ANOMALOUS DIFFUSION AND RELAXATION OF COLLAPSED POLYMER-CHAINS

Time-dependent displacement of monomers and the centre-of-gravity motion of a polymer chain at various temperatures below the theta-temperature are studied by Monte Carlo simulation of an off-lattice model. While inner monomers diffuse Rouse-like, [[r(i)(t) - r(i)(0)]2] is-proportional-to is-proportional-to t1/2, the centre of mass exhibits pronounced anomalous diffusion, [[r(c.m.)(t) - r(c.m.)(0)]2] is-proportional-to t(a), where the exponent a seems to depend on temperature. The resulting anomalous dependence of the relaxation times on chain length is discussed in terms of scaling ideas. A possible relation to a glasslike freezing in of the collapsed globules is pointed out.