warranty from Taylor & Francis of any kind, either expressed or implied, including, but not limited to, warranties of merchantability, fitness for a particular purpose, or non-infringement. Any opinions and views expressed in this article are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor & Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions It is essential that you check the license status of any given Open and Open Select article to confirm conditions of access and use.

No abstract

The SAFT-γ Mie group-contribution equation of state [ Papaioannou J. Chem. Phys. 2014 , 140 , 054107 ] is used to develop a transferable coarse-grained (CG) force-field suitable for the molecular simulation of linear alkanes. A heterogroup model is fashioned at the resolution of three carbon atoms per bead in which different Mie (generalized Lennard-Jones) interactions are used to characterize the terminal (CH-CH-CH-) and middle (-CH-CH-CH-) beads. The force field is developed by combining the SAFT-γ CG top-down approach [ Avendaño J. Phys. Chem. B 2011 , 115 , 11154 ], using experimental phase-equilibrium data for n-alkanes ranging from n-nonane to n-pentadecane to parametrize the intermolecular (nonbonded) bead-bead interactions, with a bottom-up approach relying on simulations based on the higher resolution TraPPE united-atom (UA) model [ Martin ; , Siepmann J. Phys. Chem. B 1998 , 102 , 2569 ] to establish the intramolecular (bonded) interactions. The transferability of the SAFT-γ CG model is assessed from a detailed examination of the properties of linear alkanes ranging from n-hexane ( n-CH) to n-octadecane ( n-CH), including an additional evaluation of the reliability of the description for longer chains such as n-hexacontane ( n-CH) and a prototypical linear polyethylene of moderate molecular weight ( n-CH). A variety of structural, thermodynamic, and transport properties are examined, including the pair distribution functions, vapor-liquid equilibria, interfacial tension, viscosity, and diffusivity. Particular focus is placed on the impact of incorporating intramolecular interactions on the accuracy, transferability, and representability of the CG model. The novel SAFT-γ CG force field is shown to provide a reliable description of the thermophysical properties of the n-alkanes, in most cases at a level comparable to the that obtained with higher resolution models.

The air-liquid interfacial behaviour of linear perfluoroalkylalkanes (PFAAs) is reported through a combined experimental and computer simulation study. The surface tensions of seven liquid PFAAs (perfluorobutylethane, F 4 H 2 ; perfluorobutylpentane, F 4 H 5 ; perfluorobutylhexane, F 4 H 6 , perfluorobutyloctane, F 4 H 8 ; perfluorohexylethane, F 6 H 2 ; perfluorohexylhexane, F 6 H 6 ; and perfluorohexyloctane, F 6 H 8 ) are experimentally determined over a wide temperature range (276-350 K). The corresponding surface thermodynamic properties and the critical temperatures of the studied compounds are estimated from the temperature dependence of the surface tension. Experimental density and vapour pressure data are employed to parameterize a generic heteronuclear coarse-grained intermolecular potential of the SAFT-γ family for PFAAs. The resulting force field is used in direct molecular-dynamics simulations to predict the experimental tensions with quantitative agreement and to explore the conformations of the molecules in the interfacial region revealing a preferential alignment of the PFAA molecules towards the interface and an enrichment of the perfluoro groups at the outer interface region.

An interactive tool with a browser-type interface has been developed for solvent selection using the software R. Two main classes of considerations can be taken into account: technical suitability for the intended duties, and practical considerations including costs and health, safety environment (HSE) impact. The tool builds on quantitative analyses of properties selected by the user for the application at hand. The underlying philosophy is to assist the thought processes of the tool's users, rather than to prescribe set answers. The tool is a stepping stone toward design-of-experiment in chemical process development, enabling parameter space exploration without specialized software licenses, and grouping properties to assist the users. Six examples of use are given to illustrate various methodologies. In building the tool, scientific software development was found to be more intrinsically iterative than originally expected, with mock-ups and sharing of user stories more agile than lengthy user requirement specifications. Technical improvements for the future were identified, such as the automation of regressions and Hansen parameter calculations, a more extensive chemical knowledge formalism, and the addition of electron descriptions.