Abstract
With suitably designed Monte Carlo simulations, we have investigated the properties of mobile, impenetrable, yet deformable particles that are immersed into a porous matrix, the latter one realized by a frozen configuration of spherical particles. By virtue of a model put forward by Batista and Miller [Phys. Rev. Lett. 105, 088305 (2010)], the fluid particles can change in their surroundings, formed by other fluid particles or the matrix particles, their shape within the class of ellipsoids of revolution; such a change in shape is related to a change in energy, which is fed into suitably defined selection rules in the deformation "moves" of the Monte Carlo simulations. This concept represents a simple yet powerful model of realistic, deformable molecules with complex internal structures (such as dendrimers or polymers). For the evaluation of the properties of the system, we have used the well-known quenched-annealed protocol (with its characteristic double average prescription) and have analyzed the simulation data in terms of static properties (the radial distribution function and aspect ratio distribution of the ellipsoids) and dynamic features (notably the mean squared displacement). Our data provide evidence that the degree of deformability of the fluid particles has a distinct impact on the aforementioned properties of the system.
Highlights
Experimental, theoretical, and computer simulation based investigations on fluids confined in disordered, porous confinement have received, over several decades, a steadily increasing share of interest.1–4 This is certainly due to the fact that such a scenario is ubiquitous in our daily lives, with examples ranging from biophysics over chemical engineering to technological applications
In order to quantify our findings, we have focused on the radial distribution function and the distribution of the aspect ratio of the fluid particles and on their mean squared displacement (MSD)
In the few past years, it has become common practice to introduce in the latter case Monte Carlo (MC) sweeps as “time units”: apart from oscillations occurring in the MSD in the short time range, which arise from single particle vibrational modes, the time scale of molecular dynamics (MD) simulations and the time scale of MC simulations can be mapped onto each other via a suitable scaling operation
Summary
Experimental, theoretical, and computer simulation based investigations on fluids confined in disordered, porous confinement have received, over several decades, a steadily increasing share of interest. This is certainly due to the fact that such a scenario is ubiquitous in our daily lives, with examples ranging from biophysics over chemical engineering to technological applications. We address this issue for the first time and introduce a certain degree of flexibility in the shape of the mobile particles into the QA framework To this end, we have taken the benefit of the availability of a simple yet realistic and powerful model of particles of variable shape: our investigations are based on deformable, impenetrable particles (proposed by Batista and Miller23,24), which are allowed to change—at the cost of some energy penalty—their shape in computer simulations: to be more specific, an initially spherical particle can be deformed into an ellipsoid of revolution, characterized by its aspect ratio x. This paper is closed with concluding remarks and an outlook to future work
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
