Field-Theoretic Simulation of Block Copolymers at Experimentally Relevant Molecular Weights

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• 作者：Bart Vorselaars ; Pawel Stasiak ; Mark W. Matsen
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：December 22, 2015
• 年：2015
• 卷：48
• 期：24
• 页码：9071-9080
• 全文大小：611K
• ISSN：1520-5835

文摘

Field-theoretic simulation (FTS) offers an efficient means of predicting the equilibrium behavior of high-molecular-weight structured polymers, provided one is able to deal with the strong ultraviolet (UV) divergence that occurs at realistic molecular weights. Here melts of lamellar-forming diblock copolymer are studied using a Monte Carlo version (MC-FTS), where the composition field fluctuates while the pressure field follows the mean-field approximation. We are able to control the UV divergence by introducing a new effective Flory鈥揌uggins interaction parameter, 蠂_e, thereby permitting MC-FTS for molecular weights extending down to values characteristic of experiment. Results for the disordered-state structure function, the layer spacing and compressibility of the ordered lamellar phase, and the position of the order鈥揹isorder transition (ODT) show excellent agreement with recent particle-based simulation. Given the immense versatility of FTS, this opens up the opportunity for quantitative studies on a wide range of more complicated block copolymer systems.