氧化石墨烯基纳滤膜对5种小分子生物碱的透过行为研究

Study on permeability behavior of five small molecule alkaloids in graphene oxide based nanofiltration membranes

目的研究水溶性、相对分子质量小的生物碱透过氧化石墨烯基纳滤膜的规律,为氧化石墨烯基纳滤膜应用于中药水提液药效成分分离提供依据。方法以盐酸小檗碱为模板分子,研究膜材料中氧化石墨烯含量、碳纳米管含量对分离性能的影响;进而以5种生物碱小分子——硫酸长春碱、盐酸巴马汀、盐酸小檗碱、苦参碱、槐果碱为考察对象,考察不同相对分子质量对膜截留率和通量的影响,探究氧化石墨烯基纳滤膜对小分子的选择性透过规律。结果随着氧化石墨烯用量增加,氧化石墨烯膜对盐酸小檗碱的截留率增加,膜通量随之降低;随着碳纳米管含量的增加,膜对盐酸小檗碱的截留率降低,膜通量随之升高。当生物碱相对分子质量由246.35增加至371.82时,对应的膜截留率由64.75%增加至97.29%,但继续增加相对分子质量至909.05后,膜截留率不再有显著变化。结论氧化石墨烯基纳滤膜对相对分子质量为300左右的生物碱分子具有理想的分离效果,有望实现该类小分子的高效分离。

Objective To study the law of water soluble and small relative molecular weight alkaloids permeating graphene oxide(graphene oxide,GO)based nanofiltration membrane,and to provide a basis for the separation of the active components of the aqueous extracts of traditional Chinese medicine.Methods The effect of graphene oxide and carbon nanotube(CNT)content of the membrane separation performance was studied by berberine hydrochloride.Then,five kinds of small molecules alkaloids-vinblastine sulfate,palmatine hydrochloride,berberine hydrochloride,matrine,sophocarpine were selected to investigate the effects of relative molecular weight on membrane rejection rate and flux,and to explore the selective permeability of graphene oxide based nanofiltration membranes.Results With the increases of GO content,the rejection rate of berberine hydrochloride through GO membrane increased and the flux decreased.As the increases of CNT content,the rejection rate of berberine hydrochloride through GO membranes decreased and the flux increased accordingly.When the relative molecular weight of the alkaloids increased from 246.35 to 371.82,the corresponding rejection rate increased from 64.75%to 97.29%,but the rejection rate no longer changed significantly after continuing to increase the molecular weight to 909.05.Conclusion Graphene oxide based nanofiltration membranes has a good separation effect on alkaloid molecules with relative molecule weight about 300,which is expected to achieve efficient separation of such small molecules.