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| 001 | vtls000103093 | ||
| 003 | KUKTEM | ||
| 005 | 20251117113437.0 | ||
| 008 | 180312s2017 my da f am 000 0 eng d | ||
| 020 | _aTHE0008058(Local) | ||
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_a201906181324 _bamy2 _y201803121124 _zsaini |
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_aUMP _beng _cUMP _erda |
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| 090 | _aFKP .Z854 2017 r Thesis | ||
| 100 | 0 |
_aZulhelmi Ismail, _eauthor. |
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| 245 | 1 | 0 |
_aGum arabic assisted liquid-phase exfoliation of graphene flakes as filler for PVA nanocomposite / _cZulhelmi Ismail |
| 264 | 1 |
_aKuantan, Pahang : _bUMP, _c2017 |
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| 264 | 4 | _c© 2017 | |
| 300 |
_axiii, 201 pages : _billustrations (some color), chart ; _c30 cm. + _e1 CD-ROM |
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_atext _2rdacontent |
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_acomputer _2rdamedia |
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_atext file _bPDF _2rda |
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| 500 | _aFaculty of Manufacturing Engineering | ||
| 502 | _aThesis (Doctor of Philosophy in Manufacturing Engineering) -- Universiti Malaysia Pahang – 2017 | ||
| 504 | _aIncludes bibliographical references | ||
| 520 | 3 | _aLiquid-phase exfoliation (LPE) by a kitchen mixer is one of the reported top-down approaches for the production of graphene. The main advantages of this method against bottom-up strategies such as chemical vapor disposition or epitaxial growth are a possible preparation of low-defect graphene with good process scalability and the production cost that is strongly economical. However, the majority of current works on the graphene preparation by LPE are involving the application of dimethylformamide or N-methyl-2-pyrrolidone, which are toxic and dangerous for the environment as the dispersing solvent for graphene. Notably, the role of these solvents must be replaced with water, which certainly is natural and non-toxic liquid. In order to allow the application of water as a medium for exfoliation and stabilization of graphene, the presence of natural surfactant is required. Therefore, the exfoliation of graphene in this thesis was carried out in a gum Arabic solution with the assistance of a kitchen mixer. Gum Arabic is an excellent dispersant and stabilizer for carbon-based material during the exfoliation stage. The presence of gum Arabic-graphene, GGA in the resulting supernatant was majorly confirmed from the initial characterizations of graphene by transmission electron microscopy, atomic force microscopy, and Raman spectroscopy. Mean length and thickness of exfoliated GGA were measured at 450 nm and 1.75 nm (~5 layers) with the minor defect level was evaluated by the small intensity ratio of D and G bands for graphene. The scalability of kitchen mixer for production of GGA meanwhile was investigated using power-law and two-level factorial study. Impressively, the scalability of production of graphene by gum Arabic was verified from the positive master plot for yield efficiency and production rate. The highest yield of 0.3 % and production rate of 17.3 mg/h was recorded for the productivity study of graphene. The influence of interactive effects in the production of GGA by a kitchen mixer though was represented by a factor of 4.2 from the power-law versus factorial plot. As a proof of concept, the produced GGA in this work was applied as filler for tensile strength, ζ and elastic modulus, E reinforcement of polyvinyl alcohol, PVA. Impressively, the improvement of ζ and E for PVA/GGA film to 200 % and 187 % from the original values is proving the potential of produced GGA in this thesis. In conclusion, the possibility of graphene exfoliation in gum Arabic-water by a kitchen mixer has been extensively evaluated in this thesis. In addition, the quality of produced graphene in this work also has been verified from the excellent mechanical performance of PVA after addition of the graphene. The application of mixer as a tool for green and scalable exfoliation of graphene flakes is likely to reduce the future cost of graphene and improve the application progress of PVA/graphene composite. | |
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_aFaculty of Manufacturing Engineering _xDissertations |
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_aUniversities and colleges _xDisertations |
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| 650 | 0 | _aTheses | |
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