环形高分子链在表面上的吸附转变.docVIP

环形高分子链在表面上的吸附转变 盛俊芳 ，罗开富 中国科学技术大学高分子科学与工程系，合肥　230026 摘要：采用三维朗之万动力学模拟方法研究了接枝于表面上的环形高分子链的吸附动力学。与 线形链相比，环形链有相同的临界吸附点（CAP），且在CAP处的吸附链段数与链长的标度指 数都是0.46，明显小于0.5，与目前的最佳估计值0.48吻合。在CAP处，环形高分子的吸附链段 数比相同链长的线形链多，与实验结果一致。此外，环形链比线形链更快达到吸附平衡状态。 关键词：环形高分子; 吸附转变; 临界吸附点; 临界吸附指数 中图分类号： O631.1 Adsorption transition of a ring polymer at an attractive surface SHENG Jun-Fang , LUO Kaifu Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026 Abstract: We investigate the adsorption dynamics of a ?exible ring polymer chain with one bead grafted to a ?at solid surface and the conformation of the adsorbed chain using 3D Langevin dynamics simulations. Compared with the linear chain, the ring chain has the same critical adsorption point (CAP). At the CAP, the crossover exponent of the number of adsorbed beads with chain length is about 0.46 for both ring and linear chains, which is smaller than 0.5, in agreement with the current best estimated value 0.48. At the CAP, ring polymers are adsorbed on the surface more than linear chains, which agrees with experiments, and the ratio is about 1.2. In addition, We further observe that, compared with linear chains, the adsorption of ring polymers is faster to reach equilibrium state. Key words: Ring polymers; Adsorption transition; Critical adsorption point; Crossover exponent  0  Introduction  The adsorption of polymer chain on a solid surface has been investigated for many years by theories [1, 2, 3, 4, 5, 6, 7, 8, 9], experiments [10, 11, 12, 13, 14, 15, 16] and simulations 基 金 项 目： The Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20103402110032) 作者简介： Sheng Junfang（1987-），female，graduate student，major research direction：Polymer physics. Cor- respondence author：Luo Kaifu（1971-），male，professor，major research direction：Soft matter and biological physics. -2- [4, 17, 18, 19, 20, 21, 22, 2, 23, 24, 25] due to its importance to practical applications, such as coll