Pusat Pengajian Sains Kimia - Tesis
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- PublicationSynthesis And Application Of Glycerin Pitch-Derived Activated Carbon For Model Fuel Oil Desulfurization And Electrode Use(2024-06)Zulkefli, Maryam SolehahDesulfurization of fuel is crucial in meeting environmental regulations in reducing the sulfur content to minimize air pollution and protect human health. Adsorptive desulfurization (ads) has emerged as a viable and efficient method for sulfur compounds removal from diesel fuel. This method requires the ability of adsorbents, such as activated carbon (acs) to selectively capture sulfur-containing compounds. Activated carbons was produced from glycerin pitch, a natural resource and industrial waste material, through the wet impregnation method employing activating agents, namely phosphoric acid (h3po4), and ferum nitrate (fe(no3)3.9 h2o). The primary aim of this study is to emphasize the potential of glycerin pitch activated carbon as an efficient and eco-friendly material means to attain ultra-low sulfur fuel standards. The prepared activated carbons were characterized by x-ray diffraction (xrd), nitrogen absorption analysis (na), field emission scanning electron microscopy-energy dispersion x-ray (fesem and edx), fourier transform infrared spectroscopy (ftir), thermogravimetric analysis (tga). Acs impregnated with phosphoric acid have exceptionally high surface area (860 m2/g) and porous structure (0.4012 cm3/g) which provides ample sites for adsorption of sulfur compounds such as dibenzothiophene (dbt).
- PublicationSynthesis And Characterisation Of Carbon, Nitrogen Co-Doped-Titanium Dioxide/Sodium Alginate Buoyant Photocatalyst For Degradation Of Diazinon(2024-06)Idris, Nurul Hidayah MohamadThe utilisation of titanium dioxide (tio2)- based photocatalysts has garnered significant attention among researchers due to their promising potential for removing pollutants from wastewater. Buoyant photocatalysts are being explored as viable candidates for wastewater treatment applications, aiming to address filtration challenges during the treatment process. In this study, the design of modified tio2 with a highly durable buoyant carrier is essential to enhance its photocatalytic performance in degrading pollutants from wastewater. Subsequently, carbon (c) and nitrogen (n)-codoped tio2 nps with varying c:n percentages were successfully developed using the sol-gel method. These optimised c, n-tio2 nps exhibit favorable attributes, including activity in the visible light region with a lower bandgap energy of 2.94 ev compared to the 3.0 ev of the synthesised tio2 nps, as well as slower recombination of electron-hole pairs than the synthesised tio2 nps. X-ray photoelectron spectroscopy (xps) analysis further verified the co-doping of c and n into tio2, evidenced by the shift in ti2p binding energy.
- PublicationDocking And Molecular Dynamics Simulation Studies Of Insulin-P- Cyclodextrin Interactions(2016-02)Muhammad, Erma FatihaProtein-ligand interactions play an essential role in the design of new pharmaceutical products. This study attempts to understand the theoretical basis on the structure and dynamics of insulin-cyclodextrin complex for new oral insulin formulation. Docking and molecular dynamics simulations explore the interactions between insulin monomer and insulin dimer with 0- cyclodextrins (0-CDs). A multiple molecular docking study was performed using the Autodock v4.2 program to determine the number of 0-CD that can adhere to the binding sites of insulin as well as to determine the most stable conformations of insulin to p-CDs. A 100 random structure docking using 1:1 insulin monomer-P-CD and insulin dimer-p-CD ratio were conducted and from the final docked structure, additional 0-CDs were added and the process were repeated until the energy increase. Molecular docking results revealed that a maximum of four 0-CDs can bind to an insulin structure with the 1:3 insulin-P-CD ratios having the lowest binding free energy. A 100 ns molecular dynamics simulation was then conducted to verify the results obtained by molecular docking.
- PublicationBis-, Tris-, And Tetrakisbenzimidazolium Salts And Their Silver(I) Complexes: Synthesis, Characterization And Biological Applications(2024-09)Abdurrahman, NuraddeenThis research describes the synthesis, characterization, crystal structure and cytotoxicity activity of several new bis-, tris- and tetrakis-benzimidazolium salts, (1- 24) and their respective silver(I)-benzimidazol-2-ylidene complexes, (Ag1-Ag24). All the compounds synthesized were new based on literature reviewed, it was achieved by changing the either the alkyl or aryl substituents on the benzimidazolium systems and or the bridging ligands related to the previously reported compounds. The salts were synthesized by nucleophilic substitution reaction and were categorized into five series. The salts were 1-5, 6-9, 10-14, 15-19, 20-24 as first, second, third, fourth and fifth series respectively. The synthesized salts were utilized for the synthesis of their respective silver(I)-benzimidazol-2-ylidene complexes, by in-situ deprotonation method in the presence of silver(I)oxide. The cytotoxicity potential of the synthesized compounds was carried out by MTT assay method, in which the breast and cervical cancer cell lines were used. Salt 1-5, 6-9, 15-19, and their silver(I)-benzimidazol-2-ylidene complexes, (Ag1-Ag5, Ag6 -Ag9, Ag15-Ag19) were tested against breast cancer cell lines, while salts, 10-14, 20-24, and their silver(I)-benzimidazol-2-ylidene complexes, (Ag10-Ag14, Ag20-Ag24) were tested against cervical cancer cell lines. The positive control used for the breast cancer cell was tamoxifen and etoposide for the cervical cancer cell. All the salts and their respective silver(I)-benzimidazol-2-ylidene complexes synthesized were characterized using various characterization techniques including FTIR, 1H, 13C NMR, elemental analysis, and single crystal X-ray diffraction method. Physical properties were accessed by melting point analysis, and solubility tests in various organic solvents. From structural elucidation, it was confirmed that Ag2 was dinuclear silver(I)-benzimidazol-2-ylidene complex, with two PF6 anions as counterions balancing the charges of the entire molecule. Complex Ag13 confirmed to be a cylinder-like trinuclear silver(I)-benzimidazol-2-ylidene complex containing three silver(I) ions bridged by two disc-like ligands.
- PublicationDevelopment Of Fatty Acid-Based Deep Eutectic Solvents In Liquid Phase Microextraction With Back Extraction For Determination Of Selected Organic Pollutants(2024-04)Sazali, Nur HidayahEnvironmental pollution has become a significant global issue in recent times. The primary sources of this pollution are human activities such as industrial processes, marine dumping, agricultural practices, and wastewater discharges. Some of the most concerning environmental pollutants are pesticides, herbicides, and polycyclic aromatic hydrocarbons (PAHs) due to their high toxicity and their persistence in the environment. These pollutants have harmful effects on human health and the ecosystem. Due to their high toxicity and trace amount in environment, developing an effective extraction method is essential. Deep eutectic solvent (DES) is a possible green alternative to the conventional solvent utilised in most extraction procedures in light of the increased demand for developing green extraction techniques. Microextraction-based DES fits favourably with the Green Analytical Chemistry (GAC) concept because of its rapid sample preparation time, low organic solvent usage, and straightforward procedure. In this study, an eco-friendly microextraction utilising hydrophobic deep eutectic solvents from fatty acids derived from the combination of lauric acid, which acted as a hydrogen bond acceptor (HBA), and pelargonic acid, which acted as a hydrogen bond donor (HBD), was prepared to determine herbicide mixtures using emulsification liquid-liquid microextraction with back extraction (ELLME-BE) method. In addition, a ferrofluid was developed by incorporating DES, a combination of lauric acid (HBA) and caprylic acid (HBD) with magnetic nanoparticles (MNP) to determine polycyclic aromatic hydrocarbons xxviii (PAHs) using liquid phase microextraction with back extraction (LPME-BE) method. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA),