The Experts below are selected from a list of 471 Experts worldwide ranked by ideXlab platform

Lars Wagberg - One of the best experts on this subject based on the ideXlab platform.

R Miller - One of the best experts on this subject based on the ideXlab platform.

  • effect of surfactant hydrophobicity on the interfacial properties of Polyallylamine Hydrochloride sodium alkylsulphate at water hexane interface
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
    Co-Authors: A Sharipova, Saule Aidarova, Peter Cernoch, R Miller
    Abstract:

    The bulk, interfacial and emulsion (water/hexane interface) properties of mixtures of the cationic polyelectrolyte Polyallylamine Hydrochloride (PAH) and anionic surfactants sodium alkyl sulphates with different alkyl chain length from C10 to C16 are studied via zeta potential (ζ), dynamic light scattering, interfacial tension and dilational rheology measurements. It was established that with increasing surfactant’s alkyl chain length the interfacial tension of mixtures with the polymer decreases as expected while ζ-potentials change remarkably when passing from C12 to C14. Based on the hydrodynamic radii of the formed complexes it can be concluded that for SDS the most dense compact statistical coils of polycomplexes are formed due to both electrostatic and hydrophobic interactions. The large hydrodynamic radii of the PAH/STS and PAH/SHS polycomplexes indicate the formation of bulky swollen associates. The difference in the structure of the polycomplexes changing from dense dispersed particles to bulky associates, at large radicals can effect to the strength and the physical and mechanical characteristic parameters of the interfacial adsorption layers and determines the stability of corresponding emulsion films.

  • dynamics of adsorption of Polyallylamine Hydrochloride sodium dodecyl sulphate at water air and water hexane interfaces
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: A Sharipova, Saule Aidarova, V B Fainerman, Antonio Stocco, Peter Cernoch, R Miller
    Abstract:

    Abstract The present work is devoted to the study of interactions between a cationic polyelectrolyte and an anionic surfactant in the solution bulk and at the water/air and water/oil interfaces. For this purpose surface and interfacial tensions, zeta potential, ellipsometry and dynamic light scattering (DLS) were used to describe the formation of complexes of Polyallylamine Hydrochloride (PAH) and sodium dodecyl sulphate (SDS). Surface and interfacial tension results are supported by zeta potential measurements and aggregation size measurements via DLS. Due to electrostatic binding of dodecyl sulphate anions to the positive charges of the polyelectrolyte chains the resulting complexes become more hydrophobic. At the 1:1 ratio of PAH:SDS the complexes precipitate and become recharged due to the additional hydrophobic binding of SDS ions. The complexation leads to a depletion of surfactant and hence to an increase in surface and interfacial tensions.

Christopher J Barrett - One of the best experts on this subject based on the ideXlab platform.

  • swelling behavior of hyaluronic acid Polyallylamine Hydrochloride multilayer films
    Biomacromolecules, 2005
    Co-Authors: Susan E Burke, Christopher J Barrett
    Abstract:

    The reversible swelling behavior of multilayer films containing hyaluronic acid and Polyallylamine Hydrochloride was investigated using in situ ellipsometry, since many of the natural functions and applied uses of hyaluronic acid are related to the extraordinary ability of this biopolymer to swell, and to respond conformationally to the local solution environment. This swelling was observed to be substantial, and depended strongly on the film thickness, the pH conditions used to prepare the films, and the swelling solution pH and ionic strength. The swelling results were also rationalized in terms of the dissociation behavior of the polyelectrolytes in the multilayer assemblies, measured by the zeta potential, on colloidal particles. The films were found to swell by as much as 8 times their dry thickness, and the extent of film hydration was observed to depend on the thickness of the films in a nonlinear fashion. This was related to the internal structure of the films, which is dictated by the assembly pH conditions. In addition, the swelling solution pH and ionic strength influence the electrostatic environment in the films and, in turn, have a substantial effect on the overall swelling behavior.

  • Swelling Behavior of Hyaluronic Acid/Polyallylamine Hydrochloride Multilayer Films
    2004
    Co-Authors: Susan E Burke, Christopher J Barrett
    Abstract:

    The reversible swelling behavior of multilayer films containing hyaluronic acid and Polyallylamine Hydrochloride was investigated using in situ ellipsometry, since many of the natural functions and applied uses of hyaluronic acid are related to the extraordinary ability of this biopolymer to swell, and to respond conformationally to the local solution environment. This swelling was observed to be substantial, and depended strongly on the film thickness, the pH conditions used to prepare the films, and the swelling solution pH and ionic strength. The swelling results were also rationalized in terms of the dissociation behavior of the polyelectrolytes in the multilayer assemblies, measured by the œ potential, on colloidal particles. The films were found to swell by as much as 8 times their dry thickness, and the extent of film hydration was observed to depend on the thickness of the films in a nonlinear fashion. This was related to the internal structure of the films, which is dictated by the assembly pH conditions. In addition, the swelling solution pH and ionic strength influence the electrostatic environment in the films and, in turn, have a substantial effect on the overall swelling behavior

A Sharipova - One of the best experts on this subject based on the ideXlab platform.

  • effect of surfactant hydrophobicity on the interfacial properties of Polyallylamine Hydrochloride sodium alkylsulphate at water hexane interface
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013
    Co-Authors: A Sharipova, Saule Aidarova, Peter Cernoch, R Miller
    Abstract:

    The bulk, interfacial and emulsion (water/hexane interface) properties of mixtures of the cationic polyelectrolyte Polyallylamine Hydrochloride (PAH) and anionic surfactants sodium alkyl sulphates with different alkyl chain length from C10 to C16 are studied via zeta potential (ζ), dynamic light scattering, interfacial tension and dilational rheology measurements. It was established that with increasing surfactant’s alkyl chain length the interfacial tension of mixtures with the polymer decreases as expected while ζ-potentials change remarkably when passing from C12 to C14. Based on the hydrodynamic radii of the formed complexes it can be concluded that for SDS the most dense compact statistical coils of polycomplexes are formed due to both electrostatic and hydrophobic interactions. The large hydrodynamic radii of the PAH/STS and PAH/SHS polycomplexes indicate the formation of bulky swollen associates. The difference in the structure of the polycomplexes changing from dense dispersed particles to bulky associates, at large radicals can effect to the strength and the physical and mechanical characteristic parameters of the interfacial adsorption layers and determines the stability of corresponding emulsion films.

  • dynamics of adsorption of Polyallylamine Hydrochloride sodium dodecyl sulphate at water air and water hexane interfaces
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011
    Co-Authors: A Sharipova, Saule Aidarova, V B Fainerman, Antonio Stocco, Peter Cernoch, R Miller
    Abstract:

    Abstract The present work is devoted to the study of interactions between a cationic polyelectrolyte and an anionic surfactant in the solution bulk and at the water/air and water/oil interfaces. For this purpose surface and interfacial tensions, zeta potential, ellipsometry and dynamic light scattering (DLS) were used to describe the formation of complexes of Polyallylamine Hydrochloride (PAH) and sodium dodecyl sulphate (SDS). Surface and interfacial tension results are supported by zeta potential measurements and aggregation size measurements via DLS. Due to electrostatic binding of dodecyl sulphate anions to the positive charges of the polyelectrolyte chains the resulting complexes become more hydrophobic. At the 1:1 ratio of PAH:SDS the complexes precipitate and become recharged due to the additional hydrophobic binding of SDS ions. The complexation leads to a depletion of surfactant and hence to an increase in surface and interfacial tensions.

Susan E Burke - One of the best experts on this subject based on the ideXlab platform.

  • swelling behavior of hyaluronic acid Polyallylamine Hydrochloride multilayer films
    Biomacromolecules, 2005
    Co-Authors: Susan E Burke, Christopher J Barrett
    Abstract:

    The reversible swelling behavior of multilayer films containing hyaluronic acid and Polyallylamine Hydrochloride was investigated using in situ ellipsometry, since many of the natural functions and applied uses of hyaluronic acid are related to the extraordinary ability of this biopolymer to swell, and to respond conformationally to the local solution environment. This swelling was observed to be substantial, and depended strongly on the film thickness, the pH conditions used to prepare the films, and the swelling solution pH and ionic strength. The swelling results were also rationalized in terms of the dissociation behavior of the polyelectrolytes in the multilayer assemblies, measured by the zeta potential, on colloidal particles. The films were found to swell by as much as 8 times their dry thickness, and the extent of film hydration was observed to depend on the thickness of the films in a nonlinear fashion. This was related to the internal structure of the films, which is dictated by the assembly pH conditions. In addition, the swelling solution pH and ionic strength influence the electrostatic environment in the films and, in turn, have a substantial effect on the overall swelling behavior.

  • Swelling Behavior of Hyaluronic Acid/Polyallylamine Hydrochloride Multilayer Films
    2004
    Co-Authors: Susan E Burke, Christopher J Barrett
    Abstract:

    The reversible swelling behavior of multilayer films containing hyaluronic acid and Polyallylamine Hydrochloride was investigated using in situ ellipsometry, since many of the natural functions and applied uses of hyaluronic acid are related to the extraordinary ability of this biopolymer to swell, and to respond conformationally to the local solution environment. This swelling was observed to be substantial, and depended strongly on the film thickness, the pH conditions used to prepare the films, and the swelling solution pH and ionic strength. The swelling results were also rationalized in terms of the dissociation behavior of the polyelectrolytes in the multilayer assemblies, measured by the œ potential, on colloidal particles. The films were found to swell by as much as 8 times their dry thickness, and the extent of film hydration was observed to depend on the thickness of the films in a nonlinear fashion. This was related to the internal structure of the films, which is dictated by the assembly pH conditions. In addition, the swelling solution pH and ionic strength influence the electrostatic environment in the films and, in turn, have a substantial effect on the overall swelling behavior