Premium
Effects of counter cations on the water vapor sorption properties of alginic acid and alginates
Author(s) -
Shimanuki Niina,
Imai Miho,
Nagai Kazukiyo
Publication year - 2020
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49326
Subject(s) - alginic acid , sorption , hydrogen bond , crystallization , chemistry , fourier transform infrared spectroscopy , water vapor , infrared spectroscopy , crystallography , inorganic chemistry , molecule , chemical engineering , adsorption , organic chemistry , biochemistry , engineering
Abstract In this study, the water vapor sorption of four types of alginate, namely, alginic acid (Alg), Na‐Alg, Ca‐Alg, and NH 4 ‐Alg, were measured, and the effect of differences in counter cations on water vapor solubility and crystallization mechanism associated with the arrangement of hydrogen bonds generated during humidification was investigated. The sorption amounts in the high‐humidity region can be arranged as follows: Na‐Alg > NH 4 ‐Alg > Ca‐Alg > Alg. All samples formed a (C)‐type double helix structure before and after the sorption based on the results of Fourier transform infrared spectroscopy and wide‐angle X‐ray diffraction. The counter cation affects the arrangement of the hydrogen bonds in this structure. Only Ca‐Alg possessed a pseudocrosslinking among the (C)‐type double helix structures due to the divalent Ca 2+ ions, which induced variations in the crystal arrangement behavior of the other three samples before and after sorption. Cases I–III show a case of how the orientation is aligned with a new hydrogen bond and classified for each sample.