Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

The Rheology, Adhesion, and Stability of Complex Coacervates

Ogundeji, Lamide Isiak
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1620419882571928

Abstract Details

2021, Master of Science, University of Toledo, Chemical Engineering.
Polyelectrolytes are polymers with ionizable groups on their chains, which (like regular electrolytes) become charged when dissolved in solution. Polyelectrolytes are widely used in areas including drug delivery, water treatment, and underwater adhesives. The polyelectrolyte examined here is polyallylamine (PAH), which can be crosslinked by multivalent counterions, such as sodium tripolyphosphate (TPP), to form adhesive viscoelastic materials known as coacervates. PAH-based adhesives have previously been shown to be able to adhere to both hydrophobic and hydrophilic surfaces under water. The adhesive properties of these coacervates can also be reversed by raising or lowering the pH. This thesis further explores the rheological and adhesion properties of underwater adhesive coacervates formed via the coacervation of PAH and TPP. The adhesive properties of the material are examined on various substrates, including stainless steel, copper, polyvinyl chloride, polyethylene, and polypropylene under varying pH and ionic strength conditions. The adhesion strengths achieved with PAH/TPP coacervates are also examined in various water types, such as tap water, lake water, and artificial seawater. iv Finally, the shelf-life of the adhesive coacervates is studied over a 9-month storage period while varying the solution pH and ionic strength used during their preparation and their storage temperature. The PAH/TPP coacervates, when prepared from neutral-pH parent PAH and TPP solutions, deliver the highest adhesion strength (with tensile bond strengths on stainless steel surfaces reaching 0.6 MPa), which remains undiminished when the deionized water medium is replaced with tap, lake, or artificial seawater. The coacervates can also bond low-energy surfaces, such as high-density polyethylene, consistently delivering tensile adhesion strengths above 0.1 MPa with all examined substrates. Finally, the rheological and adhesion properties of PAH/TPP coacervates can be maintained (with or without refrigeration) over 9 months, demonstrating the storage stability of the PAH/TPP adhesive coacervates.
Yakov Lapitsky, Dr. (Committee Chair)
Matthew Liberatore, Dr. (Committee Member)
Maria Coleman, Dr. (Committee Member)
155 p.
Chemical Engineering
Underwater Adhesives, Coacervates, Polyelectrolytes, Rheology, Adhesion, Storage Stability

Recommended Citations

Citations

  • Ogundeji, L. I. (2021). The Rheology, Adhesion, and Stability of Complex Coacervates [Master's thesis, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1620419882571928

    APA Style (7th edition)

  • Ogundeji, Lamide. The Rheology, Adhesion, and Stability of Complex Coacervates. 2021. University of Toledo, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1620419882571928.

    MLA Style (8th edition)

  • Ogundeji, Lamide. "The Rheology, Adhesion, and Stability of Complex Coacervates." Master's thesis, University of Toledo, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1620419882571928

    Chicago Manual of Style (17th edition)

toledo1620419882571928
135
© 2021, all rights reserved.
This open access ETD is published by University of Toledo and OhioLINK.