Emulsion intercalation of smectite clays with comb-branched copolymers consisting of multiple quaternary amine salts and a poly(styrene-butadiene- styrene) backbone
Journal
Langmuir
Journal Volume
21
Journal Issue
15
Pages
7023-7028
Date Issued
2005
Author(s)
Abstract
Layered silicates were intercalated with comb-branched copolymers consisting of a hydrophobic polystyrene-b-poly(ethylene/butylene)-b-polystyrene (SEBS) backbone and multiple pendants of poly(oxyalkylene) (POA) quaternary ammonium salts. The requisite intercalating agents were synthesized by grafting POA amines on the maleated SEBS. The corresponding SEBS-POA amine salts were found to have two functions, the capability to emulsify toluene/water mixtures to fine particle sizes of 60-70 nm in diameter and to exchange ions with sodium montmorillonite. The resulting silicate hybrids were characterized by X-ray diffraction and transmission electron microscopy. Two types of intercalations with silicate d spacing of 18 and 50 A were obtained, in which the dissimilarity is attributed to disparate polymer incorporations, POA pendants only or the combination of both the SEBS backbone and POA in the gallery. Furthermore, the two conformations of polymer-intercalated silicates are reversibly transformable by varying emulsion conditions, micelle sizes, and solvents.
SDGs
Type
journal article