Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, D-55128 Mainz, Germany.
J Chem Phys. 2013 May 7;138(17):174905. doi: 10.1063/1.4803021.
Surface-induced selective adsorption of homopolymers on a generic level is numerically analyzed for freely jointed chains (with a fixed bond length) whose monomers are attracted by the sites of regular periodic patterns. In particular, the behavior of the specific heat, the gyration tensor, and the bond order tensor are investigated as functions of the temperature. The properties of the transition are related to the interplay of the characteristic lengths. The adsorption proceeds in two steps for certain incommensurabilities of the bond length and the lattice constant. The corresponding adsorption mechanisms are elucidated by looking at the evolution of the inter bond angle distribution upon adsorption. Moreover, the origin of two steps in contrast to adsorption in one step is traced back to entropic restrictions caused by a strongly reduced phase space of the polymer for certain values of the incommensurability.
表面诱导的均聚物在通用水平上的选择吸附在数值上分析了自由连接链(具有固定键长),其单体被规则周期性图案的位点吸引。特别是,研究了比热、回转张量和键序张量作为温度函数的行为。转变的性质与特征长度的相互作用有关。对于键长和晶格常数的某些非整比,吸附分两步进行。通过观察吸附过程中键间角度分布的演化,阐明了相应的吸附机制。此外,与一步吸附相比,两步吸附的起源可以追溯到由于非整比性的某些值导致聚合物的相空间大大减小而引起的熵限制。