A systematic coarse-graining strategy for semi-dilute copolymer solutions: from monomers to micelles
- Author(s)
- Barbara Capone, Ivan Coluzza, Jean-Pierre Hansen
- Abstract
A systematic coarse-graining procedure is proposed for the description and simulation of AB diblock copolymers in selective solvents. Each block is represented by a small number, n(A) or n(B), of effective segments or blobs, containing a large number of microscopic monomers. n(A) and n(B) are unequivocally determined by imposing that blobs do not, on average, overlap, even if complete copolymer coils interpenetrate (semi-dilute regime). Ultra-soft effective interactions between blobs are determined by a rigorous inversion procedure in the low concentration limit. The methodology is applied to an athermal copolymer model where A blocks are ideal (theta solvent), B blocks self-avoiding (good solvent), while A and B blocks are mutually avoiding. The model leads to aggregation into polydisperse spherical micelles beyond a critical micellar concentration determined by Monte Carlo simulations for several size ratios f of the two blocks. The simulations also provide accurate estimates of the osmotic pressure and of the free energy of the copolymer solutions over a wide range of concentrations. The mean micellar aggregation numbers are found to be significantly lower than those predicted by an earlier, minimal two-blob representation (Capone et al 2009 J. Phys. Chem. B 113 3629).
- Organisation(s)
- Computational and Soft Matter Physics
- External organisation(s)
- University of Cambridge
- Journal
- Journal of Physics: Condensed Matter
- Volume
- 23
- No. of pages
- 16
- ISSN
- 0953-8984
- DOI
- https://doi.org/10.1088/0953-8984/23/19/194102
- Publication date
- 2011
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103002 Acoustics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/122f5a78-95d4-4f5a-bed3-c2ebd274d3b1