van Buel Reinier, Spitzer Daniel, Berac Christian Marijan, van der Schoot Paul, Besenius Pol, Jabbari-Farouji Sara
Institute of Physics, Johannes Gutenberg-University, Staudingerweg 7-9, 55128 Mainz, Germany.
Institute of Organic Chemistry, Johannes Gutenberg-University Mainz, Duesbergweg 10-14, 55128 Mainz, Germany.
J Chem Phys. 2019 Jul 7;151(1):014902. doi: 10.1063/1.5097577.
We investigate the copolymerization behavior of a two-component system into quasilinear self-assemblies under conditions that interspecies binding is favored over identical species binding. The theoretical framework is based on a coarse-grained self-assembled Ising model with nearest neighbor interactions. In Ising language, such conditions correspond to the antiferromagnetic case giving rise to copolymers with predominantly alternating configurations. In the strong coupling limit, we show that the maximum fraction of polymerized material and the average length of strictly alternating copolymers depend on the stoichiometric ratio and the activation free energy of the more abundant species. They are substantially reduced when the stoichiometric ratio noticeably differs from unity. Moreover, for stoichiometric ratios close to unity, the copolymerization critical concentration is remarkably lower than the homopolymerization critical concentration of either species. We further analyze the polymerization behavior for a finite and negative coupling constant and characterize the composition of supramolecular copolymers. Our theoretical insights rationalize experimental results of supramolecular polymerization of oppositely charged monomeric species in aqueous solutions.
我们研究了在物种间结合优于同种物种结合的条件下，两组分体系聚合成准线性自组装体的共聚行为。理论框架基于具有最近邻相互作用的粗粒化自组装伊辛模型。用伊辛语言来说，这种条件对应于反铁磁情况，会产生主要为交替构型的共聚物。在强耦合极限下，我们表明聚合材料的最大分数和严格交替共聚物的平均长度取决于化学计量比和更丰富物种的活化自由能。当化学计量比明显不同于1时，它们会大幅降低。此外，对于接近1的化学计量比，共聚临界浓度显著低于任何一种物种的均聚临界浓度。我们进一步分析了有限负耦合常数下的聚合行为，并表征了超分子共聚物的组成。我们的理论见解使水溶液中带相反电荷的单体物种超分子聚合的实验结果合理化。
