Polyelectrolytes Carrying Pendant (Cyanobiphenylyl)oxy Mesogenic Groups. Preparation, Characterization, and pH-Dependent Behavior in Aqueous Solution

Nieuwkerk, A.C.; Marcelis, Antonius T. M.; Sudhölter, Ernst J. R.

doi:10.1021/ma00118a029

Cited by 13 publications

(26 citation statements)

References 26 publications

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“…The poly(maleic acid-co-n-[(4-cyano-4′-biphenylyl)oxy]alkyl vinyl ether)s I-n were synthesized as described before. 14 Found: C, 67.74; H, 7.23; N, 2.37. Gel permeation chromatography (GPC) of the anhydrides of I-n showed a degree of polymerization of at least 250.…”

Section: Methodsmentioning

confidence: 98%

“…Gel permeation chromatography (GPC) of the anhydrides of I-n showed a degree of polymerization of at least 250. 14 The poly(maleic acid-co-n-alkyl vinyl ether)s PSX were synthesized following a literature procedure. 18 PS4: 1 19 N-dodecyl-N,N,N-trimethylammonium bromide (Aldrich) and N-hexadecyl-N,N,N-trimethylammonium bromide (Merck) were recrystallized from ethanol before use.…”

Section: Methodsmentioning

confidence: 99%

“…The radius increase observed for I-6 and I-12 upon increasing pH is in agreement with the loss of chromophore stacking as previously observed by UV measurements. 14 Polyelectrolyte-Surfactant Interactions. By use of chromophore-labeled polyelectrolytes and/or surfactants, the events occurring upon addition of surfactants to the polyelectrolytes are studied using UV spectroscopy.…”

Section: Dynamic Light Scattering Of the Polyelectrolytesmentioning

confidence: 99%

“…By use of UV spectroscopy, the conformation of the (cyanobiphenylyl)oxy-carrying polyelectrolytes in aqueous solution was seen to change from a more compact globular coil at low pH to the more extended, swollen conformation at high pH. 14 An effect of the side chain hydrophobicity was seen on both the compactness of the microdomains and on the degree of π-π stacking interactions between the mesogenic units.…”

Section: Introductionmentioning

confidence: 99%

“…11 Poly(maleic acid-co-alkyl vinyl ether)s carrying (cyanobiphenylyl)oxy moieties at the ends of the alkyl chains have previously been studied by us. 14 The (cyanobiphenylyl)oxy units have been incorporated to modify the polyelectrolyte's hydrophobicity and also to act as an intrinsic probe to monitor directly changes in the chromophore stacking upon the addition of base and/or surfactants. UV spectroscopy is used to monitor the changes of the (cyanobiphenylyl)oxy environment.…”

Section: Introductionmentioning

confidence: 99%

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Chromophore Labeling as a Tool To Study Interactions between Maleic Acid Copolymers and Ammonium Surfactants

et al. 1997

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The binding of n- dodecyl-, n-hexadecyl-and N-(ω-(4′-cyanoazobenz-4-oxy)decyl)-N,N,N-trimethylammonium bromide to poly(maleic acid-co-alkyl vinyl ether)s with n-butyl, n-dodecyl, n-[(4-cyano-4′-biphenylyl)oxy]hexyl and n- [(4-cyano-4′-biphenylyl)oxy]dodecyl side chains has been investigated by UV spectroscopy. Results from dynamic light scattering studies of the polyelectrolytes in the absence of surfactants are in agreement with the presence of the extended conformation for the butyl copolymer between pH 7 and 11. For the other polyelectrolytes an increase in hydrodynamic radius is observed upon increasing the pH. By UV spectroscopy the shifts in absorption maxima of the (cyanobiphenylyl)oxy and cyanoazobenzoxy chromophores, due to mutual π-π stacking interactions, were monitored to provide information on the interaction between polyelectrolytes and surfactants. Changes on both polyelectrolyte and surfactant could be studied upon addition of surfactant to polyelectrolyte in aqueous solution. For the butyl polyelectrolyte, cooperative interaction is observed (pH > 7), whereas for the other copolymers no cooperativity is observed. A model for the different interactions is proposed.

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Section: Methodsmentioning

confidence: 98%

Section: Methodsmentioning

confidence: 99%

Section: Dynamic Light Scattering Of the Polyelectrolytesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Chromophore Labeling as a Tool To Study Interactions between Maleic Acid Copolymers and Ammonium Surfactants

et al. 1997

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Interactions between Chromophore-Labelled Ammonium Surfactants and Hydrophobically Modified Polyelectrolytes

Nieuwkerk¹,

Kan²,

Koudijs³

et al. 1999

Eur. J. Org. Chem.

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The interaction of poly(maleic acid‐co‐alkyl vinyl ether)s and poly(sulfonylethyl maleic acid monoamide‐co‐alkyl vinyl ether)s with and without (cyanobiphenylyl)oxy chromophores with N‐[ω‐(substituted azobenzoxy)alkyl]‐N,N‐dimethyl‐N‐hydroxyethylammonium bromide surfactants has been studied by UV spectroscopy. The azobenzene unit is functionalized at the 4′‐position with a cyano or fluoro substituent and is connected to the surfactant headgroup via a decyl or dodecyl spacer. Upon addition of surfactants to poly(maleic acid‐co‐butyl vinyl ether) the absorption maxima (λmax) of the azobenzene chromophores immediately show their maximum blue shift. This indicates cooperative binding of surfactant to this polymer, and the formation of micelle‐like aggregates surrounded by polyelectrolyte is assumed. Upon addition of the surfactants to the other polyelectrolytes λmax values of the azobenzoxy chromophores gradually shift to lower values indicating a lower cooperativity of surfactant binding. This is attributed to the formation of microdomains by the polyelectrolytes themselves. For these systems the formation of mixed micelles is assumed. The compactness of the microdomains of the maleic acid copolymers is influenced by the pH and binding with surfactants is also influenced by pH. The sulfonylethyl maleic acid monoamide copolymers show no pH dependence in binding above neutral pH. For these polyelectrolytes the cooperativity also becomes less with a longer spacer between backbone and chromophore. Upon elongation of the surfactant spacer or changing the end group from a cyano to the more hydrophobic fluoro substituent a lower λmaxis observed for the chromophores upon initial binding to the polyelectrolytes indicating more cooperative binding. When surfactants and polyelectrolytes are both labelled with chromophores, binding proceeds noncooperatively and the formation of mixed micelles is assumed.

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Ionic‐Strength‐ and pH‐Responsive Poly[acrylamide‐co‐(maleic acid)] Hydrogel Nanofibers

Liu

Mao

2007

Macro Chemistry & Physics

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A novel acrylamide/maleic acid copolymer [P(AM‐MA)] hydrogel nanofibrous membrane with a fiber diameter of ca. 120 nm is prepared by electrospinning an aqueous P(AM‐MA) solution with diethylene glycol as crosslinker, followed by a heat‐induced esterification crosslinking reaction at 145 °C. This hydrogel nanofiber can maintain a fiber form, but becomes distorted and merges to form many physical crosslinking points after immersion in water. The P(AM‐MA) hydrogel nanofibers are sensitive to external stimuli ionic strength and pH. Their water‐swelling ratio decreases with increasing solution ionic strength, and it shows a characteristic two‐step increase at pH = 2.5 and 8.5 in response to the increase of solution pH. The maximum water‐swelling ratios of the P(AM‐MA) hydrogel nanofibers are 18.1 and 22.5 g · g−1 in a solution of 0.05 mol · dm−3 ionic strength and in an aqueous solution of pH 11, respectively.magnified image

show abstract

Polyelectrolytes Carrying Pendant (Cyanobiphenylyl)oxy Mesogenic Groups. Preparation, Characterization, and pH-Dependent Behavior in Aqueous Solution

Cited by 13 publications

References 26 publications

Chromophore Labeling as a Tool To Study Interactions between Maleic Acid Copolymers and Ammonium Surfactants

Chromophore Labeling as a Tool To Study Interactions between Maleic Acid Copolymers and Ammonium Surfactants

Interactions between Chromophore-Labelled Ammonium Surfactants and Hydrophobically Modified Polyelectrolytes

Ionic‐Strength‐ and pH‐Responsive Poly[acrylamide‐co‐(maleic acid)] Hydrogel Nanofibers

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