| Summary: | 碩士 === 明志科技大學 === 化學工程系生化工程碩士班 === 106 === In this study, polyacrylonitrile nanofiber membrane (PAN) was successfully prepared by electrospinning technology. The PAN nanofiber membrane was modified by hot alkali method under the conditions of 3 M NaOH, alkalization temperature 85 oC and hydrolysis time 25 min. The nitrile groups (-CN) on the PAN membrane was oxidized to become hydrophilic carboxylate groups (-COO-Na+) in a strong alkaline environment. Then, the carboxylate groups were protonated into carboxyl group (-COOH). The carboxylic acid groups at the surface of the membrane were then coupled with ethylene diamine and grafted with reactive green 19 to obtain a dye pseudo affinity nanofiber membrane with multi-negative charged sulfonate groups. The chemical structure and surface morphology of the dyed nanofiber membrane were characterized by FTIR (Fourier Transform Infrared Spectrometer), SEM (Scanning Electron Microscope), and TGA (Thermo-gravimetric Analyzer) analysis. In this work, the pure lysozyme as a model protein was used to search for the maximum adsorption capacity by the dyed membrane. Moreover, the experiments were carried out by using the experimental design method (i.e., Taguchi method) to calculate the more comprehensive scouting conditions to obtain the optimal adsorption conditions. The maximum adsorption capacity for lysozyme can be found from the SN ratio value. The reproducibility experiments were to ensure the practicality of the optimal conditions. Based on the optimal conditions, the thermodynamic and kinetic studies were investigated under various operating conditions, such as adsorption pH, lysozyme concentration and temperature. Finally, to purify the lysozyme from chicken egg white by using the membrane chromatography to find the optimal purification conditions, including adsorption (e.g., adsorption pH, concentration of CEW, and operating velocity), wash (e.g., liquid velocity) and elution (e.g., type of salt and concentration and liquid velocity) stages were investigated. Under optimal conditions, the results obtained from CEW solution in the purification process of lysozyme using dye affinity nanofiber membrane show that the lysozyme was recovered with a high yield of 98.52% and a high purification factor of 143.33 in a single step.
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