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Title: Perforated Layer Structures in Liquid Crystalline Rod-coil Block Copolymers

Abstract

We report a novel observation of the tetragonal perforated layer structures in a series of rod-coil liquid crystalline block copolymers (BCPs), poly(styrene-block-(2, 5-bis[4-methoxyphenyl]oxycarbonyl)styrene) (PS-b-PMPCS). PMPCS forms rigid rods while PS forms the coil block. Differential scanning calorimetry (DSC), polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and transmission electron microscopy (TEM) techniques were used to investigate these rod-coil molecules, and a perforated layer structure was observed at {sup fPMPCS} {approx} 0.37 in relatively low molecular weight (M{sub w}) samples and {approx}0.5 in high M{sub w} PS-b-PMPCS. This substantial phase boundary shift was attributed to the rod-coil nature of the BCP. The perforation obeys a tetragonal instead of hexagonal symmetry. The 'onset' of perforation was also observed in real space in sample PS{sub 272}-b-PMPCS{sub 93} ({sup fPMPCS} {approx} 0.52), in which few PS chains punctuate PMPCS layers. A slight increase in f{sub PS}, by blending with PS homopolymer, led to a dramatic change in the BCP morphology, and uniform tetragonal perforations were observed at {sup fPMPCS} {approx} 0.48.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
913904
Report Number(s):
BNL-78472-2007-JA
Journal ID: ISSN 0002-7863; JACSAT; TRN: US200804%%116
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
J. Am. Chem. Soc.
Additional Journal Information:
Journal Volume: 127; Journal Issue: 44; Journal ID: ISSN 0002-7863
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COPOLYMERS; MORPHOLOGY; SHAPE; LIQUID CRYSTALS; POLYSTYRENE; MOLECULAR WEIGHT; national synchrotron light source

Citation Formats

Tenneti, K, Chen, X, Li, C, Tu, Y, Wan, X, Zhou, Q, Sics, I, and Hsiao, B. Perforated Layer Structures in Liquid Crystalline Rod-coil Block Copolymers. United States: N. p., 2005. Web. doi:10.1021/ja053548k.
Tenneti, K, Chen, X, Li, C, Tu, Y, Wan, X, Zhou, Q, Sics, I, & Hsiao, B. Perforated Layer Structures in Liquid Crystalline Rod-coil Block Copolymers. United States. https://doi.org/10.1021/ja053548k
Tenneti, K, Chen, X, Li, C, Tu, Y, Wan, X, Zhou, Q, Sics, I, and Hsiao, B. 2005. "Perforated Layer Structures in Liquid Crystalline Rod-coil Block Copolymers". United States. https://doi.org/10.1021/ja053548k.
@article{osti_913904,
title = {Perforated Layer Structures in Liquid Crystalline Rod-coil Block Copolymers},
author = {Tenneti, K and Chen, X and Li, C and Tu, Y and Wan, X and Zhou, Q and Sics, I and Hsiao, B},
abstractNote = {We report a novel observation of the tetragonal perforated layer structures in a series of rod-coil liquid crystalline block copolymers (BCPs), poly(styrene-block-(2, 5-bis[4-methoxyphenyl]oxycarbonyl)styrene) (PS-b-PMPCS). PMPCS forms rigid rods while PS forms the coil block. Differential scanning calorimetry (DSC), polarized light microscopy (PLM), small-angle X-ray scattering (SAXS), wide-angle X-ray diffraction (WAXD), and transmission electron microscopy (TEM) techniques were used to investigate these rod-coil molecules, and a perforated layer structure was observed at {sup fPMPCS} {approx} 0.37 in relatively low molecular weight (M{sub w}) samples and {approx}0.5 in high M{sub w} PS-b-PMPCS. This substantial phase boundary shift was attributed to the rod-coil nature of the BCP. The perforation obeys a tetragonal instead of hexagonal symmetry. The 'onset' of perforation was also observed in real space in sample PS{sub 272}-b-PMPCS{sub 93} ({sup fPMPCS} {approx} 0.52), in which few PS chains punctuate PMPCS layers. A slight increase in f{sub PS}, by blending with PS homopolymer, led to a dramatic change in the BCP morphology, and uniform tetragonal perforations were observed at {sup fPMPCS} {approx} 0.48.},
doi = {10.1021/ja053548k},
url = {https://www.osti.gov/biblio/913904}, journal = {J. Am. Chem. Soc.},
issn = {0002-7863},
number = 44,
volume = 127,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2005},
month = {Sat Jan 01 00:00:00 EST 2005}
}