Biomedical subjects

Michael Plischke

Publications and source records attributed to Michael Plischke.

2 recordsLinked to original sources

PubMed2003

Transport properties of incipient gels.

We investigate the behavior of the shear viscosity eta(p) and the mass-dependent diffusion coefficient D(m,p) in the context of a simple model that, as the cross link density p is increased, undergoes a continuous transition from a fluid to a gel. The shear viscosity diverges at the gel point according to eta(p) approximately (p(c)-p)(-s) with s approximately 0.65. The diffusion constant shows a remarkable dependence on the mass of the clusters: D(m,p) approximately m(-0.69), not only at p(c) but well into the liquid phase. We also find that the Stokes-Einstein relation Deta proportional, variant k(B)T breaks down already quite far from the gel point.

Journal Article↗

PubMed2003

Model for gelation with explicit solvent effects: structure and dynamics.

We study a two-component model for gelation consisting of f-functional monomers (the gel) and inert particles (the solvent). After equilibration as a simple liquid, the gel particles are gradually cross linked to each other until the desired number of cross links have been attained. At a critical cross-link density, the largest gel cluster percolates and an amorphous solid forms. This percolation process is different from ordinary lattice or continuum percolation of a single species in the sense that the critical exponents are new. As the cross-link density p approaches its critical value p(c), the shear viscosity diverges: eta(p) approximately (p(c)-p)(-s) with s a nonuniversal concentration-dependent exponent.

Journal Article↗