An Associative Polyelectrolyte End-Capped with Short Polystyrene Chains. Synthesis and Rheological Behavior

Tsitsilianis, Constantinos; Iliopoulos, Ilias; Ducouret, Guylaine

doi:10.1021/ma991410e

Cited by 113 publications

(123 citation statements)

References 60 publications

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“…Polymers with longer hydrophilic blocks form micelles with a larger PMAA corona. This results in stronger interactions between the micelles due to electrostatic forces and entanglement, which are less easily disrupted by shear [23,27]. ; 1 wt%) as a function of the hydrophobic and hydrophilic block length (in monomeric units) is given.…”

Section: Rheologymentioning

confidence: 99%

“…In all cases, sigmoidal curves are obtained. At very low concentrations (the diluted regime [27]), the polymers are non-interacting and form isolated micelles with the hydrophilic block fully stretched into the solution. This is the result of the osmotic pressure exerted by the counter ions trapped in the corona by Coulombic interaction [23].…”

Section: Rheologymentioning

confidence: 99%

“…The aggregates of the diblock PS-b-PAA constituteof a dense rigid PS core surrounded by a hydrophilic corona of PAA brushes. Rheological studies show that amphiphilic block copolymers form viscoelastic solutions and turn into gels after a critical concentration [26,27].…”

Section: Introductionmentioning

confidence: 99%

“…However some studies propose that the system can be dynamic if the hydrophobic block is short enough, [27,33] which makes it interesting to study the aggregation and properties of amphiphilic block copolymers with short hydrophobic blocks. Nevertheless, the absence or an extreme low CMC is advantageous for many applications, since only traces of polymer are required to form micelles.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

Meijerink

Mastrigt

Franken³

et al. 2017

Pure and Applied Chemistry

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Well-defined amphiphilic triblock poly(sodium methacrylate)-polystyrene-poly(sodium methacrylate) (PMAA-b-PS-b-PMAA) copolymers characterized by a different length of either the hydrophilic or the hydrophobic block have been synthesized by ATRP. In solution the micelle-like aggregates consist of a collapsed PS core surrounded by stretched charged PMAA chains. The micelles are kinetically 'frozen' and as a consequence the triblock copolymers do not show a significant surface activity. The hydrophilic block length has a major influence on the rheology, the shortest PMAA blocks yielding the strongest gels (at the same total weight concentration). The hydrophobic block length has only a minor influence until a certain threshold, below which the hydrophobic interactions are too weak resulting in weak gels. A mathematical model is used to describe the micelle radius and the results were in good agreement with the experimentally found radius in transmission electron microscopy. The influences of the ionic strength, pH and temperature on the rheology has also been investigated, showing the potential of these polymers as smart hydrogels. The change in conformation of the hydrophilic corona from the collapsed state to the stretched state by changing the pH was quantified with zeta-potential measurements. To the best of our knowledge, this is the first systematic investigation of this kind of triblock copolymers in terms of their rheological behavior in water.

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Section: Rheologymentioning

confidence: 99%

Section: Rheologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

Meijerink

Mastrigt

Franken³

et al. 2017

Pure and Applied Chemistry

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show abstract

“…Moreover, the highly elastic behavior of the gel (i. e. G 9 L 500 Pa and virtually independent of x) in such a low concentration, resembles those observed in telechelic polyelectrolytes, where a transient network is formed, consisting of PS physical cross-links interconnected by stretched polyelectrolyte chains. [59] However the architecture of the A n B n heteroarm star copolymers is different to that of ABA triblock copolymers and cannot lead to the In the inset shear stress is plotted as a function of shear rate (c). Figure 5.…”

Section: Solution Properties Of Ps 12 Paa 12 Star Copolymermentioning

confidence: 99%

Aggregation Behavior of Polystyrene/Poly(acrylic acid) Heteroarm Star Copolymers in 1,4-Dioxane and Aqueous Media

Voulgaris

Tsitsilianis²

2001

Macromol. Chem. Phys.

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Ionic heteroarm star copolymers bearing polystyrene (PS) and poly(acrylic acid) (PAA) arms (PSnPAAn) were prepared by quantitative hydrolysis of the poly(tert‐butyl acrylate) (PtBA) arms of the corresponding PSnPtBAn star copolymer. The aggregation properties of these copolymers were studied in various solvents. In 1,4‐dioxane PS12PAA12 (with nearly symmetrical PS and PAA arms) forms reverse micelles of low aggregation number (Nagg) and spherical morphology. In an 80 : 20 (v/v) 1,4‐dioxane/water mixture these micelles are transformed to regular micelles with an unexpectedly high Nagg and an elongated rod‐like structure. An abnormal behavior was observed in aqueous solutions of charged PS24PANa24 (with asymmetrical PS and PAA arms, WPS = 19 wt.‐%) at low concentrations. A non‐equilibrium physical gel is formed, characterized by a very high viscosity and an elastic response upon oscillatory shearing.

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Block Copolymer Hydrogels

Gao

Lee

2012

Encyclopedia of Polymer Science and Technology

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Block copolymer hydrogels are three‐dimensional polymeric networks that can absorb a considerable amount of water to maintain their semisolid morphology. Chemically cross‐linked hydrogels which can be prepared through disulfide bond formation, photopolymerization, or click chemistry, exhibit a nonreversible phase transition state. In contrast, physically cross‐linked hydrogels can be formed via self‐assembly of amphiphilic block copolymers, in response to environmental stimuli, including pH and/or temperature, and show a sol‐gel phase transition. Importantly, these stimuli‐sensitive physical hydrogels can exist as a sol state prior to administration, and subsequently translate to a gel state after administration under the human body condition. Consequently, the stimuli‐sensitive hydrogels have attracted significant interest for their potential applications in the site‐specific pharmaceutical (drug/protein) delivery and tissue regeneration. The article focuses on synthesis, properties, and biomedical applications of stimuli‐responsive block copolymer hydrogels that exhibit a reversible sol‐gel phase transition in response to temperature, pH, pH/temperature, and other stimulus conditions.

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An Associative Polyelectrolyte End-Capped with Short Polystyrene Chains. Synthesis and Rheological Behavior

Cited by 113 publications

References 60 publications

Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

Triblock copolymers of styrene and sodium methacrylate as smart materials: synthesis and rheological characterization

Aggregation Behavior of Polystyrene/Poly(acrylic acid) Heteroarm Star Copolymers in 1,4-Dioxane and Aqueous Media

Block Copolymer Hydrogels

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