Sinelnikova A, Niemi A J, Ulybyshev M
Institute for Theoretical Problems of Microphysics, Moscow State University, Moscow 119899, Russia.
Department of Physics and Astronomy, Uppsala University, P.O. Box 803, S-75108, Uppsala, Sweden.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Sep;92(3):032602. doi: 10.1103/PhysRevE.92.032602. Epub 2015 Sep 17.
The phase structure of a single self-interacting homopolymer chain is investigated in terms of a universal theoretical model, designed to describe the chain in the infrared limit of slow spatial variations. The effects of chirality are studied and compared with the influence of a short-range attractive interaction between monomers, at various ambient temperature values. In the high-temperature limit the homopolymer chain is in the self-avoiding random walk phase. At very low temperatures two different phases are possible: When short-range attractive interactions dominate over chirality, the chain collapses into a space-filling conformation. But when the attractive interactions weaken, there is a low-temperature unfolding transition and the chain becomes like a straight rod. Between the high- and low-temperature limits, several intermediate states are observed, including the θ regime and pseudogap state, which is a novel form of phase state in the context of polymer chains. Applications to polymers and proteins, in particular collagen, are suggested.
基于一个通用理论模型研究了单个自相互作用均聚物链的相结构，该模型旨在描述链在空间缓慢变化的红外极限情况下的行为。研究了手性的影响，并在不同环境温度值下，将其与单体之间短程吸引相互作用的影响进行了比较。在高温极限下，均聚物链处于自回避随机行走相。在非常低的温度下，可能存在两种不同的相：当短程吸引相互作用比手性占主导时，链坍缩成一种充满空间的构象。但当吸引相互作用减弱时，会发生低温展开转变，链变得像一根直杆。在高温和低温极限之间，观察到了几种中间状态，包括θ区域和赝能隙状态，赝能隙状态在聚合物链的背景下是一种新型的相态形式。文中还提出了该模型在聚合物和蛋白质，特别是胶原蛋白方面的应用。
