Surfactant-induced phase separation and network formation of surface-active graft copolymers.
Item
-
Title
-
Surfactant-induced phase separation and network formation of surface-active graft copolymers.
-
Identifier
-
AAI9108093
-
identifier
-
9108093
-
Creator
-
Dualeh, Abdulkadir Jibril.
-
Contributor
-
Adviser: Carol Steiner
-
Date
-
1990
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Engineering, Chemical
-
Abstract
-
An extensive experimental investigation of the behavior of a particular class of surface active graft copolymer in aqueous surfactant solution is presented. The experiments performed include fluorescence spectroscopy and rheology.;The specific copolymer used in this study is hydrophobically modified hydroxyethyl cellulose (HMHEC) and is shown in appendix 2. It is a surface active copolymer composed of a hydrophilic cellulose backbone grafted with linear hydrophobic side chains (C{dollar}\sb{12}{dollar} alkyl hydrocarbons). The properties of this copolymer in aqueous sodium dodecyl sulfate solution are presented.;Strong site-specific adsorption of surfactant occurs on the hydrophobic side chains of water-insoluble HMHEC. The resulting interactions give rise to a network composed of hydrophobic microdomains dispersed throughout an aqueous polymer solution or gel, depending on the composition of the system.;The hydrogel phase which forms from HMHEC below the cmc of the surfactant appears to be an important new material. It is clear, flexible, viscoelastic, and homogeneous. It is composed of hydrophobic microdomains, which can solubilize a water-insoluble probe, dispersed throughout a water-swollen gel. The size as well as compositions of the microdomains can be varied. These characteristics, coupled with the mechanical stability of the gels, makes these new materials interesting candidates for such applications as chromatography or controlled drug release.;This study is intended to contribute towards our understanding of the bulk and microscopic properties of amphiphilic copolymers in surfactant solutions. We have identified the physico-chemical interactions between the polymer and surfactant that give rise to these bulk properties. We present evidence showing that the properties observed in this system are due to comicellization among the alkyl grafts from the polymer and the free surfactant molecules.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
