茶碱分子印迹聚酰亚胺纳米纤维膜的制备与表征

Preparation and Characterization of Theophylline Molecularly Imprinted Polyimide Nanofiber Membrane

以聚酰胺酸(PAA)溶液为原料,采用静电纺丝法制备了聚酰胺酸纳米纤维膜(PAAM),热处理脱水后获得聚酰亚胺纳米纤维膜(PIM)。采用PIM表面预涂覆聚甲基丙烯酸(PMAA),以茶碱(THO)为模板分子、偶氮二异丁腈(AIBN)为引发剂、乙二醇二甲基丙烯酸酯(EDMA)为交联剂、氯仿为溶剂,在PIM表面进行了热交联反应,制备了THO分子印迹聚酰亚胺纳米纤维复合膜(PIMIM)。讨论了纺膜条件,并用傅里叶红外光谱与扫描电镜分别表征了PIMIM的结构和形态,比较了THO的洗脱方式。结果表明:较佳的纺膜条件为纺丝电压15.0kV、接收距离12.0cm和纺丝液流量0.5mL/h。以PIM为支撑体,获得了聚酰亚胺纳米纤维间有分子印迹层的PIMIM。PIMIM对THO的静态吸附结合容量达144μmol/g,对THO与可可碱(TB)的选择性分离因子达1.96。对PIMIM循环再生,索氏提取法优于超声洗脱法。

Polyamide acid nanofiber membrane（PAAM）was prepared through electrospinning method using polyamide acid（PAA）solution as the raw material.Polyimide nanofiber membrane（PIM）was prepared by heat dehydration from PAAM.Using theophylline（THO）as the template molecule,azobisisobutyronitrile（AIBN）as the initiator,ethylene glycol dimethacrylate（EDMA）as the crosslinker,chloroform as the solvent,THO molecularly imprinted polyimide nanofiber composite membrane（PIMIM）were synthesized by surface thermal crosslinking reaction on PIM,which was pre-coated by polymethacrylic acid（PMAA）.Electrospinning conditions were investigated.The structure and morphology of PIMIM were characterized by FT-IR and SEM.Methods of THO elution were compared.Results showed that better electrospinning conditions were electrospun voltage 15.0kV,receiving distance 12.0cm,and spinning dope flow rate 0.5 mL/h.Using PIM as the support,PIMIM was a composite membrane containing the molecularly imprinted layer.Static adsorption binding capacity of PIMIM for THO was 144μmol/g,and the selective separation factor of THO and theobromine（TB）was 1.96.For the cyclic regeneration of PIMIM,Soxhlet extraction method was superior compared to ultrasound washing method.