Hierarchical Structure of Supramolecular Polymers Formed by N,N′-Di(2-ethylhexyl)urea in Solutions

From supramolecular to conventional polymers: polyethylene glycol

Increasing the polymerization degree of polyethylene glycol (PEG), HO-(CH₂CH₂O-)_nH, entails lowering the number of hydroxyl groups per unit volume; therefore, supramolecular polymers are gradually replaced by longer and longer conventional polymers. This paper concerns an estimation of the polymerization degree (n) where PEG changes its nature from a supramolecular polymer to a conventional polymer. It was found that that virtual transformation takes place when n reaches the value of about 9. The conclusion follows from the different thermal behaviors of the dipolar orientational effects in liquid PEG detected for n below and above 9. The result reflects a diametrically different impact of the temperature on the linkages between the monomers in supramolecular and conventional polymers.

Hydration and self-aggregation of a neutral cosolute from dielectric relaxation spectroscopy and MD simulations: the case of 1,3-dimethylurea

1,3-Dimethylurea irrotationally binds 1–2H₂O molecules close to its carbonyl and impedes dynamics of ca. 40 H₂O molecules by methyl substituents.