Effects of additives on mechanical and structural properties on bacterial cellulose composites
- Dayal, Manmeet
- [University Park, Pennsylvania] : Pennsylvania State University, 2014.
- Physical Description:
- 1 electronic document
- Additional Creators:
- Catchmark, Jeffrey, Puri, Virendra, and Soybel, David I.
- Restrictions on Access:
- Open Access.
- Bacterial cellulose (BC) exhibits unique properties including high mechanical strength and high crystallinity. Improvement in the mechanical properties of BC is sought for many applications ranging from structural composites to biomedical materials. In this study, different additives including carboxymethyl cellulose (CMC), pectin, gelatin, corn starch, and corn steep liquor were added into the fermentation media to alter the BC produced. Three different concentrations (1%, 3% and 5%) were chosen for each of the additives, with no additive (0%) being the control. The produced BC was then analyzed to determine tensile and compression modulus, and a significant increase in these value were observed (p<0.05). Amongst the tested additives, BC produced in media containing 3% (w/v) pectin had a maximum compressive modulus (142 kPa), and BC produced in media containing 1% (w/v) gelatin exhibited the maximum tensile modulus (21 MPa). Pellicle from pectin in media was comparatively harder than control. Substantial variation in porosity and water holding capacity of BC pellicles were also observed under the influence of media additives (p<0.05). Structural characteristics of BC and BC-additive composites were compared using X-Ray diffraction (XRD). The crystal size and crystallinity of BC was reduced when grown in the presence of CMC and gelatin; of the additions, pectin only decreased the crystallite size. This suggested that CMC and gelatin were incorporated into the BC fibril structure. The field emission scanning electron microscopy (FESEM) images showed the increased micro-fibril aggregation in BC pellicle on addition of additives to the culture media.
- Other Subject(s):
- Dissertation Note:
- M.S. Pennsylvania State University 2014.
- Reproduction Note:
- Library holds archival microfiches negative and service copy. 1 fiche. (Micrographics International, 2015)
- Technical Details:
- The full text of the dissertation is available as an Adobe Acrobat .pdf file ; Adobe Acrobat Reader required to view the file.
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