3D-Printed conductive cellulose cryogels for electromagnetic interference shielding : exploring structural design, printability, and shape fidelity
department or school: Applied Science, Faculty of
department or school: Engineering, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Amini, Majed
issued: 2024-10-24T16:18:13Z
issued: 2024
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: This thesis presents the development of three-dimensional (3D)-printed conductive cellulose cryogels designed for electromagnetic interference (EMI) shielding. The motivation for this work arises from the need to find environmentally friendly alternatives to petroleum-based conductive polymers, turning attention to biopolymers derived from natural carbohydrates like cellulose. The research began with optimizing cellulose nanocrystal (CNC) inks to achieve high-resolution 3D structures. This involved creating a "3D-printing" map to demonstrate the relationship between CNC/salt ink rheology and printing fidelity. This map revealed that high fidelity could be achieved within specific concentration ranges, significantly influenced by the type of salt used. Among the ten salts evaluated, FeClâ, CaSOâ, and NaHCOâ were particularly effective, enhancing the ink's rheological properties and enabling precise 3D printing. To impart conductivity to the cellulose inks, poly(3,4-ethylenedioxythiophene) (PEDOT) was used. This step was crucial for the application of cryogels in EMI shielding. At the macro scale, manipulating the grid dimensions of the 3D-printed cryogels revealed a clear relationship between grid size and shielding effectiveness (SE). Larger grid sizes, ranging from 1 mm to 3 mm, resulted in a 30% reduction in SE and shifted the shielding mechanism from reflection to absorption. At the micro-scale, altering pore sizes from approximately 50 microns to 170 microns demonstrated a similar shift from reflection to absorption, highlighting the impact of pore structure on performance. On the nano-scale, modifications using TEMPO-oxidized cellulose nanofibers (CNFs) coated with PEDOT achieved a high conductivity of up to 546 S/m. This enhancement in conductivity greatly improved the EMI shielding effectiveness, outperforming traditional fabrication methods. Overall, this thesis not only advances the understanding of 3D-printed cellulose cryogels but also establishes their p…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/89496
note: 3D-Printed Conductive Cellulose Cryogels for Electromagnetic Interference Shielding: Exploring Structural Design, Printability, and Shape Fidelity by Majed Amini B.Sc., Sahand University of Technology, 2015 M.Sc., Sharif University of Technology, 2018 A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE COLLEGE OF GRADUATE STUDIES (Mechanical Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Okanagan) October 2024 © Majed Amini, 2024ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a dissertation entitled: 3D-Printed Conductive Cellulose Cryogels for Electromagnetic Interference Shielding: Exploring Structural Design, Printability, and Shape Fidelity submitted by Majed Amini in partial fulfillment of the requirements of the degree of Doctor of Philosophy Dr. Mohammad Arjmand, School of Engineering Supervisor Dr. Abbas Milani, School of Engineering Supervisory Committee Member Dr. Orlando Rojas, University of British Columbia (Vancouver) Supervisory Committee Member Dr. Shahria Alam, School of Engineering University Examiner Dr. Nicole R. Demarquette, Ãcole de technologie supérieure External Examiner iii Abstract This thesis presents the development of three-dimensional (3D)-printed conductive cellulose cryogels designed for electromagnetic interference (EMI) shielding. The motivation for this work arises from the need to find environmentally friendly alternatives to petroleum-based conductive polymers, turning attention to biopolymers derived from natural carbohydrates like cellulose. The research began with optimizing cellulose nanocrystal (CNC) inks to achieve high-resolution 3D structures. This involved creating a "3D-printing" map to demonstrate the relationship between CNC/salt ink rheology and printing fidelity. This map revealed that high fidelity could be achieved within specific concentration ranges, significantly influenced…
has type: Thesis/Dissertation
date issued: 2024-11
is shown at: 10.14288/1.0447123
language: eng
degree discipline: Mechanical Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Arjmand, Mohammad
type: Text
identifier URI: http://hdl.handle.net/2429/89496