Dipartimento di Scienze Chimiche, Università di Padova, Padova, Italy.
J Chem Phys. 2013 Apr 28;138(16):164906. doi: 10.1063/1.4802005.
We investigate the isotropic-to-nematic phase transition in systems of hard helical particles, using Onsager theory and Monte Carlo computer simulations. Motivation of this work resides in the ubiquity of the helical shape motif in many natural and synthetic polymers, as well as in the well known importance that the details of size and shape have in determining the phase behaviour and properties of (soft) condensed matter systems. We discuss the differences with the corresponding spherocylinder phase diagram and find that the helix parameters affect the phase behaviour and the existence of the nematic phase. We find that for high helicity Onsager theory significantly departs from numerical simulations even when a modified form of the Parsons-Lee rescaling is included to account for the non-convexity of particles.
我们使用昂萨格理论和蒙特卡罗计算机模拟研究了硬螺旋粒子系统中的各向同性-向列相转变。这项工作的动机在于，在许多天然和合成聚合物中，螺旋形状基元无处不在，以及尺寸和形状的细节在确定（软）凝聚态物质系统的相行为和性质方面具有重要意义。我们讨论了与相应的球柱相图的差异，并发现螺旋参数会影响相行为和向列相的存在。我们发现，对于高螺旋度，即使包括帕森斯-李重标度的修正形式来考虑粒子的非凸性，昂萨格理论也与数值模拟有很大的偏离。
