Tahir, Souma (2020). Physicochemical and biological properties of modified bacterial cellulose. University of Birmingham. Ph.D.
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Tahir2020PhD.pdf
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Abstract
Bacterial cellulose (BC) was biosynthesised by Gluconacetobacter xylinus. The aim of this work was to study the effect of surface treatment with 5, 7 and 9 wt.% NaOH on the properties and structure of BC. The effect of BC (2, 4, 6 8 and 10 wt.%) as a filler on the mechanical properties and biocompatibility of reinforced polycaprolactone (PCL) composites processed by electrospinning and twin extrusion followed by injection moulding was also studied.
FTIR showed an increase in crystallinity and cellulose II/I ratio with increasing NaOH concentration and treatment time. Thermogravimetric analysis (TGA) showed improved thermal stability of BC with increasing NaOH solution concentration and time. There was a significant difference between the viability of bone marrow cells on days 6 and 10 for the samples treated with higher NaOH concentration, leading to the conclusion that mercerisation did have a significant effect on the biocompatibility, studied by MTT assay. Cryogenic SEM studies showed that the morphology of BC changed with NaOH treatments from a dense fibre network to randomly distributed fibres with increased porosity.
PCL-BC composites did not show significant improvement in the thermal stability studied by DSC with increasing BC content. An increase in the melting temperature of PCL-BC composites with increasing BC content was observed. A decrease in the ultimate tensile strength was observed with increasing BC content, whereas the yield strength did not show much change. The Young’s modulus increased significantly with increasing BC content.
The electrospun PCL-BC composites showed a decrease in the degree of crystallinity studied by DSC as the BC content increased. Cell studies showed successful cell proliferation and viability.
| Type of Work: | Thesis (Doctorates > Ph.D.) | |||||||||
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| Award Type: | Doctorates > Ph.D. | |||||||||
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| Licence: | All rights reserved | |||||||||
| College/Faculty: | Colleges (2008 onwards) > College of Engineering & Physical Sciences | |||||||||
| School or Department: | School of Metallurgy and Materials | |||||||||
| Funders: | Engineering and Physical Sciences Research Council | |||||||||
| Subjects: | Q Science > Q Science (General) | |||||||||
| URI: | http://etheses.bham.ac.uk/id/eprint/9877 |
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