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Cellulose acetate is a chemical of great industrial importance. Its uses range from the manufacture of textiles to cigarette filters. Cellulose acetate is not biodegraded easily. The aim of this project was to identify, micro-organisms that would attack cellulose acetate and to propose a possible mechanism for the biodegradation process. Discarded cigarette filters were taken from the street and they were plated onto Sabouraud medium, a selective medium for fungi. The growth observed was on the outside of the filters. The middle portion of discarded cigarette filters was opened asceptically, and added in flasks containing nutrient broth. Eighty percent of the flasks showed no signs of bacteriological growth after 24 hours, showing that the inside of the filters was sterile. It would appear, that cigarette filters are a very effective barrier towards microbial penetration. Cigarette filters were laid on potting compost, sand and tile surfaces, in order to monitor their progress over a period of 12 months. These experiments took place under moist and warm conditions, in order to enhance biological growth. The sand and tile experiments were abandoned after a relatively short period as no obvious changes could be seen. The experiments on compost did not show any visible signs of biodegradation for 7 months. After that period, algal growth developed on the filters exposed to light, and a slight decrease in the degree of substitution (the average number of acetyl groups per anhydroglucose unit) was observed. Cellulose acetates with varying degrees of substitution were synthesised and used as carbon source for the growth of the fungus Aspergillus jilmigatus, a common soil species. Previous experiments had shown that this species was the predominant one growing on the filters. It was found that biodegradability varied with the degree of substitution. The higher the degree of substitution, the slower the biodegradation. Biodegradation could not be shown in cellulose acetate with a degree of substitution of 2.5, the material from which cigarette filters are made. The degradation products were analysed by means of FTIR spectroscopy, IH and \3C NMR, solution viscosity and GPC. From the results obtained, it could be deduced that the biodegradation proceeded by a mild de-acetylation (esterase) prior to de-polymerisation (cellulase).

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Glucosyl and galactosyl bearing methacrylates were synthesised using a combination of well known carbohydrate chemistry and ultrasonic chemistry. Polymerisation of these monomers by aqueous reversible addition-fragmentation chain transfer polymerisation yielded glycosylated polymers in high yield with a high degree of control over molecular weight and narrow polydispersity. Polymers of varying levels of glycosylation could be achieved through addition of a comonomer. Block copolymers were synthesised through sequential monomer addition. Binding studies of these polymers to Ricinus communis agglutinin 120 by both isothermal titration calorimetry and surface plasmon resonance found a high degree of molecular weight dependence on avidity. Studies also suggest that the increase in avidity through multivalency is due to both simultaneous binding to multiple receptors and the increased probability of binding due to the high local concentration of ligands. Polymers synthesised have been used in the synthesis of glycosylated gold nano-particles. Some degree of control over nanoparticle size was achieved through adjustment of the gold:polymer ratio but was found to be limited. Agglutination assays show the particles display specific lectin binding but in vitro cell studies were unable to give conclusive information regarding the uptake of particles into cells.

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