Premium
Hydration Characterization of Hydrophobically Modified Polymers by Dielectric Measurements in the Millimeter Range
Author(s) -
Vorob'ev Mikhail,
Churochkitalia,
Khokhlov Alexei,
Stepnova Evgenia
Publication year - 2007
Publication title -
macromolecular bioscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.924
H-Index - 105
eISSN - 1616-5195
pISSN - 1616-5187
DOI - 10.1002/mabi.200600231
Subject(s) - polymer , dielectric , bound water , chemistry , polyacrylamide , polymer chemistry , molecule , polyelectrolyte , chemical engineering , materials science , organic chemistry , optoelectronics , engineering
Bound water molecules, the fraction of water molecules that are present in the hydration shells of polymers, lose their rotational mobility in the time scale of 10–50 ps, leading to additional ordering compared with unperturbed water. The amount of bound water per number of carbons in the nonpolar groups as measured by the method of waveguide dielectric resonance increased in the following order: hydrophobically modified chitosan < globular protein < hydrophobically modified polyacrylamide. The hydrophobic modification of acrylamide and chitosan polymers gave smaller variation in hydration than did both the coil‐to‐globule transition of poly( N ‐isopropylacrylamide) and the masking of nonpolar groups within the protein globule.