Jon Samseth - Academia.edu (original) (raw)

Papers by Jon Samseth

Research paper thumbnail of The Structural Evolution of SDS Micelles in Brine Solution upon Addition of Medium Chain Alcohols

Research paper thumbnail of The Effect of Medium Chain Length Alcohols on the Micellar Properties of Sodium Dodecyl Sulfate in Sodium Chloride Solutions

Journal of Colloid and Interface Science, 1994

ABSTRACT The effect of medium chain length alcohols on the micellar size and shape of sodium dode... more ABSTRACT The effect of medium chain length alcohols on the micellar size and shape of sodium dodecyl sulfate in electrolyte solutions has been investigated by means of small angle neutron scattering (SANS), dynamic light scattering (DLS), and viscosity measurements. The surfactant content was kept constant throughout, at 0.04 m, and the alcohols used were 1-butanol, 1-pentanol, and 1-hexanol. The data from the various techniques are qualitatively in agreement. The SANS data generally fit a model for prolate ellipsoids with varying ratios of the major to minor axis. Addition of butanol first leads to a decrease in micellar size, the major to minor axis ratio decreases from about 6 to less than 2. However, as the butanol concentration exceeds 0.5 m, the micelles starts to grow again. The same can be seen from the diffusion coefficient as measured by DLS. Addition of pentanol or hexanol do not bring about this minimum in micellar size. The minor axis decreases and the major axis increases as these alcohols are added. Thus these alcohols make the prolate ellipsoidal micelles grow continuously towards large rod-like structures. The viscosity data are less detailed, but confirm the general trend upon alcohol addition.

Research paper thumbnail of Influence of Alcohol on the Behavior of Sodium Dodecylsulfate Micelles

Journal of Colloid and Interface Science, 1998

ing neutral salt and a medium chain alcohol . There-The effect of medium chain alcohol molecules ... more ing neutral salt and a medium chain alcohol . There-The effect of medium chain alcohol molecules on the size and fore, these elements make the basic components in most shape of sodium dodecylsulfate micelles, and on the self-diffusion microemulsions. However, the intricate behavior of these coefficient of the surfactant and alcohol, has been investigated by mixed micellar aggregates makes it difficult to predict any means of small angle neutron scattering (SANS), and Fourier variation in the system upon variation in the composition of transform pulsed field gradient spin echo (FT-PGSE) nuclear the solution. This problem is caused by a delicate balance magnetic resonance measurements. All measurements were done of attractive and repulsive forces among the amphiphilic in D 2 O containing a sodium chloride concentration of 0.4 mol/kg, molecules in the micelles. and a surfactant concentration of 0.04 mol/kg. The alcohols used

Research paper thumbnail of Thermodynamic theory and experimental studies on mixed short-chain lecithin micelles

Progress in Colloid & Polymer Science, 2000

ABSTRACT

Research paper thumbnail of Structural evolution of bicontinuous microemulsions

The Journal of Physical Chemistry, 1991

ABSTRACT

Research paper thumbnail of Nanoparticle-Regulated Phase Behavior and Morphological Development in an Ordered Block Copolymer

Aps Meeting Abstracts, Mar 1, 2008

Although microphase-ordered block copolymer motifs are employed to template inorganic nanoparticl... more Although microphase-ordered block copolymer motifs are employed to template inorganic nanoparticles, only recently has the effect of nanoparticles on copolymer self-assembly been explored. In this work, we examine the influence of nanoparticles on the copolymer order-disorder transition (ODT) temperature. Theoretical results from a hybrid self-consistent field/density functional theory -- supported by experimental observations of a model copolymer/nanoparticle system -- confirm that judicious selection of nanoparticle size and selectivity can be used to increase the ODT temperature at constant concentration. For a given nanoparticle size and selectivity, we show that there likewise exists a critical nanoparticle concentration beyond which the ODT temperature decreases. The ability of nanoparticles to increase the ODT temperature is a unique consequence of their size and is not expected for small-molecule additives. At high concentrations, the nanoparticles form percolated colloidal networks that represent highly confined environments for the copolymer molecules.

Research paper thumbnail of SANS studies of the microstructure of a three-componnent microemulsion

Journal of Applied Crystallography

ABSTRACT

Research paper thumbnail of Microstructure Characteristics of Microphase-Separated Tapered Block Copolymers

Research paper thumbnail of A Small-Angle-Neutron-Scattering Study of a Synthetic Clay

The synthetic monodisperse model clay Laponite RD has been studied by means of Small-Angle-Neutro... more The synthetic monodisperse model clay Laponite RD has been studied by means of Small-Angle-Neutron-Scattering (SANS). The investigated clay-water concentration regime include the reported(J-C P. Gabriel et.al., J.Phys.Chem. 100, 11139 (1996))transitions from isotropic liquid (IL) to isotropic gel (IG) to nematic gel (NG) in pure water. The present SANS data scale with the number of scatterers which is proportional to the

Research paper thumbnail of Morphological Studies of Weakly-Segregated Diblock Copolymer/Homopolymer and Copolymer/Copolymer Blends

Research paper thumbnail of The Structural Evolution of SDS Micelles in Brine Solution upon Addition of Medium Chain Alcohols

Research paper thumbnail of Effect of the wind turbine wake in large offshore wind farms

The aim of this paper is to evaluate the wake effect on the performance of a wind farm using two ... more The aim of this paper is to evaluate the wake effect on the performance of a wind farm using two approaches: CFD (OffWindSolver) and engineering model (OffWindEng). CFD computation is developed with in the OpenFoam architecture. Unsteady PisoFoam solver is extended to account for wind turbines, where each turbine is modeled as a sink term in the momentum equation. Turbine modeling is based on actuator line concept derived from SOWFA code, where each blades of the turbine is represented as a line points. A second approach is a simplified explicit model of the wake (enginnering model), which includes: the cumulative impact of multiple shadowing, the effects of wind direction and the wind speed time delay. Results from two approaches are applied to Lillgrund wind turbine farm to illustrate the importance of wind turbine spacing: the presence of the wake can induce dramatic energy production. The maximum loss is 50% from the designed farm production, which occurs when the wind direction...

Research paper thumbnail of Configurational studies of microphase-separated diblock copolymers in the solid state

Polymer, 1991

... Configurational studies of microphase-separated diblock copolymers in the solid state Richard... more ... Configurational studies of microphase-separated diblock copolymers in the solid state Richard J. Spontak* and Jon Samseth Department of Physics, Institute for Energy Technology, 2007 Kjeller, Norway and John M. Zielinski ... 1984, 25, 265 11 Vang, Z.-G.andSafran, SAPolym. ...

Research paper thumbnail of Macromolecular self-assembly in dilute sequence-controlled block copolymer/homopolymer blends

Supramolecular Science, 1997

Conventional block copolymers consist of two long contiguous monomer sequences ('blocks') that ca... more Conventional block copolymers consist of two long contiguous monomer sequences ('blocks') that can, in the same fashion as low-molar-mass surfactants, self-assemble into various microstructural elements (e.g., micelles at low copolymer concentrations) to minimize repulsive contacts in the presence of a parent homopolymer. In this work, we explore the existence of segment-specific interactions, as well as the possibility of tailoring these blend morphologies (and producing altogether new ones), with novel sequence-controlled block copolymers. These copolymers are comprised of at least one block that is a random segment composed of both constituent monomer species. Transmission electron microscopy is employed here to examine the bilayered membranes and channel structures that form in two different series of such copolymers in dilute copolymer/homopolymer blends. 0 1997 Elsevier Science Ltd. All rights reserved.

Research paper thumbnail of Band formation during gaseous diffusion in aerogels

Physical Review E, 1998

We study experimentally how gaseous HCl and NH3 diffuse from opposite sides of and react in silic... more We study experimentally how gaseous HCl and NH3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.

Research paper thumbnail of Nanoparticle-regulated phase behavior of ordered block copolymers

Soft Matter, 2008

Although block copolymer motifs have received considerable attention as supramolecular templates ... more Although block copolymer motifs have received considerable attention as supramolecular templates for inorganic nanoparticles, experimental observations of a nanostructured diblock copolymer containing inorganic nanoparticles-supported by theoretical trends predicted from a hybrid self-consistent field/density functional theory-confirm that nanoparticle size and selectivity can likewise stabilize the copolymer nanostructure by increasing its orderdisorder transition temperature.

Research paper thumbnail of OffWindSolver: Wind farm design tool based on actuator line/actuator disk concept in OpenFoam architecture

ITM Web of Conferences, 2014

Research paper thumbnail of Crosslinking High Free Volume Polymers - Effect on Gas Separation Properties

MRS Proceedings, 2007

ABSTRACT

Research paper thumbnail of Effect of Plasma Treatment on the Gas Permeability of Poly(4-methyl-2-pentyne) Membranes

Plasma Processes and Polymers, 2007

ABSTRACT

Research paper thumbnail of Small-angle neutron scattering studies on the size distribution of mixed micelles

Physica B: Condensed Matter, 1997

diC6PC and diC7PC mixed micelles are investigated by small-angle neutron scattering. The size dis... more diC6PC and diC7PC mixed micelles are investigated by small-angle neutron scattering. The size distribution of the mixed micelles is determined from the SANS data by using the indirect transform method and is found to have only a single distribution peak. This indicates that the diC6PC and diC7PC do not segregate to form two size groups of micelles. The size distribution peak of these mixed micelles is also found to change from broad to narrow as the percentage of diC6PC is increased, indicative of changing from polydisperse rod-like micelles to globular micelles.

Research paper thumbnail of The Structural Evolution of SDS Micelles in Brine Solution upon Addition of Medium Chain Alcohols

Research paper thumbnail of The Effect of Medium Chain Length Alcohols on the Micellar Properties of Sodium Dodecyl Sulfate in Sodium Chloride Solutions

Journal of Colloid and Interface Science, 1994

ABSTRACT The effect of medium chain length alcohols on the micellar size and shape of sodium dode... more ABSTRACT The effect of medium chain length alcohols on the micellar size and shape of sodium dodecyl sulfate in electrolyte solutions has been investigated by means of small angle neutron scattering (SANS), dynamic light scattering (DLS), and viscosity measurements. The surfactant content was kept constant throughout, at 0.04 m, and the alcohols used were 1-butanol, 1-pentanol, and 1-hexanol. The data from the various techniques are qualitatively in agreement. The SANS data generally fit a model for prolate ellipsoids with varying ratios of the major to minor axis. Addition of butanol first leads to a decrease in micellar size, the major to minor axis ratio decreases from about 6 to less than 2. However, as the butanol concentration exceeds 0.5 m, the micelles starts to grow again. The same can be seen from the diffusion coefficient as measured by DLS. Addition of pentanol or hexanol do not bring about this minimum in micellar size. The minor axis decreases and the major axis increases as these alcohols are added. Thus these alcohols make the prolate ellipsoidal micelles grow continuously towards large rod-like structures. The viscosity data are less detailed, but confirm the general trend upon alcohol addition.

Research paper thumbnail of Influence of Alcohol on the Behavior of Sodium Dodecylsulfate Micelles

Journal of Colloid and Interface Science, 1998

ing neutral salt and a medium chain alcohol . There-The effect of medium chain alcohol molecules ... more ing neutral salt and a medium chain alcohol . There-The effect of medium chain alcohol molecules on the size and fore, these elements make the basic components in most shape of sodium dodecylsulfate micelles, and on the self-diffusion microemulsions. However, the intricate behavior of these coefficient of the surfactant and alcohol, has been investigated by mixed micellar aggregates makes it difficult to predict any means of small angle neutron scattering (SANS), and Fourier variation in the system upon variation in the composition of transform pulsed field gradient spin echo (FT-PGSE) nuclear the solution. This problem is caused by a delicate balance magnetic resonance measurements. All measurements were done of attractive and repulsive forces among the amphiphilic in D 2 O containing a sodium chloride concentration of 0.4 mol/kg, molecules in the micelles. and a surfactant concentration of 0.04 mol/kg. The alcohols used

Research paper thumbnail of Thermodynamic theory and experimental studies on mixed short-chain lecithin micelles

Progress in Colloid & Polymer Science, 2000

ABSTRACT

Research paper thumbnail of Structural evolution of bicontinuous microemulsions

The Journal of Physical Chemistry, 1991

ABSTRACT

Research paper thumbnail of Nanoparticle-Regulated Phase Behavior and Morphological Development in an Ordered Block Copolymer

Aps Meeting Abstracts, Mar 1, 2008

Although microphase-ordered block copolymer motifs are employed to template inorganic nanoparticl... more Although microphase-ordered block copolymer motifs are employed to template inorganic nanoparticles, only recently has the effect of nanoparticles on copolymer self-assembly been explored. In this work, we examine the influence of nanoparticles on the copolymer order-disorder transition (ODT) temperature. Theoretical results from a hybrid self-consistent field/density functional theory -- supported by experimental observations of a model copolymer/nanoparticle system -- confirm that judicious selection of nanoparticle size and selectivity can be used to increase the ODT temperature at constant concentration. For a given nanoparticle size and selectivity, we show that there likewise exists a critical nanoparticle concentration beyond which the ODT temperature decreases. The ability of nanoparticles to increase the ODT temperature is a unique consequence of their size and is not expected for small-molecule additives. At high concentrations, the nanoparticles form percolated colloidal networks that represent highly confined environments for the copolymer molecules.

Research paper thumbnail of SANS studies of the microstructure of a three-componnent microemulsion

Journal of Applied Crystallography

ABSTRACT

Research paper thumbnail of Microstructure Characteristics of Microphase-Separated Tapered Block Copolymers

Research paper thumbnail of A Small-Angle-Neutron-Scattering Study of a Synthetic Clay

The synthetic monodisperse model clay Laponite RD has been studied by means of Small-Angle-Neutro... more The synthetic monodisperse model clay Laponite RD has been studied by means of Small-Angle-Neutron-Scattering (SANS). The investigated clay-water concentration regime include the reported(J-C P. Gabriel et.al., J.Phys.Chem. 100, 11139 (1996))transitions from isotropic liquid (IL) to isotropic gel (IG) to nematic gel (NG) in pure water. The present SANS data scale with the number of scatterers which is proportional to the

Research paper thumbnail of Morphological Studies of Weakly-Segregated Diblock Copolymer/Homopolymer and Copolymer/Copolymer Blends

Research paper thumbnail of The Structural Evolution of SDS Micelles in Brine Solution upon Addition of Medium Chain Alcohols

Research paper thumbnail of Effect of the wind turbine wake in large offshore wind farms

The aim of this paper is to evaluate the wake effect on the performance of a wind farm using two ... more The aim of this paper is to evaluate the wake effect on the performance of a wind farm using two approaches: CFD (OffWindSolver) and engineering model (OffWindEng). CFD computation is developed with in the OpenFoam architecture. Unsteady PisoFoam solver is extended to account for wind turbines, where each turbine is modeled as a sink term in the momentum equation. Turbine modeling is based on actuator line concept derived from SOWFA code, where each blades of the turbine is represented as a line points. A second approach is a simplified explicit model of the wake (enginnering model), which includes: the cumulative impact of multiple shadowing, the effects of wind direction and the wind speed time delay. Results from two approaches are applied to Lillgrund wind turbine farm to illustrate the importance of wind turbine spacing: the presence of the wake can induce dramatic energy production. The maximum loss is 50% from the designed farm production, which occurs when the wind direction...

Research paper thumbnail of Configurational studies of microphase-separated diblock copolymers in the solid state

Polymer, 1991

... Configurational studies of microphase-separated diblock copolymers in the solid state Richard... more ... Configurational studies of microphase-separated diblock copolymers in the solid state Richard J. Spontak* and Jon Samseth Department of Physics, Institute for Energy Technology, 2007 Kjeller, Norway and John M. Zielinski ... 1984, 25, 265 11 Vang, Z.-G.andSafran, SAPolym. ...

Research paper thumbnail of Macromolecular self-assembly in dilute sequence-controlled block copolymer/homopolymer blends

Supramolecular Science, 1997

Conventional block copolymers consist of two long contiguous monomer sequences ('blocks') that ca... more Conventional block copolymers consist of two long contiguous monomer sequences ('blocks') that can, in the same fashion as low-molar-mass surfactants, self-assemble into various microstructural elements (e.g., micelles at low copolymer concentrations) to minimize repulsive contacts in the presence of a parent homopolymer. In this work, we explore the existence of segment-specific interactions, as well as the possibility of tailoring these blend morphologies (and producing altogether new ones), with novel sequence-controlled block copolymers. These copolymers are comprised of at least one block that is a random segment composed of both constituent monomer species. Transmission electron microscopy is employed here to examine the bilayered membranes and channel structures that form in two different series of such copolymers in dilute copolymer/homopolymer blends. 0 1997 Elsevier Science Ltd. All rights reserved.

Research paper thumbnail of Band formation during gaseous diffusion in aerogels

Physical Review E, 1998

We study experimentally how gaseous HCl and NH3 diffuse from opposite sides of and react in silic... more We study experimentally how gaseous HCl and NH3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.

Research paper thumbnail of Nanoparticle-regulated phase behavior of ordered block copolymers

Soft Matter, 2008

Although block copolymer motifs have received considerable attention as supramolecular templates ... more Although block copolymer motifs have received considerable attention as supramolecular templates for inorganic nanoparticles, experimental observations of a nanostructured diblock copolymer containing inorganic nanoparticles-supported by theoretical trends predicted from a hybrid self-consistent field/density functional theory-confirm that nanoparticle size and selectivity can likewise stabilize the copolymer nanostructure by increasing its orderdisorder transition temperature.

Research paper thumbnail of OffWindSolver: Wind farm design tool based on actuator line/actuator disk concept in OpenFoam architecture

ITM Web of Conferences, 2014

Research paper thumbnail of Crosslinking High Free Volume Polymers - Effect on Gas Separation Properties

MRS Proceedings, 2007

ABSTRACT

Research paper thumbnail of Effect of Plasma Treatment on the Gas Permeability of Poly(4-methyl-2-pentyne) Membranes

Plasma Processes and Polymers, 2007

ABSTRACT

Research paper thumbnail of Small-angle neutron scattering studies on the size distribution of mixed micelles

Physica B: Condensed Matter, 1997

diC6PC and diC7PC mixed micelles are investigated by small-angle neutron scattering. The size dis... more diC6PC and diC7PC mixed micelles are investigated by small-angle neutron scattering. The size distribution of the mixed micelles is determined from the SANS data by using the indirect transform method and is found to have only a single distribution peak. This indicates that the diC6PC and diC7PC do not segregate to form two size groups of micelles. The size distribution peak of these mixed micelles is also found to change from broad to narrow as the percentage of diC6PC is increased, indicative of changing from polydisperse rod-like micelles to globular micelles.