Related Experiment Video
Updated: Oct 13, 2026

16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
[NMR spin-echo study of the effect of hydration on the mobility and conformation of linear polyethyleneimine]
Biofizika
|January 1, 1976
Abstract:
It has been shown that mobility of protons in different groups of linear polyethylenimine (LPEI) is sensitive to the formation of H-bonds between amino groups of a polymer. Upon hydration of LPEI most of direct bonds between amino groups are substituted by the bonds via water molecules. This results in a conformational change of the polymer. Similar process may also occur in biopolymers.
Related Concept Videos
π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...
Determination of Molar Masses of Polymers II
Polymer samples typically consist of macromolecular chains with a distribution of lengths, resulting in a range of molar masses rather than a single discrete value. Conventional descriptors such as the number-average molar mass and weight-average molar mass quantify this distribution but do not fully capture polymer behavior in solution..The viscosity-average molar mass provides a more realistic description of polymer behavior in solution because it accounts for the enhanced contribution of...

