Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
4 results
Search Results
Item Biocomposite composed of PVA reinforced with cellulose microfibers isolated from biofuel industrial dissipate: Jatropha Curcus L. seed shell(Elsevier Ltd, 2017) Manjula, M.; Srinikethan, G.; Shetty K, V.K.Biofuel production by Jatropha Curcas L. (JC) seeds result in large quantities of unused seed shells contributing as an extensive potential source for cellulose production. Present work consummates on isolation of cellulose microfibers (CMF) from JC seed shell by chlorination treatment and were characterized using Scanning Electron Microscope (SEM), Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and 13C NMR. Removal of hemicellulose and lignin were confirmed from FTIR results. Cellulose microfibers with diameter 0.23-1.04 ?m demonstrated considerable increase in crystallinity and thermal stability by chlorination treatment. Procured cellulose microfibers were reinforced in Poly-vinyl Alcohol (PVA) by solution casting in water to form biocomposites. Mechanical properties and thermal stability of these biocomposites increased on addition of cellulose microfiber, ensuring the potentiality of cellulose fibers as filler in biocomposites which can reinstate traditional plastics. © 2017 Published by Elsevier Ltd.Item Biofibres from biofuel industrial byproduct—Pongamia pinnata seed hull(Springer Science and Business Media Deutschland GmbH, 2017) Manjula, P.; Srinikethan, G.; Shetty K, K.V.Background: Biodiesel production using Pongamia pinnata (P. pinnata) seeds results in large amount of unused seed hull. These seed hulls serve as a potential source for cellulose fibres which can be exploited as reinforcement in composites. Methods: These seed hulls were processed using chlorination and alkaline extraction process in order to isolate cellulose fibres. Scanning electron microscopy (SEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR) analysis demonstrated the morphological changes in the fibre structure. Results: Cellulose microfibres of diameter 6–8 µm, hydrodynamic diameter of 58.4 nm and length of 535 nm were isolated. Thermal stability was enhanced by 70 °C and crystallinity index (CI) by 19.8% ensuring isolation of crystalline cellulose fibres. Conclusion: The sequential chlorination and alkaline treatment stemmed to the isolation of cellulose fibres from P. pinnata seed hull. The isolated cellulose fibres possessed enhanced morphological, thermal, and crystalline properties in comparison with P. pinnata seed hull. These cellulose microfibres may potentially find application as biofillers in biodegradable composites by augmenting their properties. © 2017, The Author(s).Item Production of bacterial cellulose from Komagataeibacter saccharivorans strain BC1 isolated from rotten green grapes(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2018) Gopu, G.; Srinikethan, G.Bacterial cellulose (BC) is one of the prominent biopolymers that has been acquiring attention currently due to its distinctive properties and applications in various fields. The current work presents the isolation of Komagataeibacter saccharivorans strain BC1 isolated from rotten green grapes, followed by biochemical and genotypic characterization, which confirmed that the strain is capable of synthesizing cellulose. Further, production media was designed and certain variables such as carbon, nitrogen sources, pH, and temperature were optimized in order to obtain the maximum concentration of cellulose production. We found mannitol to be the ideal carbon source and yeast extract as the ideal nitrogen source with a highest BC dry yield of 1.81 ± 0.25 g/100 mL at pH 5.76 for a week at 30 °C.The charcterization of pellicles by FTIR spectrum depicted similar functional groups present in synthesized BC as that of the commercial cellulose. X-ray diffraction revealed that BC showed 82% crystallinity. Surface morphology of the dried pellicle was studied by SEM image which showed that the BC surface was tightly packed with thin fibers with less porosity. Hence the study demonstrates that the isolates of K.saccharivorans could be used to produce a biopolymer in a short period of time using a modified production medium. © 2018, © 2018 Taylor & Francis.Item Bacterial Cellulose production by K. saccharivorans BC1 strain using crude distillery effluent as cheap and cost effective nutrient medium(Elsevier B.V., 2019) Gopu, G.; Srinikethan, G.Bacterial Cellulose (BC), a valuable biopolymer gaining importance over the past few decades due to its remarkable properties and applications. In this study, crude distillery effluent having a high COD value of 87,433 mg/L was used to produce Bacterial Cellulose under static fermentation by Komagataeibacter saccharivorans, a novel isolated bacterial strain. 1.24 g/L of cellulose production was noted after eight days along with 23.6% reduction in COD value. The BC pellicle was purified, lyophilized and stored. Further, the lyophilized BC pellicle was subjected to characterization techniques such as SEM, ATR-FTIR, XRD, NMR and TLC. Morphological analysis revealed that cellulose fibers were dense with higher porosity and an average fiber width of 60 nm. FTIR depicted similar functional groups as that of BC-HS medium. TLC of the biopolymer was performed to evaluate its purity. X-ray diffraction and 13C NMR studies gave more insights about the crystalline and the amorphous regions; the synthesized polymer exhibited 80.2% as crystallinity and crystallite size of 8.36. Hence, the present study demonstrates that distillery effluent waters could be effectively reused as production medium fulfilling two objectives namely one reducing COD and making the effluent safe for disposal and two to produce a value-added product. © 2019 Elsevier B.V.