Pusat Pengajian Sains Kimia - Tesis

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Computational Design And Investigation Of New Benzophenones And Benzophenone Imines Inhibitors For Breast Cancer
(2018-10)
Shtaiwi, Amneh Mohammad
The computational methods of protein-ligand interactions are core components in drug design and modem drug discovery. This study attempted to design and investigate the interactions of new human estrogen receptor (hERa) inhibitors to treat breast cancer cells using molecular modeling approach. The proposed inhibitors were designed by replacing the triarylethylene estrogenic scaffold found in the synthetic inhibitor 4-hydroxytamoxifen (4-0HT) with triarylimine Schiff bases.
Synthesis And Characterization Of Mil-101(Cr) And Zno@mil-101(Cr) For Photocatalytic Degradation Of Phenanthrene
(2024-09)
Adamu, Usman Abubakar
In this study, a low-temperature hydrothermal method was employed to prepare highly porous and well-defined MIL-101(Cr) metal-organic frameworks. A series of chromium-based MOFs (MIL-101) was synthesized at different temperatures: 150, 160, 170, 180, 200, and 220 ºC. The synthesized MOFs were characterized using various techniques. The effectiveness of these synthesized photocatalysts was assessed for the photocatalytic degradation of phenanthrene (PHE) under UV light exposure. Remarkably, 98% degradation of PHE was obtained within 150 minutes of UV light irradiation with MIL-101@160 under specific optimized conditions, which included a PHE concentration of 2 ppm, pH 7, and a catalyst dosage of 30 mg. The enhanced degradation efficiency of MIL-101@160 could be attributed to its high specific surface area and thermal stability. ZnO was synthesized through a biosynthesis method and subsequently utilized to fabricate ZnO@MIL-101(Cr) nanocomposites, with preparation carried out at temperatures of 160 ºC and 220 ºC, respectively. These catalysts were characterized using fourier tranform infrared, X-ray diffraction, Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence analyses, The effectiveness of the ZnO@MIL-101(Cr) nanocomposite in photocatalysis was evaluated for the degradation of PHE, utilizing both UV and visible light irradiation. The effect of different parameters such as solution pH, catalyst loading, the source of light, catalyst reusability, and the effect of temperature on PHE degradation were evaluated.
Extraction Of Flavonoids From Butterfly Pea (Clitoria Ternatea) Flower And Their Inhibitive Effect For Corrosion Under Co2 In Low-carbon Steel
(2024-09)
Azahar, Siti Shafiqah
The present study emphasizes the extraction of flavonoids which are quercetin and kaempferol from Butterfly blue pea (Clitoria ternatea) flower containing very strong antioxidant properties. The extracts were prepared using solvents with different polarities, namely chloroform (CTCH), ethanol (CTET), ethyl acetate (CTEA), and water (CTW). The phytochemical studies for all extracts were evaluated to screen the phenolic content, flavonoid content, reducing power assay, and tannin content as a potential source of antioxidant properties of the flower. All the extracts were then characterized using complementary analyses, including Fourier-transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), Nuclear magnetic resonance (NMR) analysis (including 1H and 13C NMR). According to High-performance liquid chromatography (HPLC) and Liquid chromatography-mass spectrometry (LC-MS) analysis, the compounds found in CT extracts were identified both qualitatively and quantitatively. Electrochemical measurements, including Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization (PD), and Electrochemical noise measurement (ENM) revealed the anticorrosion performance of mild steel under a CO2 atmosphere. The performances of mild steel to prevent corrosion in 3.5% NaCl medium containing CTW and CTET extracts at different concentrations and temperatures were ascertained through electrochemical measurements.
Synthesis And Mesomorphic Properties Of Bent-shaped 1,4-disubstituted Triazole-cored Schiff Base With Lateral Ethoxy Group
(2024-09)
Ismail, Siti Norhazwani
Two series of bent-shaped liquid crystalline molecules, incorporating 1,4-disubstituted triazole-cored Schiff bases with lateral ethoxy groups, were successfully synthesized via the copper-catalyzed azide-alkyne cycloaddition reaction. Molecular elucidation was conducted using spectroscopic techniques, while polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) were employed to investigate the optical and thermal properties of the molecules. In the first series, molecules were designed as simple bent monomers containing lateral ethoxy Schiff base with terminal flexible alkyl chains of varying lengths. Subseries A consists of cyanobiphenyl Schiff base at terminal position, exhibited stable SmA phases in compounds with longer alkyl chains, suggesting that an increase in molecular flexibility with chain lengthening favours smectogenic character. In contrast, all derivatives of subseries B with phenyl methoxy Schiff base at terminal position showed non-mesomorphic behaviour with significant overcooling tendencies. The second series, which is analogous to the first but extending into a dimer with a triazole core and an alkoxy spacer linked to a biphenyl ester on one side, displayed more distinct and pronounced mesophase characteristics. This demonstrates the significant impact of these structural modification on mesomorphic properties. All derivatives in subseries A, 8aA – 8fA exhibited nematogenic character with birefringent Schlieren texture.
Synthesis And Characterizations Of Various Metal-based Halloysite Nanocomposites For The Photo-degradation Of Liquid Epoxidized Natural Rubber
(2024-09)
Saad, Abdullahi Shehu
In this research, various metal oxides (CuO, NiO, Co3O4, CrO and ZnO) based supported HNT photocatalysts were synthesized via wet impregnation of various metal salts (Cu(NO3)2.3H2O, NiSO4.6H2O, Ni(NO3)2.6H2O, Co(NO3)2.6H2O, Cr(NO3)3.9H2O, and Zn(NO3)2.6H2O) on HNT, followed by subsequent calcination techniques. HNT and photocatalysts were characterized by FTIR, XRD, AAS, SEM/EDX, BET, UV–Vis (DRS), and PL techniques and results confirmed the successful formation of photocatalysts (CuO, NiO, Co3O4, CrO and ZnO) supported HNT. The photocatalysts were subsequently employed to degrade LENR in the presence of UV irradiation. The photodegradation of LENR into shorter chains using metal oxide-supported catalysts is an alternative method which is efficient compared to the use of chemicals. It is significant for polymer industries due to its ability to produce low molecular weight components that can be used as raw materials. When compared to pristine LENR, the functional groups of degraded LENR exhibited some changes. GPC analysis reveals that the Mw of the degraded LENR was dramatically reduced, leading to the possibility of more chain scission. Thus, it can be established that the photocatalytic degradation of LENR is effective in the presence of photocatalysts. The Mw of LENR decreases after UV light exposure but increases with Ni2+-HNT catalyst. The Mw of 3H D-LENR(NiO-HNTs) reduced significantly from 25,732 for pristine LENR to 2.344 g/mol when calcined NiO-HNT was used for 3 hours of degradation. However, longer degradation times resulted in the crosslinking of short unstable chains formed.

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