|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1997 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1996 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Macromolecules, such as synthetic polymers, proteinsa, and DNAs, have attracted great attention due to their novel properties that have never been studied for usual low molecular mass substances. Especially the macromolecular ordering is of great interest since it is a fundamental process involved in polymer crystallization, protein folding, etc. We have here investigated the molecular process of macromolecular ordering by experiments and computer simulations.
A molecular level structure of the crystal growth front is of fundamental importance in considering the polymer crystallization. We here investigated, by molecular dynamics and Monte Carlo simulations, the structure and molecular mobility at the crystal surface, and found that the crystal surface is considerably disordered and that the molecular mobility is there greatly enhanced. Furthermore the disordered structure at the surface was found to correspond to that of the high temperature crystalline phase. The large mobility of the molecule at the surface should be reflected in the microscopic process of polymer crystallization at the crystal surface. We have simulated the process of chain folded crystallization by the molecular dynamics method, and we have found that the polymer chain forms a rather neat chain folded lamella within several nanoseconds.
The chain molecules, such as n- alkanes, are known to form monolayrs or bilayrs. Recently, the liquid of n-alkane was found to exhibit peculiar ordered surface-monolayr. The formation of such peculiar ordered structure is very interesting with respect to its mechanism. We have investigated, by molecular dynamics simulation, the surface structure of n-alkane liquid. We have found that there appears peculiar ordered monlayr within a few degree above the melting point.