Dilute-solution structure of charged arborescent graft polymer

Yun, Seok Il; Briber, Robert M.; Kee, R. Andrew; Gauthier, Mario

doi:10.1016/j.polymer.2006.02.018

Cited by 12 publications

(12 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, their presence in the system does not significantly influence the behavior of the small particles that appear in both methanolic and aqueous solutions and that we focus on. With regard to the problem of the origin of the aggregates, we note that similar aggregation behavior was reported for both homopolymers and copolymers and that the aggregates are often described as long-living metastable domains in microphase-separated polymer solution. However, we restrain ourselves from elucidating the formation of large aggregates in P4MS- g -PMAA aqueous solutions on the basis of our experimental results.…”

Section: Resultssupporting

confidence: 65%

Self-Assembly of Poly(4-methylstyrene)-g-poly(methacrylic acid) Graft Copolymer in Selective Solvents for Grafts: Scattering and Molecular Dynamics Simulation Study

Štěpánek¹,

Košovan²,

Procházka³

et al. 2010

Langmuir

View full text Add to dashboard Cite

Poly(4-methylstyrene)-g-poly(methacrylic acid) (P4MS-g-PMAA) graft copolymer was synthesized by the grafting-onto method from poly(4-methylstyrene), selectively brominated on methyl groups, and "living" poly(tert-butyl methacrylate). The average degree of polymerization of the backbone and the grafts and the average number of grafts per backbone were 251, 21, and 25, respectively. The self-assembly of P4MS-g-PMAA was studied in methanol and aqueous buffers (selective solvents for grafts). Micelles of P4MS-g-PMAA in methanol were studied by a combination of static and dynamic light scattering, TEM and SAXS. It was found that their spherical core/shell morphology resembles that of diblock copolymer micelles but they have a very low aggregation number (approximately 3) and a high cmc (approximately 0.8 mg/mL). The spherical core-shell structure revealed by SAXS was confirmed by the molecular dynamics study emulating an associate of comblike copolymers with structural parameters close to those of the experimentally studied system. Because P4MS-g-PMAA was not directly soluble in water, its aqueous solutions had to be prepared by dialysis of the methanolic solutions. In aqueous solutions, unlike in methanol, small P4MS-g-PMAA micelles (approximately 20 nm in diameter) form large secondary aggregates (approximately 100-400 nm).

show abstract

Section: Resultssupporting

confidence: 65%

Self-Assembly of Poly(4-methylstyrene)-g-poly(methacrylic acid) Graft Copolymer in Selective Solvents for Grafts: Scattering and Molecular Dynamics Simulation Study

Štěpánek¹,

Košovan²,

Procházka³

et al. 2010

Langmuir

View full text Add to dashboard Cite

show abstract

“…Furthermore, the G1 copolymer grafted with long P2VP side-chains (M w = 30,000) formed a gel upon addition of HCl for volume fractions >0.01. This result is consistent with enhanced molecular expansion promoting gelation for these branched polyelectrolytes, the aggregated network breaking up upon addition of NaCl or excess HCl due to screening of the electrostatic interactions [26].…”

Section: Poly(2-vinylpyridine) Copolymerssupporting

confidence: 80%

“…It was also larger for copolymers containing longer, more flexible side-chains. An investigation on the dilute-solution structure of aggregated, partially ionized arborescent P2VP copolymer molecules at low ionic strengths was completed by Yun et al using SANS measurements [26]. Solutions of charged G1 arborescent polystyrene-graft-poly(2-vinylpyridine) copolymers in methanol-d4 and in D 2 O were characterized in the dilute concentration regime (mass fraction f = 0.005-0.05).…”

Section: Poly(2-vinylpyridine) Copolymersmentioning

confidence: 99%

Phase-Segregated Dendrigraft Copolymer Architectures

Cadena

Gauthier

2010

Polymers

Self Cite

View full text Add to dashboard Cite

Dendrigraft polymers have a multi-level branched architecture resulting from the covalent assembly of macromolecular building blocks. Most of these materials are obtained in divergent (core-first) synthetic procedures whereby the molecule grows outwards in successive grafting reactions or generations. Two main types of dendrigraft polymers can be identified depending on the distribution of reactive sites over the grafting substrate: Arborescent polymers have a large and variable number of more or less uniformly distributed sites, while dendrimer-like star polymers have a lower but well-defined number of grafting sites strictly located at the ends of the substrate chains. An overview of the synthesis and the characterization of dendrigraft copolymers with phase-segregated morphologies is provided in this review for both dendrigraft polymer families. The tethering of side-chains with a different composition onto branched substrates confers unusual physical properties to these copolymers, which are highlighted through selected examples.

show abstract

“…The presence of aggregates in aqueous polymeric solutions is not uncommon and has been reported for both neutral polymers 27,28 and polyelectrolytes. 29 In the case of QNPHOSÀPEO, the tendency to form aggregates is probably supported by poor solvation of the hydrophobic QNPHOS backbone, which can induce microphase separation of polymer chains.…”

Section: ' Introductionmentioning

confidence: 99%

Polyelectrolyte−Surfactant Complexes Formed by Poly[3,5-bis(trimethylammoniummethyl)4-hydroxystyrene iodide]-block-poly(ethylene oxide) and Sodium Dodecyl Sulfate in Aqueous Solutions

et al. 2011

View full text Add to dashboard Cite

Formation of polyelectrolyte-surfactant (PE-S) complexes of poly[3,5-bis(trimethylammoniummethyl)-4-hydroxystyrene iodide]-block-poly(ethylene oxide) (QNPHOS-PEO) and sodium dodecyl sulfate (SDS) in aqueous solution was studied by dynamic and electrophoretic light scattering, small-angle X-ray scattering (SAXS), atomic force microscopy, and fluorometry, using pyrene as a fluorescent probe. SAXS data from the QNPHOS-PEO/SDS solutions were fitted assuming contributions from free copolymer, PE-S aggregates described by a mass fractal model, and densely packed surfactant micelles inside the aggregates. It was found that, unlike other systems of a double hydrophilic block polyelectrolyte and an oppositely charged surfactant, PE-S aggregates of the QNPHOS-PEO/SDS system do not form core-shell particles and the PE-S complex precipitates before reaching the charge equivalence between dodecyl sulfate anions and QNPHOS polycationic blocks, most likely because of conformational rigidity of the QNPHOS blocks, which prevents the system from the corresponding rearrangement.

show abstract

Dilute-solution structure of charged arborescent graft polymer

Cited by 12 publications

References 40 publications

Self-Assembly of Poly(4-methylstyrene)-g-poly(methacrylic acid) Graft Copolymer in Selective Solvents for Grafts: Scattering and Molecular Dynamics Simulation Study

Self-Assembly of Poly(4-methylstyrene)-g-poly(methacrylic acid) Graft Copolymer in Selective Solvents for Grafts: Scattering and Molecular Dynamics Simulation Study

Phase-Segregated Dendrigraft Copolymer Architectures

Polyelectrolyte−Surfactant Complexes Formed by Poly[3,5-bis(trimethylammoniummethyl)4-hydroxystyrene iodide]-block-poly(ethylene oxide) and Sodium Dodecyl Sulfate in Aqueous Solutions

Contact Info

Product

Resources

About