Polystyrene/poly(2-vinyl pyridine) heteroarm star copolymer micelles in toluene: morphology and thermodynamics1Part of this work was presented at the 17th `Hellenic Conference on Chemistry' held in Patras, Greece, December 1996.1

Voulgaris, Dimitris; Tsitsilianis, Constantinos; Esselink, F.J; Hadziioannou, Georges

doi:10.1016/s0032-3861(98)00035-4

Cited by 82 publications

(87 citation statements)

References 26 publications

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“…Recently we have reported results dealing with the aggregation of heteroarm star copolymers in selective solvents. These copolymers show a lower tendency to associate than the corresponding block copolymers [38] and their micelles resemble amphiphile micelles. [40,44] They form spherical micelles with a low aggregation number N agg and a high critical micellization concentration cmc.…”

Section: Introductionmentioning

confidence: 89%

“…The aggregation number, N agg , is low, in agreement with recent results for heteroarm star copolymers in organic media. [38,40] In order to obtain the correct micellar weight of PS 12 PAA 12 copolymer in the solvent mixture 80 D/20 W, the possibility of preferential adsorption has to be examined. Tuzar et al [20] investigated the aggregation of polystyrene/poly(methacrylic acid) diblock and triblock copolymers in the same mixture of solvents.…”

Section: Solution Properties Of Ps 12 Paa 12 Star Copolymermentioning

confidence: 99%

“…This shape has also been detected for other heteroarm star copolymers in organic solvents. [38,40] The micellar core radius (R c ) of spherical micelles was determined for two extreme cases, i.e. dry and swollen core ( Table 2).…”

Section: Solution Properties Of Ps 12 Paa 12 Star Copolymermentioning

confidence: 99%

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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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Section: Introductionmentioning

confidence: 89%

Section: Solution Properties Of Ps 12 Paa 12 Star Copolymermentioning

confidence: 99%

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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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“…[7][8][9][10][11] Highly branched polymers with cores, joints and branches, tree-like architecture, and a low level of entanglements possess different physical properties when compared with linear polymers. 12,13 Other macromolecular architectures, such as star-shaped block copolymers, have been found to exhibit interesting aggregation behavior, [14][15][16][17][18][19][20][21] which can be used for a guided formation of fluorescent nanofibers and microfibers. 22,23 The multiple terminal groups are used to control the assembly of the molecules in solution, and at surfaces and interfaces [24][25][26][27][28][29][30][31][32] as well as their stimuli-responsive behavior.…”

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confidence: 99%

Assembling hyperbranched polymerics

Peleshanko¹,

Tsukruk²

2011

J Polym Sci B Polym Phys

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A condensed overview discusses the existing grafting approaches and the surface behavior of various hyperbranched polymers. We focus on the recent strategies and corresponding characterization of the resulting surface morphologies and structures with a number of relevant recent results from the authors' own research and existing literature. Some results discussed here are important for prospective applications of hyperbranched polymers in biomedical fields, for resistive coatings, tough blends, and reinforced nanocomposites are briefly summarized as well. V C 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: 83-100, 2012 KEYWORDS: adsorption; hyperbranched; LB films; structural characterization; surfaces INTRODUCTION This publication presents a condensed overview of the existing grafting approaches as applied to hyperbranched polymers and discusses the surface morphologies of these polymers and corresponding composites and coatings. We mostly focus on the recent strategies and corresponding characterization of the resulting surface morphologies and structures developed in the authors' group with some relevant examples from current literature. A number of relevant results are also included here especially in relation to recent developments related to novel synthetic approaches of hyperbranched molecules as well as emerging applications of hyperbranched polymers and coatings for biomedical purposes, as resistive coatings, tough blends, and reinforced nanocomposites. Some comprehensive recent reviews on highly branched polymers, which are focused mainly on synthetic aspects can be found in literature.

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“…In most cases, when various ''living'' polymerization techniques are involved, the cross-linked microgel core of the formed star polymer is capable of initiating the same or a different type of monomer. [11,[22][23][24][25][26][27][28][29] Thus, although this approach usually leads to star polymers with less well-defined structures, they provides a facile ''in-out'' method for the preparation of heteroarm star polymers, such as (PS) n -PDVB-(PCL) m , [23] (PS) n -PDVB-(PI) m , [22,24] (PS) n -PDVB-(P2VP) m , [25,26] (PS) n -PDVB-(PBA) m , [27] and (PtBA) n -PDVB-(PBA) m , [28] where PS, PEO, PCL, PI, P2VP, PBA, PtBA, and PDVB are polystyrene, poly(ethylene oxide), poly(e-caprolactone), polyisoprene, poly(2-vinylpyridine), poly(tert-butyl acrylate), poly(n-butyl acrylate), and cross-linked poly(DVB) core, respectively.…”

Section: Full Papermentioning

confidence: 99%

pH‐Switchable Complexation between Double Hydrophilic Heteroarm Star Copolymers and a Cationic Block Polyelectrolyte

et al. 2008

Macro Chemistry & Physics

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Double hydrophilic heteroarm star copolymers of poly(methacrylic acid) (PMAA) and poly(ethylene oxide) (PEO) were synthesized via atom‐transfer radical polymerization (ATRP) using the “in‐out” method. The synthesis consisted of three steps. Namely, ATRP was applied to the preparation of a star macroinitiator with PEO arms and a cross‐linked core resulting from the polymerization of divinylbenzene (DVB) in the first step, chain extension with tert‐butyl methacrylate (tBMA) under ATRP conditions, and subsequent hydrolysis of the tert‐butyl groups afforded (PEO)n‐PDVB‐(PMAA)n heteroarm star copolymers with a cross‐linked microgel core. This novel type of double hydrophilic heteroarm star copolymer can be considered as unimolecular micelles with hybrid coronas. The star copolymers exhibited pH‐dependent solubility in water, being soluble at high pH and insoluble at low pH, due to the formation of hydrogen‐bonded complexes between the PEO and PMAA arms. A mixed solution of the heteroarm star copolymer and a PEO‐b‐PQDMA diblock copolymer, where PQDMA is poly(2‐(dimethylamino)ethyl methacrylate) fully quaternized with methyl iodide, remained stable in the whole pH range, and exhibited an intriguing pH‐switchable complexation behavior accompanied with structural rearrangement.magnified image

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Polystyrene/poly(2-vinyl pyridine) heteroarm star copolymer micelles in toluene: morphology and thermodynamics1Part of this work was presented at the 17th `Hellenic Conference on Chemistry' held in Patras, Greece, December 1996.1

Cited by 82 publications

References 26 publications

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

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

Assembling hyperbranched polymerics

pH‐Switchable Complexation between Double Hydrophilic Heteroarm Star Copolymers and a Cationic Block Polyelectrolyte

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