接枝型镉离子印迹膜的制备及其识别选择性能

Preparation of Graft Cd^(2+) Ion-Imprinted Membrane and Its Recognition Selectivity

以乙二胺(EDA)为试剂,对氯甲基化聚砜微滤膜(CMPSF)进行化学改性,制得胺基化聚砜微滤膜(AMPSF);然后在AMPSF膜与水溶液界面处,构建—NH2/S2O2-8表面引发体系;最后以对苯乙烯磺酸钠(SSS)为单体、Cd^(2+)为模板、N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用接枝/交联与离子印迹同步进行的方法,制得接枝型Cd^(2+)印迹膜(GIIM)。采用傅里叶红外光谱(FTIR)、扫描电子显微镜(SEM)及光学显微镜(OM)对印迹膜进行表征,并深入研究了印迹膜对Cd^(2+)的识别选择性能和渗透分离性能。结果表明,印迹膜对Cd^(2+)具有优良的结合亲和性、识别选择性及渗透分离性,结合量与渗透量分别高达1.41 mmol/cm2和0.95mg/mL,而相对于参比离子Pb^(2+)和Zn^(2+),印迹膜对Cd^(2+)的选择系数分别为9.97和11.9。

By using ethylenediamine（EDA）as the reagent,aminated microfiltration membrane of polysulfone（AMPSF）was prepared through chemical modification of chloromethylated polysulfone microfiltration membrane（CMPSF）.Then surface-initiating system of —NH2/S2 O2-8 was constituted at the interface between AMPSF membrane and aqueous solution using AMPSF membrane as basement membrane,sodiump-styrene sulfonate（SSS）as functional monomer,Cd^2＋ as template ion,and N,N-methylene double acrylamide（MBA）as cross linker.Graft Cd^2＋ ion-imprinted membrane（GIIM）was then prepared through the method of graft/crosslinking-polymerizing and simultaneous ion imprinted on the membrane surface.Fourier transform infrared spectroscopy（FT-IR）was adopted to determine the structure of the graft Cd^2＋ ion-imprinted membrane,scanning electron microscope（SEM）was used to observe the crosssectional morphology of the GIIM,and optical microscope（OM）was used to observe the surface morphology of the GIIM.Furthermore approaches like static binding,competitive adsorption,separation and osmosis were adopted to examine the performance of the imprinted membrane in recognition selectivity and osmotic separation of Cd^2＋ .Results indicate that the Cd^2＋ ion-imprinted membranes with grafting type have sound performances in binding affinity,recognition selectivity and osmotic separation of Cd^2＋ .The combination capacity of the GIIM reaches as high as 1.41 mmol/cm^2,and the penetration capacity of the GIIM reaches as high as 0.95 mg/mL.The selection coefficients of the imprinted membrane to Cd^2＋ ,which are relative to the reference ion Pb^2＋ and Zn^2＋ ,are 9.97 and 11.9 respectively.As a result,the imprinted membrane is expected to provide an effective way for the selective separation of Cd^2＋ in waste water.