Computer Simulations of the Thermodynamic and Phase Diagrams of Polymeric Systems

小行星9311915 本研究的主要重点是从分子的角度来理解聚合物体系的相容性的实际重要问题。 一个论点是，在这个时候，聚合物系统的本体热力学知之甚少，因为它们强烈依赖于本地方面，如链结构，刚度和包装，这是不准确捕获粗粒度的聚合物理论。 因此，在真实的链模型上进行计算机模拟将是一种精确的技术，可以捕捉到局部结构和解包对热力学性质的影响。 除了PVT状态方程的属性，这可以通过标准的计算机模拟方法获得，新提出的技术将被用来枚举这些系统的热力学性质，特别是相行为。 在平行的膜厚度的影响，在相分离的聚合物共混物膜将被研究。 它强调，一个很好的理解这一根本上重要的物理现象的前提是理解，不仅是聚合物系统的表面行为，而且是本体热力学。 这个问题已经从理论的角度进行了一些详细的研究，目前正在进行实验研究。 最后，一个很好的理解这种情况还需要知识的空间位阻处罚与限制分子附近的表面，这些方面将通过研究的液晶分子的排列在平坦的表面附近进行检查。 ***

9311915 Kumar The primary focus of this research is to understand the practically important question of the miscibility of polymeric systems from a molecular view point. An argument is made that the bulk thermodynamics of polymeric systems are poorly understood at this time since they are strongly dependent on local aspects, such as chain structure, stiffness and packing, which are not captured accurately by coarse-grained polymeric theories. Consequently, computer simulation on realistic chain models would represent an accurate technique to capture the effects of local structure and unpacking on thermodynamics properties. In addition to PVT equation of state properties, which can be obtained through standard computer simulation methods, newly proposed techniques will be used to enumerate the thermodynamic properties, especially the phase behavior, of these systems. In parallel the effect of film thickness on the phase separation in ultrathin polymer blends films will be studied. It is emphasized that a good understanding of this fundamentally important physical phenomenon is predicated on understanding, not only the surface behavior of polymeric systems, but also the bulk thermodynamics. This issue has already been studied in some detail from a theoretical viewpoint and experimental investigations are currently in progress. Finally, a good understanding of this situation also requires knowledge of the steric penalty associated with confining molecules near surfaces, and these aspects will be examined through a study of the alignment of liquid crystalline molecules in the vicinity of flat surfaces. ***