Catalysts derived from metal-organic frameworks : a thesis presented in partial fulfilment of the requirements of the degree of Doctor of Philosophy in Chemistry at Massey University, Manawatu, New Zealand

The synthesis of atomic-scale catalysts is a blooming field, and these replace the conventional nanocatalysts due to their high atom utilization, selectivity, and unique catalytic activity. Metal-organic frameworks (MOFs) serve as promising precursors for the synthesis of single-atom catalysts (SACs). This study focused on the synthesis of SACs on nitrogen-doped hollow carbon by using MOFs and MOF composites followed by pyrolysis. The synthesis of two SACs namely rhodium SACs (Rh SACs) and cobalt SACs (Co SACs) by different methods, their characterization, and catalysis was explored. Rh SAC synthesized in this work hydrogenates nitroarenes with high consumption and high selectivity. Moreover, Co SAC did little or no hydrogenation of the nitroarenes. Further applications of these SACs were explored by employing them in oxygen reduction reaction (ORR), NO abatement, and Fenton-like catalysis. Moreover, the synthesis of two types of hollow nanoboxes (HNB) namely HNB-1 and HNB-2; using MOFs and MOF composites, their characterization and applications were also investigated. HNB-1 was used to make electrode supercapacitors and it showed comparable activity to activated carbon. Further attempts were made to use HNB-2 as a fluorescence sensor. Finally, several ideas on synthesising SACs and HNBs were proposed as a part of future work

Improving Dispersion of Recycled Discontinuous Carbon Fibres to Increase Fibre Throughput in the HiPerDiF Process

In order to increase the material throughput of aligned discontinuous fibre composites using technologies such as HiPerDiF, stability of the carbon fibres in an aqueous solution needs to be achieved. Subsequently, a range of surfactants, typically employed to disperse carbon-based materials, have been assessed to determine the most appropriate for use in this regard. The optimum stability of the discontinuous fibres was observed when using the anionic surfactant, sodium dodecylbenzene sulphonate, which was superior to a range of other non-ionic and anionic surfactants, and single-fibre fragmentation demonstrated that the employment of sodium dodecylbenzene sulphonate did not affect the interfacial adhesion between fibres. Rheometry was used to complement the study, to understand the potential mechanisms of the improved stability of discontinuous fibres in aqueous suspension, and it led to the understanding that the increased viscosity was a significant factor. For the shear rates employed, fibre deformation was neither expected nor observed

Antibacterial activity of eight invasive alien plants against selected multi-drug resistant microorganisms

NA

The KMOS^3D Survey: design, first results, and the evolution of galaxy kinematics from 0.7<z<2.7

We present the KMOS^3D survey, a new integral field survey of over 600 galaxies at 0.7<z<2.7 using KMOS at the Very Large Telescope (VLT). The KMOS^3D survey utilizes synergies with multi-wavelength ground and space-based surveys to trace the evolution of spatially-resolved kinematics and star formation from a homogeneous sample over 5 Gyrs of cosmic history. Targets, drawn from a mass-selected parent sample from the 3D-HST survey, cover the star formation-stellar mass ($M_*$) and rest-frame $(U-V)-M_*$ planes uniformly. We describe the selection of targets, the observations, and the data reduction. In the first year of data we detect Halpha emission in 191 $M_*=3\times10^{9}-7\times10^{11}$ Msun galaxies at z=0.7-1.1 and z=1.9-2.7. In the current sample 83% of the resolved galaxies are rotation-dominated, determined from a continuous velocity gradient and $v_{rot}/\sigma>1$, implying that the star-forming 'main sequence' (MS) is primarily composed of rotating galaxies at both redshift regimes. When considering additional stricter criteria, the Halpha kinematic maps indicate at least ~70% of the resolved galaxies are disk-like systems. Our high-quality KMOS data confirm the elevated velocity dispersions reported in previous IFS studies at z>0.7. For rotation-dominated disks, the average intrinsic velocity dispersion decreases by a factor of two from 50 km/s at z~2.3 to 25 km/s at z~0.9 while the rotational velocities at the two redshifts are comparable. Combined with existing results spanning z~0-3, disk velocity dispersions follow an approximate (1+z) evolution that is consistent with the dependence of velocity dispersion on gas fractions predicted by marginally-stable disk theory.Comment: 20 pages, 11 figures, 1 Appendix; Accepted to ApJ November 2

Monomer-on-Monomer (MoM) Mitsunobu Reaction: Facile Purification Utilizing Surface-Initiated Sequestration

A monomer-on-monomer (MoM) Mitsunobu reaction utilizing norbornenyl-tagged (Nb-tagged) reagents is reported, whereby purification was rapidly achieved by employing ring-opening metathesis polymerization which is initiated by any of three methods utilizing Grubbs catalyst (i) free catalyst in solution, (ii) surface-initiated catalyst-armed silica or (iii) surface-initiated catalyst-armed Co/C magnetic nanoparticles

Antimicrobial activity of some Sri Lankan Rubiaceae and Meliaceae

Ninety solvent extracts (n-hexane, dichloromethane and methanol) obtained from the leaves, bark and stem of 13 Sri Lankan Rubiaceae and two Sri Lankan Meliaceae plants have been screened for antibacterial and antifungal activities. Morinda tinctoria, Mussaenda frondosa, Psychotria gardneri and Psychotria stenophylla displayed the widest spectrum of antibacterial activity