General intercalation of poly(oxyalkylene)-amidoacids for anionic and cationic layered clays
Journal
Industrial and Engineering Chemistry Research
Journal Volume
49
Journal Issue
10
Pages
5001-5005
Date Issued
2010
Author(s)
Abstract
The same poly(oxyalkylene)-amidoacids (POA-amidoacid) were incorporated into two different types of ionic clays, anionic layered-double-hydroxides (Mg-Al LDH), and cationic montmorillonite (MMT). Conventionally, the intercalation is an ionic exchange reaction, i.e. anionic organic salts for LDH and cationic salts for MMT. The successful intercalation using the neutral species of POA-amidoacid implies the existence of a new mechanism for clay intercalation. We prepared the POA-amidoacid from the reaction of maleic anhydride and poly(oxyalkylene)-diamine (POA-amine) with different hydrophobic and hydrophilic POA-backbones of 600-4200 molecular weight. The intercalation has resulted in the expansion of the clay basal spacing from 7.8 to 63 Å for LDH and from 12.4 to 51 Å for MMT, with a high Braggs regularity of XRD analyses. It appears that the driving force for the intercalation and organic incorporation into the silicate interlayer galleries is dissimilar to the counterion exchange but involving noncovalent bonding between amidoacid functionalities and - SiOH species in clay. The intercalation without ionic exchange reaction is effective for generating new clay hybrids with thermal responsiveness in water. © 2010 American Chemical Society.
Type
journal article