Viscoelastic properties of rigid and semiflexible particles in solution. I

Abstract

A theory of Erpenbeck and Kirkwood, which describes viscoelastic behavior of macromolecules in a general way, is transformed so that it can be applied practically to ’’semiflexible particles,’’ which are partly deformable but have definite shape in solution. A basic idea of the present work is that, by introducing proper auxiliary coordinates and an imaginary rigid core which is made zero at the final stage of calculation, derivatives ∂?i/∂xi and ∂xj/∂?i and Jacobian J=∂{?i}/∂{xj} associated with a coordinate transformation from a lab system {?i} to a body system {xj} can be computed explicitly, and contravariant components of a diffusion-coefficient tensor in a ’’diffusional space’’ are derived easily. The particles are assumed to be composed of many points, which are arranged arbitrarily and move within the particles under the influences of intramolecular potentials, hydrodynamic resistance of solvent and ’’internal friction’’ caused by other points in the same particles. As the base for treating the semiflexible particles.