P. D. Olmsted

Publication List Details

Period

1997 - 2009

Number

43

Co-Authors

Adams and Olmsted Reply to comment on article "A non-monotonic constitutive model is not necessary to obtain shear banding phenomena in entangled polymer solution" [Phys. Rev. Lett. 102, 067801 (2009), arXiv:0805.0679] (2009)

Adams, J. M., Olmsted, P. D.

Wang [Phys. Rev. Lett. 103, 219801 (2009)] makes the following points about our Letter [Phys. Rev. Lett. 102, 067801 (2009), arXiv:0805.0679]: (1) He infers that, "contrary to its title, shear...

Statistical mechanics far from equilibrium: prediction and test for a sheared system (2009)

Evans, R. M. L., Simha, R. A., Baule, A., Olmsted, P. D.

We report the complete statistical treatment of a system of particles interacting via Newtonian forces in continuous boundary-driven flow, far from equilibrium. By numerically time-stepping the...

Two-dimensional perturbations in a scalar model for shear banding (2009)

Dubbeldam, Johan L. A., Olmsted, P. D.

We present an analytical study of a toy model for shear banding, without normal stresses, which uses a piecewise linear approximation to the flow curve (shear stress as a function of shear rate)....

A non-monotonic constitutive model is not necessary to obtain shear banding phenomena in entangled polymer solutions (2008)

Adams, J. M., Olmsted, P. D.

In 1975 Doi and Edwards predicted that entangled polymer melts and solutions can have a constitutive instability, signified by a decreasing stress for shear rates greater than the inverse of the...

The interplay between boundary conditions and flow geometries in shear banding: Hysteresis, band configurations, and surface transitions (2008)

Adams, J.M., Fielding, S.M., Olmsted, P.D.

We study shear banding flows in models of wormlike micelles or polymer solutions, and explore the effects of different boundary conditions for the viscoelastic stress. These are needed because the...

The interplay between boundary conditions and flow geometries in shear banding: hysteresis, band configurations, and surface transitions (2007)

Adams, J. M., Fielding, S. M., Olmsted, P. D.

We study shear banding flows in models of wormlike micelles or polymer solutions, and explore the effects of different boundary conditions for the viscoelastic stress. These are needed because the...

Timescales in shear banding of wormlike micelles (2007)

Radulescu, O., Olmsted, P. D., Decruppe, J. P., Lerouge, S., Berret, J. F., Porte, G.

We show the existence of three well defined time scales in the dynamics of wormlike micelles after a step between two shear rates on the stress plateau. These time scales are compatible with the...

Equilibrium Onions? (2006)

Ramos, L., Roux, D., Olmsted, P. D., Cates, M. E.

We demonstrate the possibility of a stable equilibrium multi-lamellar (``onion'') phase in pure lamellar systems (no excess solvent) due to a sufficiently negative Gaussian curvature modulus. The...

Internal protein dynamics shifts the distance to the mechanical transition state (2006)

West, D.K., Paci, E., Olmsted, P.D.

Mechanical unfolding of polyproteins by force spectroscopy provides valuable insight into their free energy landscapes. Most experiments of the unfolding process have been fit to two-state and/or one...

Validation of the Jarzynski relation for a system with strong thermal coupling: an isothermal ideal gas model (2006)

Baule, A., Evans, R.M.L., Olmsted, P.D.

We revisit the paradigm of an ideal gas under isothermal conditions. A moving piston performs work on an ideal gas in a container that is strongly coupled to a heat reservoir. The thermal coupling is...

Internal protein dynamics shifts the distance to the mechanical transition state (2006)

West, D.K., Paci, E., Olmsted, P.D.

Mechanical unfolding of polyproteins by force spectroscopy provides valuable insight into their free energy landscapes. Most experiments of the unfolding process have been fit to two-state and/or one...

Validation of the Jarzynski relation for a system with strong thermal coupling: an isothermal ideal gas model (2006)

Baule, A., Evans, R.M.L., Olmsted, P.D.

We revisit the paradigm of an ideal gas under isothermal conditions. A moving piston performs work on an ideal gas in a container that is strongly coupled to a heat reservoir. The thermal coupling is...

Validation of the Jarzynski relation for a system with strong thermal coupling: an isothermal ideal gas model (2006)

Baule, A., Evans, R. M. L., Olmsted, P. D.

We revisit the paradigm of an ideal gas under isothermal conditions. A moving piston performs work on an ideal gas in a container that is strongly coupled to a heat reservoir. The thermal coupling is...

Nonlinear dynamics of an interface between shear bands (2006)

Fielding, S.M., Olmsted, P.D.

We study numerically the nonlinear dynamics of a shear banding interface in two-dimensional planar shear flow, within the nonlocal Johnson-Segalman model. Consistent with a recent linear stability...

Equilibrium Onions? (2004)

Ramos, L., Roux, D., Olmsted, P. D., Cates, M. E.

We demonstrate the possibility of a stable equilibrium multi-lamellar (``onion'') phase in pure lamellar systems (no excess solvent) due to a sufficiently negative Gaussian curvature modulus. The...

Lateral phase separation in mixtures of lipids and cholesterol (2004)

Komura, S., Shirotori, H., Olmsted, P.D., Andelman, D.

In an effort to understand "rafts" in biological membranes, we propose phenomenological models for saturated and unsaturated lipid mixtures, and lipid-cholesterol mixtures. We consider simple...

Lateral phase separation in mixtures of lipids and cholesterol (2004)

Komura, S., Shirotori, H., Olmsted, P.D., Andelman, D.

In an effort to understand "rafts" in biological membranes, we propose phenomenological models for saturated and unsaturated lipid mixtures, and lipid-cholesterol mixtures. We consider simple...

Equilibrium onions? (2004)

Ramos, L., Roux, D., Olmsted, P.D., Cates, M.E.

We demonstrate the possibility of a stable equilibrium multi-lamellar ("onion") phase in pure lamellar systems (no excess solvent) due to a sufficiently negative Gaussian curvature modulus. The onion...

Equilibrium onions? (2004)

Ramos, L., Roux, D., Olmsted, P.D., Cates, M.E.

We demonstrate the possibility of a stable equilibrium multi-lamellar ("onion") phase in pure lamellar systems (no excess solvent) due to a sufficiently negative Gaussian curvature modulus. The onion...

Spatio-temporal oscillations and rheochaos in a simple model of shear banding (2004)

Fielding, S.M., Olmsted, P.D.

We study a simple model of shear banding in which the flow-induced phase is destabilized by coupling between flow and microstructure (wormlike micellar length). By varying the strength of instability...

Early stages of crystallization in Isotactic Polypropylene (2003)

Heeley, E.L., Maidens, A.V., Olmsted, P.D., Bras, W., Dolbyna, I.P., Fairclough, J.P.A., ...

An experimental study of the early stages of crystallization in iPP has shown a qualitative difference between the behavior at low supercooling with that observed with a deep quench. To address...

Unfolding dynamics of proteins under applied force (2003)

Smith, D.A., Brockwell, D.J., Zinober, R.C., Blake, A.W., Beddard, G.S., Olmsted, P.D., ...

Understanding the mechanisms of protein folding is a major challenge that is being addressed effectively by collaboration between researchers in the physical and life sciences. Recently, it has...

Time scales in shear banding of wormlike micelles (2003)

Radulescu, O., Olmsted, P.D., Decruppe, J.P., Lerouge, S., Berret, J.F., Porte, G.

Transient stress and birefringence measurements are performed on wormlike micellar solutions that "shear band", i.e. undergo flow-induced coexistence of states of different viscosities along a...

Time scales in shear banding of wormlike micelles (2003)

Radulescu, O., Olmsted, P.D., Decruppe, J.P., Lerouge, S., Berret, J.F., Porte, G.

Transient stress and birefringence measurements are performed on wormlike micellar solutions that "shear band", i.e. undergo flow-induced coexistence of states of different viscosities along a...

Early stage kinetics in a unified model of shear-induced demixing and mechanical shear banding instabilities (2003)

Fielding, S.M., Olmsted, P.D.

We present a unified model of shear-induced demixing and "mechanical" shear banding instabilities in polymeric and surfactant solutions, by combining a simple flow instability with a two-fluid...

Kinetics of the shear banding instability in startup flows (2003)

Fielding, S.M., Olmsted, P.D.

Motivated by recent light scattering experiments on semidilute wormlike micelles, we study the early stages of the shear banding instability using the nonlocal Johnson-Segalman model with a...

Flow phase diagrams for concentration-coupled shear banding (2003)

Fielding, S.M., Olmsted, P.D.

After surveying the experimental evidence for concentration coupling in the shear banding of wormlike micellar surfactant systems, we present flow phase diagrams spanned by shear stress $\Sigma$ (or...

Timescales in shear banding of wormlike micelles (2002)

Radulescu, O., Olmsted, P. D., Decruppe, J. P., Lerouge, S., Berret, J. F., Porte, G.

We show the existence of three well defined time scales in the dynamics of wormlike micelles after a step between two shear rates on the stress plateau. These time scales are compatible with the...

Transient and stationary flow behaviour of side chain liquid-crystalline polymers: Evidence of a shear-induced isotropic-to-nematic phase transition (2002)

Pujolle-Robic, C., Olmsted, P.D., Noirez, L.

This letter describes the non-linear rheology of the isotropic phase of a thermotropic side chain liquid-crystal polymer (SCLCP), from which we infer a flow-induced iso- tropic-to-nematic (IN) phase...

Transient and stationary flow behaviour of side chain liquid-crystalline polymers: Evidence of a shear-induced isotropic-to-nematic phase transition (2002)

Pujolle-Robic, C., Olmsted, P.D., Noirez, L.

This letter describes the non-linear rheology of the isotropic phase of a thermotropic side chain liquid-crystal polymer (SCLCP), from which we infer a flow-induced iso- tropic-to-nematic (IN) phase...

Instability of Myelin Tubes under Dehydration: deswelling of layered cylindrical structures (2001)

Schmidt, C. F., Olmsted, P. D., MacKintosh, F. C.

We report experimental observations of an undulational instability of myelin figures. Motivated by this, we examine theoretically the deformation and possible instability of concentric, cylindrical,...

A Minimal Model for Vorticity and Gradient Banding in Complex Fluids (2001)

Goveas, J. L., Olmsted, P. D.

A general phenomenological reaction-diffusion model for flow-induced phase transitions in complex fluids is presented. The model consists of an equation of motion for a nonconserved composition...

Micro- vs. macro-phase separation in binary blends of poly(styrene)-poly(isoprene) and poly(isoprene)-poly(ethylene oxide) diblock copolymers (2001)

Frielinghaus, H., Hermsdorf, N., Almdal, K., Mortensen, K., Messe, L., Corvazier, L., ...

In this paper we present an experimentally determined phase diagram of binary blends of the diblock copolymers poly(styrene)-poly(isoprene) and poly(isoprene)-poly(ethylene oxide). At high...

Micro- vs. macro-phase separation in binary blends of poly(styrene)-poly(isoprene) and poly(isoprene)-poly(ethylene oxide) diblock copolymers (2001)

Frielinghaus, H., Hermsdorf, N., Almdal, K., Mortensen, K., Messe, L., Corvazier, L., ...

In this paper we present an experimentally determined phase diagram of binary blends of the diblock copolymers poly(styrene)-poly(isoprene) and poly(isoprene)-poly(ethylene oxide). At high...

Matched asymptotic solutions for the steady banded flow of the diffusive Johnson-Segalman model in various geometries (1999)

Radulescu, O, Olmsted, P. D.

We present analytic solutions for steady flow of the Johnson-Segalman (JS) model with a diffusion term in various geometries and under controlled strain rate conditions, using matched asymptotic...

Two-state shear diagrams for complex fluids in shear flow (1999)

Olmsted, P.D.

The possible "phase diagrams'' for shear-induced phase transitions between two phases are collected. We consider shear-thickening and shear-thinning fluids, under conditions of both common strain...

Two-state shear diagrams for complex fluids in shear flow (1999)

Olmsted, P.D.

The possible "phase diagrams'' for shear-induced phase transitions between two phases are collected. We consider shear-thickening and shear-thinning fluids, under conditions of both common strain...

Lifshitz points in blends of AB and BC diblock copolymers (1999)

Olmsted, P.D., Hamley, I.W.

We consider micro- and macro-phase separation in blends of AB and BC flexible diblock copolymers. We show that, depending on architecture, a number of phase diagram topologies are possible....

Lifshitz points in blends of AB and BC diblock copolymers (1999)

Olmsted, P.D., Hamley, I.W.

We consider micro- and macro-phase separation in blends of AB and BC flexible diblock copolymers. We show that, depending on architecture, a number of phase diagram topologies are possible....

Spinodal-assisted crystallization in polymer melts (1998)

Olmsted, P.D., Poon, W.C.K., McLeish, T.C.B., Terrill, N.J., Ryan, A.J.

Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To...

Spinodal-assisted crystallization in polymer melts (1998)

Olmsted, P.D., Poon, W.C.K., McLeish, T.C.B., Terrill, N.J., Ryan, A.J.

Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To...

The Johnson-Segalman model with a diffusion term in Couette flow (1998)

Olmsted, P. D., Radulescu, O., Lu, C. -Y. D.

We study the Johnson-Segalman (JS) model as a paradigm for some complex fluids which are observed to phase separate, or ``shear-band'' in flow. We analyze the behavior of this model in cylindrical...

Microscopic Viscoelasticity: Shear Moduli of Soft Materials Determined from Thermal Fluctuations (1997)

Gittes, F., Schnurr, B., Olmsted, P. D., MacKintosh, F. C., Schmidt, C. F.

We describe a high-resolution, high-bandwidth technique for determining the local viscoelasticity of soft materials such as polymer gels. Loss and storage shear moduli are determined from the power...