Coexistence of spheres and rods in micellar solution of dodecyldimethylamine oxide

P.R. Majhi, P.L. Dubin, X.H. Feng, X.H. Ruo, F.A.M. Leermakers, C. Tribet

    Research output: Contribution to journalArticleAcademicpeer-review

    43 Citations (Scopus)

    Abstract

    Micelles of dimethyldodecylamine oxide (DMDAO) are known to exhibit sphere-to-rod transitions as a function of pH and ionic strength. Long micelles are stabilized at pH corresponding to half-protonation, because hydrogen bonding between nonionic and protonated monomers yields an effectively double-tailed monomer whose geometry favors cylindrical growth. Dynamic light scattering (DLS) was used to follow particle size distribution as a function of pH, ionic strength (I), and surfactant concentration. The key finding was the coexistence of spherical micelles with rodlike ones at 4 <pH <6 and I > 0.2 M. These observations have been verified by varying the algorithm used for the Laplace transformation of the autocorrelation function and also with different DLS systems. The effect of surfactant concentration was used to confirm the absence of any influence of micelle - micelle interaction on the dynamics of diffusion. A molecular level self-consistent field analysis of finite size rodlike micelles confirms the idea that the endcaps are swollen with respect to the cylindrical part. The theoretical results support the coexistence of rods and spherical micelles, i.e., the existence of gaps in the size distribution of wormlike micelles. The cause of coexistence has been explained in terms of the instability of dumbbell-like micelles with domains of negative curvature (neck). The endcap energy is shown to be given (in first order) by the grand potential of spherical micelles that coexist with the wormlike micelles.
    Original languageEnglish
    Pages (from-to)5980-5988
    JournalThe Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical
    Volume108
    Issue number19
    DOIs
    Publication statusPublished - 2004

    Fingerprint

    Micelles
    micelles
    rods
    Oxides
    oxides
    Dynamic light scattering
    Ionic strength
    Surface-Active Agents
    Surface active agents
    dodecyldimethylamine oxide
    light scattering
    monomers
    Monomers
    surfactants
    Laplace transformation
    Protonation
    particle size distribution
    Autocorrelation
    Particle size analysis
    autocorrelation

    Keywords

    • interacting chain molecules
    • dynamic light-scattering
    • dimethyldodecylamine oxide
    • statistical thermodynamics
    • aqueous-solutions
    • association colloids
    • cationic surfactant
    • ionic-strength
    • salt-solutions
    • size

    Cite this

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    title = "Coexistence of spheres and rods in micellar solution of dodecyldimethylamine oxide",
    abstract = "Micelles of dimethyldodecylamine oxide (DMDAO) are known to exhibit sphere-to-rod transitions as a function of pH and ionic strength. Long micelles are stabilized at pH corresponding to half-protonation, because hydrogen bonding between nonionic and protonated monomers yields an effectively double-tailed monomer whose geometry favors cylindrical growth. Dynamic light scattering (DLS) was used to follow particle size distribution as a function of pH, ionic strength (I), and surfactant concentration. The key finding was the coexistence of spherical micelles with rodlike ones at 4 0.2 M. These observations have been verified by varying the algorithm used for the Laplace transformation of the autocorrelation function and also with different DLS systems. The effect of surfactant concentration was used to confirm the absence of any influence of micelle - micelle interaction on the dynamics of diffusion. A molecular level self-consistent field analysis of finite size rodlike micelles confirms the idea that the endcaps are swollen with respect to the cylindrical part. The theoretical results support the coexistence of rods and spherical micelles, i.e., the existence of gaps in the size distribution of wormlike micelles. The cause of coexistence has been explained in terms of the instability of dumbbell-like micelles with domains of negative curvature (neck). The endcap energy is shown to be given (in first order) by the grand potential of spherical micelles that coexist with the wormlike micelles.",
    keywords = "interacting chain molecules, dynamic light-scattering, dimethyldodecylamine oxide, statistical thermodynamics, aqueous-solutions, association colloids, cationic surfactant, ionic-strength, salt-solutions, size",
    author = "P.R. Majhi and P.L. Dubin and X.H. Feng and X.H. Ruo and F.A.M. Leermakers and C. Tribet",
    year = "2004",
    doi = "10.1021/jp0374307",
    language = "English",
    volume = "108",
    pages = "5980--5988",
    journal = "The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical",
    issn = "1520-6106",
    publisher = "American Chemical Society",
    number = "19",

    }

    Coexistence of spheres and rods in micellar solution of dodecyldimethylamine oxide. / Majhi, P.R.; Dubin, P.L.; Feng, X.H.; Ruo, X.H.; Leermakers, F.A.M.; Tribet, C.

    In: The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical, Vol. 108, No. 19, 2004, p. 5980-5988.

    Research output: Contribution to journalArticleAcademicpeer-review

    TY - JOUR

    T1 - Coexistence of spheres and rods in micellar solution of dodecyldimethylamine oxide

    AU - Majhi, P.R.

    AU - Dubin, P.L.

    AU - Feng, X.H.

    AU - Ruo, X.H.

    AU - Leermakers, F.A.M.

    AU - Tribet, C.

    PY - 2004

    Y1 - 2004

    N2 - Micelles of dimethyldodecylamine oxide (DMDAO) are known to exhibit sphere-to-rod transitions as a function of pH and ionic strength. Long micelles are stabilized at pH corresponding to half-protonation, because hydrogen bonding between nonionic and protonated monomers yields an effectively double-tailed monomer whose geometry favors cylindrical growth. Dynamic light scattering (DLS) was used to follow particle size distribution as a function of pH, ionic strength (I), and surfactant concentration. The key finding was the coexistence of spherical micelles with rodlike ones at 4 0.2 M. These observations have been verified by varying the algorithm used for the Laplace transformation of the autocorrelation function and also with different DLS systems. The effect of surfactant concentration was used to confirm the absence of any influence of micelle - micelle interaction on the dynamics of diffusion. A molecular level self-consistent field analysis of finite size rodlike micelles confirms the idea that the endcaps are swollen with respect to the cylindrical part. The theoretical results support the coexistence of rods and spherical micelles, i.e., the existence of gaps in the size distribution of wormlike micelles. The cause of coexistence has been explained in terms of the instability of dumbbell-like micelles with domains of negative curvature (neck). The endcap energy is shown to be given (in first order) by the grand potential of spherical micelles that coexist with the wormlike micelles.

    AB - Micelles of dimethyldodecylamine oxide (DMDAO) are known to exhibit sphere-to-rod transitions as a function of pH and ionic strength. Long micelles are stabilized at pH corresponding to half-protonation, because hydrogen bonding between nonionic and protonated monomers yields an effectively double-tailed monomer whose geometry favors cylindrical growth. Dynamic light scattering (DLS) was used to follow particle size distribution as a function of pH, ionic strength (I), and surfactant concentration. The key finding was the coexistence of spherical micelles with rodlike ones at 4 0.2 M. These observations have been verified by varying the algorithm used for the Laplace transformation of the autocorrelation function and also with different DLS systems. The effect of surfactant concentration was used to confirm the absence of any influence of micelle - micelle interaction on the dynamics of diffusion. A molecular level self-consistent field analysis of finite size rodlike micelles confirms the idea that the endcaps are swollen with respect to the cylindrical part. The theoretical results support the coexistence of rods and spherical micelles, i.e., the existence of gaps in the size distribution of wormlike micelles. The cause of coexistence has been explained in terms of the instability of dumbbell-like micelles with domains of negative curvature (neck). The endcap energy is shown to be given (in first order) by the grand potential of spherical micelles that coexist with the wormlike micelles.

    KW - interacting chain molecules

    KW - dynamic light-scattering

    KW - dimethyldodecylamine oxide

    KW - statistical thermodynamics

    KW - aqueous-solutions

    KW - association colloids

    KW - cationic surfactant

    KW - ionic-strength

    KW - salt-solutions

    KW - size

    U2 - 10.1021/jp0374307

    DO - 10.1021/jp0374307

    M3 - Article

    VL - 108

    SP - 5980

    EP - 5988

    JO - The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical

    JF - The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces & Biophysical

    SN - 1520-6106

    IS - 19

    ER -