http://hdl.handle.net/10204/1873 2013-05-23T12:36:55Z 2013-05-23T12:36:55Z Pillai, SK Moyo, L Sinha Ray, S Scriba, M http://hdl.handle.net/10204/6705 2013-04-19T21:55:18Z 2012-11-01T00:00:00Z

Title: Microwave assisted organic modification and surface functionalization of Phyllosilicates Authors: Pillai, SK; Moyo, L; Sinha Ray, S; Scriba, M Abstract: Organically modified phyllosilicates (montmorillonite and palygorskite) using Arquad 2HT-75 surfactant were effectively synthesized utilizing a microwave irradiation technique. The microwave method was successfully used also for the surface decoration of raw montmorillonite clays with metal (Ag, Fe) nano-particles. The composites were characterized by transmission electron microscopy; x-ray diffraction; energy dispersive x-ray spectroscopy and Fourier transform infrared spectroscopy. Compared to the conventional thermal process, the synthesis under microwave conditions was more effective, faster and environmental friendly. The antimicrobial properties of the microwave synthesized metal-clay samples against Gram-negative bacteria, ie, Escherichia coli were also investigated. Description: Composites and Nanocomposites in Civil, Offshore and Mining Infrastructure (ACUN6), Melbourne, Australia, 14-16 November 2012

2012-11-01T00:00:00Z Pillai, SK Gheevarghese, O Tleane, IV http://hdl.handle.net/10204/6703 2013-04-29T21:55:13Z 2012-01-01T00:00:00Z

Title: Friedel-Crafts Alkylation of o-xylene over V2O5/ZrO2 Catalysts Authors: Pillai, SK; Gheevarghese, O; Tleane, IV Abstract: The present study has undertaken the Friedel-Crafts benzylation of aromatics over the V2O5/ZrO2 catalysts systems. Catalysts with different V2O5 content (0-15wt %) was prepared by wet impregnation method and characterized by XRD, BET surface area, FTIR and 5’V NMR techniques. The surface acidic properties were determined by temperature programmed desorption of NH3, cumene cracking and perylene adsorption. Under the optimized reaction conditions, these catalysts are found to be very effective and considerably more selective than the conventional homogeneous Lewis acid catalysts. The investigation of vanadia systems-catalyzed benzylation of o-xylene with benzyl chloride revealed that the catalytic activity and product selectivity are sensitive to the precise reaction parameters and can be related to the Lewis acidity of the systems. The reaction is found to be very clean and produces the desired monoalkylated product with high yield. Description: Copyright: 2012 Mapana Journal of Sciences, vol. 11(2), pp 1-16

2012-01-01T00:00:00Z Motaung, DE Malgas, GF Arendse, CJ Mavundla, SE http://hdl.handle.net/10204/6689 2013-04-29T21:55:14Z 2012-08-01T00:00:00Z

Title: Determination of the structure, morphology and complex refractive index in ZnO-nanopencils/P3HT hybrid structures Authors: Motaung, DE; Malgas, GF; Arendse, CJ; Mavundla, SE Abstract: Well crystallized flower-shaped ZnO-structures composed of a perfectly hexagonal-shaped ZnO structure were successfully synthesized using a simple microwave assisted hydrothermal method. The NPs with a hexagonal stem and a tapering tip grows out of the base of the flower-shapes. ZnO-NPs were incorporated into the nanomorphology of P3HT and two variations of P3HT:C60 and P3HT: PCBM blended films in order to facilitate charge separation and transport. Thermo-gravimetric analysis revealed that ZnONPs are more stable and are of high purity. A complete PL quenching was demonstrated upon incorporating ZnO-NPs on the surface of P3HT and blended films indicating a charge transfer along the ZnO/P3HT and ZnO/P3HT: fullerenes induced by the aligned nanorods which are working as effective electron collectors by shortening the average electron diffusion distance in the P3HT and fullerenes network. Spectroscopic ellipsometry demonstrated that infiltrating of ZnO-NPs, results in the improved refractive index, extinction coefficient and shifts to lower photon energies. Such shifts can be inferred to the improved light absorption through the waveguide effect from the NPs and an increased interfacial area between the ZnO-NPs and P3HT. An improvement in the mobility and conductivity of P3HT films was observed with an incorporation of ZnO. Description: Copyright: 2012 Elsevier. This is an ABSTRACT ONLY. The definitive version is published in Materials Chemistry and Physics, vol. 135(2-3), pp 401-410

2012-08-01T00:00:00Z Ojijo, V Sinha Ray, S http://hdl.handle.net/10204/6657 2013-04-11T21:55:18Z 2012-01-01T00:00:00Z

Title: Poly(Butylene Succinate) and Poly[(Butylene Succinate)-co-Adipate] Nanocomposites Authors: Ojijo, V; Sinha Ray, S Abstract: In the recent years, biodegradable aliphatic polyesters-based composite materials have attracted substantial interest, primarily due to their sustainable production, use and end-life. This chapter discusses the preparation, characterisation, and properties of nanoclay-containing composites of biodegradable poly(butylene succinate) (PBS) and poly[(butylene succinate)-co-adipate] (PBSA). Various nanocomposite structures arising from the incorporation of layered silicate particles, both pristine and organically modified, into the neat PBS and PBSA matrices is critically reviewed. Good dispersion of the layered silicates, especially the organically modified layered silicates, tends to result in an improvement in a number of properties of the final nanocomposites: storage modulus, tensile modulus, gas barrier properties, degradability, and thermal stability, when compared with the neat polymers. Description: Copyright:Springer, London

2012-01-01T00:00:00Z