Morphology of multi-component polymer systems: single chain in mean field simulation studies

Abstract

Recent work exploring phase separation and self-assembly in multicomponent polymer fluids using a particle-based self-consistent field simulation method is reviewed. The computational method is placed in the context of classical molecular dynamics and Monte Carlo simulations as well as field-theoretic approaches. Its potential is illustrated by applications ranging from spinodal decomposition in symmetric polymer blends and the ordering of diblock copolymers in the bulk to more complex phenomena such as solvent evaporation from thin polymer films and the fabrication of three-dimensional bicontinuous diblock copolymer morphologies via reconstruction on patterned substrates.

Micellar drug nanocarriers and biomembranes: how do they interact?

“…41 All simulations have been performed with velocity Verlet 35 algorithm using a time steep of 0.03 ps in the NVT ensemble by keeping the temperature constant at 325 K using Andersen thermostat with a collision frequency of 7 ps -1 . The calculation of the fields have been performed using a grid resolution of 0.705 nm and an update frequency (∆t update ) of 300 steps.…”

“…For this main reason, nanosized drugs tend to accumulate in tumor tissue much more than they do in normal tissues. Due to EPR effect, for these drug 35 vectors, it is clear that the size of the drug carrier plays an important role. In fact, constructs in the size range of 5-30 nm are considered optimal, and thus the control of the size of systems for drug delivery is a key point.…”

“…32 Very recently, Sevink et al 33 introduced a hybrid scheme, combining 20 Brownian dynamics (BD) and dynamic density functional theory (DDFT), that is able to model efficiently complete vesicles with molecular detail. Particle and field representation of coarse-grained models has been considered in the single chain in mean field (SCMF) method 25 and has been applied to homopolymer and block copolymer systems as reported by Muller et al [34][35] More recently, the Molecular Dynamic (MD) method has been combined with selfconsistent field (SCF) description, which hereafter we call "MD-SCF" approach. In particular, an implementation suitable for the 30 treatment of atomistic force fields and/or specific CG models has been reported and validated.…”

“…In particular, an implementation suitable for the 30 treatment of atomistic force fields and/or specific CG models has been reported and validated. [36][37] The main feature of the MD-SCF approach, is that the evaluation of non-bonded forces and the potential between atoms of different molecules is replaced by the evaluation of a potential 35 dependent on the local density at position r. According to SCF theory, a many body problem like molecular motion in a manymolecule system is reduced to the derivation of a partition function of a single molecule in an external potential V(r). Then, forces between non-bonded particles can be obtained from a 40 suitable expression of the V(r) and its derivatives.…”

“…The main advantage of hybrid MD-SCF scheme is that the most 35 computationally expensive part of the MD simulations, the calculation of the non-bonded forces, is replaced by the evaluation of forces between single particles with external potentials. In order to connect particle and field models, for the proposed hybrid MD-SCF scheme, it is necessary to obtain a 40 smooth coarse-grained density function directly from the particle position Γ.…”