Brownian dynamics simulation of amphiphilic block copolymers with different tail lengths, comparison with theory and comicelles

• Published in: Journal of molecular graphics & modelling Vol. 62; pp. 165 - 173
• Main Authors: Hafezi, Mohammad-Javad, Sharif, Farhad
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2015
• Subjects: Amphiphilic block copolymers; Block copolymers; Brownian dynamics simulation; Comicelle; Computer simulation; Dynamical systems; Dynamics; Hydrophobic and Hydrophilic Interactions; Kinetics; Mathematical models; Micelle; Micelles; Molecular Conformation; Molecular Dynamics Simulation; Polymerization; Polymers - chemistry; Power law; Self assembly; Solutions; Micelle; Comicelle; Self-assembly; Brownian dynamics simulation; Amphiphilic block copolymers
• ISSN: 1093-3263; 1873-4243; 1873-4243
• DOI: 10.1016/j.jmgm.2015.09.005

[Display omitted] •The structural and dynamics properties of pure and mixed block copolymer showed similar dependence on the hydrophobic block length.•The dependence of simulated equilibrium aggregation number is in good agreement with the theory for hydrophobic tail length.•The power law dependency of CMC from simulation results is different from theoretical predictions.•The linear relation of log (CMC) against hydrophobic block length was confirmed.•The aggregate size distribution becomes narrower by the increase of hydrophobic block length. Study on the effect of amphiphilic copolymers structure on their self assembly is an interesting subject, with important applications in the area of drug delivery and biological system treatments. Brownian dynamics simulations were performed to study self-assembly of the linear amphiphilic block copolymers with the same hydrophilic head, but hydrophobic tails of different lengths. Critical micelle concentration (CMC), gyration radius distribution, micelle size distribution, density profiles of micelles, shape anisotropy, and dynamics of micellization were investigated as a function of tail length. Simulation results were compared with predictions from theory and simulation for mixed systems of block copolymers with long and short hydrophobic tail, reported in our previous work. Interestingly, the equilibrium structural and dynamic parameters of pure and mixed block copolymers were similarly dependant on the intrinsic/apparent hydrophobic block length. Log (CMC) was, however; proportional to the tail length and had a different behavior compared to the mixed system. The power law scaling relation of equilibrium structural parameters for amphiphilic block copolymers predicts the same dependence for similar hydrophobic tail lengths, but the power law prediction of CMC is different, which is due to its simplifying assumptions as discussed here.