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Extraction, Characterization, and Optimization of Cellulose Nanocrystals from Corncob

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dc.contributor.advisor Hundessa, Dessalegn (PhD)
dc.contributor.author Getahun, Esubalew
dc.date.accessioned 2020-12-31T05:58:38Z
dc.date.available 2020-12-31T05:58:38Z
dc.date.issued 2020-10
dc.identifier.uri http://etd.aau.edu.et/handle/123456789/24411
dc.description.abstract In this study cellulose nanocrystals were extracted from corncob by the method of sulfuric acid hydrolysis, followed by separation using centrifugation, dialysis, and ultrasonication with the objective of achieving maximum yield. The maximum yield (41.8%) of cellulose nanocrystal was found at the parameter interaction of 65wt.% sulfuric acid concentration,45℃ reaction temperature, and 60 minutes of hydrolysis time. The effect of process parameters (acid concentration, temperature, and hydrolysis time) on the yield of cellulose nanocrystals was optimized using response surface methodology(RSM) and gave 41.74% of cellulose nanocrystals yield with the sulfuric acid concentration 61.66wt.%, the reaction temperature 45℃, and the hydrolysis time 59. 92minutes.The experimental yield was 40.94±0.25% after doing triple experiments using the optimal conditions are acid concentration (61.66wt.%), reaction time (59.93 min), and temperature (45℃). The size and surface morphology of cellulose nanocrystals were characterized by particle size analyzer and scanning electron microscopy respectively. Fourier transform infrared showed that the structural change occurs by the chemical treatments (by alkaline treatment and bleaching) due to most of the lignin and hemicellulose were removed from the raw corncob. The result reveals Cellulose nanocrystals prepared from the hydrolysis of the isolated cellulose in the sulfuric acid had needle-shaped morphology, an average length of 170.3nm, and a crystallinity index of 79.3%. The crystallinity index obtained from x-ray diffraction for cellulose nanocrystal was found higher than extracted cellulose with a value of 79.3% and 76.4% respectively.Thermal stability by thermogravimetric analysis showed that the degradation temperature of the cellulose nanocrystals reached around 327℃, which was higher than that of the raw corncob and extracted corncob cellulose. These results showed that corncob cellulose and cellulose nanocrystals (CNCS) were successfully extracted from corncob by sulfuric acid and might be potentially used for different applications. en_US
dc.language.iso en_US en_US
dc.publisher Addis Ababa University en_US
dc.subject Corncob en_US
dc.subject Cellulose nanocrystals en_US
dc.subject Acid hydrolysis en_US
dc.subject Characterization en_US
dc.subject Optimization en_US
dc.title Extraction, Characterization, and Optimization of Cellulose Nanocrystals from Corncob en_US
dc.type Thesis en_US

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