Capillary wave studies of polystyrene-b-poly(methacrylic acid) diblock copolymer films at the toluene/water interface

May-Colaianni, S. E.; Gandhi, J.V.; Måløy, Knut Jørgen; Maher, J. V.; Kuhar, K. A.; Chapman, Toby M.

doi:10.1021/ma00076a044

Cited by 8 publications

(13 citation statements)

References 10 publications

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“…The amphiphilic block copolymers containing poly(methacrylic acid) (poly(MAA)) as hydrophilic segment have been widely investigated because of their interesting surface properties . These copolymers exhibit microphase separation in solid state and form spherical micelles in selective solvents.…”

Section: Introductionmentioning

confidence: 99%

Living Anionic Copolymerization of 1-(Alkoxy)ethyl Methacrylates with Polar and/or Nonpolar Monomers and the Preparation of Amphiphilic Block Copolymers Containing Poly(methacrylic acid) Hydrophilic Segments at Higher Temperatures Than Usually Employed

Ruckenstein

Zhang

1998

Macromolecules

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The anionic copolymerization of each of the following three novel methacrylate monomers1-(ethoxy)ethyl methacrylate (EEMA), 1-(butoxy)ethyl methacrylate (BEMA), and 1-(tert-butoxy)ethyl methacrylate (tBEMA)with methyl methacrylate (MMA) and/or styrene (St) was carried out. (1) The random copolymerization with MMA proceeded smoothly in tetrahydrofuran (THF), using 1,1-diphenylhexyllithium (DPHL) as the initiator, in the presence of LiCl ([LiCl]/[DPHL]0 = 1), at −40 °C. The copolymer thus obtained possessed controlled molecular weight and composition, and its molecular weight distribution (MWD) was narrow (M w/M n = 1.08−1.10). (2) The block copolymer of each of the new monomers with MMA was prepared by the sequential anionic polymerization of the two monomers; the polymerization sequence MMA−new monomer controlled better the molecular weight and led to a narrower MWD than the inverse one. (3) A well-controlled block copolymerization of St with EEMA or with tBEMA was achieved at higher temperatures (≥−35 °C) than usually employed (−78 °C), and it should be emphasized that, even at 0 °C, a well-defined diblock copolymer consisting of poly(St) and poly(tBEMA) could be obtained. (4) A block copolymer consisting of poly(St) and a random copolymer of MMA and EEMA, poly[St-b-(MMA-co-EEMA)], was prepared by the sequential monomer addition St−mixture of MMA and EEMA, for various weight ratios of MMA and EEMA. (5) In the preparation of the triblock copolymer with the sequence St, MMA, and EEMA, the molecular weight of the polymer increased step by step and the MWD remained narrow (M w/M n = 1.09). By changing the polymerization sequence, the hydrophilic segment could be located either in the middle or at the end of the copolymer chain. The protecting group, 1-(alkoxy)ethyl of each of the new monomers, could be easily eliminated after copolymerization, using a mild acidic environment. Thus a copolymer, containing poly(MAA) as hydrophilic segment, with different solubility than its precursor copolymer could be obtained.

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Section: Introductionmentioning

confidence: 99%

Living Anionic Copolymerization of 1-(Alkoxy)ethyl Methacrylates with Polar and/or Nonpolar Monomers and the Preparation of Amphiphilic Block Copolymers Containing Poly(methacrylic acid) Hydrophilic Segments at Higher Temperatures Than Usually Employed

Ruckenstein

Zhang

1998

Macromolecules

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“…Ignoring this factor may also bias the results obtained. Lastly, apart from one recent study of a block copolymer at the toluenewater interface, 32 the range of momentum transfer (scattering angle) and hence capillary wave frequency (see below) has been limited, and thus an examination of phenomenological models was prevented. Moreover, in all the cases mentioned, nothing was known about the surface organization of the spread polymer at the interface although in some cases deductions about this aspect were attempted from the SQELS data.…”

Section: Introductionmentioning

confidence: 99%

Surface Quasi-Elastic Light Scattering From Spread Monolayers of a Poly(methyl methacrylate)−Poly(ethylene oxide) Block Copolymer

1996

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A linear diblock copolymer of poly(methyl methacrylate) and poly(ethylene oxide), with a mole ratio of methyl methacrylate to ethylene oxide units of 1:1, has been spread at the air-water interface. The surface visco-elastic parameters of this spread film, surface tension, γ0, transverse surface shear viscosity, γ′, dilational modulus, 0, and dilational viscosity, ′, have been determined using surface quasielastic light scattering. For a fixed value of the scattering vector parallel to the water surface, the surface visco-elastic parameters have been determined as a function of surface concentration of block copolymer. From the surface tension and transverse shear viscosity and using a simple Maxwell fluid model of the spread polymer, a relaxation time has been obtained which, from its concentration dependence at fixed angle of incidence for the incident light beam, suggests only a single relaxational process. Use of dilational parameters produces relaxation times of the same order which suggests that the same molecular process is involved in the relaxation process. For a fixed surface concentration of block copolymer the frequency dependence of the surface visco-elastic parameters has been investigated by selecting different scattering vectors. A capillary wave frequency from circa 1 × 10 4 s -1 to 2 × 10 5 s -1 has been explored here. A Maxwell model can be fitted to these data to provide a single relaxation time but the value is considerably different from that obtained using concentration dependent data at a single scattering vector. A Cole-Cole plot of these frequency dependent surface visco-elastic parameters clearly shows that a single relaxation time cannot prevail. A distribution in relaxation times is evident with the distribution apparently skewed to the high frequency side of the spectrum, but the frequency range we are able to explore is too limited to be able to define any parameters of this distribution.

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“…Copolymer films dissolved at a fluid−fluid interface are interesting for their intriguing surface properties. − Surface pressure vs molecular area isotherms of copolymer monolayers at an air−water (A/W) interface have shown a variety of interesting properties. ,,− , Interesting behaviors like novel surface micelle formation by diblock copolymers have also been observed recently. , However, the only experiment available where the quality of one of the solvents forming the interface has been changed and the corresponding effect on the interfacial viscoelastic properties has been measured has been performed with very low molecular weight poly(ethylene oxide)−polystyrene block copolymer at the A/W and oil−water interfaces by Sauer et al…”

Section: Introductionmentioning

confidence: 99%

“…In our previous work, we measured capillary wave dispersion relations and extracted viscoelastic moduli for adsorbed monolayers of polystyrene- b -poly(methacrylic acid) (PS−PMAA) diblock copolymer at the toluene−water (T/W) interface, as a function of copolymer molecular weight and copolymer number density. In this paper, we report measurements of the capillary wave dispersion relation and the extracted viscoelastic moduli of the adsorbed monolayers of the same diblock copolymer (PS−PMAA) over the same range of copolymer molecular weight and nominal number density at an A/W interface.…”

Section: Introductionmentioning

confidence: 99%

Capillary Wave Studies of Polystyrene-b-poly(methacrylic acid) Diblock Copolymer Films at the Air−Water Interface

Gandhi¹,

Maher²,

Shaffer³

et al. 1997

Langmuir

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We have used mechanically generated capillary wave and ellipsometric techniques to investigate interfacial viscoelastic properties of adsorbed monolayers of polystyrene-b-poly(methacrylic acid) diblock copolymer at an air−water interface, as a function of both the overall molecular weight, M w, and the nominal interfacial number density of the copolymer. This experiment is a follow-up of our earlier experiment, in which we studied adsorbed monolayers of the same diblock copolymer at the toluene−water interface (Macromolecules 1993, 26, 6595). Now we have changed the environment of the polystyrene block from toluene to air and have studied the effect of such a change. The most prominent effect of this change is that it is more difficult to attain equilibrium at the air−water interface. Unlike the toluene−water case, no clear saturation of surface pressure is observed at the air−water interface. The maximum surface pressure values measured at the air−water interface are smaller than the saturation surface pressure values in the toluene−water case for all the three molecular weights we have investigated. Ellipsometric study shows that only a very small fraction of the copolymer molecules added to the system is adsorbed at the air−water interface. However, substantial changes in the longitudinal elasticity and longitudinal viscosity are observed.

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Capillary wave studies of polystyrene-b-poly(methacrylic acid) diblock copolymer films at the toluene/water interface

Cited by 8 publications

References 10 publications

Living Anionic Copolymerization of 1-(Alkoxy)ethyl Methacrylates with Polar and/or Nonpolar Monomers and the Preparation of Amphiphilic Block Copolymers Containing Poly(methacrylic acid) Hydrophilic Segments at Higher Temperatures Than Usually Employed

Living Anionic Copolymerization of 1-(Alkoxy)ethyl Methacrylates with Polar and/or Nonpolar Monomers and the Preparation of Amphiphilic Block Copolymers Containing Poly(methacrylic acid) Hydrophilic Segments at Higher Temperatures Than Usually Employed

Surface Quasi-Elastic Light Scattering From Spread Monolayers of a Poly(methyl methacrylate)−Poly(ethylene oxide) Block Copolymer

Capillary Wave Studies of Polystyrene-b-poly(methacrylic acid) Diblock Copolymer Films at the Air−Water Interface

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