Abstract/Details

Rheology, structure and transport properties of hybrid hairy nanoparticles and their applications

Agrawal, Akanksha.  Cornell University. ProQuest Dissertations Publishing, 2016. 10171381.

Abstract (summary)

Polymer grafted nanoparticles have been of increasing scientific interest due to their potential applications in numerous fields. They have emerged as model systems to understand the structure, dynamics and phase stability of molecular and atomic liquids. One such class of polymer-tethered nanoparticles are the self-suspended hairy nanoparticles created by covalent attachment of polymer chains to inorganic nanostructures without any dispersing medium. The work reported in this thesis examines the flow, structural and dynamical properties of these self-suspended hybrid hairy nanoparticles with a particular emphasis on understanding the roles played by interactions between tethered chains on material structure and dynamics. By means of Small Angle X-ray Scattering (SAXS), rheology, and dielectric relaxation experiments coupled with theoretical studies, it is shown that interpenetration of the grafted polymer chains under the action of temperature, enthalpic attraction of tethered polymer chains, nanoparticle curvature size and the requirement that tethered chains must fill the inter-particle space; has a profound effect on structural, mechanical, dynamic, and transport properties of the materials. With the help of these findings the present work provides new insights into a variety of heretofore poorly understood phenomena in self-suspended materials, including observation of a stress overshoot during start-up of steady shear flow, thermal jamming, and dramatic slowing down of polymer chain dynamics. Additionally, it is shown that armed with these physical phenomena one can easily manipulate the design variables (e.g. size distribution of the core particles, polydispersity in the corona molecular weight, dispersity in corona grafting density and chemistry of the corona chains) to create novel materials with unusual property profiles. Research reported in this thesis shows, for example, that a blend of self-suspended hairy particles comprised of bi-disperse core sizes exhibits multiple yielding transitions, jamming to unjamming state transitions, and facilitates fast transport of ions in bulk electrolytes and at electrochemical interfaces. Extending these ideas to create self-suspended nanoparticle blends in which hairy particles comprised of chemically dissimilar corona, but the same core, are shown to enable even more unusual materials designs that facilitate fundamental studies of interactions across tethered during start-up of steady shear flow, thermal jamming, and dramatic slowing down of polymer chain dynamics. Additionally, it is shown that armed with these physical phenomena one can easily manipulate the design variables (e.g. size distribution of the core particles, polydispersity in the corona molecular weight, dispersity in corona grafting density and chemistry of the corona chains) to create novel materials with unusual property profiles. Research reported in this thesis shows, for example, that a blend of self-suspended hairy particles comprised of bi-disperse core sizes exhibits multiple yielding transitions, jamming to unjamming state transitions, and facilitates fast transport of ions in bulk electrolytes and at electrochemical interfaces. Extending these ideas to create self-suspended nanoparticle blends in which hairy particles comprised of chemically dissimilar corona, but the same core, are shown to enable even more unusual materials designs that facilitate fundamental studies of interactions across tethered polymer interfaces from high signal-to-noise bulk experiments.

Indexing (details)


Subject
Physical chemistry;
Chemical engineering;
Materials science
Classification
0494: Physical chemistry
0542: Chemical engineering
0794: Materials science
Identifier / keyword
Pure sciences; Applied sciences; Colloids; Lithium metal batteries; Nanoparticles; Polymer nanocomposites; Polymers; Rheology
Title
Rheology, structure and transport properties of hybrid hairy nanoparticles and their applications
Author
Agrawal, Akanksha
Number of pages
259
Degree date
2016
School code
0058
Source
DAI-B 78/02(E), Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
978-1-369-25418-1
Advisor
Archer, Lynden A.
University/institution
Cornell University
University location
United States -- New York
Degree
Ph.D.
Source type
Dissertation or Thesis
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
10171381
ProQuest document ID
1827600131
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
https://www.proquest.com/docview/1827600131