Preparation and characterisation of chitosan-graphene oxide nanocomposites as water-solubilising agents for rotenone
This research aimed to prepare and characterise chitosan-graphene oxide (CS-GO)nanocomposites, namely CS-GO 1% (w/w), CS-GO 2% (w/w) and CS-GO 3% (w/w). In thisresearch, the potential of CS-GO nanocomposites as water-solubilising agents for rotenone wasevaluated. The CS-GO nanocomposites wer...
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| Format: | thesis |
| Language: | eng |
| Published: |
2020
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| Subjects: | |
| Online Access: | https://ir.upsi.edu.my/detailsg.php?det=6724 |
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| Summary: | This research aimed to prepare and characterise chitosan-graphene oxide (CS-GO)nanocomposites, namely CS-GO 1% (w/w), CS-GO 2% (w/w) and CS-GO 3% (w/w). In thisresearch, the potential of CS-GO nanocomposites as water-solubilising agents for rotenone wasevaluated. The CS-GO nanocomposites were characterised by using fourier transform infrared(FTIR) spectrometer, scanning electron microscope (SEM), transmission electron microscope(TEM), X-ray diffraction (XRD) spectrometer and thermogravimetric analyser (TGA). Theinteractions of nanocomposites with rotenone were carried out through adsorption studiesby using Ultraviolet-Visible (UV-Vis) spectrometer, involving several experimentalparameters such as solution pH, initial concentration and contact time. The adsorption behaviour ofrotenone was studied by using the Freundlich and Langmuir isotherm models. The isotherm models wereemployed to correlate with the adsorption equilibrium data. The adsorption kinetic data followedthe pseudo-first order kinetic model. The interaction between CS-GO nanocomposites androtenone was assessed through desorption study by using hydrochloric acid and sodiumhydroxide as desorption agents. Research findings found that GO nanoparticle aggregates have aspherical shape with size in the range of 1.40 to 34.7 nm. XRD results show that the crystallinityof CS was increased following interaction with GO with a signal counts value more than 3000. Basedon Langmuir isotherm model, CS-GO 3% exhibited the highest adsorption capacity for rotenone withQm?? value of 92.59 mg/g. The main mechanism for interaction of CS-GO nanocompositeswith rotenone was through formation of hydrogen bonding. CS-GO 1%, CS-GO 2% and CS-GO 3%nanocomposites were able to increase the solubility of rotenone in water by 34.40%, 38.80% and46.30%, respectively. In conclusion, the presence of functional groups such as hydroxyl, carboxyland amide on CS-GO nanocomposites significantly contributed to water- solubilising mechanism. Theimplication of CS-GO nanocomposites as water-solubilising agents in pesticide formulations couldreduce the amount of organic solvent, producing eco-friendlypesticides for a safer environment. |
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