Fluorescence studies of amphiphilic poly(methacrylic acid)-block-polystyrene-block-poly(methacrylic acid) micelles

Cao, Ti; Munk, Petr; Ramireddy, C.; Tuzar, Zdeněk; Webber, S. E.

doi:10.1021/ma00023a036

Cited by 157 publications

(144 citation statements)

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(1 reference statement)

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“…Cao and others prepared polystyrene-poly(methacrylic acid) (PS-PMA) block copolymer micelles by directly adding the polymer to 80:20 v/v dioxane:water followed by a stepwise dialysis to pure aqueous buffer [106].…”

Section: Methods Of Preparationmentioning

confidence: 99%

Polymeric micelles: authoritative aspects for drug delivery

Kulthe

Choudhari

Inamdar

et al. 2012

Designed Monomers and Polymers

187

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Section: Methods Of Preparationmentioning

confidence: 99%

Polymeric micelles: authoritative aspects for drug delivery

Kulthe

Choudhari

Inamdar

et al. 2012

Designed Monomers and Polymers

187

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“…Several studies have focused on 2.6 to 14 units, were determined by SLS. The cmc values for the characterization of these micelles (4,(18)(19)(20). In organic these micelles were found to be of the order of 10-8 M (27).…”

Section: Introductionmentioning

confidence: 95%

Effect of the degree of neutralization on the micellization of block ionomers

Khougaz¹,

Nguyen²,

Eisenberg³

et al. 1995

Can. J. Chem.

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Abstract:The effect of neutralization on the micellization of polystyrene-b-poly(acry1ic acid) (PS-b-PAA) was investigated by static light scattering (SLS) and small-angle X-ray scattering (SAXS). The block copolymers, present initially in single chain form in either dioxane or benzene-methanol (90110 (vlv)), were neutralized to different degrees by the addition of cesium hydroxide dissolved in methanol. The solutions were simultaneously monitored by SLS. It was found that micelle formation began near 5% neutralization. The normalized scattered light intensity at 90' (19dc) increased dramatically in the neutralization range between ca. 10 and 60%. For neutralization degrees between 60 and ca. loo%, 19dc did not change significantly with a further increase in the percent of neutralization. In the second part of the study, two block copolymers, PS(600)-b-PAA(34) and PS(600)-b-PAA(45) (the number of monomer units is given in parentheses), were prepared from benzenemethanol (90110 (vlv)) with different degrees of neutralization: 5, 25, 60, 100, and 150%. The resulting solutions were freeze-dried and the dried samples were redissolved in toluene. These samples were investigated by SLS and SAXS. By SLS, the aggregation numbers (fl were found to be the same between 5 and 60% neutralization. An increase in f was observed in going from 60 to 100%; i.e., f increased from 82 to 92 for PS(600)-b-PAA(34), and from 79 to 110 for PS(600)-b-PAA(45). The f values for the two block copolymers at 150% neutralization were found to be the same as those for 100% neutralization. The core radii values (R,,,) were measured for the neutralized PS(600)-b-PAA(45) samples at 0.05 g1mL in toluene by SAXS. The R,,,, values increased from 5 to 60% neutralization, remained constant from 60 to loo%, and increased again in the range from 100 to 150%. The results are explained by dynamic considerations. For low percent neutralization, between 5 and 60%, the micelles and single chains are proposed to be in a dynamic equilibrium state. For higher percent neutralization, between 60 and 10070, the dynamics are probably much slower.Key words: block copolymers, micelles, ionomers, light scattering, small angle X-ray scattering (or SAXS).RCsume : Faisant appel A la diffusion statique de la lumitre (SLS) et la diffusion des rayons X A petit angle (SAXS), on a Ctudit l'effet de la neutralisation sur la micellisation du polystyrtne-b-poly(acide acrylique) (PSb-PAA). Les copolymtres A blocs, qui sont prisents initialement sous la forme d'une chaine simple dans le dioxane ou dans un melange benztne-mtthanol(90110 (vlv)), se neutralisent A des degrts divers par l'addition d'hydroxyde de ctsium dissous dans le mCthanol. On a examink les solutions simultaniment par SLS. On a trouvt que la formation de micelles commence prts d'environ 5% de neutralisation. L'intensitC.normalisCe de la lumitre diffuste A 90 ' (19dc) This paper is dedicated to Professor J.E. (Jim) Guillet in recognition of his contributions to Canadian chemistry.

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“…Poly (methacrylic acid) (PMAA), an important watersoluble polymer, has many industrial and medical applications, such as a dispersant for coatings [1], a hydrophilic modifier on a surface [2], and a component of drug carriers, like micelles, in drug delivery systems [3,4]. With the aim of precisely synthesizing hydrophilic architectures based on PMAA, the controlled radical polymerization of methacrylic acid (MAA) was exploited using various catalysts.…”

Section: Introductionmentioning

confidence: 99%

Nitroxide-Mediated Photo-Controlled/Living Radical Polymerization of Methacrylic Acid

Yoshida

2013

OJPChem

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The photo-controlled/living radical polymerization of methacrylic acid (MAA) was performed at room temperature by irradiation with a high-pressure mercury lamp using azo initiators and 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl as the mediator in the presence of (4-tert-butylphenyl)diphenylsulfonium triflate ( t BuS) as the accelerator. Whereas the bulk polymerization yielded polymers with a bimodal molecular weight distribution in both the absence and presence of t BuS, the solution polymerization in methanol produced unimodal polymers with the molecular weight distribution of 2.0 -2.3 in the presence of t BuS. The molecular weight distribution of the resulting poly (MAA) decreased with an increase in t BuS. The dilution of the monomer concentration also reduced the molecular weight distribution. The use of the initiator with a low 10-h half-life temperature also effectively controlled the molecular weight. The livingness of the polymerization was confirmed by obtaining linear increases in the first-order conversion versus time, the molecular weight versus the conversion, and the molecular weight versus the reciprocal of the initiator concentration.

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Fluorescence studies of amphiphilic poly(methacrylic acid)-block-polystyrene-block-poly(methacrylic acid) micelles

Cited by 157 publications

References 1 publication

Polymeric micelles: authoritative aspects for drug delivery

Polymeric micelles: authoritative aspects for drug delivery

Effect of the degree of neutralization on the micellization of block ionomers

Nitroxide-Mediated Photo-Controlled/Living Radical Polymerization of Methacrylic Acid

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