Strong influence of branching on the early stage of nucleation and crystal formation of fast cooled ultralong n-alkanes as revealed by computer simulation

摘要: Abstract Molecular dynamics simulations were performed on a series of ultralong n -alkanes in order to shed light the early stage processes crystallization from melt at high undercooling. The study contemplates linear (C 191 H 384 ) and two symmetrically branched [C 96 193 CH(CH 3 )C 94 189 C CH(C 4 9 ] n-alkane samples. These systems can be considered as good models for mechanism polymer folding crystal formation. First all, it is observed that short branch provokes delay nucleation compared chain. Additionally this process further delayed length increases. To follow we compute time evolution structure factor S ( q material undercooled. It obtained both thickness chain packing are dramatically affected by presence branches. crystallinity, expressed mass ratio ordered total amount material, also decreases system closer irregular model least stages clearly determines its inclusion or not nuclei consequently disturbs different way formation crystals.