Abstract
D.Phil. (Chemistry)
The application of dendritic-based materials has attracted great interest. For the first time this research has investigated the feasibility of poly (propyleneimine) (PPI) dendrimers and hyperbranched polyethyleneimine (HPEI) in combination with beta-cyclodextrin (β-CD) embedded in polysulfone (PSf) membrane for water treatment. The advantage of embedding these conjugates (β-CD-PPI and β-CD-HPEI) in PSf membranes is the presence of numerous nanocavities which can act as water channels allowing easy water passage through the membrane improving water permeability. Secondly, the presence of functional groups such as –OH and –NH greatly improves hydrophilicity of membranes. Commercial polysulfone (PSf) ultrafiltration membranes were crosslinked with β-cyclodextrin-poly (propyleneimine) (β-CD-PPI) and β-cyclodextrin-hyperbranched polyethyleneimine (β-CD-HPEI) using trimesoyl chloride (TMC) by interfacial polymerisation. These membranes were used in the rejection of Aldrich humic acid (molecular weight: 4.1 kDa) from synthetic water samples prepared in the laboratory. Moreover, β-cyclodextrin-poly (propyleneimine) (β-CD-PPI) was used as a host for the preparation of Fe/Ni nanoparticles. The new membranes were synthesised by crosslinking β-CD-PPI with trimesoyl chloride and subsequently loading Fe/Ni nanoparticles and this was supported on a commercial polysulphone (PSf) layer for the degradation of 2,4,6-trichlorophenol (2,4,6-TCP). The membrane surfaces were characterised using Fourier transform infrared/attenuated total reflectance (FT-IR/ATR) spectroscopy , scanning electron microscopy (SEM), atomic force microscopy (AFM), high resolution transmission electron microscopy (HR-TEM), water-contact angle, and water-intake capacity...