Nuclear magnetic resonance studies of domain growth in the late stage of phase separation of a binary liquid mixture

Cau, Franco; Lacelle, Serge

doi:10.1063/1.470527

Cited by 3 publications

(1 citation statement)

References 37 publications

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“…The unimer thus resembles a unimolecular micelle. Additional evidence for such structure has been given by 1 H-NMR relaxation studies by Cau and Lacelle [39].…”

Section: Unimersmentioning

confidence: 79%

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

Mortensen

1996

J. Phys.: Condens. Matter

365

478

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The structural characteristics of aqueous solutions of the Pluronic triblock copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, and their self-associated assemblies are reviewed. It is shown by small-angle neutron scattering that at low temperatures and/or concentration the individual copolymers exist in solution as individual unimers. Thermodynamically stable micelles are formed with increasing copolymer concentration and/or temperature. The unimer-to-micelle transition is not sharp, however. Micelles of well defined spherical shape and size coexist with unimers over a relatively wide temperature/concentration range. The micellar volume fraction increases accordingly with increasing temperature, increasing copolymer concentration and decreasing hydrostatic pressure. The copolymer suspension undergoes as a result a transition from a Newtonian liquid to a soft solid material when the micellar volume fraction crosses the critical value for hard-sphere crystallization. Crystallographic investigations on shear-aligned monodomain samples prove that the micelles in the solid phase are organized on a body-centred cubic lattice. As a result of an increasing micellar size upon increasing the temperature, the micelles themselves undergo a sphere-to-rod transition at elevated temperatures. In a shear field these rod-like micelles form a macroscopic nematic phase for low copolymer concentration, and a hexagonal solid phase for higher concentrations. For even higher concentrations, lamellar phases are observed: one lamellar type which is still governed by the hydrophobic interactions, and one type which appears as a result of crystallization of the PEO blocks.

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“…The unimer thus resembles a unimolecular micelle. Additional evidence for such structure has been given by 1 H-NMR relaxation studies by Cau and Lacelle [39].…”

Section: Unimersmentioning

confidence: 79%

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

Mortensen

1996

J. Phys.: Condens. Matter

365

478

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An analytical form describing T2 dispersions resulting from diffusive exchange

Williams¹,

Halstead²

1998

Mol. Phys.

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An analytical form describing T ₂ dispersions resulting from diffusive exchange

Williams¹,

Halstead²

1998

Molecular Physics

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Dispersions in the 1 H T 2 (Carr± Purcell± Meiboom± Gill) relaxation behaviour analogous to those well known to result from chemical exchange have been generated by numerical simulations of fast di usive exchange between two spatially resolved regions having distinct NMR parameters. These resultant curves have been successfully ® tted to a Carver± Richards functional form. Hence, apparent exchange rates and geometry-dependent scaling factors of the frequency di erence between regions have been extracted, which allow dispersions arising from spatially heterogeneous systems to be described by a two-site exchange model.

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Nuclear magnetic resonance studies of domain growth in the late stage of phase separation of a binary liquid mixture

Abstract: Articles you may be interested inPhase separation of a binary liquid mixture in porous media studied by nuclear magnetic resonance cryoporometry

Cited by 3 publications

References 37 publications

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

An analytical form describing T2 dispersions resulting from diffusive exchange

An analytical form describing T ₂ dispersions resulting from diffusive exchange

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Nuclear magnetic resonance studies of domain growth in the late stage of phase separation of a binary liquid mixture

Abstract: Articles you may be interested inPhase separation of a binary liquid mixture in porous media studied by nuclear magnetic resonance cryoporometry

Cited by 3 publications

References 37 publications

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

Structural studies of aqueous solutions of PEO - PPO - PEO triblock copolymers, their micellar aggregates and mesophases; a small-angle neutron scattering study

An analytical form describing T2 dispersions resulting from diffusive exchange

An analytical form describing T 2 dispersions resulting from diffusive exchange

Contact Info

Product

Resources

About

An analytical form describing T ₂ dispersions resulting from diffusive exchange