고분자 & 나노물질 이론 및 시뮬레이션 연구실

Theoretical & Computational study of Polymer and Nanomaterial Lab. Significant advances in the field of computer simulations (both methodological and algorithmic) and the rapid increase in computing power have led to the development of powerful multi-scale simulation tools (i.e., from the microscopic quantum/atomistic level via mesoscopic coarse-graining procedures all the way up to the macroscopic or continuum level). These developments have the potential to address fundamental issues in materials science and technology by revealing the molecular origin of unique phenomena exhibited at the macroscopic level and by elucidating the structure-property-processing relationships in systems with a complex internal microstructure of synthetic polymers and biopolymers. Motivated by these advances, our research interests are below as shown. Atomistic configurations of C128H258 linear polyethylene (PE) melt under shear flow. Despite numerous experimental and theoretical efforts to elucidate the role of chain architecture (i.e., chain-branching) on polymer rheology, a sound microscopic-level understanding is still missing. We will address this issue through direct atomistic Nonequilibrium molecular dynamics (NEMD) simulations both in shear and elongational flows, which will help us collect detailed information about local structure and dynamics at various length and time scales. Various kinds of polymers will be studied: (a) long-branched polymers with different degrees of branching, i.e., H-polymer, (b) short chain branched (SCB) polymers with different branching frequency and branch length, and (c) ring polymers of varying size. The last type of polymer has recently attracted considerable attention due to its peculiar rheological properties (e.g., absence of distinct plateau mod