| Ion exchange membrane has important application in the separation and purification of biological macromolecules. The ion exchange membrane prepared by conventional method has existed flaws including low density of functional groups and low ion exchange capacity. A new method for preparation of high-capacity ion exchange membrane with Surface-initiated atom transfer radical polymerization acts as a new surface modification technology, significantly improving the density of the membrane surface functional groups. On the base of the tetrazole-functionalized adsorbent studies in our research group, this paper prepared a tetrazole-functionalized weak cation exchange membrane via SI-ATRP and investigated the adsorption properties of protein and application it to the purification of lysozyme from egg white.Intiator was firstly introduced onto the surface of regenerated cellulose (RC) membranes, then acrylonitrile (AN) was anchored on the surface of membrane via SI-ATRP, subsequently inverted the functional groups from the nitrile to the tetrazole on the membrane surface by "click chemistry" to prepare weak cation exchange membrane. The chemical composition of membrane surface was characterized by XPS and ATR-FTIR. The effect of polymerization time on grafting degree, pure water flux, surface morphology were discussed. Lysozyme was used as a model protein to evaluate the adsorption properties of different modified membranes varying the ATRP reaction time under static and dynamic conditions.The results demonstrated that the protein adsorption capacity increased with increasing polymerization time. Maximum values of83.30mg/ml (static) and43.33mg/ml (dynamic) at polymerization time of24h were higher than the values reported in the literature.The weak cation exchange membranes prepared in this paper proved also to be effective in the separation of lysozyme from egg white,showing great potential in the purification of biomacromolecule. |
PDF Full Text Request