- 學位論文
無機奈米管式薄膜於巨分子溶液中分離胺基酸之探討
Separations of Amino Acid from Macromolecules by Inorganic Nanofiltration Membrane
摘要
本研究探討在不同的操作變數下無機奈米管式薄膜於巨分子溶液中分離胺基酸之最佳操作條件，操作參數包括有pH值、不同溶質、濃度及掃流流速等，實驗結果包括有溶液濾速與溶質阻隔率的變化。 實驗結果顯示，濾速方面，胺基酸與BSA混合水溶液之濾速隨pH値的改變並無明顯的變化；但隨掃流速度的增高而些許增加是由於增加掃流速度會增加膜內流體的擾動，減少濃度極化層阻力； BSA溶液之濾速隨著濃度的增高而減少是由於濃度極化層阻力隨著濃度增高而增加。阻隔率方面，帶電溶質如BSA(pI=4.9)、Glu (pI=3.3)及Lysine (pI=9.74)之阻隔率隨著pH値的改變而有不同的變化，是由於無機陶瓷薄膜（pI=4.22）均隨著pH値的改變而改變電性，但β-cyclodextrin為不帶電溶質，因此pH値的改變不影響其電性，因此對於β-cyclodextrin之阻隔率而言不受pH値影響。選擇率方面，在胺基酸與BSA混合水溶液中，MWCO為1kDa的薄膜在pH値為3.3時有最佳之選擇率；MWCO為5kDa的薄膜在pH値為10時有最佳之選擇率。但由胺基酸與β-cyclodextrin混合水溶液之選擇率發現，其選擇率不理想，因此此薄膜不適用於較為精密之分離。 此外本文中以阻力串連模式與滲透壓模式，預測出BSA之理論濾速，理論濾速與實驗值比較發現阻力串連模式趨勢吻合；滲透壓模式之理論濾速在趨近於直線，與實驗值趨勢不同。
並列摘要
In this study, separations of amino acid from macromolecules by inorganic nanofiltration membrane was investigated under various operating parameters, such as pH value, different solutes, concentration and cross flow rate. The results have the changes of permeate flux and solute rejection. Experimental results indicate that about the results of flux, the flux of the mixed solution of amino acid and BSA doesn’t have a significant influence with changing pH value, but it increases with the cross flow rate due to the resistance of concentration polarization layer decreases with increasing cross flow rate. The flux of BSA solution decreases with increasing concentration due to the resistance of concentration polarization layer increases with increasing concentration. About the results of rejection, the rejections of the charged solutes, such as BSA (pI=4.9), Glu (pI=3.3) and Lysine (pI=9.74), change with changing pH value due to the charged of inorganic membrane (pI=4.22) change with changing pH value. The rejection of β-cyclodextrin doesn’t have a significant influence because it isn’t a charged solute. About selectivity, the best selectivity of the mixed solution of amino acid and BSA withn MWCO 1kDa membrane is at pH 3.3; the best selectivity with MWCO 5kDa membrane is at pH 10. However, selectivity of the mixed solution of amino acid andβ-cyclodextrin isn’t ideal, so inorganic membrane doesn’t suit the exact separation. In this work, predicting flux of BSA with resistance-in-series model and the osmosis pressure model. Then theoretical flux will compare with experiment flux. The theoretical flux of resistance-in-series model agree with the experimental data. The trend of theoretical flux of osmosis pressure model is near the linear but it’s not similar to the experiment flux.