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Title: Confined Cylinders Constructed by a Poly(ethylene oxide)-b-polystyrene Diblock Copolymer and a Blend of Poly(ethylene Oxide)-b-Polystyrene and Polystyrene

Abstract

A poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymer with a number average molecular weight of PEO blocks, M{sub N}{sup PEO}=8.8 kg/mol, and a number average molecular weight of PS blocks, M{sub N}{sup PS}=24.5 kg/mol, (volume fraction of the PEO blocks, f{sub PEO}, was 0.26) exhibited a hexagonal cylinder (HC) phase structure. Small angle X-ray scattering results showed that the PEO cylinder diameter was 13.3 nm, and the hexagonal lattice was a=25.1 nm. The cylinder diameter of this HC phase structure was virtually the same as that in the blend system constructed by a PEO-b-PS diblock copolymer (M{sub N}{sup PEO}=8.7 kg/mol and M{sub N}{sup PS}=9.2 kg/mol) and a PS homo-polymer (M{sub N}{sup PS}=4.6 kg/mol) in which the f{sub PEO} was 0.32. The cylinder diameter in this blend sample was 13.7 nm and the hexagonal lattice was a=23.1 nm. Comparing crystal orientation and crystallization behaviors of this PEO-b-PS copolymer with the blend, it was found that the crystal orientation change with respect to crystallization temperature was almost identical. This is attributed to the fact that in both cases the PEO block tethering densities and confinement sizes are very similar. This indicates that when the M{sub N}{sup PS} of PS homo-polymer is lower than themore » PS blocks, the PS homo-polymer is located inside of the PS matrix rather than at the interface between the PEO and PS in the HC phase structure. On the other hand, a substantial difference of crystallization behaviors was observed between these two samples. The PEO-b-PS copolymer exhibited much more retarded crystallization kinetics than that of the blend. Based on the small angle X-ray scattering results, it was found that in the blend sample, the HC phase structure was not as regularly ordered as that in the PEO-b-PS copolymer, and thus, the HC phase structure contained more defects in the blend. This led to a suggestion that the primary nucleation process in the confined crystallization is a defect-controlled process. The mean crystallite sizes were estimated by the Scherer equation, and the PEO crystal sizes are on the scale of the confined size.« less

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
914329
Report Number(s):
BNL-78897-2007-JA
Journal ID: ISSN 0032-3861; POLMAG; TRN: US200809%%26
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Polymer; Journal Volume: 47; Journal Issue: 15
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CONFINEMENT; COPOLYMERS; CRYSTALLIZATION; HEXAGONAL LATTICES; MOLECULAR WEIGHT; POLYSTYRENE; POLYETHYLENE GLYCOLS; CYLINDRICAL CONFIGURATION; PHASE STUDIES; national synchrotron light source

Citation Formats

Huang,P., Guo, Y., Quirk, R., Ruan, J., Lotz, B., Thomas, E., Hsiao, B., Avila-Orta, C., Sics, I., and Cheng, S.. Confined Cylinders Constructed by a Poly(ethylene oxide)-b-polystyrene Diblock Copolymer and a Blend of Poly(ethylene Oxide)-b-Polystyrene and Polystyrene. United States: N. p., 2006. Web. doi:10.1016/j.polymer.2005.06.129.
Huang,P., Guo, Y., Quirk, R., Ruan, J., Lotz, B., Thomas, E., Hsiao, B., Avila-Orta, C., Sics, I., & Cheng, S.. Confined Cylinders Constructed by a Poly(ethylene oxide)-b-polystyrene Diblock Copolymer and a Blend of Poly(ethylene Oxide)-b-Polystyrene and Polystyrene. United States. doi:10.1016/j.polymer.2005.06.129.
Huang,P., Guo, Y., Quirk, R., Ruan, J., Lotz, B., Thomas, E., Hsiao, B., Avila-Orta, C., Sics, I., and Cheng, S.. Sun . "Confined Cylinders Constructed by a Poly(ethylene oxide)-b-polystyrene Diblock Copolymer and a Blend of Poly(ethylene Oxide)-b-Polystyrene and Polystyrene". United States. doi:10.1016/j.polymer.2005.06.129.
@article{osti_914329,
title = {Confined Cylinders Constructed by a Poly(ethylene oxide)-b-polystyrene Diblock Copolymer and a Blend of Poly(ethylene Oxide)-b-Polystyrene and Polystyrene},
author = {Huang,P. and Guo, Y. and Quirk, R. and Ruan, J. and Lotz, B. and Thomas, E. and Hsiao, B. and Avila-Orta, C. and Sics, I. and Cheng, S.},
abstractNote = {A poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymer with a number average molecular weight of PEO blocks, M{sub N}{sup PEO}=8.8 kg/mol, and a number average molecular weight of PS blocks, M{sub N}{sup PS}=24.5 kg/mol, (volume fraction of the PEO blocks, f{sub PEO}, was 0.26) exhibited a hexagonal cylinder (HC) phase structure. Small angle X-ray scattering results showed that the PEO cylinder diameter was 13.3 nm, and the hexagonal lattice was a=25.1 nm. The cylinder diameter of this HC phase structure was virtually the same as that in the blend system constructed by a PEO-b-PS diblock copolymer (M{sub N}{sup PEO}=8.7 kg/mol and M{sub N}{sup PS}=9.2 kg/mol) and a PS homo-polymer (M{sub N}{sup PS}=4.6 kg/mol) in which the f{sub PEO} was 0.32. The cylinder diameter in this blend sample was 13.7 nm and the hexagonal lattice was a=23.1 nm. Comparing crystal orientation and crystallization behaviors of this PEO-b-PS copolymer with the blend, it was found that the crystal orientation change with respect to crystallization temperature was almost identical. This is attributed to the fact that in both cases the PEO block tethering densities and confinement sizes are very similar. This indicates that when the M{sub N}{sup PS} of PS homo-polymer is lower than the PS blocks, the PS homo-polymer is located inside of the PS matrix rather than at the interface between the PEO and PS in the HC phase structure. On the other hand, a substantial difference of crystallization behaviors was observed between these two samples. The PEO-b-PS copolymer exhibited much more retarded crystallization kinetics than that of the blend. Based on the small angle X-ray scattering results, it was found that in the blend sample, the HC phase structure was not as regularly ordered as that in the PEO-b-PS copolymer, and thus, the HC phase structure contained more defects in the blend. This led to a suggestion that the primary nucleation process in the confined crystallization is a defect-controlled process. The mean crystallite sizes were estimated by the Scherer equation, and the PEO crystal sizes are on the scale of the confined size.},
doi = {10.1016/j.polymer.2005.06.129},
journal = {Polymer},
number = 15,
volume = 47,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}