Limits...
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.


A schematic representation of PAA21-b-PAPEO14, including a hydrophobic end-group C12H25 being a residue of the primer used during the synthesis of this grafted block copolymer
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3102187&req=5

Fig2: A schematic representation of PAA21-b-PAPEO14, including a hydrophobic end-group C12H25 being a residue of the primer used during the synthesis of this grafted block copolymer

Mentions: Poly(2-vinyl pyridine) (P2VP43; Mn = 4.15 kg/mol, PDI = 1.09) was purchased from Polymer Standard Service (Mainz, Germany). Poly(N-methyl 2-vinyl pyridinium iodide) (P2MVPI228; Mw = 56 kg/mol, PDI = 1.09) was purchased from Polymer Source Inc, Canada. Poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)) (PAA21-b-PAPEO14; Mn = 8.86 kg/mol, PDI = 1.4, the molecular mass of graft is Mgraft = 0.450 kg/mol corresponding to a length of 8–9 monomers per grafted PEO chain), and poly(acrylic acid)-co-poly(acrylate methoxy poly(ethylene oxide)) (PAA28-co-PAPEO22; Mn = 8.86 kg/mol, PDI = 1.4, Mgraft = 0.450 kg/mol, also corresponding to 8–9 monomers per grafted PEO chain) were a kind gift from Christophe Detrembleur, Université de Liège. The synthesis and characterization of these polymers are described in detail elsewhere [21]. Schematic representations of the polymeric molecules used in this study are shown in Figs. 2, 3, and 4. Poly(allylamine hydrochloride) (PAH·HCl160; Mn = 15 kg/mol, ≥95%), sodium chloride (NaCl), sodium hydroxide (NaOH, 1 M), hydrochloric acid (HCl, 1 M), and toluene of analytical grade were purchased from Sigma. All chemicals were used as received.Fig. 2


Formation and structure of ionomer complexes from grafted polyelectrolytes.

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

A schematic representation of PAA21-b-PAPEO14, including a hydrophobic end-group C12H25 being a residue of the primer used during the synthesis of this grafted block copolymer
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3102187&req=5

Fig2: A schematic representation of PAA21-b-PAPEO14, including a hydrophobic end-group C12H25 being a residue of the primer used during the synthesis of this grafted block copolymer
Mentions: Poly(2-vinyl pyridine) (P2VP43; Mn = 4.15 kg/mol, PDI = 1.09) was purchased from Polymer Standard Service (Mainz, Germany). Poly(N-methyl 2-vinyl pyridinium iodide) (P2MVPI228; Mw = 56 kg/mol, PDI = 1.09) was purchased from Polymer Source Inc, Canada. Poly(acrylic acid)-b-poly(acrylate methoxy poly(ethylene oxide)) (PAA21-b-PAPEO14; Mn = 8.86 kg/mol, PDI = 1.4, the molecular mass of graft is Mgraft = 0.450 kg/mol corresponding to a length of 8–9 monomers per grafted PEO chain), and poly(acrylic acid)-co-poly(acrylate methoxy poly(ethylene oxide)) (PAA28-co-PAPEO22; Mn = 8.86 kg/mol, PDI = 1.4, Mgraft = 0.450 kg/mol, also corresponding to 8–9 monomers per grafted PEO chain) were a kind gift from Christophe Detrembleur, Université de Liège. The synthesis and characterization of these polymers are described in detail elsewhere [21]. Schematic representations of the polymeric molecules used in this study are shown in Figs. 2, 3, and 4. Poly(allylamine hydrochloride) (PAH·HCl160; Mn = 15 kg/mol, ≥95%), sodium chloride (NaCl), sodium hydroxide (NaOH, 1 M), hydrochloric acid (HCl, 1 M), and toluene of analytical grade were purchased from Sigma. All chemicals were used as received.Fig. 2

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.