Synthesis and Structural Analysis of Self-Associating Amphiphilic Statistical Copolymers in Aqueous Media

Hashidzume, Akihito; Kawaguchi, Atsushı; Tagawa, Akiyo; Hyoda, and Katsuhiro; Sato, Takahiro

doi:10.1021/ma051950d

Cited by 50 publications

(73 citation statements)

References 25 publications

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“…Figure 2a illustrates examples of the relaxation time spectra Að; kÞ obtained by dynamic light scattering (x methanol ¼ 0:06 and c ¼ 0:018 g/cm 3 ). The spectra are bimodal, being similar to those reported previously for other p(AMPS/C6) samples in 0.1 M aqueous sodium chloride, 5 and indicating the existence of two scattering components with fast and slow relaxation times. Most of solutions with x methanol ¼ 0 and 0.06 exhibited similar bimodal Að; kÞ.…”

Section: Resultssupporting

confidence: 87%

“…5 The upper bound of w slow obtained by the above method was less than 0.5% both at x methanol ¼ 0 and 0.06. Therefore, although the slow relaxation component was detectable by light scattering due to its very high scattering power, it may not affect sedimentation equilibrium results.…”

Section: Resultsmentioning

confidence: 84%

“…5 The sample was purified by reprecipitation and dialysis, and then freeze-dried from aqueous solution.…”

Section: Experimental P(amps/c6) Sample and Test Solutionsmentioning

confidence: 99%

“…below). The mole fraction x of the hydrophobic monomer units in the copolymer sample was estimated by 1 H NMR using D 2 O as the solvent at 30 C. 5 All the results are listed in Table I. The M z =M w value indicates a narrow molecular weight distribution of the sample prepared by the RAFT polymerization.…”

Section: Experimental P(amps/c6) Sample and Test Solutionsmentioning

confidence: 99%

“…Recently, Hashidzume et al 5 investigated the micellar structure of an amphiphilic statistical copolymer p(AMPS/C6), made of sodium 2-(acrylamido)-2-methylpropane-sulfonate (AMPS) and n-hexyl methacrylate (C6), in aqueous salt solution. The copolymer aggregation number m of the micelle and the number of hydrophobic cores per micelle depended on the copolymer molecular weight and hydrophobic monomer content.…”

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confidence: 99%

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Micellization Behavior of an Amphiphilic Statistical Copolymer in Water-Methanol Mixtures

2009

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Sedimentation equilibrium measurements were made on an amphiphilic statistical copolymer p(AMPS/C6) made of sodium 2-(acrylamido)-2-methylpropane-sulfonate (AMPS) and n-hexyl methacrylate (C6), dissolved in water-methanol mixtures with 0.2 M LiClO 4 and different methanol contents over a wide polymer concentration range. The experimental results were analyzed in terms of a micellar solution theory for amphiphilic polyelectrolytes to estimate the aggregation number m of the micelle and the internal free energy change Á m =m (per polymer chain) due to micellization. Both m and Á m =m decreased with increasing the methanol content in the solvent. In addition, dynamic light scattering for the same copolymer system indicated that p(AMPS/C6) formed a uni-core star-like micelle in water-methanol mixture with the methanol mole fractions of 0 and 0.06.KEY WORDS: Micelle / Amphiphilic Polymer / Statistical Copolymer / Sedimentation Equilibrium / Dynamic Light Scattering / Amphiphilic copolymers form micelles in aqueous media due to the strong hydrophobic interaction among the polymer chains.1 The micellization is important for their applications to the rheology modifier, emulsifier, drag delivery system, and so on, 2-4 because the micellization changes remarkably their solution properties. In the practical applications for those purposes, their aqueous solutions are often mixed with various additives, e.g., low molar mass organic compounds, salts, surfactants, and other polymers. Those additives can modify the micellization behavior of the polymers in aqueous media by interacting with the hydrophobic or hydrophilic moieties of the copolymer chain, so that it is essentially important to understand the effect of additives on the micellization behavior in aqueous solutions of amphiphilic copolymers.Recently, Hashidzume et al. 5 investigated the micellar structure of an amphiphilic statistical copolymer p(AMPS/C6), made of sodium 2-(acrylamido)-2-methylpropane-sulfonate (AMPS) and n-hexyl methacrylate (C6), in aqueous salt solution. The copolymer aggregation number m of the micelle and the number of hydrophobic cores per micelle depended on the copolymer molecular weight and hydrophobic monomer content. Furthermore, their hydrodynamic radius data indicated that the copolymer formed a uni-core star-like micelle at low copolymer molecular weights.Afterward, Nojima et al. 6 refined the data analysis for the p(AMPS/C6) micelle in aqueous salt solution by taking into account the association-dissociation equilibrium in the micellar solution. Using a micellar solution theory for amphiphilic polyelectrolytes, they estimated more precise m for the p(AMPS/C6) micelle in aqueous salt solution.In the present study, we have made sedimentation equilibrium and dynamic light scattering measurements on p(AMPS/C6) dissolved in water-methanol mixtures with 0.2 M LiClO 4 and different methanol mole fraction x methanol . Applying the micellar solution theory, we have estimated m and also the internal free energy change Á m =m due to micellization...

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 84%

“…5 The sample was purified by reprecipitation and dialysis, and then freeze-dried from aqueous solution.…”

Section: Experimental P(amps/c6) Sample and Test Solutionsmentioning

confidence: 99%

Section: Experimental P(amps/c6) Sample and Test Solutionsmentioning

confidence: 99%

mentioning

confidence: 99%

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Micellization Behavior of an Amphiphilic Statistical Copolymer in Water-Methanol Mixtures

2009

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Electric‐field‐induced aggregation of polymeric micelles to construct secondary assembly films

Ren

Luo

Tao

et al. 2012

J of Applied Polymer Sci

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A new amphiphilic quaternary random ionomer (PIDHES) was used to construct self-assembly films. PIDHES was prepared by a selective ionization of quaternary random copolymer, poly(N,N-domethyl amimethyl methartylate-co-2-hydroxypropyl methacrylate-co-2-ethylhexyl acrylate-co-styrene) precursor, which was synthesized by free radical copolymerization of commercial hydrophilic monomers N, N-domethyl amimethyl methartylate and 2-hydroxypropyl methacrylate and hydrophobic monomers 2-ethylhexyl acrylate and styrene PIDHES could self-assemble into polymer micelles in water, which underwent orientated deposition in the electric field and ultimately produced secondary assembly films. Scanning electron microscopy studies showed that the resultant PIDHES secondary assembly film was smooth and compact. Moreover, it was found that PIDHES micelles concentration and electricfield-induced time had a strong influence on the morphologies of the resultant secondary assembly film.

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Status report for pediatric rheumatology: What needs to be done?

Passo

2006

Arthritis & Rheumatism

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Synthesis and Structural Analysis of Self-Associating Amphiphilic Statistical Copolymers in Aqueous Media

Cited by 50 publications

References 25 publications

Micellization Behavior of an Amphiphilic Statistical Copolymer in Water-Methanol Mixtures

Micellization Behavior of an Amphiphilic Statistical Copolymer in Water-Methanol Mixtures

Electric‐field‐induced aggregation of polymeric micelles to construct secondary assembly films

Status report for pediatric rheumatology: What needs to be done?

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