IPRC - 2016
Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/157
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Item Montmorillonite/TiO2 Advanced Hybrid Material Using Sri Lankan Clay: Preparation and Characterization(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.Montmorillonite (MMT) is a naturally occurring crystalline silicate clay mineral. Nano titanium dioxide (nano-TiO2), particularly in the anatase form, is a photocatalyst under ultraviolet (UV) light. Nano-TiO2 is thus added to paints, ceramics, tiles, or other products for its sterilizing, deodorizing and anti-fouling properties and is used as a hydrolysis catalyst. The objective of this research is to enhance the photocatalytic activity of TiO2 by forming a hybrid material with MMT. Therefore, montmorillonite/TiO2 advanced hybrid materials was prepared using montmorillonite clay from Murunkan deposit in Sri Lanka. The cation exchange capacity (CEC) of Murunkan clay was found as 65 meq/100 g. Raw materials, intermediate products, and the MMT/TiO2 hybrid material were analyzed using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). XRD and EDX data analysis revealed the presence of TiO2 in the hybrid material as anatase form. According to XRD and SEM data analysis average particle size of the nano TiO2 was found to be 60 nm. SEM images showed that the microstructure of the clay has not been destroyed during the formation of the MMT/TiO2 hybrid material. UV-Visible spectroscopy was used to measure the effectiveness of the photocatalytic activity of the hybrid material versus nano TiO2 for the degradation of methyl orange. In this experiment methyl orange was used as a model organic pollutant. Experimental results showed that after 4 hours MMT/TiO2 hybrid material degraded 92% of methyl orange while nano TiO2 has only degraded 67% under diffused light. The synthesized MMT/TiO2 advanced hybrid material exhibited much higher efficiency in degrading methyl orange compared to the same weight of nano TiO2 alone.Item Nanosilica from Sri Lankan Vein Quartz: Synthesis, Surface Modification and Characterization(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Premaratne, W.A.P.J.; Priyadarshana, W.M.G.I.Vein quartz is one of the most abundant minerals in Sri Lanka and it is mainly mined for porcelain and materials industries. Vein quartz is an economically viable earth resource for the production of nanosilica through chemical methods as a value added product. Nanosilica is one of the widely used nanomaterials in adhesives, sealants, paints & coatings, cement-based building materials and rubber composites as a reinforcing, thickening and flattening agent. In this research work, pure nanosilica was synthesized by a chemical precipitation method from Sri Lankan vein quartz. Finley ground quartz was refluxed with 3 M NaOH and then 0.5 M H2SO4 was added drop wise to adjust the pH of the solution to be around 8.0 to precipitate nanosilica. X-ray diffraction (XRD) data indicated that the natural Sri Lankan vein quartz is highly crystalline and pure. Energy dispersive X-ray spectroscopy (EDX) data confirmed that vein quartz comprises pure silicon oxide with less impurities. Scanning electron micrographs (SEM) data showed that synthesized nanosilica particles from vein quartz were in the agglomerate form with average particle size of 50 nm. XRD data showed a strong broad peak around 22.14o (2) indicating synthesized nanosilica was in amorphous form. Fourier transform infrared spectroscopy (FTIR) data indicated the structural change from crystalline silica (in vein quartz) to amorphous silica by the absence of a sharp peak at 695 cm-1 in the FTIR spectrum of nanosilica synthesized. Silica nanoparticles were subjected to surface modification by oleic acid (C18H34O2). Thermo gravimetric analysis (TGA) graph indicated the thermal decomposition of oleic acid in functionalized nanosilica with a significant weight loss between 350 ºC to 400 ºC. FTIR data showed that modified nanosilica with oleic acid indicated a carbonyl stretching peak of an ester bond at 1711 cm-1, which confirmed the ester bonding between silinol group and the carboxylic group of the oleic acid.