Creating Extremely Asymmetric Lamellar Structures via Fluctuation-Assisted Unbinding of Miktoarm Star Block Copolymer Alloys.
We report the creation of highly asymmetric lamellar structures with a well-designed miktoarm star block copolymer of the S(IS')3 type, where S and S' are polystyrenes of different lengths and I is poly(isoprene). The domain spacing can be tuned continuously from 37 nm to over 300 nm when the miktoarm star block copolymer is blended with suitable molecular weight polystyrene homopolymers. Beyond the unbinding transition of the lamellar phase, extremely asymmetric lamellar structures were obtained with up to 97 wt % polystyrene, remarkably leaving the poly(isoprene) layers intact at only 3 wt %!
Weichao
W
Shi
Andrew L
AL
Hamilton
Kris T
KT
Delaney
Glenn H
GH
Fredrickson
Edward J
EJ
Kramer
#Department of Materials Science and Engineering, University of Ioannina, University Campus, Ioannina, Greece 45110.
Christos
C
Ntaras
#Department of Materials Science and Engineering, University of Ioannina, University Campus, Ioannina, Greece 45110.
Apostolos
A
Avgeropoulos
⊥McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, United States.|¶Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Nathaniel A
NA
Lynd