Theory of copolymer micellization

Duque, Daniel

doi:10.1063/1.1599279

Cited by 31 publications

(47 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Self-consistent field theory (SCFT) [27] has been used with success to investigate the equilibrium structures formed in melts and blends of polymers [28][29][30], and may also be used to study metastable structures, [31,32] and amphiphiles in solution [33,34]. It can be applied to a wide range of amphiphilic molecules, including simple homopolymers [35], more complex copolymers [36,37] and any given mixture of these [38].…”

Section: Self-consistent Field Theorymentioning

confidence: 99%

Hydrophobic droplets in amphiphilic bilayers: a coarse-grained mean-field theory study

Greenall

Marques

2012

Soft Matter

View full text Add to dashboard Cite

Hydrophobic molecules such as oils and certain drugs can be encapsulated between the two leaflets of an amphiphilic bilayer in both lipid and polymer systems. We investigate the case where the hydrophobic molecules are incompatible with the amphiphile tails and so form droplets. Using a coarse-grained mean-field model (self-consistent field theory, or SCFT), we find that droplets of a wide range of sizes have the same characteristic lens shape, and explain this result in terms of simple capillarity arguments, consistent with the measured variations of surface concentrations of amphiphile in the bilayer and in the monolayers that cover the droplet. We study the effect of the strength χ BO of the repulsion between the hydrophobic liquid and the amphiphile tails on the droplet shape, and find a gradual flattening of the droplet as χ BO is reduced. The droplet remains at least metastable even at very low values of χ BO . This is in contrast to the behavior as the length of the hydrophobic molecules is varied. Specifically, if these molecules are at least as long as the amphiphile tails, increasing their length further is found to have little effect on the droplet shape, while reducing their length below this value quickly causes the droplet to become unstable.

show abstract

Section: Self-consistent Field Theorymentioning

confidence: 99%

Hydrophobic droplets in amphiphilic bilayers: a coarse-grained mean-field theory study

Greenall

Marques

2012

Soft Matter

View full text Add to dashboard Cite

show abstract

“…46 We note that micellization can also be studied using SCFT in the grand canonical ensemble. 29,47 The present approach was introduced since it uses the total copolymer volume fraction as input and this quantity can be directly measured in experiments.…”

Section: Self-consistent Field Theorymentioning

confidence: 99%

“…Self-consistent field theory (SCFT) 25 is a coarse-grained mean-field model that has been used successfully to model equilibrium [26][27][28] and metastable 29,30 structures in polymer blends and melts.…”

Section: Self-consistent Field Theorymentioning

confidence: 99%

Simple and Complex Micelles in Amphiphilic Mixtures: A Coarse-Grained Mean-Field Study

Greenall¹,

Gompper

2011

Macromolecules

View full text Add to dashboard Cite

Binary mixtures of amphiphiles in solution can self-assemble into a wide range of structures when the two species individually form aggregates of different curvatures. In this paper, we focus on small, spherically-symmetric aggregates in a solution of sphere-forming amphiphile mixed with a smaller amount of lamella-forming amphiphile. Using a coarsegrained mean-field model (self-consistent field theory, or SCFT), we scan the parameter space of this system and find a range of morphologies as the interaction strength, architecture and mixing ratio of the amphiphiles are varied. When the two species are quite similar in architecture, or when only a small amount of lamella-former is added, we find simple spherical micelles with cores formed from a mixture of the hydrophobic blocks of the two amphiphiles.For more strongly mismatched amphiphiles and higher lamella-former concentrations, we instead find small vesicles and more complex micelles. In these latter structures, the lamella- Simple and complex micelles in . . . be large, and the implications of this for the solubilization of hydrophobic chemicals are considered. The mechanisms behind the formation of the above structures are discussed, with a particular emphasis on the sorting of amphiphiles according to their preferred curvature.

show abstract

“…SCFT can be used to perform calculations in different thermodynamical ensembles [52,64]. In this paper, we perform all calculations in the canonical ensemble, which corresponds to keeping the amounts of copolymer and homopolymer in the simulation box fixed.…”

Section: Self-consistent Field Theorymentioning

confidence: 99%

“…Self-consistent field theory (SCFT) [33] is a mean-field model that has been used with success to calculate the form and free energy of equilibrium [49][50][51] and metastable [52,53] structures in systems composed of homopolymers [54], copolymers [55,56] and mixtures of these [57]. SCFT has several features that make it especially suited to the current problem.…”

Section: Self-consistent Field Theorymentioning

confidence: 99%

Disk-Shaped Bicelles in Block Copolymer/Homopolymer Blends

Greenall

2016

Macromolecules

View full text Add to dashboard Cite

Mixtures of micelle-forming and lamella-forming amphiphiles in solution can form disk-shaped bilayers, sometimes referred to as bicelles. Using self-consistent field theory (SCFT), we investigate the structure and stability of these aggregates in a blend of two species of PS-PDMS diblock with PDMS homopolymer at 225 • C. We find that the center of each disk is mainly composed of lamellaforming diblocks, while its thicker rim is mostly formed of micelle-forming diblocks. However, this segregation is not perfect, and the concentration of micelle formers is of the order of 10% on the flat central surface of the bicelle. We also find that the addition of micelle former to the mixture of lamella former and homopolymer is necessary for disk-like bicelles to be stable. Specifically, the free energy density of the disk has a minimum as a function of the disk radius when both micelle-and lamella-forming diblocks are present, indicating that the bicelles have a preferred, finite radius. However, it decays monotonically when only lamella former is present, indicating that the bicelle structure is always unstable with respect to further aggregation in these systems.Finally, we identify a concentration range where the bicelle is predicted to have a lower free energy density than the simple cylindrical and lamellar aggregates, and so might be thermodynamically stable.PACS numbers:

show abstract

Theory of copolymer micellization

Cited by 31 publications

References 19 publications

Hydrophobic droplets in amphiphilic bilayers: a coarse-grained mean-field theory study

Hydrophobic droplets in amphiphilic bilayers: a coarse-grained mean-field theory study

Simple and Complex Micelles in Amphiphilic Mixtures: A Coarse-Grained Mean-Field Study

Disk-Shaped Bicelles in Block Copolymer/Homopolymer Blends

Contact Info

Product

Resources

About