Equilibrium Structure of a Triblock Copolymer System Revealed by Mesoscale Simulation and Neutron Scattering

Journal Article · Mon Dec 31 23:00:00 EST 2012 · Physica B: Condensed Matter

DOI:https://doi.org/10.1016/j.physb.2013.08.019· OSTI ID:1110916

Do, Changwoo ^[1]; Chen, Wei-Ren ^[1]; Hong, Kunlun ^[1]; Smith, Gregory Scott ^[1]

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1. ORNL

We have performed both mesoscale simulations and neutron scattering experiments on Pluronic L62, a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer system in aqueous solution. The influence of simulation variables such PEO/PPO block ratio, interaction parameters, and coarse-graining methods is extensively investigated by covering all permutations of parameters found in the literatures. Upon increasing the polymer weight fraction from 50 wt% to 90 wt%, the equilibrium structure of the isotropic, reverse micellar, bicontinuous, worm-like micelle network, and lamellar phases are respectively predicted from the simulation depending on the choices of simulation parameters. Small angle neutron scattering (SANS) measurements show that the same polymer systems exhibit the spherical micellar, lamellar, and reverse micellar phases with the increase of the copolymer concentration at room temperature. Detailed structural analysis and comparison with simulations suggest that one of the simulation parameter sets can provide reasonable agreement with the experimentally observed structures.

• Research Organization: Oak Ridge National Laboratory (ORNL); Spallation Neutron Source
• Sponsoring Organization: ORNL LDRD Seed-Money; SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1110916
• Journal Information: Physica B: Condensed Matter, Journal Name: Physica B: Condensed Matter Vol. 430; ISSN 0921-4526
• Country of Publication: United States
• Language: English