超薄磺酸化垂直介孔二氧化硅膜的制备及选择透过性研究

Preparation and permselectivity of ultrathin sulfonated SiO_(2) film with perpendicular mesoporous

介孔二氧化硅膜因纳米孔道孔径小、垂直且带负电荷而具有良好的阳离子选择透过性。将磺酸基负载于二氧化硅膜的介孔孔道可以增加孔道表面电荷密度,提高膜对阳离子的选择透过性。结合St9ber溶液生长法和共缩合法在氧化铟锡镀膜基片上原位合成了具有垂直介孔的超薄磺酸化二氧化硅膜(SMSF)。通过透射电子显微镜、扫描电子显微镜以及电化学等手段对样品进行表征。结果表明,制备的SMSF连续致密,厚度约为50nm,其纳米通道具有垂直取向。选择透过性实验表明,当电解液浓度低于0.1mol/L时,SMSF对阳离子的选择透过性较好。当浓度差值在5~100时,SMSF对Na^(+)的选择透过性与浓度差呈正相关。因此,在适当的浓度范围内通过提高浓度差可使膜对阳离子获得较高的选择透过性。SMSF有望在盐差能的收集方面得到广泛应用。

Mesoporous silica film has good cation permselectivity,due to the small pore size,perpendicular and negative charge of nanochannels.The surface charge density of nanochannels can be increased after loading with sulfonic acid groups,inducing improvement of permselectivity of the silica film.The ultrathin sulfonated silica film with perpendicular mesoporous(SMSF) was in-situ synthesized on indium tin oxid(ITO) substrate by St9 ber approach combining with co-condensation method.The samples were characterized by TEM,SEM and electrochemical methods.The results showed that the prepared SMSF was continuous without any cracks.The thickness of the film was about 50 nm and the nanochannels had perpendicular orientation.The permselectivity test showed that the permselectivity of the SMSF was better as electrolyte concentration was lower than 0.1 mol/L.The permselectivity to Na^(+) was positively correlated with concentration difference when the concentration difference value ranged from 5 to 100.Therefore,higher permselectivity to cations could be obtained by increasing concentration difference in an appropriate concentration range.The SMSF were expected to be widely used in the collection of salt differential energy.