TY - JOUR
T1 - A theoretical and simulation study of the self-assembly of a binary blend of diblock copolymers
AU - Padmanabhan, Poornima
AU - Martinez-Veracoechea, Francisco J.
AU - Araque, Juan C.
AU - Escobedo, Fernando A.
N1 - KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: This work was supported by Grant CBET 0756248 from the National Science Foundation. This publication is also based on work supported in part by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). F.J.M.V. was supported by the ERC (Advanced Grant Agreement No. 227758). We are thankful to Professor David Morse from University of Minnesota for the code for implementing SCFT.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
PY - 2012/6/19
Y1 - 2012/6/19
N2 - Pure diblock copolymer melts exhibit a narrow range of conditions at which bicontinuous and cocontinuous phases are stable; such conditions and the morphology of such phases can be tuned by the use of additives. In this work, we have studied a bidisperse system of diblock copolymers using theory and simulation. In particular, we elucidated how a short, lamellar-forming diblock copolymer modifies the phase behavior of a longer, cylinder-forming diblock copolymer. In a narrow range of intermediate compositions, self-consistent field theory predicts the formation of a gyroid phase although particle-based simulations show that three phases compete: the gyroid phase, a disordered cocontinuous phase, and the cylinder phase, all having free energies within error bars of each other. Former experimental studies of a similar system have yielded an unidentified, partially irregular bicontinuous phase, and our simulations suggest that at such conditions the formation of a partially transformed network phase is indeed plausible. Close examination of the spatial distribution of chains reveals that packing frustration (manifested by chain stretching and low density spots) occurs in the majority-block domains of the three competing phases simulated. In all cases, a double interface around the minority-block domains is also detected with the outer one formed by the short chains, and the inner one formed by the longer chains. © 2012 American Institute of Physics.
AB - Pure diblock copolymer melts exhibit a narrow range of conditions at which bicontinuous and cocontinuous phases are stable; such conditions and the morphology of such phases can be tuned by the use of additives. In this work, we have studied a bidisperse system of diblock copolymers using theory and simulation. In particular, we elucidated how a short, lamellar-forming diblock copolymer modifies the phase behavior of a longer, cylinder-forming diblock copolymer. In a narrow range of intermediate compositions, self-consistent field theory predicts the formation of a gyroid phase although particle-based simulations show that three phases compete: the gyroid phase, a disordered cocontinuous phase, and the cylinder phase, all having free energies within error bars of each other. Former experimental studies of a similar system have yielded an unidentified, partially irregular bicontinuous phase, and our simulations suggest that at such conditions the formation of a partially transformed network phase is indeed plausible. Close examination of the spatial distribution of chains reveals that packing frustration (manifested by chain stretching and low density spots) occurs in the majority-block domains of the three competing phases simulated. In all cases, a double interface around the minority-block domains is also detected with the outer one formed by the short chains, and the inner one formed by the longer chains. © 2012 American Institute of Physics.
UR - http://hdl.handle.net/10754/597423
UR - http://aip.scitation.org/doi/10.1063/1.4729159
UR - http://www.scopus.com/inward/record.url?scp=84863746627&partnerID=8YFLogxK
U2 - 10.1063/1.4729159
DO - 10.1063/1.4729159
M3 - Article
C2 - 22779617
SN - 0021-9606
VL - 136
SP - 234905
JO - The Journal of Chemical Physics
JF - The Journal of Chemical Physics
IS - 23
ER -