Coupled Monte Carlo and Molecular Dynamics Simulations on Interfacial Properties of Antifouling Polymer Membranes

Abstract

We use molecular simulation to study the wetting behavior of antifouling polymer-tethered membranes. We obtain the interfacial properties (e.g., contact angle) of water at various temperatures for five polymer membranes, including a base polysulfone (PSF) membrane and four other PSF membranes grafted with antifouling polymers (two poly­(ethylene glycol) (PEG) tethers and two zwitterionic tethers). We implement a coupled Monte Carlo (MC)/molecular dynamics (MD) approach to determine the interface potentials of water on the membrane surfaces in an efficient manner. Within this method, short MC and MD simulations are performed in cycles to collect the surface excess free energy of a thin water film on polymer membrane surfaces. Simulation results show that the grafting of zwitterionic tethers provides a more significant enhancement in the hydrophilicity of the PSF membrane than that of the PEG tethers. Water completely wets the surface of zwitterionic polymer membranes.

Surface Tension of Organophosphorus Compounds: Sarin and its Surrogates

“…The results of our simulations are in agreement with our experimental data for both DIMP and DMMP, suggesting that the TraPPE force field is applicable for predicting not only liquid density and vapor pressure, , but also surface tension. Our modeled and measured surface tensions differ significantly from the only MD simulation-based prediction available in the literature, as shown in Figure . The results in ref .…”

“…When experimental measurements are not readily available, theoretical methods, such as molecular dynamics (MD) simulations, provide a viable alternative for predicting thermodynamic properties. To our knowledge, there has been only one MD simulation to predict the surface tension for DMMP and DIMP . While the results for DIMP agreed with the experimental data point from ref , the prediction for DMMP did not.…”

“…Our modeled and measured values of the surface tension of DMMP and DIMP, along with the literature data ,, are shown in Figure . Experimental uncertainties account for systematic errors in droplet neck diameter and volume along with random error associated with averaging repeated measurements.…”

“…Filled circles show our experimental data (solid line represents weighted linear fit), and unfilled circles show our simulation data (dashed line represents weighted linear fit). Filled triangles represent experimental data from the literature (for DMMP and DIMP), and unfilled triangles–molecular simulation data for DMMP and DIMP from the literature …”

Molecular dynamics study of the interactions between a hydrophilic polymer brush on graphene and amino acid side chain analogues in water

“…[1][2][3] Tethered polymer chains can change the surface property drastically. [4][5][6][7][8][9] Organic molecules, including proteins, often bind strongly to hydrophobic surfaces. [10][11][12] Brushes of hydrophilic polymers exhibit fouling resistance when the coverage is high enough on the hydrophobic surface.…”