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Preparation, Characterization, and Applications of Nanomaterials functionalized Cellulose Extracted from Crops Residues and Wastes.
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Abstract: The objectives of this work are summarized in:
1. Access to the best catalyst and the most favorable conditions for the production of biodiesel via esterification of oleic acid with methanol using the prepared derivatives of nanocellulose as catalysts.
2. The use of rice straw (as an agricultural residue that causes pollution of the environment and the spread of diseases associated with it) for the production of nanocellulose, which has been modified to produce acid-functionalized nanocellulose species. The acidic functionalization of nanocellulose was achieved using organic groups (acetate or succinate) and inorganic groups (phosphorylate or sulfonate), followed by doping of magnetite on their surfaces to produce cellulose-magnetite nanocomposits.
The thesis consists of three chapters as follow:
Chapter 1: Introduction
This chapter contains a background on experimental and theoretical studies on cellulose, nanocellulose, biodiesel, esterification of free fatty acids and catalysts.
Chapter 2: Materials and Methods
This chapter focuses on methods and procedures used in this work. These include the following:
1- Extraction of nano-cellulose from rice straw.
2- Methods used for surfaces functionalized of nanocellulose, using different organic (acetate and suuccinate) and inorganic (phosphate and sulfonate) groups.
3- Preparation of cellulose-magnetite nanocomposites via the adsorption of magnetite onto the surfaces of nanocellulose and its functionalized species.
4- Characterization techniques of the produced derivatives using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), energydispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), magnetic properties measurements, and thermal analysis.
5- The catalytic activity of the functionalized nanocellulose and cellulose-magnetite nanocomposites towards the esterification of oleic acid with methanol for the production of methyl oleate (biodiesel).
6- The effects of different reaction parameters (including molar ratio of oleic acid to methanol, catalyst dosage, reaction temperature and reaction time) on the catalytic activity toward esterification of oleic acid.
7- The reusability of the MSNC nanocomposite as best derivative.
8- The chemical reactivity of all derivatives within a density functional theory (DFT) framework.
Chapter 3: Results and Discussions
This chapter contains the results obtained and their discussion which are summarized as follows:
The catalytic activity of the functionalized nanocellulose and cellulose-magnetite nanocomposites was evaluated towards the esterification of oleic acid with methanol for the production of methyl oleate (biodiesel). The sulfonated cellulose-magnetite nanocomposite (MSNC) showed the highest catalytic activity toward the esterification reaction (96%) due to the high dispersion of the Lewis acid sites resulted from the impregnation of magnetite (0.98 wt%) in addition to the already presented Br?nsted acid sites in the surface of the nanocellulose.
The maximum ester yield (100%) was obtained when the reaction was performed at optimal conditions of 1:15 oleic acid to methanol molar ratio, 3wt% catalyst dose, at 60? C and 1h. The esterification of oleic acid over MSNC follows the pseudo first-order model under the optimal experimental conditions. The synthesized catalyst shows good reusability for five trails.
Cellobiose and its modified species with acetate, succinate, phosphate and sulfonate were modeled by quantum computation using density functional theory (DFT) with the B3LYP and 6-311G(d,p) basis-set. For all derivatives, structures and energies of ground states were calculated. Global hardness and softness, deprotonation enthalpy of all species were determined. According to computational data, the sulfonated cellobiose (8.8 Debye) would be the most active species regarding catalytic activity of the esterification process.
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| Publication year |
2017
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| Organization Name |
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| Country |
Egypt
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| Author(s) from ARC |
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| Publication Type |
PhD Thesis
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