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Carbon Dioxide Absorbers for Active Food Packaging: Heterogeneous Chemical Precipitation of Lime on TEMPO Oxidized Cellulose Nanofiber Template
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- Author / Creator
- Ramachandran Shivakumar, Karthik
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Cellulose nanofibers are fibers of high aspect ratios with exceptional barrier properties and are manufactured from renewable source. In this study, cellulose from various sources such as Kraft pulp and bleached chemical thermomechanical pulp (BCTMP) with different dispersion methods was used to make cellulose nanofibers using 2,2,6,6,Tetramethylpiperidine-1-oxyl (TEMPO) mediated selective oxidation method. The oxidation levels of the fibers from different cellulose sources were correlated with the amount of primary oxidizer used. The self-assembly of the nanofibers due to freeze-drying was analysed and the thermal degradation properties of these freeze-dried fibers were studied. The nanofibers produced form the TEMPO oxidation was used as a template for the growth of calcium hydroxide particles. A novel heterogeneous chemical precipitation method was used to deposit calcium hydroxide on the surface of the nanofibers. This research was aimed at developing a carbon dioxide absorber in active food packaging applications, as calcium hydroxide could absorb the carbon dioxide to form calcium carbonate to prevent the excess carbon dioxide damage in packaged food produces, especially climacteric fruits like apple, bananas etc. The metal-fibre composite was studied under thermal degradation at high temperature before and after carbonation of the calcium hydroxide particles. The crystal formation was analysed using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy. The flow properties of cellulose nanofibers at different dilutions, cellulose nanofiber blends and hydroxyethyl cellulose blends with metal-fiber composite at different concentrations were measured and the respective films made from the blends were studied using dynamic mechanical analysis.
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- Subjects / Keywords
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- Graduation date
- Fall 2019
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.