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Formation and structure of ionomer complexes from grafted polyelectrolytes.

Brzozowska AM, Keesman KJ, de Keizer A, Leermakers FA - Colloid Polym Sci (2011)

Bottom Line: This effect is stronger for GBICs than for GICs, is reversible for GICs and GBIC-PAPEO(14)/P2MVPI(228), and shows some hysteresis for GBIC-PAPEO(14)/P2MVPI(43).The very large difference between the sizes found experimentally for GBICs and the sizes predicted from SCF calculations supports the view that there is some secondary association mechanism.A possible mechanism is discussed.

View Article: PubMed Central - PubMed

ABSTRACT
We discuss the structure and formation of Ionomer Complexes formed upon mixing a grafted block copolymer (poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)), PAA(21)-b-PAPEO(14)) with a linear polyelectrolyte (poly(N-methyl 2-vinyl pyridinium iodide), P2MVPI), called grafted block ionomer complexes (GBICs), and a chemically identical grafted copolymer (poly(acrylic acid)-co-poly(acrylate methoxy poly(ethylene oxide)), PAA(28)-co-PAPEO(22)) with a linear polyelectrolyte, called grafted ionomer complexes (GICs). Light scattering measurements show that GBICs are much bigger (~70-100 nm) and GICs are much smaller or comparable in size (6-22 nm) to regular complex coacervate core micelles (C3Ms). The mechanism of GICs formation is different from the formation of regular C3Ms and GBICs, and their size depends on the length of the homopolyelectrolyte. The sizes of GBICs and GICs slightly decrease with temperature increasing from 20 to 65 °C. This effect is stronger for GBICs than for GICs, is reversible for GICs and GBIC-PAPEO(14)/P2MVPI(228), and shows some hysteresis for GBIC-PAPEO(14)/P2MVPI(43). Self-consistent field (SCF) calculations for assembly of a grafted block copolymer (having clearly separated charged and grafted blocks) with an oppositely charged linear polyelectrolyte of length comparable to the charged copolymer block predict formation of relatively small spherical micelles (~6 nm), with a composition close to complete charge neutralization. The formation of micellar assemblies is suppressed if charged and grafted monomers are evenly distributed along the backbone, i.e., in case of a grafted copolymer. The very large difference between the sizes found experimentally for GBICs and the sizes predicted from SCF calculations supports the view that there is some secondary association mechanism. A possible mechanism is discussed.

No MeSH data available.


Related in: MedlinePlus

DLS results: ΓDLS (left) and Rh (right) as functions of q2 measured for solutions of GIC-PAPEO22/P2MVPI43 (filled circles) and GIC-PAPEO22/PAH160 (empty circles) in 1 mM NaCl, pH 7. Total polymer concentration, 2 (g/l). A slight increase of Rh measured for GIC-PAPEO22/P2MVPI43 is most probably a consequence of presence of larger aggregates in the solution. Solid lines in the left panel correspond to linear fits of the experimental data
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Fig10: DLS results: ΓDLS (left) and Rh (right) as functions of q2 measured for solutions of GIC-PAPEO22/P2MVPI43 (filled circles) and GIC-PAPEO22/PAH160 (empty circles) in 1 mM NaCl, pH 7. Total polymer concentration, 2 (g/l). A slight increase of Rh measured for GIC-PAPEO22/P2MVPI43 is most probably a consequence of presence of larger aggregates in the solution. Solid lines in the left panel correspond to linear fits of the experimental data

Mentions: Multi-angle light scattering measurements for GIC-PAPEO22/P2MVPI43 and GIC-PAPEO14/PAH160 show that for both systems the decay coefficient Γ changes linearly with q2 (Fig. 10). Consequently, the corresponding hydrodynamic radius depends only slightly on the angle of detection, indicating that GICs are most likely spherical structures with a narrow size distribution.Fig. 10


Formation and structure of ionomer complexes from grafted polyelectrolytes.

Brzozowska AM, Keesman KJ, de Keizer A, Leermakers FA - Colloid Polym Sci (2011)

DLS results: ΓDLS (left) and Rh (right) as functions of q2 measured for solutions of GIC-PAPEO22/P2MVPI43 (filled circles) and GIC-PAPEO22/PAH160 (empty circles) in 1 mM NaCl, pH 7. Total polymer concentration, 2 (g/l). A slight increase of Rh measured for GIC-PAPEO22/P2MVPI43 is most probably a consequence of presence of larger aggregates in the solution. Solid lines in the left panel correspond to linear fits of the experimental data
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3102187&req=5

Fig10: DLS results: ΓDLS (left) and Rh (right) as functions of q2 measured for solutions of GIC-PAPEO22/P2MVPI43 (filled circles) and GIC-PAPEO22/PAH160 (empty circles) in 1 mM NaCl, pH 7. Total polymer concentration, 2 (g/l). A slight increase of Rh measured for GIC-PAPEO22/P2MVPI43 is most probably a consequence of presence of larger aggregates in the solution. Solid lines in the left panel correspond to linear fits of the experimental data
Mentions: Multi-angle light scattering measurements for GIC-PAPEO22/P2MVPI43 and GIC-PAPEO14/PAH160 show that for both systems the decay coefficient Γ changes linearly with q2 (Fig. 10). Consequently, the corresponding hydrodynamic radius depends only slightly on the angle of detection, indicating that GICs are most likely spherical structures with a narrow size distribution.Fig. 10

Bottom Line: This effect is stronger for GBICs than for GICs, is reversible for GICs and GBIC-PAPEO(14)/P2MVPI(228), and shows some hysteresis for GBIC-PAPEO(14)/P2MVPI(43).The very large difference between the sizes found experimentally for GBICs and the sizes predicted from SCF calculations supports the view that there is some secondary association mechanism.A possible mechanism is discussed.

View Article: PubMed Central - PubMed

ABSTRACT
We discuss the structure and formation of Ionomer Complexes formed upon mixing a grafted block copolymer (poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)), PAA(21)-b-PAPEO(14)) with a linear polyelectrolyte (poly(N-methyl 2-vinyl pyridinium iodide), P2MVPI), called grafted block ionomer complexes (GBICs), and a chemically identical grafted copolymer (poly(acrylic acid)-co-poly(acrylate methoxy poly(ethylene oxide)), PAA(28)-co-PAPEO(22)) with a linear polyelectrolyte, called grafted ionomer complexes (GICs). Light scattering measurements show that GBICs are much bigger (~70-100 nm) and GICs are much smaller or comparable in size (6-22 nm) to regular complex coacervate core micelles (C3Ms). The mechanism of GICs formation is different from the formation of regular C3Ms and GBICs, and their size depends on the length of the homopolyelectrolyte. The sizes of GBICs and GICs slightly decrease with temperature increasing from 20 to 65 °C. This effect is stronger for GBICs than for GICs, is reversible for GICs and GBIC-PAPEO(14)/P2MVPI(228), and shows some hysteresis for GBIC-PAPEO(14)/P2MVPI(43). Self-consistent field (SCF) calculations for assembly of a grafted block copolymer (having clearly separated charged and grafted blocks) with an oppositely charged linear polyelectrolyte of length comparable to the charged copolymer block predict formation of relatively small spherical micelles (~6 nm), with a composition close to complete charge neutralization. The formation of micellar assemblies is suppressed if charged and grafted monomers are evenly distributed along the backbone, i.e., in case of a grafted copolymer. The very large difference between the sizes found experimentally for GBICs and the sizes predicted from SCF calculations supports the view that there is some secondary association mechanism. A possible mechanism is discussed.

No MeSH data available.


Related in: MedlinePlus