| Abstract: | We present the results of analytical calculations and numerical simulations of the behavior of a new class of chain molecules that we call thick polymers. The concept of the thickness of such a polymer, viewed as a tube, is encapsulated by a special three‐body interaction and impacts on the behavior both locally and nonlocally. When thick polymers undergo compaction because of an attractive self‐interaction, we find a new type of phase transition between a compact phase and a swollen phase at zero temperature with increasing thickness. In the vicinity of this transition, short tubes form space‐filling helices and sheets as observed in protein native‐state structures. With increasing chain length, or with an increasing number of chains, we numerically find a crossover from secondary‐structure motifs to a quite distinct class of structures akin to the semicrystalline phases of polymers or amyloid fibers in polypeptides. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 650–679, 2005 |
