Doctoral Dissertations

Ashish Zore

Keywords and Phrases

Chain collapse; Colloidal; dumbbell conformation; Hansen parameters; Single chain nanoparticles; Surface tension

Abstract

"Colloidal Unimolecular Polymer (CUP) particles are 3-9 nm size single-chain polymer nanoparticles that are made from amphiphilic acrylic co-polymers using the process of water reduction. The formation of CUP particles was driven by the polymer-polymer interactions being greater than polymer-solvent interactions as well as the charge-charge repulsion due to the increasing dielectric of the medium. CUPs provide a surfactant or additive-free nanoparticle system that was useful for studying the interfacial behavior of pure aqueous nanoparticles using a maximum bubble pressure tensiometer. The equilibrium surface tension shows a dependence on concentration and the charge density of the CUP particle. The equilibrium surface tension becomes constant at higher concentrations due to the counterion condensation effect. The dynamic surface tension is dominated by the rate of diffusion of CUP particles to the interface. The water reduction process which transforms a single polymer chain into a particle was observed using viscosity measurements on a vibration viscometer. Changing the hydrophobic and hydrophilic ratios in the co-polymer, changed the THF-water composition required to cause the collapse or self-organization of the polymer chain. The design of the CUP polymer was optimized by defining the charge density limits for stable and spheroidal CUP particle formation. It was found that the charge density (ions/nm²) of the particle must be between 0.32 to 0.85 to form a stable and spheroidal particle. When the Charge density (ions/nm²) is higher than 0.85, it would result in non-spheroid conformation (like dumbbell, pearl necklace, etc.) whereas when it is lower than 0.32, it would result in aggregation of the particles due to poor stability"--Abstract, page iv.

Advisor(s)

Van-De-Mark, Michael R.

Committee Member(s)

Sotiriou-Leventis, Lia
Schuman, Thomas P.
Winiarz, Jeffrey G.
Mormile, Melanie R.

Department(s)

Chemistry

Degree Name

Ph. D. in Chemistry

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2022

Journal article titles appearing in thesis/dissertation

  • Colloidal unimolecular polymer particles: CUP
  • Equilibrium and dynamic surface tension behavior in colloidal unimolecular polymers (CUP)
  • Defining the collapse point in colloidal unimolecular polymer (CUP) formation
  • Synthesis and water reduction optimization of colloidal unimolecular polymers (CUP)
  • Surface tension studies in colloidal unimolecular polymers

Pagination

xxi, 243 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2022 Ashish Zore, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12171

Electronic OCLC #

1344518779

Download

Included in

Chemistry Commons

Share

 
COinS