PREPARATION AND CHARACTERIZATION OF POLYANILINE-BASED MATERIALS FOR ELECTROCHEMICAL DETECTION OF NITROPHENOLS
| dc.contributor.committeeMember | Grosvenor, Andrew | |
| dc.contributor.committeeMember | Odeshi, Akindele | |
| dc.contributor.committeeMember | Gravel, Michel | |
| dc.creator | Khani, Milad | |
| dc.creator.orcid | 0000-0002-7596-5451 | |
| dc.date.accessioned | 2022-11-17T18:52:19Z | |
| dc.date.available | 2023-09-01T06:05:07Z | |
| dc.date.copyright | 2022 | |
| dc.date.created | 2022-08 | |
| dc.date.issued | 2022-09-01 | |
| dc.date.submitted | August 2022 | |
| dc.date.updated | 2022-11-17T18:52:19Z | |
| dc.description.abstract | The development of modified polyaniline (PANI)-based composites is an emerging field of advanced materials with fascinating applications such as the adsorption of metals and dyes, sensors, and biocatalysts. The electrical conductivity of PANI and its structural properties are influenced by the method used for its synthesis. Thus, if an appropriate synthetic method is employed, modified PANI-based composites can be utilized for sensor-based applications. Unfortunately, pristine PANI presents numerous challenges. It is difficult to process and has poor film-forming ability, which limits its application for practical environmental applications. The mentioned disadvantages can be addressed through formation of composites, where the use of additives or supporting materials are combined with PANI. Chitosan (CHI) is a biopolymer that includes hydroxyl and amine functional groups that can be modified by forming a composite with PANI (CHI-PANI). Doping PANI with organic acids such as citric acid can improve its hydrophilicity and conductivity. To study the electrocatalytic properties of modified PANI-based composites, silver nanoparticles (Ag NPs) were deposited onto the composites to monitor the oxidation of 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP) in aqueous media. Cyclic voltammetry (CV) was chosen as the electrochemical method for the analytical detection of 2-NP and 4-NP. The short-term objectives of the thesis are summarized below: (i) To synthesize ternary composites of Ag NPs-Chitosan-PANI (Ag@CP(x), where x = 25, 50, or 75, referring to the weight fraction (%) of aniline relative to CHI) and Ag NPs-PANI-citric acid (Ag@P-CA). (ii) To carry out structural and physicochemical characterization of modified PANI-based composites with thermogravimetric analysis (TGA), atomic absorption analysis (AAS), 13C solid-state NMR spectroscopy, FTIR spectroscopy, X-ray diffraction (XRD), UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS) and dye adsorption techniques. (iii) A CV study that employs modified PANI-based electrode materials (Ag@CHI-PANI and Ag@P-CA) for electrochemical characterization of properties and nitrophenol detection. The long-term objective of this thesis is to develop novel modified PANI-based electrode materials for the electrochemical detection of 2-NP in water and environmental groundwater samples. Based on the 2-NP adsorption isotherms, Ag@CP75 was effective as an electrode material with 40% and 330% higher 2-NP adsorption capacity than PANI and CHI, respectively. Based on the CV of modified PANI-based composites in nitrophenol solutions, the relative standard deviation (RSD) of 5.70% was assigned to Ag@CP75's selectivity in the presence of nitrophenol isomers and inorganic salts. The RSD’s of 2.68% and 2.64% were accredited to Ag@CP75's stability (nine cycles) and reproducibility (ten cycles) for the electrochemical detection of 2-NP, respectively. CV studies on Ag@P-CA supported the increase in electron transfer rate after the deposition of Ag NPs onto P-CA. Lastly, an illustration of the pathway for the detection of nitrophenols with PANI-modified electrode materials was proposed based on the electrochemical results obtained in this thesis and the theory of electrochemistry (cf. Figure 5-11). This illustrated pathway divides 2-NP detection mechanism into various steps (chemical reaction, adsorption, desorption, electrochemical reaction). By optimizing each of these steps, the detection mechanism can be improved for future studies. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.uri | https://hdl.handle.net/10388/14307 | |
| dc.language.iso | en | |
| dc.subject | Polyaniline | |
| dc.subject | Chitosan | |
| dc.subject | Citric acid | |
| dc.subject | silver nanoparticle | |
| dc.subject | nitrophenol | |
| dc.subject | electrochemistry | |
| dc.subject | detection | |
| dc.title | PREPARATION AND CHARACTERIZATION OF POLYANILINE-BASED MATERIALS FOR ELECTROCHEMICAL DETECTION OF NITROPHENOLS | |
| dc.type | Thesis | |
| dc.type.material | text | |
| local.embargo.terms | 2023-09-01 | |
| thesis.degree.department | Chemistry | |
| thesis.degree.discipline | Chemistry | |
| thesis.degree.grantor | University of Saskatchewan | |
| thesis.degree.level | Masters | |
| thesis.degree.name | Master of Science (M.Sc.) |