Structural property relation in improving chemically and physically crosslinked hydrogel surface properties

Chowdhury, Nusrat

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https://hdl.handle.net/2142/122018 Copy

Description

Title

Structural property relation in improving chemically and physically crosslinked hydrogel surface properties

Author(s)

Chowdhury, Nusrat

Issue Date

2023-12-07

Director of Research (if dissertation) or Advisor (if thesis)

Dunn, Alison C

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

Hydrogel, permeability, solid volume fraction, surface properties, friction, physical-chemical crosslinking

Abstract

Hydrogels are materials composed of solid and fluid components in their structure. The transport properties of hydrogels largely depend on their concentration, as solutes can pass through the polymer mesh and can be determined by the polymer density. A flow pressure-controlled permeameter was developed to determine the permeability of hydrogels at various polymer concentrations ranging from 4% to 17% for physically crosslinked and chemically crosslinked hydrogels. The permeability was determined by measuring the flow rate of aqueous solutions as a function of pressure drop across the membranes using a biphasic model to evaluate intrinsic permeability. The permeability derived from Darcy’s law showed a negative power law relation as the volume fraction of solid increases in a hydrogel. The process can determine the permeability of various hydrogels with varying charge and polymer concentrations and cross-linking. Our work aimed to validate the classical Darcy’s law equation for hydrogel composition structure and whether the equations established apply to varying pressure phenomena. The results indicate that Darcy’s law evaluates the hydrogel permeability for physical and chemical crosslinking. Additionally, this work focuses on the mechanical, tribological, and structural property variation due to the polymerization technique of hydrogels and how it varies based on the chemical and physical crosslinking of polyacrylamide and PVA hydrogel. The swelling ratio, elastic modulus, permeability, and friction coefficient of the physically and chemically crosslinked hydrogels were compared, and their chemical structure was analyzed to understand the connection between the structural and tribological relation of the hydrogels.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Nusrat Chowdhury

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