Evaluation of Coarse Grained Potential
The Coarse Grained Molecular Dynamics of polybutadiene were conducted. The Coarse Grained Potential was estimated by using modeling function of J-OCTA. The method follows that in Reference (1). First, molecular dynamics was conducted for a single chain in vacuum (total time=10 [ns]) for cis-polybutadiene (N=50) based on Full Atomistic model. |
Fig1. Distribution of length, angle and torsion angle. (unit = one monomer)
(Red = Coarse grained model, Blue = Full Atomistic model) |
NPT ensemble calculations were conducted at 300 [K], 0.1 [MPa] for each bulk state with different degrees of polymerization N. The total number of particles was the same at 5000 and long term simulation (400[ns]) was applied for the N=200 system. |
Fig2. R^2/Rg^2 and Density at bulk state. |
Finally, a bulk structure of Full Atomistic MD was created by using J-OCTA's reverse mapping function (Fig. 3). From the results of Coarse Grained MD, the monomers of the Full Atomistic model corresponding to each Coarse Grained unit were arranged and connected so that the direction of the each bond vector is matched. This process allows the creation of a more relaxed structure of Full Atomistic model. |
Fig3. Reverse mapping (left = coarse grained model , right = full atomistic model) |
Reference
(1) J. Chem. Phys., 116, 8183, (2002) (2) Macromolecules, 42, 791, (2009) |