Formation of lenticular platelet micelles via the interplay of crystallization and chain stretching: Solution self-assembly of poly(ferrocenyldimethylsilane)- Block -poly(2-vinylpyridine) with a crystallizable core-forming metalloblock

Siti Fairus Mohd Yusoff, Ming Siao Hsiao, Felix H. Schacher, Mitchell A. Winnik, Ian Manners

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Abstract

The influence of solvent composition on micelle morphology has been investigated for two crystalline-coil poly(ferrocenyldimethylsilane-block-2- vinylpyridine) (PFS-b-P2VP) diblock copolymers with different block ratios (5:1 and 1:1). The solution self-assembly of these materials was explored in solvent mixtures containing different ratios of a good solvent for both blocks (THF) and a selective solvent for the P2VP block (isopropanol). Various micellar morphologies such as spheres and platelets were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), dynamic light scattering (DLS), wide-angle X-ray scattering (WAXS), and atomic force microscopy (AFM). The results showed that the solution self-assembly of PFS-b-P2VP block copolymers (5:1, 1:1) gave spherical micelles with an amorphous PFS core at low THF content (10 vol %). Subsequently, the amorphous spheres were slowly transformed into platelet micelles with a lenticular shape that consisted of a crystalline PFS core sandwiched by two coronal P2VP layers. This indicated that the amorphous spherical micelles were in a metastable state. The transformation of spheres into platelets was significantly slower for the 5:1 block copolymer with the longer PFS core-forming segment presumably due to a lower rate of crystallization of the metalloblock. Platelets were found to be dominant for both block copolymers at higher THF content (THF ≥ 30 vol %). The formation of lenticular rather than regular platelets was attributed to a poisoning effect whereby interference of the P2VP corona-forming blocks in the growth of the crystalline PFS core leads to the creation of defects in the crystal growth fronts.

Original languageEnglish
Pages (from-to)3883-3891
Number of pages9
JournalMacromolecules
Volume45
Issue number9
DOIs
Publication statusPublished - 8 May 2012

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Micelles
Platelets
Crystallization
Self assembly
Stretching
Block copolymers
Crystalline materials
2-Propanol
Dynamic light scattering
X ray scattering
Crystal growth
Electron diffraction
Atomic force microscopy
poly(2-vinylpyridine)
Transmission electron microscopy
Defects
Chemical analysis

ASJC Scopus subject areas

  • Organic Chemistry
  • Materials Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry

Cite this

@article{8d695c6ce8404dd8b2479bb4b987e455,
title = "Formation of lenticular platelet micelles via the interplay of crystallization and chain stretching: Solution self-assembly of poly(ferrocenyldimethylsilane)- Block -poly(2-vinylpyridine) with a crystallizable core-forming metalloblock",
abstract = "The influence of solvent composition on micelle morphology has been investigated for two crystalline-coil poly(ferrocenyldimethylsilane-block-2- vinylpyridine) (PFS-b-P2VP) diblock copolymers with different block ratios (5:1 and 1:1). The solution self-assembly of these materials was explored in solvent mixtures containing different ratios of a good solvent for both blocks (THF) and a selective solvent for the P2VP block (isopropanol). Various micellar morphologies such as spheres and platelets were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), dynamic light scattering (DLS), wide-angle X-ray scattering (WAXS), and atomic force microscopy (AFM). The results showed that the solution self-assembly of PFS-b-P2VP block copolymers (5:1, 1:1) gave spherical micelles with an amorphous PFS core at low THF content (10 vol {\%}). Subsequently, the amorphous spheres were slowly transformed into platelet micelles with a lenticular shape that consisted of a crystalline PFS core sandwiched by two coronal P2VP layers. This indicated that the amorphous spherical micelles were in a metastable state. The transformation of spheres into platelets was significantly slower for the 5:1 block copolymer with the longer PFS core-forming segment presumably due to a lower rate of crystallization of the metalloblock. Platelets were found to be dominant for both block copolymers at higher THF content (THF ≥ 30 vol {\%}). The formation of lenticular rather than regular platelets was attributed to a poisoning effect whereby interference of the P2VP corona-forming blocks in the growth of the crystalline PFS core leads to the creation of defects in the crystal growth fronts.",
author = "{Mohd Yusoff}, {Siti Fairus} and Hsiao, {Ming Siao} and Schacher, {Felix H.} and Winnik, {Mitchell A.} and Ian Manners",
year = "2012",
month = "5",
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doi = "10.1021/ma2027726",
language = "English",
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pages = "3883--3891",
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publisher = "American Chemical Society",
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T1 - Formation of lenticular platelet micelles via the interplay of crystallization and chain stretching

T2 - Solution self-assembly of poly(ferrocenyldimethylsilane)- Block -poly(2-vinylpyridine) with a crystallizable core-forming metalloblock

AU - Mohd Yusoff, Siti Fairus

AU - Hsiao, Ming Siao

AU - Schacher, Felix H.

AU - Winnik, Mitchell A.

AU - Manners, Ian

PY - 2012/5/8

Y1 - 2012/5/8

N2 - The influence of solvent composition on micelle morphology has been investigated for two crystalline-coil poly(ferrocenyldimethylsilane-block-2- vinylpyridine) (PFS-b-P2VP) diblock copolymers with different block ratios (5:1 and 1:1). The solution self-assembly of these materials was explored in solvent mixtures containing different ratios of a good solvent for both blocks (THF) and a selective solvent for the P2VP block (isopropanol). Various micellar morphologies such as spheres and platelets were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), dynamic light scattering (DLS), wide-angle X-ray scattering (WAXS), and atomic force microscopy (AFM). The results showed that the solution self-assembly of PFS-b-P2VP block copolymers (5:1, 1:1) gave spherical micelles with an amorphous PFS core at low THF content (10 vol %). Subsequently, the amorphous spheres were slowly transformed into platelet micelles with a lenticular shape that consisted of a crystalline PFS core sandwiched by two coronal P2VP layers. This indicated that the amorphous spherical micelles were in a metastable state. The transformation of spheres into platelets was significantly slower for the 5:1 block copolymer with the longer PFS core-forming segment presumably due to a lower rate of crystallization of the metalloblock. Platelets were found to be dominant for both block copolymers at higher THF content (THF ≥ 30 vol %). The formation of lenticular rather than regular platelets was attributed to a poisoning effect whereby interference of the P2VP corona-forming blocks in the growth of the crystalline PFS core leads to the creation of defects in the crystal growth fronts.

AB - The influence of solvent composition on micelle morphology has been investigated for two crystalline-coil poly(ferrocenyldimethylsilane-block-2- vinylpyridine) (PFS-b-P2VP) diblock copolymers with different block ratios (5:1 and 1:1). The solution self-assembly of these materials was explored in solvent mixtures containing different ratios of a good solvent for both blocks (THF) and a selective solvent for the P2VP block (isopropanol). Various micellar morphologies such as spheres and platelets were characterized using transmission electron microscopy (TEM), selected area electron diffraction (SAED), dynamic light scattering (DLS), wide-angle X-ray scattering (WAXS), and atomic force microscopy (AFM). The results showed that the solution self-assembly of PFS-b-P2VP block copolymers (5:1, 1:1) gave spherical micelles with an amorphous PFS core at low THF content (10 vol %). Subsequently, the amorphous spheres were slowly transformed into platelet micelles with a lenticular shape that consisted of a crystalline PFS core sandwiched by two coronal P2VP layers. This indicated that the amorphous spherical micelles were in a metastable state. The transformation of spheres into platelets was significantly slower for the 5:1 block copolymer with the longer PFS core-forming segment presumably due to a lower rate of crystallization of the metalloblock. Platelets were found to be dominant for both block copolymers at higher THF content (THF ≥ 30 vol %). The formation of lenticular rather than regular platelets was attributed to a poisoning effect whereby interference of the P2VP corona-forming blocks in the growth of the crystalline PFS core leads to the creation of defects in the crystal growth fronts.

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