Surfactant Responsive Cross-Linked Polymer Hydrogels

Research output: ThesisDoctoral Thesis (compilation)

Abstract

The focus of the thesis is on chemically cross-linked hydrogels which drastically change their volume when immersed in solutions of different ionic surfactants (with or without added salt). The two main questions addressed are: (1) How useful are simple gel swelling experiments to the study of polymer-surfactant interactions?, and (2) How does the volume of a cross-linked polymer gel change when it is immersed in a surfactant solution, both with respect to the equilibrium swelling and with respect to transient volume changes?

Most of the gels studied were prepared by cross-linking linear polymers, which were well studied derivatives of hydroxyethyl cellulose (HEC). Therefore, it was possible to compare the results from the gel swelling experiments with results from previous studies on the same polymer-surfactant systems using other experimental methods, such as solubility studies, NMR self-diffusion measurements, and fluorescence measurements. For comparison, chemically simpler vinyl type gels were synthesized and included in the study.

It is concluded that the gel swelling experiment is a simple, but potent, method to study polymer-surfactant interactions. It is especially useful for distinguishing between associating and nonassociating polymer-surfactant pairs, for detecting critical association concentrations (cac:s), and for studying the changes in the polymer dimensions that occur within the one- and two-phase regions of the corresponding mixtures of linear polymers and surfactants. The gel-surfactant systems studied are classified into three groups: (1) slightly hydrophobic nonionic gels, (2) polyelectrolyte gels (with oppositely charged surfactants), and (3) hydrophobically modified gels. For the two first groups generic swelling isotherms are discussed. The hydrophobicity of both the gel polymer and the surfactant tail is shown to be of great importance.

The thesis also includes two literature reviews, which place surfactant responsive gels in a broader scientific context. The first review deals with the history of cross-linked gels, and the second with general swelling trends of responsive hydrogels.

Details

Authors
  • Jesper Sjöström
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry

Keywords

  • Physical chemistry, Fysikalisk kemi, Two-step binding isotherms, Resolubilization, Nonmonotonic transient volume changes, Swelling isotherms, Divinyl sulfone (DVS), Polyquaternium, Cellulose ethers, Amphiphilic cross-linked polymers, Responsive gels, Polymer-surfactant interactions
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
  • [unknown], [unknown], Supervisor, External person
Award date2002 May 25
Publisher
  • Physical Chemistry 1, Lund University
Print ISBNs91-628-5155-1
Publication statusPublished - 2002
Publication categoryResearch

Bibliographic note

Defence details Date: 2002-05-25 Time: 10:15 Place: Hall A, Center for Chemistry and Chemical Engineering External reviewer(s) Name: Hansson, Per Title: Doc Affiliation: Uppsala University --- Article: The thesis consists of three parts: (1) background and summary, (2) two literature reviews, and (3) seven original research papers. Article: Literature reviews: Article: I.) J. Sjöström. "The History of Cross-Linked Polymer Gels – A case in modern science history", Manuscript, (2002). Article: II.) J. Sjöström. "Responsive Hydrogels: General trends of equilibrium swelling", Manuscript, (2002). Article: Original research papers: Article: III.) O. Rosén, J. Sjöström and L. Piculell. "Responsive Polymer Gels Based on Hydrophobically Modified Cellulose Ethers and Their Interactions with Ionic Surfactants", Langmuir, (1998). 14:5795-5801 Article: IV.) J. Sjöström and L. Piculell. "Nonmonotonic Transient Volume Changes of Cross-Linked Polymer Gels Immersed in Amphiphile Solutions", Langmuir, (2000). 16:4770-4773 Article: V.) L. Piculell, S. Nilsson, J. Sjöström and K. Thuresson. "How Much Surfactant Binds to an Associating Polymer? The HMHEC/SDS Case Revisited", Chapter 19 (p. 317-335) in ACS Symposium Series No. 765 / "Associative Polymers in Aqueous Media", (2000). Editor: J. E. Glass; American Chemical Society: Washington, DC. Article: VI.) J. Sjöström and L. Piculell. "Simple Gel Swelling Experiments Distinguish between Associating and Nonassociating Polymer-Surfactant Pairs", Langmuir, (2001). 17:3836-3843 Article: VII.) J. Sjöström and L. Piculell. "Interactions between cationically modified hydroxyethyl cellulose and oppositely charged surfactants studied by gel swelling experiments – effects of surfactant type, hydrophobic modification and added salt", Colloids Surf. A, (2001). 183-185:429-448 Article: VIII.) I. Lynch, J. Sjöström and L. Piculell. "Hydrophobicity and counterion effects on the binding of ionic surfactants to uncharged polymeric hydrogels", Manuscript, (2002). Article: IX.) I. Lynch, J. Sjöström and L. Piculell. "Reswelling of polyelectrolyte hydrogels by oppositely charged surfactants", Manuscript, (2002).

Related research output

Jesper Sjöström, 2001, Forskning & framsteg, 3, p. 16-17.

Research output: Contribution to specialist publication or newspaperSpecialist publication article

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