Viscoelasticity of Polymer Liquid

Polymer melt dynamics: microscopic roots of fractional viscoelasticity.

The rheological properties of polymer melts and other complex macromolecular fluids are often successfully modeled by phenomenological constitutive equations containing fractional differential operators. We suggest a molecular basis for such fractional equations in terms of the generalized Langevin equation (GLE) that underlies the renormalized Rouse model developed by Schweizer [J. Chem. Phys....

Linear viscoelasticity of a single semiflexible polymer with internal friction.

The linear viscoelastic behaviors of single semiflexible chains with internal friction are studied based on the wormlike-chain model. It is shown that the frequency dependence of the complex compliance in the high frequency limit is the same as that of the Voigt model. This asymptotic behavior appears also for the Rouse model with internal friction. We derive the characteristic times for both t...

Viscoelasticity of Depletion-Induced Gels in Emulsion-Polymer Systems

Using rheometry and light scattering, we have studied the viscoelasticity of gels formed by the kinetically arrested phase separation in an emulsion-polymer mixture; to prevent the gels from collapsing under their own weight, we have used an isopycnic solvent. At constant osmotic pressure (set by the polymer concentration) and droplet volume fractionsφ well above the gelation transition, we fin...

Viscoelasticity of nematic liquid crystals at a glance.

Polarised microscopy is shown to be a powerful alternative to light scattering for the determination of the viscoelasticity of aligned nematic liquid crystals. We perform experiments in a wide range of temperatures by using an adapted version of the recently introduced differential dynamic microscopy technique, which enables us to extract scattering information directly from the microscope imag...

Viscoelasticity in Nanoscale Friction on Thin Polymer Films