Persistence length of polymers

Besides extensive experiments, many computer simulations have been carried out on polymer blends, primarily, including Monte Carlo (MC) [15-18], molecular dynamics (MD) [12,19-35], mesoscopic dynamics (MesoDyn) [12,24,25], and dissipative particle dynamics (DPD) [33,36,37]. In the area of theoretical polymer physics, MesoDyn and DPD have been used to treat polymeric chains in a coarse-grained (mesoscopic) level by grouping atoms together up to the persistence length of polymers. Recent trends in the use of MD simulations on bulk polymers have led to the calculations of important... 

Everaers R, Milchev A, Yamakov V (2002) The electrostatic persistence length of polymers beyond the OSF limit. Eur Phys J E 8(1) 3-14. doi 10.1140/epje/i2002-10007-3... 

All this leads to the question of how DNA affects nucleosomal stability at the molecular level. DNA bendability has been repeatedly put forward as a candidate to play an important role [280-282]. This property is related to the persistence length of DNA [283]. A study on the characterization of nucleosomes reconstituted onto methylated DNA [poly(dG-m dC) poly (dG-m dC)] [284] provides support to this hypothesis. Poly(dG-m dC) poly (dG-m dQ DNA can be induced to change from its B to its Z conformation in the presence of millimolar amounts of divalent ions [285] such as MgCl2. The persistence length of poly(dG-m dC) poly (dG-m dC) in the Z form in high salt was found to be 208 nm (ca. 612 bp) [286], a value much lower than that of the same polymer in the B form (93.8 nm, 276 bp) at... 

Since the persistence length, q, of 6 in isooctane was determined to be 70 nm, this value is similar to that of 4-S (q = 85 nm) and much longer than that of 3 (q = 6.2 nm), confirming the previous conclusion that polysilanes with / -branched alkyl side chains are much stiffer compared to those without such branching [56]. The persistence length of helical polymers can be determined by the steepness of the internal rotation potential in the main chain [56]. The slightly shorter q of 6 than that of 4-S implies that the longer nonbranched alkyl side chain makes the internal rotation double-well potential of the silicon main chain less steep. 

If the length of the most probable chain configuration z is assumed to be equal to the thickness of the brush L, eq 14 provides the same dependence between the graft density and thickness as the Alexander theory. Whereas eq 14 accounts explicitly for the persistence length of a polymer (its degree of flexibility), with the simplified assumptions that l a, Ni N, v a3 the Alexander scaling law is completely recovered ... 

Table 14. Persistence length of stiff and flexible polymers estimated by various methods67 ...

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