W. J. Briels

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Atomistic molecular dynamics simulations of a lipid bilayer were performed to calculate the free energy of a trans-membrane pore as a function of its radius. The free energy was calculated as a function of a reaction coordinate using a potential of mean constraint force. The pore radius was then calculated from the reaction coordinate using Monte Carlo(More)
We present a computer simulation model of polymer melts representing each chain as one single particle. Besides the position coordinate of each particle, we introduce a parameter n(ij) for each pair of particles i and j within a specified distance from each other. These numbers, called entanglement numbers, describe the deviation of the system of ignored(More)
The formation of a pore in a membrane requires a considerable rearrangement of the amphiphilic molecules about to form the bilayer edge surrounding the pore, and hence is accompanied by a steep increase of the free energy. Recent rupture and conductance experiments suggest that this reshuffling process is also responsible for a small energy barrier that(More)
The isotropic-nematic spinodals of solutions of rigid spherocylindrical colloids with various shape anisotropies L/D in a wide range from 10 to 60 are investigated by means of Brownian dynamics simulations. To make these simulations feasible, we developed a new event-driven algorithm that takes the excluded volume interactions between particles into account(More)
On the basis of Onsager’s hypothesis a new method is presented to calculate growth rate constants of various crystal faces from the fluctuations of interfaces during NVT simulations. The method is applied to the (100) face of a Lennard-Jones crystal grown from the melt. The results are in perfect agreement with those obtained by means of NPT nonequilibrium(More)
The excess free energy of small molecules in the amorphous polymers poly~ethylene! and poly~dimethylsiloxane! was calculated, using the test-particle-insertion method. The method was applied to polymer configurations obtained from molecular dynamics simulations with differently prepared initial guess configurations. It was found that the calculated(More)
The two initial stages of spinodal decomposition of a symmetric binary Lennard-Jones fluid have been simulated by molecular dynamics simulations, using a hydrodynamics-conserving thermostat. By analyzing the growth of the average domain size R(t) with time, a satisfactory agreement is found with the R(t) proportional t1/3 Lifshitz-Slyozov growth law for the(More)
Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a number of complications, ranging from singularities when using(More)
The double-layer contribution to the single-particle thermal diffusion coefficient of charged, spherical colloids with arbitrary double-layer thickness is calculated and compared to experiments. The calculation is based on an extension of the Debye-Hückel theory for the double-layer structure that includes a small temperature gradient. There are three(More)
The flow properties of an amphiphilic bilayer are studied in molecular dynamics simulations, by exposing a coarse grained model bilayer to two shear flows directed along the bilayer surface. The first field, with a vorticity perpendicular to the bilayer, induces a regular shear deformation, allowing a direct calculation of the surface viscosity. In(More)