Controllable laning phase for oppositely driven disk systems

A two-dimensional binary driven disk system embedded by impermeable tilted plates is investigated through nonequilibrium computer simulations. It is well known that a binary disk system in which two particle species are driven in opposite directions exhibits jammed, phase separated, disordered, and laning states. The presence of tilted plates can not only advance the formation of laning phase, but also effectively stabilize laning phase by suppressing massively drifting behavior perpendicular to the driving force. The lane width distribution can be controlled easily by the interplate distance. The collective behavior of driven particles in laning phase is guided by the funnel-shaped confinements constituted by the neighboring tilted plates. Our results provide the important clues for investigating the mechanism of laning formation in driven system.

Multinanoparticle Translocations in Phospholipid Membranes:Translocation Modes and Dynamic Processes

Multinanoparticles interacting with the phospholipid membranes in solution were studied by dissipative particle dynamics simulation.The selected nanoparticles have spherical or cylindrical shapes,and they have various initial velocities in the dynamical processes.Several translocation modes are defined according to their characteristics in the dynamical processes,in which the phase diagrams are constructed based on the interaction strengths between the particles and membranes and the initial velocities of particles.Furthermore,several parameters,such as the system energy and radius of gyration,are investigated in the dynamical processes for the various translocation modes.Results elucidate the effects of multiparticles interacting with the membranes in the biological processes.

Effects of chain stiffness and shear flow on nanoparticle dispersion and distribution in ring polymer melts

The dispersion behavior and spatial distribution of nanoparticles(NPs)in ring polymer melts are explored by using molecular dynamics(MD)simulations.As polymer-NP interactions increase,three general categories of polymer-mediated NP organization are observed,namely,contact aggregation,bridging,and steric dispersion,consistent with the results of equivalent linear ones in previous studies.In the case of direct contact aggregation among NPs,the explicit aggregation-dispersion transition of NPs in ring polymer melts can be induced by increasing the chain stiffness or applying a steady shear flow.Results further indicate that NPs can achieve an optimal dispersed state with the appropriate chain stiffness and shear flow.Moreover,shear flow cannot only improve the dispersion of NPs in ring polymer melts but also control the spatial distribution of NPs into a well-ordered structure.This improvement becomes more evident under stronger polymer-NP interactions.The observed induced-dispersion or ordered distribution of NPs may provide efficient access to the design and manufacture of high-performance polymer nanocomposites(PNCs).

Liquid-crystal Assembly of Semiflexible-coil/Homopolymer Blends: a Dissipative Particle Dynamics Study

The liquid-crystal assembly of semiflexible-coil diblock copolymers with coil or semiflexible homopolymers is studied by dissipative particle dynamics simulation. Phase diagrams of the blends and orientation ordering parameters among semiflexible blocks are constructed as a function of chain stiffness and homopolymer volume fraction. For semiflexible-coil/coil blends with varying stiffness of semiflexible blocks, we display the rich phase behaviors of the system transited from coil-coil/coil to rod-coil/coil blends. The disorder- lamellae or lamellae-liquid crystalline transition and ＂dry brush＂ phenomenon induced by coil homopolymers are observed. For semiflexible-coil/semiflexible blends, adding semiflexible homopolymers also leads to a disorder-order transition and even a transition between monolayer and bilayer smectic-A phase. The results demonstrate that blending homopolymers into semiflexible copolymers can induce liquid-crystal assembly and even improve the orientation ordering of semiflexible blocks effectively.